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Depolymerization of polyamide 6 in hydrophilic ionic liquids 预览
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作者 Akio Kamimura Yuto Shiramatsu Takuji Kawamoto 《绿色能源与环境:英文版》 CSCD 2019年第2期166-170,共5页
Polyamide 6 underwent an efficient depolymerization in hydrophilic ionic liquids under microwave irradiation at 300℃.The depolymerization completed within 60 min.Caprolactam was readily separated by simple extraction... Polyamide 6 underwent an efficient depolymerization in hydrophilic ionic liquids under microwave irradiation at 300℃.The depolymerization completed within 60 min.Caprolactam was readily separated by simple extraction procedure and the ionic liquids were recovered and reused for several times.Addition of catalytic amounts of DMAP(N,N-dimethylaminopyridine)promoted the depolymerization effectively.The present improved procedure provides a method to avoid direct distillation procedure,which consumes energy for the separation of caprolactam from ionic liquids.Although some contamination of ionic liquids was observed,the present procedure provides a new possibility for the use of ionic liquids for plastic chemical recycling from the viewpoint of development of an energy-saving methodology.Use of solubility switchable ionic liquids is also examined to explore a possibility for better separation although depolymerization did not work well. 展开更多
关键词 CHEMICAL RECYCLING Polyamides CHEMICAL conversion IONIC liquids
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Seasonal and reproductive variation in chemical constituents of scent signals in wild giant pandas
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作者 Wenliang Zhou Yonggang Nie +4 位作者 Yibo Hu Ronald R.Swaisgood Yaohua Zhang Dingzhen Liu Fuwen Wei 《中国科学:生命科学英文版》 SCIE CAS CSCD 2019年第5期648-660,共13页
Seasonally reproducing animals show many behavioral and physiological changes during the mating period, including increased signaling for intrasexual competition and mate attraction. We collected 102 anogenital gland ... Seasonally reproducing animals show many behavioral and physiological changes during the mating period, including increased signaling for intrasexual competition and mate attraction. We collected 102 anogenital gland secretions(AGS) from marking trees in Foping Nature Reserve, and used gas chromatography mass spectrometry to analyze these chemical composition. Of these marks, all but one were from males, confirmed with DNA analysis. We found that several chemical constituents, especially volatile compounds, were present only during the mating season and that the relative abundance of many compounds changed as a function of breeding season, whereas nonvolatile compounds were lower in the mating season. This seasonal variation in chemical composition of AGS most likely plays an important role in governing giant panda reproduction, including mate location, attraction, and male-male competition. The chemical properties of many of these putative chemosignals—such as volatility and longevity—are suggestive of these roles, and undoubtedly contribute to successful reproduction for this species with a characteristically sophisticated chemical communication system. We also found a number of important differences between the chemical constituents of AGS from wild pandas and those found in previous studies with captive pandas, suggesting that inappropriate chemosignal composition may contribute to poor reproductive success in captive breeding programs. 展开更多
关键词 giant panda CHEMICAL communication anogenital GLAND SECRETIONS CHEMICAL composition reproduction
Effects of Chemical Reactions in the Hypersonic Reacting Flow around Blunt Bodies 预览
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作者 ZHAO Faming WANG Jiangfeng +1 位作者 FAN Xiaofeng YANG Tianpeng 《南京航空航天大学学报:英文版》 EI CSCD 2019年第1期71-79,共9页
The effects of chemical reactions in the hypersonic reacting flow are investigated using an integrated algorithm considering simultaneously two different reaction mechanisms,i.e.,including the high temperature air non... The effects of chemical reactions in the hypersonic reacting flow are investigated using an integrated algorithm considering simultaneously two different reaction mechanisms,i.e.,including the high temperature air non?equilibrium chemical reactions and the H2- air combustion reactions. The program is validated by the air non-equilibrium flow at Mach number of 25.9 with the RAM C-II configuration and the shock-induced combustion flow at Mach number of 4.512 6 around a sphere,respectively. Furthermore,the mixed reacting flow with the Mach number of 10.0 with an opposing jet of hydrogen is numerically analyzed. The results show that the program is reliable,and the effects of chemical reactions engender in the decrease of peak temperature along characteristic lines,as well as on the surface. The production of water is augmented in the region with high ratio of oxygen to hydrogen and weakened in the area with low ratio of oxygen to hydrogen by the air chemical non-equilibrium effects. 展开更多
关键词 HYPERSONIC air CHEMICAL NON-EQUILIBRIUM combustion EFFECTS of CHEMICAL reaction
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Resonant Light Scattering Toward Optical Fiber Humidity Sensors
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作者 Mahboubeh DEHGHANI SANIJ Abolfazl BAHRAMPOUR Ali Reza BAHRAMPOUR 《光子传感器:英文版》 EI CAS CSCD 2019年第1期60-68,共9页
The deposition of tetrakis(4-sulonatophenyl)porphyrin(TPPS)thin film on optical fibers presents many possibilities for sensing applications.The J-form aggregation with a narrow and sharp spectral feature at about 490n... The deposition of tetrakis(4-sulonatophenyl)porphyrin(TPPS)thin film on optical fibers presents many possibilities for sensing applications.The J-form aggregation with a narrow and sharp spectral feature at about 490nm and its sensitivity to humidity have been discussed;a fast change of wavelength occurs according with variation in the humidity level.The reproducibility and high sensitivity of TPPS-coated fibers,along with the capabilities of optical fibers,suggest the device as a good candidate for humidity sensing in harsh environments. 展开更多
关键词 Humidity CHEMICAL porphyrin-based CHEMICAL optical fiber SENSOR
门诊药房口服化学药品说明书中有关老年人安全用药标注情况的调查
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作者 鹿华彦 慕文璐 黄琪 《中国校医》 2019年第6期466-468,共3页
目的调查分析本院门诊药房165份口服化学药品说明书中有关老年人用药信息的标注情况,促进老年人合理安全用药。方法由专人负责查阅本院门诊药房正在使用和销售的药品,从中筛选出各类老年人常用口服化学药品说明书165份,收集所有数据,均... 目的调查分析本院门诊药房165份口服化学药品说明书中有关老年人用药信息的标注情况,促进老年人合理安全用药。方法由专人负责查阅本院门诊药房正在使用和销售的药品,从中筛选出各类老年人常用口服化学药品说明书165份,收集所有数据,均采用Microsoft Excel2013录入,并作归类分析。结果在调研的165份口服化学药品说明书中,老年人用药信息标准缺失项排列前4位的分别为"药理毒理"(98.79%)、"药物过量"(98.79%)、"禁忌"(98.79%)、"药物相互作用"(98.18%),而未给出任何有关老年人用药信息的药品说明书占12.73%。明确给出老年人用药剂量为"老年人用药"项的占49.31%,未准确给出老年人用药剂量"老年人用药"项的占34.72%。无任何"老年人用药"项的占15.97%。结论口服化学药品说明书有关老年人的用药指导信息存在不同程度缺失现象,给临床医师及药师指导老年患者用药参考带来难题,口服化学药品说明书中应完善老年人用药信息,确保老年人安全,有效用药。 展开更多
关键词 老年人 化学 药物口服 说明书 安全用药
Chemical Composition and Antioxidant Activity of Date Seeds from Different Tunisian Date Palm Cultivars 预览
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作者 Dhaouadi,K. Ammar,H. +1 位作者 Khouja,M. López,S. 《食品科学与工程:英文版(美国)》 2019年第4期123-130,共8页
Chemical composition,polyphenolic and flavonoid contents,and antioxidant activity were determined in date seeds derived from four Tunisian date palm(Phoenix dactylifera)cultivars namely:Goundi,Chekena,Mnekher and Remt... Chemical composition,polyphenolic and flavonoid contents,and antioxidant activity were determined in date seeds derived from four Tunisian date palm(Phoenix dactylifera)cultivars namely:Goundi,Chekena,Mnekher and Remtha.Sodium and potassium contents in date seeds were determined by flame photometry,phenolic compounds by the Folin-Ciocalteu method,flavonoids by colorimetric quantification,and the antioxidant activity by the DPPH free radical scavenging method.Crude protein content varied widely(p<0.001)between date seed varieties and ranged from 3.95(Goundi)to 7.51%DM(Chekena).No significant differences(p>0.001)were detected between seed varieties for their dry matter(DM)and ash contents.However,sodium,potassium and phosphorus varied widely(p<0.001)between varieties.The highest phenolic content(p<0.001)was observed in Goundi(39.4 mg gallic acid equivalent(GAE)/g DM)and Remtha(36.6 mg GAE/g DM)seed varieties.Likewise,Goundi had the highest(p<0.001)flavonoid content(16.4 mg quercetin equivalent(QE)/g DM)and antioxidant activity(1,807μM Trolox equivalent antioxidant capacity(TEAC)/g DM);however the lowest values(p<0.001)of phenolic(19.2 mg GAE/g DM),flavonoid(8.8 mg QE/g DM)and antioxidant activity(682μM TEAC/g DM)were observed for Chekena seeds.Further studies are needed to verify the potential of date seeds as alternative for animal nutrition. 展开更多
关键词 DATE SEEDS chemical composition PHENOLIC flavonoid ANTIOXIDANT activity
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The 12th Asia Chemical Fiber Industries Federation Conference 2019 showed you the report of Asian chemical fiber industry 预览
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《中国纺织:英文版》 2019年第5期22-23,共2页
On April 11th, the 12th Asian Chemical Fiber Conference, the high-est-level professional meeting of the Asian chemical fibre industry, was held in Bali, Indonesia. The theme of the conference was “Sustainable develop... On April 11th, the 12th Asian Chemical Fiber Conference, the high-est-level professional meeting of the Asian chemical fibre industry, was held in Bali, Indonesia. The theme of the conference was “Sustainable development of chemical fibers”. It was represented by chemical fibre associations from nine countries and regions in China, India, Indonesia, Japan, Korea, Malaysia, Pakistan, Taiwan China and Thailand attended the meeting. 展开更多
关键词 ASIA Chemical FIBER INDUSTRIES
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Fe-substituted Ba-hexaaluminate with enhanced oxygen mobility for CO2 capture by chemical looping combustion of methane 预览
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作者 Fei Huang Ming Tian +5 位作者 Yanyan Zhu Xiaodong Wang Aiqin Wang Lin Li Jian Lin Junhu Wang 《能源化学:英文版》 SCIE EI CAS CSCD 2019年第2期50-57,共8页
While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur afte... While Fe-based oxygen carriers(OC) are regarded to be promising for chemical looping combustion(CLC),the decrease of CO2 selectivity during deep reduction process and the severe agglomeration of Fe2O3 often occur after multiple redox cycles due to the low oxygen mobility.Herein,Fe-substituted Bahexaaluminates(Ba FexAl12– xO19,denoted as BFxA-H,x = 1 and 2) prepared by a modified two-step method exhibited not only higher amount of converted oxygen(Ot) and CH4 conversion(77% and 81% vs.17%and 75%) than those prepared by the traditional co-precipitation method(BFxA-C,x = 1 and 2) but also high CO2 selectivity above 92% during the nearly whole reduction from Fe3+ to Fe2+.Furthermore,the BFxA-H exhibited the excellent recyclability during 50 cycles.The better performance was ascribed to the markedly enhanced oxygen mobility which resulted from dominant occupancy of Fe cations in Al(5) sites(Fe5: 71% and 70% vs.49% and 41%) in mirror planes of hexaaluminate leading to larger amount of lattice oxygen coordinated with Fe5(O–Fe5)(0.45 and 0.85 mmol/g vs.0.31 and 0.50 mmol/g).The improvement of oxygen mobility also favored the preservation of chemical state of Fe cations in hexaaluminate structure in the re-oxidation step,resulting in the excellent recyclability of BFxA-H. 展开更多
关键词 CO2 CAPTURE Chemical LOOPING CH4 conversion Oxygen MOBILITY FE-BASED HEXAALUMINATE
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Insight into the Relationship Between Local Coordination of Isolated Pt Atoms and Chemical Reactivity 预览
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作者 ZHAO Ziyan ZHOU Ying 《材料导报》 EI CAS CSCD 北大核心 2019年第14期2281-2282,共2页
The supported isolated Pt atoms(Pt iso)and other rare metals have attracted intensive concern due to their maximized metal utilization efficiency,unique reactivity or selectivity,connection to organometallic catalysis... The supported isolated Pt atoms(Pt iso)and other rare metals have attracted intensive concern due to their maximized metal utilization efficiency,unique reactivity or selectivity,connection to organometallic catalysis and the potential for making well-defined active sites[1-3].As catalytic active sites,oxide-supported isolated Pt-group metal atoms are well known for their unique reactivity and efficient metal utilization[4-6].Even continuous efforts have been made,it is still challenging to characterize the intrinsic ca-talytic activity of these dispersed active sites on oxide supports at a level that relates local electronic and geometric structure to function,because of their atomic dispersion,heterogeneity in the local coordination,dynamic changes in local coordination under reactive environments and low loading of metal[7-9]. 展开更多
关键词 Relationship BETWEEN LOCAL COORDINATION ISOLATED PT ATOMS Chemical Reactivity
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An integrated cathode with bi-functional catalytic effect for excellent-performance lithium-sulfur batteries
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作者 Mengmeng Zhen Xintao Zuo +1 位作者 Juan Wang Cheng Wang 《纳米研究:英文版》 SCIE EI CAS CSCD 2019年第5期1017-1024,共8页
The high energy density of lithium-sulfur batteries (LSBs) is mainly based on the complex redox reactions and phase conversions.The sluggish redox kinetics and the large accumulation of soluble polysulfides in the ele... The high energy density of lithium-sulfur batteries (LSBs) is mainly based on the complex redox reactions and phase conversions.The sluggish redox kinetics and the large accumulation of soluble polysulfides in the electrolyte leads to low sulfur utilization and serious shuttle effect.Herein,an integrated sulfur cathode is constructed through a facile and large-scale method.It is composed of sulfur-N,S doped bamboo like CNTs@Co3S4 (NSC@Co3S4) composites on polypropylene separator.The immobilized polysulfides on the NSC@Co3S4 surface are further reduced/oxidized during the discharge/charge process via the efficient bi-functional catalytic effect of NSC@Co3S4,resulting in the rapid conversion of LiPSs.Consequently,the integrated sulfur cathode delivers a high initial reversible capacity of 1,473.6 mAh·g^-1 at 0.2 C and a high specific capacity of 979 mAh·g^-1 at 1 C after 500 cycles as well as excellent cycling stability for 1,000 cycles with a high specific capacity of 362.5 mAh·g^-1 at 5 C,which are superior to reported similar host materials. 展开更多
关键词 bi-fufictional catalysis POLYSULFIDES redox reaction chemical adsorption lithium-sulfur BATTERIES
Relations between indoor and outdoor PM2.5 and constituent concentrations
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作者 Cong Liu Yinping Zhang 《中国环境科学与工程前沿:英文版》 SCIE EI CAS CSCD 2019年第1期1-20,共20页
Outdoor PM2.5 influences both the concentration and composition of indoor PM2.5. People spend over 80% of their time indoors. Therefore, to assess possible health effects of PM2.5 it is important to accurately charact... Outdoor PM2.5 influences both the concentration and composition of indoor PM2.5. People spend over 80% of their time indoors. Therefore, to assess possible health effects of PM2.5 it is important to accurately characterize indoor PM2.5 concentrations and composition. Controlling indoor PM2.5 concentration is presently more feasible and economic than decreasing outdoor PM2.5 concentration. This study reviews modeling and measurements that address relationships between indoor and outdoor PM2.5 and the corresponding constituent concentrations. The key factors in the models are indooroutdoor air exchange rate, particle penetration, and deposition. We compiled studies that report I/O ratios of PM7.5 and typical constituents (sulfate (SO4^2-), nitrate (NO3 ), ammonium (NH4^+), elemental carbon (EC), and organic carbon (OC), iron (Fe), copper (Cu), and manganese (Mn)). From these studies we conclude that: 1) sulfate might be a reasonable tracer of non-volatile species (EC, Fe, Cu, and Mn) and PM2.5 itself;2) particulate nitrate and ammonium generally desorb to gaseous HNO3 and NH3 when they enter indoors, unless, as seldom happens, they have strong indoor sources;3) indoor-originating semi-volatile organic compounds sorb on indoor PM2.5, thereby increasing the PM2.5 OC load. We suggest further studies on indoor-outdoor relationships of PM2.5 and constituents so as to help develop standards for healthy buildings. 展开更多
关键词 INDOOR air quality Exposure SVOC REACTIVE OXIDATIVE species OXIDATIVE potential Chemical transport model
Chemical synthesis and structure determination of venom toxins
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作者 Bobo Dang 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第7期1369-1373,共5页
Venom toxins are widely spread in nature, adopting diverse structures and functions. They often function by blocking or modulating important membrane protein targets thus can be promising therapeutic candidates and bi... Venom toxins are widely spread in nature, adopting diverse structures and functions. They often function by blocking or modulating important membrane protein targets thus can be promising therapeutic candidates and biophysical probes. In this review, we briefly discuss the total chemical synthesis of venom toxins including the different refolding strategies reported during the past decade as well as innovative approaches for structure determination. 展开更多
关键词 VENOM TOXINS Chemical PROTEIN synthesis STRUCTURE DETERMINATION PROTEIN foldin Racemic PROTEIN crystallography
Chemical Components of Achyranthes bidentata Leaves by Ultra High Performance Liquid Chromatography-Mass Spectrometry 预览
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作者 Haiyang DONG Jinshuo MA Fulin YAN 《药用植物研究(英文版)》 2019年第4期16-19,共4页
[Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical c... [Objectives] To study the chemical components and relative content of Achyranthes bidentata leaves and provide a scientific basis for further development and utilization of A. bidentata leaves.[Methods] The chemical components of A. bidentata leaves were rapidly analyzed using the ultra high performance liquid chromatography-time of flight-high resolution mass spectrometry (UHPLC-TOF-MS).[Results] Thirty eight chemical compounds were identified in samples of A. bidentata leaves collected from Wen County of Henan Province, in which seven chemical compounds had the relative content higher than 5%, linoleic acid reached 25.7% and inokosterone A reached 13.8%.[Conclusions] A. bidentata leaves contain many kinds of chemical compounds. This study is expected to provide a certain basis for further extraction of linoleic acid and inokosterone A. 展开更多
关键词 Achyranthes bidentata LEAVES ULTRA high performance liquid chromatography-mass SPECTROMETRY (UHPLC-MS) Chemical components Inokosterone
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Patterning catalyst via inkjet printing to grow single-walled carbon nanotubes
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作者 Zeyao Zhang Yitan Li +6 位作者 Sheng Zhu Xiyan Liu Xiulan Zhao Meihui Li Haoyu Li Feng Yang Yan Li 《中国化学快报:英文版》 SCIE CAS CSCD 2019年第2期505-508,共4页
Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using... Controlled growth of patterned single-walled carbon nanotubes (SWNTs) is an important issue in many applications. Herein, we demonstrated a method to pattern catalyst via inkjet printing for the growth of SWNTs, using metal salt solutions as the inks and an ordinary office-use printer. We printed water solutions of cobalt acetate on hydrophilic Si substrates and grew high quality SWNT films. The composition of the precursor solutions and the hydrophilicity of the substrates were crucial factors to the patterning. 展开更多
关键词 SINGLE-WALLED carbon NANOTUBES INKJET printing PATTERNING Contact angle Chemical vapor deposition
Spatiotemporal evolution of carbon sequestration of limestone weathering in China
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作者 Huiwen LI Shijie WANG +2 位作者 Xiaoyong BAI Yue CAO Luhua WU 《中国科学:地球科学英文版》 SCIE EI CAS CSCD 2019年第6期974-991,共18页
Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribu... Carbonate carbon sequestration(CS) can aid in solving the problem of terrestrial residual carbon sinks and imbalances in the global carbon budget. Thus, complete understanding of the magnitude, spatiotemporal distribution, and evolution of this sequestration is highly desirable. On the basis of random forest regression and maximal potential dissolution model for carbonate, we estimated the CS of typical carbonate weathering in China from 2000 to 2014, that is, the sequestration of limestone weathering, using long-term ecologic, meteorological, hydrological raster data, and monitored data from 44 watersheds in China and surrounding regions. We extended our analyses by systematically exploring the spatiotemporal pattern and evolution trend of the flux and total sequestration. High levels of ionic activity coefficients of Ca2+ and HCO3- in limestone regions were observed to be mainly distributed in Northern and Northwestern China with a clear gradient from northwest to southeast. With a contrary spatial pattern, the annual average CS flux(CSF) of limestone weathering in China was estimated to be 4.28 t C km-2 yr-1, with high values mainly in the karst zones in Southeastern China. The mean CSF in different latitudes showed that Southern China(south of 28.14°N) was the region with the largest interannual fluctuation of flux and CSF increases as latitude decreases. The mean CSF in subtropical and tropical(TR) regions was the maximum of all major climate types, and for the frigid(F), mid-temperate(MTE), warm temperate(WTE), and temperate(TE) major climates;the CSF in the desert(D)subdivided climate was the minimum of these climates. By contrast, the values in grassland(G) and broad-leaved forest subdivided climate were the maximum. The pixel-based trend analysis indicated that the CSF of limestone weathering in China was slightly increasing in the period 2000–2014 with a rate of 0.036 t C km-2 yr-1. Furthermore, the annual total CS was estimated to be 7.07 Tg carbon per year(Tg C yr-1) with high levels in 2002, 2008, 展开更多
关键词 LIMESTONE Chemical WEATHERING carbon SINK SPATIOTEMPORAL evolution DISSOLUTION Random forest
Leaching of rare Earth elements from an Illinois basin coal source
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作者 X.Yang J.Werner R.Q.Honaker 《中国稀土学报:英文版》 SCIE EI CAS CSCD 2019年第3期312-321,共10页
The existence of rare earth elements(REEs) in coal sources at elevated concentrations has been the focus of several studies over the past decade. However, limited research has been conducted on methods to recover and ... The existence of rare earth elements(REEs) in coal sources at elevated concentrations has been the focus of several studies over the past decade. However, limited research has been conducted on methods to recover and refine the REEs. This paper reports the results of a detailed study into the potential of selectively recovering REEs in an Illinois basin coal source by leaching. Leaching characteristics are obtained for several segments obtained from a core sample as well as three different reject materials collected at a coal processing plant. Using a 1.2 mol/L sulfuric acid solution at 75 ℃,over 60% REE recovery is achieved from the direct floor and an inner parting material as well as the coal-rich core segments that are pretreated by low-temperature plasma oxidation to obtain access to the microdispersed mineral matter. In the leachable parting material, fluorapatite is detected by XRD analysis,which is one of the more soluble phosphate minerals with a documented association with REEs. For the three plant reject samples, the leaching recovery values obtained for the heavy REEs are higher than those obtained for the light REEs under the standard leaching conditions and when 0.1 mol/L(NH4)2SO4 was used to extract REEs by an ion exchange mechanism. Thermal activation by roasting or chemical activation by pretreatment using 8 mol/L NaOH solution increases the total REE recovery with significantly higher gains obtained for the light REEs. Leaching kinetics are relatively fast within the first 2 h and then slow to provide relatively low overall recovery values under the standard test conditions for the coarse and fine reject samples. However, significantly higher recovery values are realized when treating mixed-phase(middling) particles existing within the coarse reject material. 展开更多
关键词 LEACHING COAL Thermal ACTIVATION Chemical ACTIVATION RARE earth elements
Application of a novel porous tantalum implant in rabbit anterior lumbar spine fusion model:in vitro and in vivo experiments
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作者 Ming Lu Song Xu +9 位作者 Zi-Xiong Lei Dong LU Wei Cao Marko Huttula Chang-He Hou Shao-Hua Du Wei Chen Shuang-Wu Dai Hao-Miao Li Da-Di Jin 《中华医学杂志:英文版》 SCIE CAS CSCD 2019年第1期51-62,共12页
Background Some porous materials have been developed to enhance biologic fusion of the implants to bone in spine fusion surgeries.However,there are several inherent limitations.In this study,a novel biomedical porous ... Background Some porous materials have been developed to enhance biologic fusion of the implants to bone in spine fusion surgeries.However,there are several inherent limitations.In this study,a novel biomedical porous tantalum was applied to in vitro and in vivo experiments to test its biocompatibility and osteocompatibility.Methods Bone marrow-derived mesenchymal stem cells (BMSCs) were cultured on porous tantalum implant.Scanning electron microscope (SEM) and Cell Counting Kit-8 assay were used to evaluate the cell toxicity and biocompatibility.Twenty-four rabbits were performed discectomy only (control group),discectomy with autologous bone implanted (autograft group),and discectomy with porous tantalum implanted (tantalum group) at 3 levels:L3–L4,L4–L5,and L5–L6 in random order.All the 24 rabbits were randomly sacrificed at the different post-operative times (2,4,6,and 12 months;n = 6 at each time point).Histologic examination and micro-computed tomography scans were done to evaluate the fusion process.Comparison of fusion index scores between groups was analyzed using one-way analysis of variance.Other comparisons of numerical variables between groups were made by Student t test.Results All rabbits survived and recovered without any symptoms of nerve injury.Radiographic fusion index scores at 12 months post-operatively between autograft and tantalum groups showed no significant difference (2.89 ± 0.32 vs.2.83 ± 0.38, F= 244.60, P = 0.709).Cell Counting Kit-8 assay showed no significant difference of absorbance values between the leaching liquor group and control group (1.25 ± 0.06 vs.1.23 ± 0.04, t = –0.644, P = 0.545),which indicated the BMSC proliferation without toxicity.SEM images showed that these cells had irregular shapes with long spindles adhered to the surface of tantalum implant.No implant degradation,wear debris,or osteolysis was observed.Histologic results showed solid fusion in the porous tantalum and autologous bone implanted intervertebral spaces.Conclusion This novel porous tantal 展开更多
关键词 Porous TANTALUM ANTERIOR LUMBAR INTERBODY fusion bone INGROWTH chemical vapor deposition three-dimensional KNITTED framework
Resultant gradient information, kinetic energy and molecular virial theorem 预览
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作者 Roman F. Nalewajski 《化学报告(英文)》 2019年第1期22-35,共14页
Resultant gradient-information is introduced and applied to problems in chemical reactivity theory. This local measure of the structural information contained in (complex) wavefunctions of electronic states is related... Resultant gradient-information is introduced and applied to problems in chemical reactivity theory. This local measure of the structural information contained in (complex) wavefunctions of electronic states is related to the system overall kinetic energy combining the modulus (probability) and phase (current) contributions. The grand-ensemble representation of thermodynamic equilibria in open systems demonstrates the physical equivalence of the variational energetic and information principles. It is used and to relate the populational derivatives of ensemble-average functionals in both these representations, which represent reactivity criteria for diagnosing the charge-transfer (CT) phenomena. Their equivalence is demonstrated by using the in situ potential and hardness descriptors to predict the direction and optimum amount of CT. The virial theorem is generalized into thermodynamic quantities and used to extract the kinetic energy component from qualitative energy profiles in the bond-formation and (exo/endo)-ergic reactions. The role of electronic kinetic energy in such chemical processes is reexamined, the virial theorem implications for the Hammond postulate of reactivity theory are explored, and variations of the structural-information in chemical processes are addressed. The maximum thermodynamic information rule is formulated and "production" of the gradient-information in chemical reactions is addressed. The Hammond postulate is shown to be indexed by the geometric derivative of resultant gradient-information at transition-state complex. 展开更多
关键词 BOND formation chemical REACTIVITY grand ENSEMBLE INFORMATION theory RESULTANT INFORMATION VIRIAL theorem
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Effect of air masses motion on the rapid change of aerosols in marine atmosphere
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作者 Jinpei Yan Qi Lin +2 位作者 Miming Zhang Shuhui Zhao Liqi Chen 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第9期217-228,共12页
The impact of air masses motion on marine aerosol properties was investigated using an on-board single particle mass spectrometer(SPAMS) deployed for the determination of single particle size resolved chemical composi... The impact of air masses motion on marine aerosol properties was investigated using an on-board single particle mass spectrometer(SPAMS) deployed for the determination of single particle size resolved chemical composition over Southeast China Sea. Two aerosol blooms(E1 and E2) were observed during the cruise. High average particle number count occurred in E1(7320), followed by E2(5850), which was more than 100–150 times of the average particle number count during normal periods. Particles were classified as four major sources, including continental source, shipping source, marine source, and transport source based on the mass spectral similarity. Transport source was identified as those particles with high particle number count occurred only during aerosol bloom period. Three sub-types of EC-Ca, OC-Ca, and Al-rich were classified as transport source.EC-Ca was the dominant particles of the transport source, accounting for more than 70%of the total particles in aerosol bloom events. A uni-modal size distribution in the size range of 0.1–2.0 μm was observed during normal period, while a bimodal distribution with a tiny mode(<0.3 μm) and a coarse mode between 0.4 and 0.6 μm was present during aerosol bloom. The variation of aerosol source is consistent with air masses back trajectories, for the reason that most of the long-range air trajectories are from the ocean,while short air trajectories originate in the continental regions, which means that air masses have a significant impact on the aerosol physical–chemical properties along their tracks. 展开更多
关键词 Marine AEROSOL Chemical composition Source APPORTIONMENT Air MASSES Single PARTICLE AEROSOL mass spectrometer(SPAMS)
化学检测在环境检测中的应用分析 预览
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作者 陈赐权 《中小企业管理与科技》 2019年第16期177-177,179共2页
随着城市化与工业化的发展,不同地区的环境受到不同程度的污染,世界各国对环境的保护尤其重视,对于工厂排放、汽车排放以及其他排放做了相关制度的要求,判断是否达到排放标准或者评估空气的污染程度需要借助一些专业检测手段来完成,其... 随着城市化与工业化的发展,不同地区的环境受到不同程度的污染,世界各国对环境的保护尤其重视,对于工厂排放、汽车排放以及其他排放做了相关制度的要求,判断是否达到排放标准或者评估空气的污染程度需要借助一些专业检测手段来完成,其中化学检测是基本的又是可应用范围最广的一种手段,无论是大气检测还是水质检测,大多数被检测的对象都是对某些化学元素进行定量。基于此,论文对化学检测在环境检测中的应用进行了分析。 展开更多
关键词 环境 检测 化学 污染物
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