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Optimal precursors of double-gyre regime transitions with an adjoint-free method 预览
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作者 YUAN Shijin LI Mi +3 位作者 WANG Qiang ZHANG Kun ZHANG Huazhen MU Bin 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第4期1137-1153,共17页
In this paper, we find the optimal precursors which can cause double-gyre regime transitions based on conditional nonlinear optimal perturbation (CNOP) method with Regional Ocean Modeling System (ROMS). Firstly, we si... In this paper, we find the optimal precursors which can cause double-gyre regime transitions based on conditional nonlinear optimal perturbation (CNOP) method with Regional Ocean Modeling System (ROMS). Firstly, we simulate the multiple-equilibria regimes of double-gyre circulation under different viscosity coefficient and obtain the bifurcation diagram, then choose two equilibrium states (called jet-up state and jet-down state) as reference states respectively, propose Principal Component Analysis-based Simulated Annealing (PCASA) algorithm to solve CNOP-type initial perturbations which can induce double-gyre regime transitions between jet-up state and jet-down state. PCASA algorithm is an adjoint-free method which searches optimal solution randomly in the whole solution space. In addition, we investigate CNOP-type initial perturbations how to evolve with time. The results show:(1) the CNOP-type perturbations present a two-cell structure, and gradually evolves into a three-cell structure at predictive time;(2) by superimposing CNOP-type perturbations on the jet-up state and integrating ROMS, double-gyre circulation transfers from jet-up state to jet-down state, and vice versa, and random initial perturbations don't cause the transitions, which means CNOP-type perturbations are the optimal precursors of double-gyre regime transitions;(3) by analyzing the transition process of double-gyre regime transitions, we find that CNOP-type initial perturbations obtain energy from the background state through both barotropic and baroclinic instabilities, and barotropic instability contributes more significantly to the fast-growth of the perturbations. The optimal precursors and the dynamic mechanism of double-gyre regime transitions revealed in this paper have an important significance to enhance the predictability of double-gyre circulation. 展开更多
关键词 OPTIMAL precursors double-gyre regime transitions CONDITIONAL nonlinear OPTIMAL perturbation (CNOP) Principal Component Analysis-based Simulated Annealing (PCASA) multipleequilibria regimes
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A systematic approach in load disaggregation utilizing a multi-stage classification algorithm for consumer electrical appliances classification
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作者 Chuan Choong YANG Chit Siang SOH Vooi Voon YAP 《能源前沿:英文版》 CSCD 2019年第2期386-398,共13页
The potential to save energy in existing consumer electrical appliances is very high. One of the ways to achieve energy saving and improve energy use awareness is to recognize the energy consumption of individual elec... The potential to save energy in existing consumer electrical appliances is very high. One of the ways to achieve energy saving and improve energy use awareness is to recognize the energy consumption of individual electrical appliances. To recognize the energy consumption of consumer electrical appliances, the load disaggregation methodology is utilized. Non-intrusive appliance load monitoring (NIALM) is a load disaggrega-tion methodology that disaggregates the sum of power consumption in a single point into the power consumption of individual electrical appliances. In this study, load disaggregation is performed through voltage and current waveform, known as the V-I trajectory. The classification algorithm performs cropping and image pyramid reduction of the V-I trajectory plot template images before utilizing the principal component analysis (PCA) and the k-nearest neighbor (k-NN) algorithm. The novelty of this paper is to establish a systematic approach of load disaggregation through V-I trajectory-based load signature images by utilizing a multi-stage classification algorithm methodol-ogy. The contribution of this paper is in utilizing the “k- value,” the number of closest data points to the nearest neighbor, in the k-NN algorithm to be effective in classification of electrical appliances. The results of the multi-stage classification algorithm implementation have been discussed and the idea on future work has also been proposed. 展开更多
关键词 LOAD DISAGGREGATION voltage-current (V-I) trajectory MULTI-STAGE CLASSIFICATION algorithm principal component analysis (PCA) k-nearest NEIGHBOR (k-NN)
Identification of the anomaly component using BEMD combined with PCA from element concentrations in the Tengchong tin belt,SW China 预览
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作者 Yongqing Chen Lina Zhang Binbin Zhao 《地学前缘:英文版》 CAS CSCD 2019年第4期1561-1576,共16页
Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal com... Concentration of elements or element groups in a geological body is the result of multiple stages of rockforming and ore-forming geological processes.An ore-forming element group can be identified by PCA(principal component analysis)and be separated into two components using BEMD(bi-dimensional empirical mode decomposition):(1)a high background component which represents the ore-forming background developed in rocks through various geological processes favorable for mineralization(i.e.magmatism,sedimentation and/or metamorphism);(2)the anomaly component which reflects the oreforming anomaly that is overprinted on the high background component developed during mineralization.Anomaly components are used to identify ore-finding targets more effectively than ore-forming element groups.Three steps of data analytical procedures are described in this paper;firstly,the application of PCA to establish the ore-forming element group;secondly,using BEMD on the o re-forming element group to identify the anomaly components created by different types of mineralization processes;and finally,identifying ore-finding targets based on the anomaly components.This method is applied to the Tengchong tin-polymetallic belt to delineate ore-finding targets,where four targets for Sn(W)and three targets for Pb-Zn-Ag-Fe polymetallic mineralization are identified and defined as new areas for further prospecting.It is shown that BEMD combined with PCA can be applied not only in extracting the anomaly component for delineating the ore-finding target,but also in extracting the residual component for identifying its high background zone favorable for mineralization from its oreforming element group. 展开更多
关键词 Bi-dimensional empirical mode decomposition(BEMD) Principal COMPONENT analysis(PCA) ANOMALY components ORE-FORMING ELEMENT groups Sn(W)and Pb-Zn-Ag-Fe POLYMETALLIC deposits Tengchong tin-polymetallic BELT
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Comparison of phenolic profiles and antioxidant activities in skins and pulps of eleven grape cultivars(Vitis vinifera L.) 预览
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作者 LI Fu-xiang LI Fu-hua +2 位作者 YANG Ya-xuan YIN Ran MING Jian 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第5期1148-1158,共11页
Eleven grape cultivars were analysed to explore the variety differences of fresh grape phenolic profiles. The results showed that free phenolics were predominant in grape skins and pulps, and showed the higher antioxi... Eleven grape cultivars were analysed to explore the variety differences of fresh grape phenolic profiles. The results showed that free phenolics were predominant in grape skins and pulps, and showed the higher antioxidant activities than bound. In 11 cultivars, Muscat Kyoho extracts had the highest total phenolic content in skins(10.525 mg GAE g–1 FW) and pulps(1.134 mg GAE g–1 FW), and exhibited the highest DPPH radical scavening capacity(EC50=11.7 μg mL–1) and oxygen radical absorbance capacity(ORAC) value(190.57 μmol TE g–1 FW) of free phenolic in skin. In addition, the most abundant phenolics in grape skins were found to be flavonoids such as kaempferol in Kyoho skin(541.2 μg g–1 FW), rutin, catechin and epicatechin in Muscat Kyoho skin(262.3, 86.3 and 70.0 μg g–1 FW, respectively). Furthermore, the principal component analysis showed a strong difference of phenolic profiles with the cultivars, existing forms and distributions. Pearson correlation coefficient analysis showed a significant linear correlation between total phenolic content and antioxidant activity(P<0.05). Therefore, both skins and pulps were rich sources of bioactive phenolic compounds, and Muscat Kyoho was the ideal source among all samples. 展开更多
关键词 GRAPE phenolics varietal DIVERSITY ANTIOXIDANT activity principal COMPONENT analysis
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Discrimination of toxic ingredient between raw and processed Pinellia ternata by UPLC/Q-TOF-MS/MS with principal component analysis and T-test
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作者 Xing-ying Zhai Ling Zhang +5 位作者 Bing-tao Li Yu-lin Feng Guo-liang Xu Hui Ouyang Shi-lin Yang Chen Jin 《中草药:英文版》 CAS 2019年第2期200-208,共9页
Objective: To investigate the toxicity difference between raw and processed Pinelliae Rhizoma(Banxia in Chinese, BX), the rhizoma of Pinellia ternata, from the view of chemical composition.Methods: Sixteen samples of ... Objective: To investigate the toxicity difference between raw and processed Pinelliae Rhizoma(Banxia in Chinese, BX), the rhizoma of Pinellia ternata, from the view of chemical composition.Methods: Sixteen samples of raw and processed BX were prepared and analyzed by UPLC/Q-TOF-MS/MS.The discrimination(chemical marker) between the two group was investigated by principal component analysis(PCA) and T-test analysis. According to the accurate charge-to-mass ratio, MS/MS fragments, and comparison of corresponding data with the reference or database, the chemical markers were identified preliminarily.Results: Liquiritin, liquiritigenin, and lysophosphatidylcholine(LPC) were identified as the characteristic markers. The reducing of LPC in processed BX was one of the main reasons for detoxification because LPC could induce the inflammatory response;Liquiritin and liquiritigenin showed the anti-inflammatory effect and reduced liver injury, therefore the appearance of them in processed BX was an another reason for detoxification.Conclusion: An approach to explain the mechanisms of reducing the toxicity in medicinal plants by processing was proposed. Moreover, the chemical markers of toxicity could be used to differentiate the raw material from processed herbs for the quality control and safety application in clinical practice. 展开更多
关键词 DISCRIMINATION principal component analysis RAW and PROCESSED Pinellia ternata(Thunb.) Berit. TOXIC INGREDIENT T-TEST UPLC/Q-TOF-MS/MS
The Transfer Ideal under the Action of a Nonmetacyclic Group in the Modular Case 预览
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作者 Jia Pan-pan Nan Ji-zhu 《数学研究通讯:英文版》 CSCD 2019年第3期273-282,共10页
Let Fq be a finite field of characteristic p (p ≠2) and V4 a four-dimensional Fq-vector space. In this paper, we mainly determine the structure of the transfer ideal for the ring of polynomials Fq[V4] under the actio... Let Fq be a finite field of characteristic p (p ≠2) and V4 a four-dimensional Fq-vector space. In this paper, we mainly determine the structure of the transfer ideal for the ring of polynomials Fq[V4] under the action of a nonmetacyclic p-group P in the modular case. We prove that the height of the transfer ideal is 1 using the fixed point sets of the elements of order p in P and that the transfer ideal is a principal ideal. 展开更多
关键词 INVARIANT P-GROUP coinvariant TRANSFER IDEAL principal IDEAL
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A parallel and robust object tracking approach synthesizing adaptive Bayesian learning and improved incremental subspace learning
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作者 Kang LI Fazhi HE +1 位作者 Haiping YU Xiao CHEN 《中国计算机科学前沿:英文版》 SCIE EI CSCD 2019年第5期1116-1135,共20页
This paper presents a novel tracking algorithm which integrates two complementary trackers. Firstly, an improved Bayesian tracker(B-tracker) with adaptive learning rate is presented. The classification score of B-trac... This paper presents a novel tracking algorithm which integrates two complementary trackers. Firstly, an improved Bayesian tracker(B-tracker) with adaptive learning rate is presented. The classification score of B-tracker reflects tracking reliability, and a low score usually results from large appearance change. Therefore, if the score is low, we decrease the learning rate to update the classifier fast so that B-tracker can adapt to the variation and vice versa. In this way, B-tracker is more suitable than its traditional version to solve appearance change problem. Secondly, we present an improved incremental subspace learning method tracker(Stracker). We propose to calculate projected coordinates using maximum posterior probability, which results in a more accurate reconstruction error than traditional subspace learning tracker. Instead of updating at every time, we present a stopstrategy to deal with occlusion problem. Finally, we present an integrated framework(BAST), in which the pair of trackers run in parallel and return two candidate target states separately. For each candidate state, we define a tracking reliability metrics to measure whether the candidate state is reliable or not, and the reliable candidate state will be chosen as the target state at the end of each frame. Experimental results on challenging sequences show that the proposed approach is very robust and effective in comparison to the state-of-the-art trackers. 展开更多
关键词 OBJECT TRACKING BAYESIAN LEARNING SUBSPACE LEARNING particle filter principal component analysis
Crustal structure study based on principal component analysis of receiver functions
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作者 Jianyong ZHANG Ling CHEN Xu WANG 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第7期1110-1124,共15页
The receiver function (RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths,... The receiver function (RF) technique is an effective method for studying crustal structure. For a single station, the average 1-D crustal structure is usually derived by stacking the radial RFs from all back-azimuths, whereas structural variations (such as dipping discontinuities or anisotropy) can be constrained through analysis of waveform dependence on the backazimuth of both the radial and tangential RFs. However, it is often difficult to directly extract information about structural variations from the waveform of RF, due to the common presence of noise in real data. In this study, we proposed a new method to derive structural variation information for individual stations by applying principal component analysis (PCA) to RFs sorted by back-azimuth. In this method (termed as RF-PCA), a set of prin cipal comp on ents (PCs), which are uncorrelated with each other and reflect different characteristics of the RF data, were extracted and utilized separately to reconstruct new RFs. Synthetic tests show that the first PC of the radial RFs con tains the average structural information of the crust beneath the corresp onding station, and the second PC of the radial RFs and the first PC of the tangential RFs both reflect the variations of the crustal structure. Our synthetic modeling results indicate that the new RF-PCA method is valid for a variety of synthetic models with intra-crustal dipping discontinuities and/or anisotropy. We applied this method to the real data from a broadband temporary seismic station (s233) in the central part of the Sichuan Basin. The results suggest that the RF data can be best explained by the presence of two nearly parallel dipping discontinuities within the crust. Combining with previous logging data, seismic exploration and deep sounding observations, we interpret the shallow dipping discontinuity as the top boundary of the Precambrian crystalline basement of the Sichuan Basin and the deep one corresponding to the Conrad interface between the upper and lower crust, consistent with the g 展开更多
关键词 Principal component analysis RECEIVER function CRUSTAL structure Dipping DISCONTINUITY ANISOTROPY SICHUAN BASIN
委托代理视阈下政府购买青少年校园足球服务的制约因素与对策 预览
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作者 吴丽芳 杨献南 赵刚 《首都体育学院学报》 CSSCI 北大核心 2019年第4期327-331,共5页
各级政府通过市场竞争机制,向社会力量购买校园足球专业知识、足球技能培训、足球场地等,对青少年校园足球区域平衡发展起到了促进作用。但是,当前,政府购买青少年校园足球活动“向谁购买”“购买什么”“如何购买”?基于此,从委托代理... 各级政府通过市场竞争机制,向社会力量购买校园足球专业知识、足球技能培训、足球场地等,对青少年校园足球区域平衡发展起到了促进作用。但是,当前,政府购买青少年校园足球活动“向谁购买”“购买什么”“如何购买”?基于此,从委托代理视角,运用文献研究法、访谈法等分析政府购买青少年校园足球服务的方式,查找当前制约政府购买青少年校园足球服务的原因,构建政府购买青少年校园足球服务的路径。提出:提升对政府购买青少年校园足球服务的认识;建设政府购买青少年校园足球服务制度;培育青少年校园足球服务代理方市场;健全青少年校园足球服务监督机制——以期为完善政府购买青少年校园足球服务机制,进一步推动青少年校园足球活动开展提供理论参考。 展开更多
关键词 校园足球 青少年校园足球服务 政府购买 委托 代理
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Characteristics of size distributions and sources of water-soluble ions in Lhasa during monsoon and non-monsoon seasons
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作者 Nannan Wei Zhiyou Xu +5 位作者 Junwen Liu Guanghua Wang Wei Liu Deqing Zhuoga Detao Xiao Jian Yao 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第8期155-168,共14页
To understand the physical and chemical characteristics, particle size distribution and sources of size-separated aerosols in Lhasa, which is located on the Tibetan Plateau(TP), six sizes of aerosol samples were colle... To understand the physical and chemical characteristics, particle size distribution and sources of size-separated aerosols in Lhasa, which is located on the Tibetan Plateau(TP), six sizes of aerosol samples were collected in Lhasa in 2014. Ca^2+, NH4^+, NO3^-,SO4^2-and Cl^-were the dominant ions. The ratio of cation equivalents(CE) to anion equivalents(AE) for each particle size segment indicated that the atmospheric aerosols in Lhasa were alkaline. SO4^2-and NO3-could be neutralized by Ca^2+, but could not be neutralized by NH4^+, according to the [NH4^+]/[NO3^-+ SO4^2-] and [Ca^2+]/[NO3^-+ SO4^2-] ratios. Mobile sources were dominant in PM0.95-1.5,PM1.5-3 and PM3-7.2, while stationary sources were dominant in the other three size fractions according to the [NO3^-]/[SO4^2-] ratios. The particle size distribution of all watersoluble ions during monsoon and non-monsoon periods was characterized by a bimodal distribution due to the different sources and formation mechanisms, and it was revealed that different ions had different sources in different seasons and different particle size segments by combining particle size distribution with correlation analysis. Source analysis of aerosols in Lhasa was performed using the Principal component analysis(PCA) for the first time, which revealed that combustion sources, motor vehicle exhaust, photochemical reaction sources and various types of dust were the main sources of Lhasa aerosols.Furthermore, Lhasa’s air quality was also affected by long-distance transmission, expressed as pollutants from South Asia and West Asia, which were transmitted to Lhasa according to backward trajectory analysis. 展开更多
关键词 Atmospheric AEROSOLS WATER-SOLUBLE ions(WSIs) Size distribution Principal component analysis(PCA) BACKWARD trajectory
An Analysis of Social Vulnerability to Natural Hazards in Nepal Using a Modified Social Vulnerability Index
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作者 Sanam K.Aksha Luke Juran +1 位作者 Lynn M.Resler Yang Zhang 《国际灾害风险科学学报:英文版》 CSCD 2019年第1期103-116,共14页
Social vulnerability influences the ability to prepare for, respond to, and recover from disasters. The identification of vulnerable populations and factors that contribute to their vulnerability are crucial for effec... Social vulnerability influences the ability to prepare for, respond to, and recover from disasters. The identification of vulnerable populations and factors that contribute to their vulnerability are crucial for effective disaster risk reduction. Nepal exhibits multihazard risk and has experienced socioeconomic and political upheaval in recent decades, further increasing susceptibility to hazards.However, we still know little regarding social vulnerability in Nepal. Here, we investigate social vulnerability in Nepal by adapting Social Vulnerability Index(SoVI) methods to the Nepali context. Variables such as caste, and populations who cannot speak/understand Nepali were added to reflect the essence of the Nepali context. Using principal component analysis, 39 variables were reduced to seven factors that explained 63.02% of variance in the data.Factor scores were summarized to calculate final SoVI scores. The highest levels of social vulnerability are concentrated in the central and western Mountain, western Hill, and central and eastern Tarai regions of Nepal, while the least vulnerable areas are in the central and eastern Hill regions. These findings, supplemented with smaller-scale analyses, have the potential to assist village officers, policymakers,and emergency managers in the development of more effective and geographically targeted disaster management programs. 展开更多
关键词 DISASTER risk reduction NATURAL hazards Nepal Principal COMPONENT ANALYSIS SOCIAL VULNERABILITY Index
校长领导下的薄弱学校自我改造研究 预览
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作者 熊欣妮 《科教导刊》 2019年第17期12-13,共2页
教育公平是社会发展的必然需求,要实现这一目标就要始终把教育摆在优先发展的战略地位。薄弱学校的存在,已经严重阻碍着我国素质教育的发展进程,“办好义务教育阶段每一所学校,为每一位学生提供良好的教育”,成为了整个社会强烈关注的... 教育公平是社会发展的必然需求,要实现这一目标就要始终把教育摆在优先发展的战略地位。薄弱学校的存在,已经严重阻碍着我国素质教育的发展进程,“办好义务教育阶段每一所学校,为每一位学生提供良好的教育”,成为了整个社会强烈关注的社会热点问题。在促进我国义务教育均衡化发展的大环境下,改造薄弱学校已成为一个不容忽视的问题,作为薄弱学校关键人物的校长,他所承担的职责与任务则是薄弱学校改造问题中的灵魂。 展开更多
关键词 薄弱学校 改造 校长
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Pseudo-anti commuting Ricci tensor for real hypersurfaces in the complex hyperbolic quadric
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作者 Young Jin Suh 《中国科学:数学英文版》 SCIE CSCD 2019年第4期679-698,共20页
We introduce a new notion of pseudo-anti commuting Ricci tensor for real hypersurfaces in the noncompact complex hyperbolic quadric Q^m*= SO20,m/SO2SOm and give a complete classification of these hypersurfaces.
关键词 pseudo-anti COMMUTING Ricci tensor pseudo-Einstein A-isotropic A-principal COMPLEX conjugation COMPLEX HYPERBOLIC QUADRIC
Effect of Multi-parameter Environmental Factors on Cucumber Leaf Surface Wetness 预览
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作者 Chunyang QIAN Jianchun WANG +2 位作者 Fengju LI Zhiwen SONG Yan WANG 《农业生物技术:英文版》 CAS 2019年第2期32-34,共3页
In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature g... In this study, artificial leaf resistance was used to simulate leaf wetness. Specific to the solar greenhouse environment in Tianjin, microclimate monitoring equipment was installed for the collection of temperature group and humidity group data, as well as solar radiation and leaf wetness in the greenhouse. In order to reduce the complexity of multivariate factor prediction and ensure the richness of selected data types, correlation analysis was made to the 2 groups of data, screening 5 000 groups of data, including the humidity group data RH, RH 20 , RH 40 , temperature group data T, T20 , T40 , and solar radiation W. The data were then analyzed by principal component analysis, screening out 4 groups of principal components to show the leaf wetness index. 展开更多
关键词 CUCUMBER LEAF wetness Principal COMPONENT analysis MULTI-PARAMETER FACTORS
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Determination and Multidimensional Analysis of 22 Kinds of Inorganic Elements in Leontopodium franchetii Beauv. from Different Production Areas 预览
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作者 Pei QUN Yatao HAN +4 位作者 Zhe LIU Fang XIAO Yongxia KE Yunzhang XU Yuan LIU 《药用植物研究(英文版)》 2019年第2期6-9,13共5页
[Objectives]To determine the content of inorganic elements in Leontopodium franchetii Beauv. from different production areas, and provide a reference for quality control, safety assessment, and clinical application of... [Objectives]To determine the content of inorganic elements in Leontopodium franchetii Beauv. from different production areas, and provide a reference for quality control, safety assessment, and clinical application of L. franchetii Beauv..[Methods] The contents of Al, B, Ba, Ca, Cd, Cu, Fe, K, Mn, Mo, Na, Ni, P, Pb, Si, Sn, Sr, Ti, V, Zn, Hg, Cr in the sample of L. franchetii Beauv. were determined by the wet digestion and technique of inductively coupled plasma optical emission spectrometry(ICP-OES), and the principal component analysis was carried out for the determination results.[Results] A total of 20 inorganic elements were detected from the samples of L. franchetii Beauv. from different production areas, among which the contents of Ca, Al, P and Fe were higher. There were significant differences among different elements, and samples of different production areas show similar distribution patterns of main elements. Correlation analysis shows that 17 elements had an extremely significant positive correlation and 19 elements had a significant positive correlation. According to the principal component analysis, B, Ca, K, Mn, Mo, Pb, Sn, Sr, Fe, Ni, Ti, V, Zn, Al, and Cd were characteristic inorganic elements of L. franchetii Beauv.[Conclusions] This method is simple, rapid and accurate, and can be used for the analysis and determination of inorganic elements in L. franchetii Beauv., and provides a theoretical basis for better development and utilization of L. franchetii Beauv. 展开更多
关键词 LEONTOPODIUM franchetii Beauv. INORGANIC elements Inductively coupled plasma optical emission SPECTROMETRY (ICP-OES) Correlation ANALYSIS Principal component ANALYSIS
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Persistence of Cry1Ac Protein from Transgenic Bt Cotton Cultivation and Residue Returning in Fields and Its Effect on Functional Diversity of Soil Microbial Communities
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作者 ZHANG Meijun FENG Meichen +3 位作者 XIAO Lujie SONG Xiaoyan Guangwei DING YANG Wude 《土壤圈:英文版》 SCIE CAS CSCD 2019年第1期114-122,共9页
The persistence of Cry1 Ac protein in the soil and its effect on soil microbial communities are a core issue in assessing the ecological risk of transgenic Bacillus thuringiensis(Bt) cotton. In this study a field expe... The persistence of Cry1 Ac protein in the soil and its effect on soil microbial communities are a core issue in assessing the ecological risk of transgenic Bacillus thuringiensis(Bt) cotton. In this study a field experiment was conducted on the cultivation of transgenic Bt cotton(Jin 26 and BtJ i 668) with the immediate returning of residues to the fields, in order to quantify the Cry1 Ac protein content in the fields and investigate its effects on the functional diversity of soil microbial communities. Cry1 Ac protein in the residue-soil mixture was gradually degraded in the transgenic Bt cotton fields. After transgenic Bt cotton straw was returned to the fields for 30 d, 63.73%and 58.33% of the initial amounts of Cry1 Ac protein were degraded in the Jin 26 and BtJ i 668 fields, respectively. Before the crops were sown in the following year(180 d after returning the straw), no Cry1 Ac protein was detected in the fields. After returning the cotton straw to the fields for 30 d, the Shannon-Wiener and McIntosh indices of soil microbial communities in the transgenic Bt cotton fields were significantly higher than those in the non-transgenic cotton fields. Meanwhile, the utilization of carbon sources including amino acids, amines, and carbohydrates by the soil microbial communities significantly increased. Both the McIntosh index and the utilization of carbohydrates increased until 180 d. Principal component analysis revealed that amino acids, amides, and carbohydrates were the main carbon sources distinguishing the two principal component factors. These findings indicated that Cry1 Ac protein did not accumulate in the fields after transgenic Bt cotton was planted for one year and the residues were immediately returned to the fields;however, the original functional diversity of soil microbial communities was affected continuously. 展开更多
关键词 BIOLOG GN2 carbon source utilization diversity index principal component analysis STRAW return
Mapping intrinsic electromechanical responses at the nanoscale via sequential excitation scanning probe microscopy empowered by deep data
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作者 Boyuan Huang Ehsan Nasr Esfahani Jiangyu Li 《国家科学评论:英文版》 CSCD 2019年第1期55-63,共9页
Ever-increasing hardware capabilities and computation powers have enabled acquisition and analysis of big scientific data at the nanoscale routine, though much of the data acquired often turn out to be redundant,noisy... Ever-increasing hardware capabilities and computation powers have enabled acquisition and analysis of big scientific data at the nanoscale routine, though much of the data acquired often turn out to be redundant,noisy and/or irrelevant to the problems of interest, and it remains nontrivial to draw clear mechanistic insights from pure data analytics. In this work, we use scanning probe microscopy(SPM) as an example to demonstrate deep data methodology for nanosciences, transitioning from brute-force analytics such as data mining, correlation analysis and unsupervised classification to informed and/or targeted causative data analytics built on sound physical understanding. Three key ingredients of such deep data analytics are presented. A sequential excitation scanning probe microscopy(SE-SPM) technique is first developed to acquire high-quality, efficient and physically relevant data, which can be easily implemented on any standard atomic force microscope(AFM). Brute-force physical analysis is then carried out using a simple harmonic oscillator(SHO) model, enabling us to derive intrinsic electromechanical coupling of interest.Finally, principal component analysis(PCA) is carried out, which not only speeds up the analysis by four orders of magnitude, but also allows a clear physical interpretation of its modes in combination with SHO analysis. A rough piezoelectric material has been probed using such a strategy, enabling us to map its intrinsic electromechanical properties at the nanoscale with high fidelity, where conventional methods fail.The SE in combination with deep data methodology can be easily adapted for other SPM techniques to probe a wide range of functional phenomena at the nanoscale. 展开更多
关键词 SEQUENTIAL EXCITATION scanning probe MICROSCOPY principal component analysis simple harmonic OSCILLATOR model
新时代我国社会主要矛盾转化的三重意涵 预览
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作者 陈霄 吴波 王凤阁 《探索》 CSSCI 北大核心 2019年第1期12-18,共7页
中国特色社会主义进入了新时代,其显著标志是社会主要矛盾的内涵发生了新变化。在深入研究十九大报告基础上,坚持辩证唯物主义和历史唯物主义原理,主要立足于改革开放以后经济史的梳理,对当前社会主要矛盾变化的历史逻辑、物质基础和转... 中国特色社会主义进入了新时代,其显著标志是社会主要矛盾的内涵发生了新变化。在深入研究十九大报告基础上,坚持辩证唯物主义和历史唯物主义原理,主要立足于改革开放以后经济史的梳理,对当前社会主要矛盾变化的历史逻辑、物质基础和转化条件进行理论阐释,认为当前我国社会主要矛盾转化具有三重意涵:一是集中体现了改革开放以来中国特色社会主义市场经济建设取得的伟大成就;二是集中反映了“以人为核心冶的发展理念;三是集中表达了实现“两个一百年”目标的现实任务。 展开更多
关键词 中国特色社会主义 社会主要矛盾 发展阶段 需求
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Prospectivity modeling of porphyry copper deposits:recognition of efficient mono-and multi-element geochemical signatures in the Varzaghan district,NW Iran
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作者 Reza Ghezelbash Abbas Maghsoudi Mehrdad Daviran 《中国地球化学学报:英文版》 EI CAS CSCD 2019年第1期131-144,共14页
The Varzaghan district at the northwestern margin of the Urumieh–Dokhtar magmatic arc, is considered a promising area for the exploration of porphyry Cu deposits in Iran. In this study we identified mono-and multi-el... The Varzaghan district at the northwestern margin of the Urumieh–Dokhtar magmatic arc, is considered a promising area for the exploration of porphyry Cu deposits in Iran. In this study we identified mono-and multi-element geochemical anomalies associated with Cu–Au–Mo–Bi mineralization in the central parts of the Varzaghan district by applying the concentration–area fractal method. After mono-element geochemical investigations, principal component analysis was applied to ten selected elements in order to acquire a multi-element geochemical signature based on the mineralization-related component. Quantitative comparisons of the obtained fractal-based populations were carried out in accordance with known Cu occurrences using Student’s t-values. Then,significant mono-and multi-element geochemical layers were separately combined with related geologic and structural layers to generate prospectivity models, using the fuzzy GAMMA approach. For quantitative evaluation of the effectiveness of different geochemical signatures in final prospectivity models, a prediction-area plot was adapted. The results show that the multi-element geochemical signature of principal component one(PC1) is more effective than mono-element layers in delimiting exploration targets related to porphyry Cu deposits. 展开更多
关键词 GEOCHEMICAL signature Concentration–area(C–A) fractal Principal component analysis(PCA) Student’s t-value Fuzzy mineral prospectivity modeling(MPM) Prediction–area(P–A) PLOT
道德领导力理论视域下中小学校长道德领导力的建构 预览
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作者 苏荟 李贝贝 《兵团教育学院学报》 2019年第2期71-75,80共6页
学校教育不仅承担学生的知识传授,还要负责学生的道德培养,而学校的道德文化建设是当前学校工作管理和改进的重要内容,在此过程中,校长的道德领导力起着至关重要的作用。本文基于道德领导理论,通过分析校长道德领导力的现实需求和职能定... 学校教育不仅承担学生的知识传授,还要负责学生的道德培养,而学校的道德文化建设是当前学校工作管理和改进的重要内容,在此过程中,校长的道德领导力起着至关重要的作用。本文基于道德领导理论,通过分析校长道德领导力的现实需求和职能定位,进一步构建有效提升中小学校长道德领导力的途径。 展开更多
关键词 中小学 校长 道德领导力理论 道德领导力
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