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Environmental contribution to needle variation among natural populations of Pinus tabuliformis 预览
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作者 Jingxiang Meng Xinyu Chen +3 位作者 Yujie Huang Liming Wang Fangqian Xing Yue Li 《林业研究:英文版》 CAS CSCD 2019年第4期1311-1322,共12页
Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in s... Variations in the phenotypic characteristics of conifer needles is a consequence of genetic evolution that has been widely used in geographic variation and ecological studies.Although many studies are based on an in situ sampling strategy and generally realize the contribution of environmental effects to variation in needle traits,it is still uncertain which needle traits are most influenced by genetic effects and which are most influenced by the environment.Using both a common garden experiment to eliminate environmental heterogeneity and an in situ sampling strategy,we compared 18 Pinus tabuliformis needle traits among 10 geographical populations.Using both sampling strategies,we found significant differences in needle traits among populations and among individuals within populations.Differences in the‘‘among-population’’variance component between the two sampling strategies revealed the environmental contribution among natural populations for each trait.The among-population variance in the following traits exceeded 8%:needle length,number of stomata within 2 mm(NS2),number of stomatal lines on the planar side,number of resin canals(RCN)and the resin canal area(RCA).For the stability of needle traits,NS2,RCN,RCA,ratio of the vascular bundle area to the RCA(VBA/RCA),and MA/RCA differed significantly in more than five provenance changes between the common garden populations and natural populations,which may be susceptible to environmental effects.Conversely,the crosssectional area,mesophyll area(MA),MA/(VBA+RCA),and MA/VBA were phenotypically stable.Geographic variation patterns and systematic relation of needle traits differed between the two sampling strategies,suggesting that in situ sampling results may reflect environmental effects and deviate statistical parameters for genetic study.Future studies of genetic evolution in the context of geographic variation should be based on appropriate sampling strategies and stable phenotypic traits. 展开更多
关键词 ENVIRONMENTAL effect Genetic VARIATION GEOGRAPHICAL VARIATION In situ sampling NEEDLE TRAITS PINUS tabuliformis
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The role of genomic structural variation in the genetic improvement of polyploid crops 预览
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作者 Sarah-Veronica Schiessl Elvis Katche +2 位作者 Elizabeth Ihien Harmeet Singh Chawla Annaliese S. Mason 《作物学报:英文版》 CAS CSCD 2019年第2期127-140,共14页
Many of our major crop species are polyploids,containing more than one genome or set of chromosomes.Polyploid crops present unique challenges,including difficulties in genome assembly,in discriminating between multipl... Many of our major crop species are polyploids,containing more than one genome or set of chromosomes.Polyploid crops present unique challenges,including difficulties in genome assembly,in discriminating between multiple gene and sequence copies,and in genetic mapping,hindering use of genomic data for genetics and breeding.Polyploid genomes may also bemore prone to containing structural variation,such as loss of gene copies or sequences (presence–absence variation) and the presence of genes or sequences inmultiple copies (copynumber variation).Although the two main types of genomic structural variation commonly identified are presence–absence variation and copy-number variation,we propose that homeologous exchanges constitute a third major form of genomic structural variation in polyploids.Homeologous exchanges involve the replacement of one genomic segment by a similar copy from another genome or ancestrally duplicated region,and are known to be extremely common in polyploids.Detecting all kinds of genomic structural variation is challenging,but recent advances such as optical mapping and long-read sequencing offer potential strategies to help identify structural variants even in complex polyploid genomes.All three major types of genomic structural variation (presence–absence,copy-number,and homeologous exchange) are now known to influence phenotypes in crop plants,with examples of flowering time,frost tolerance,and adaptive and agronomic traits.In this review,we summarize the challenges of genome analysis in polyploid crops,describe the various types of genomic structural variation and the genomics technologies and data that can be used to detect them,and collate information produced to date related to the impact of genomic structural variation on crop phenotypes.We highlight the importance of genomic structural variation for the future genetic improvement of polyploid crops. 展开更多
关键词 Presence–absence VARIATION COPY-NUMBER VARIATION Homeologous exchanges Genome structure PAN-GENOME
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Spatial and seasonal distribution of intertidal macrobenthos with their biomass and functional feeding guilds in the Naf River estuary,Bangladesh 预览
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作者 Md. Abu NOMAN MAMUNUR Rashid +1 位作者 M SHAHANUL Islam M. Belal HOSSAIN 《海洋湖沼学报(英文)》 SCIE CAS CSCD 2019年第3期1010-1023,共14页
The Naf River estuary is one of the most productive ecological ecosystems in Bangladesh providing an important feeding area for fishes and other aquatic animals.However,detailed information on macrobenthic communities... The Naf River estuary is one of the most productive ecological ecosystems in Bangladesh providing an important feeding area for fishes and other aquatic animals.However,detailed information on macrobenthic communities is rarely available in this area.Our study focused on the seasonal and spatial variability of macrobenthic community structure with their biomass and functional guilds.In total,fortyseven taxa were identified under nine major groups and seven functional feeding guilds.Among macrobenthic taxa,Polychaeta was dominant in both seasons and all over the estuary contributing 60%of total benthos.The mean abundance of macrobenthos was higher during the pre-monsoon(2 972±1 994 inds./m^2)than the monsoon(1 572±361 inds./m^2)being maximum at mid-estuary region and minimum at upper and lower estuary regions.Of the diversity indices,density(P=0.01,P=0.003),the number of taxa(P=0.000 3,P=0.000 9)and Margalef′s Index(P=0.000 4,P=0.001)of macrobenthos were significantly different among stations and seasons.Shannon-Weiner index(P=0.009,P=0.12)and Pielou’s evenness index(P=0.03,P=0.14)had significant differences among stations but not among seasons.Cluster analysis suggested that distribution of macrofauna is strongly influenced by seasonality.Among the feeding types,carnivorous were found to be dominant at the upper and mid-estuarine regions,and herbivorous were at lower estuarine regions.Carnivorous species were dominant in both seasons.Omnivores have shown to be the most abundant feeding type in terms of biomass though herbivores were highest during monsoon. 展开更多
关键词 MACROBENTHOS seasonal VARIATION SPATIAL VARIATION feeding GUILDS BIOMASS NAF River estuary
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Martingale Musielak-Orlicz Hardy spaces
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作者 Guangheng Xie Yong Jiao Dachun Yang 《中国科学:数学英文版》 SCIE CSCD 2019年第8期1567-1584,共18页
In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ^*(■),Pφ(?),H_φ^S(■),Qφ(?)and H_φ^s(■),respectively,via the maximal function,the quadratic variation and the conditional quadratic va... In this article,we introduce the martingale Musielak-Orlicz Hardy spaces H_φ^*(■),Pφ(?),H_φ^S(■),Qφ(?)and H_φ^s(■),respectively,via the maximal function,the quadratic variation and the conditional quadratic variation of martingales.We then establish the atomic characterizations of H_φ^s(■),Pφ(■)and Qφ(■).As applications,we obtain the dual space of H_φ^s(■)and several martingale inequalities which further clarify the relations among H_φ^*(■),Pφ(■),H_φ^S(■),Qφ(■)and H_φ^s(■).Especially,as special cases,the results on atomic characterizations of H_φ^s(■),Pφ(?)and Qφ(■)as well as on the dual space of H_φ^s(■)in the weighted case are also new. 展开更多
关键词 MARTINGALE Musielak-Orlicz Hardy space maximal function QUADRATIC VARIATION CONDITIONAL QUADRATIC VARIATION atom DUALITY
Dimensional Variation Modeling of Aircraft Compliant Part Assembly Considering Clamping Force Change 预览
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作者 TAN Changbai ZHANG Wei WANG Zhiguo 《南京航空航天大学学报:英文版》 EI CSCD 2019年第2期298-305,共8页
Compliant parts are widely applied to aircraft structures.Due to the ease of deformation of compliant parts in assembly,the prediction of assembly variation is especially important for assembly quality control.A dimen... Compliant parts are widely applied to aircraft structures.Due to the ease of deformation of compliant parts in assembly,the prediction of assembly variation is especially important for assembly quality control.A dimensional variation model considering the clamping force change in assembly is proposed based on the method of influence coefficient(MIC).First,the assembly process is decomposed into several steps including positioning,clamping,joining,and spring-back.Then,the force-displacement relationship is formulated according to the varied force conditions on the parts in each assembly step.Finally,two examples are illustrated to validate the proposed assembly variation model.The results show the impact of clamping force change is significant on the assembly variation,and the proposed model can predict the assembly variation more accurately than the referred method without clamping force correction at the over-constrained locating points of fixture. 展开更多
关键词 AIRCRAFT dimensional variation compliant parts CLAMPING force CHANGE method of influence coefficient(MIC)
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基于DI指数的佛山市气象干旱变化趋势分析 预览
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作者 麦雪湖 梁华玲 +1 位作者 麦文强 程银琳 《中低纬山地气象》 2019年第3期75-77,共3页
该文根据逐日气象干旱指数DI指数统计佛山1959—2017年气象干旱日数,采用“二项式系数加权平均法”进行趋势分析,结合M-K检验和小波分析等方法分析气候突变和周期变化,对佛山市59a的气象干旱日数变化趋势进行分析研究。结果表明:近59a... 该文根据逐日气象干旱指数DI指数统计佛山1959—2017年气象干旱日数,采用“二项式系数加权平均法”进行趋势分析,结合M-K检验和小波分析等方法分析气候突变和周期变化,对佛山市59a的气象干旱日数变化趋势进行分析研究。结果表明:近59a佛山年气象干旱日数总体呈减少的趋势,2015年以后年气象干旱日数呈显著减少的趋势,2010—2011年是气象干旱日数突变减少的开始时段;年气象干旱日数存在着3a、7a及20a的周期时间尺度,准3a的短周期存在于1980年前,准7a的周期出现在1980年后,20a的周期有着最强的振荡,是年气象干旱日数变化的首要主周期。 展开更多
关键词 气象干旱 变化趋势 佛山
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Using proximal sensor data for soil salinity management and mapping 预览
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作者 GUO Yan ZHOU Yin +5 位作者 ZHOU Lian-qing LIU Ting WANG Lai-gang CHENG Yong-zheng HE Jia ZHENG Guo-qing 《农业科学学报:英文版》 SCIE CAS CSCD 2019年第2期340-349,共10页
Over the past five decades, increased pressure caused by the rapidly growing population has resulted in a reclamation of agricultural and urban buffer zones along China’s coastline. However, information about the spa... Over the past five decades, increased pressure caused by the rapidly growing population has resulted in a reclamation of agricultural and urban buffer zones along China’s coastline. However, information about the spatio–temporal variation of soil salinity in these reclaimed regions is limited. As such, obtaining this information is crucial for mapping the variation in saline areas and to identify suitable salinity management strategies. In this study, we employed EM38 data to conduct digital soil mapping of spatio–temporal variation and map these variations of different site-specific zones. The results indicated that the distribution of soil salinity was heterogeneous in the middle of, and that the leaching of salts was significant at the edges of, the study field. Afterwards, fuzzy-k means algorithm was used to divide the site-specific management zones within the time series apparent soil electrical conductivity(ECa) data and the spatial correlations of variation. We concluded that two management zones are optimal to guide precision management. Zone A had an average salinity level of about 165 mS m–1, in which salt-tolerant crops, such as cotton and barley can grow normally, while crops such as soybean and cowpeas may be planted using leaching and increasing the mulching film methods to reduce the accumulation of salt in surface soil. In Zone B, there was a low salinity level with a mean of 89 mS m–1 for ECa, which allows for rice, wheat, and a wide range of vegetables to be grown normally. In such situations, measures such as an optimized combination of irrigation and drainage, as well as soil amendment can be taken to adjust and control the salt content. Particularly, flattening the land with a large-scale machine was used to improve the ability of micro-topography to influence salt migration;rice and other dry, land crops were planted in rotation in combination with utilizing salt-leaching multiple times to speed up desalinization. 展开更多
关键词 apparent SOIL electrical conductivity(ECa) SOIL SALINITY EM38 spatial variation MANAGEMENT zone
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2014-2017年中国部分地区PEDV流行株S基因遗传进化分析
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作者 郑慧华 张鸿鑫 +3 位作者 韩昊莹 乔涵 赵宇 陈红英 《安徽农业大学学报》 CAS CSCD 2019年第2期249-255,共7页
参考GenBank中PEDV经典CV777毒株基因组序列设计特异性引物,采用RT-PCR方法对临床采集的疑似PEDV样品进行S基因扩增、克隆和测序,拼接获得30条完整S基因序列,并进行遗传进化及同源性分析。结果显示,获得的30条PEDV S基因与25个参考株S... 参考GenBank中PEDV经典CV777毒株基因组序列设计特异性引物,采用RT-PCR方法对临床采集的疑似PEDV样品进行S基因扩增、克隆和测序,拼接获得30条完整S基因序列,并进行遗传进化及同源性分析。结果显示,获得的30条PEDV S基因与25个参考株S基因的核苷酸相似性介于93.6%~99.8%;且各流行毒株与经典毒株比较,具有多处的点突变、插入和缺失。与其他参考株相比,S1区存在157个氨基酸突变位点,占总数的65.7%(157/239),暗示PEDV的S1区域比S2区域易发生变异;表明目前中国PEDV流行株已经发生了变异,在一定程度揭示了免疫猪群仍然发病的原因。 展开更多
关键词 PEDV S基因 遗传进化分析 变异
大花序桉种源幼龄材木材物理性质变异 预览
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作者 余玉珠 苏远玉 +4 位作者 陆艳柳 任世奇 杨中宁 卢翠香 周维 《桉树科技》 2019年第2期9-15,共7页
用伐倒木取样,按国家标准制作测定试件,研究6a生大花序桉9个种源木材物理性质在种源间、树干高度及径向上的变异规律。结果表明:大花序桉木材树皮率、横向全干缩率、差异干缩和体积全干缩率在种源间均存在显著差异;各种源木材密度在树... 用伐倒木取样,按国家标准制作测定试件,研究6a生大花序桉9个种源木材物理性质在种源间、树干高度及径向上的变异规律。结果表明:大花序桉木材树皮率、横向全干缩率、差异干缩和体积全干缩率在种源间均存在显著差异;各种源木材密度在树干高度上无明显规律,大部分种源木材密度沿髓心向外逐渐增大。6a生的大花序桉木材差异干缩属中级。 展开更多
关键词 大花序桉 幼龄材 物理性质 变异
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楸树心材与边材的生长特征及变异规律 预览
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作者 邓丽萍 任素红 +3 位作者 吕建雄 王玉荣 任海青 赵荣军 《木材工业》 北大核心 2019年第4期9-13,共5页
为系统了解珍贵阔叶树楸树心材与边材的生长特征及边心材转化规律,采用树木年轮分析仪对5株楸树不同树高处的圆盘进行年轮数、宽度等生长特征测定,建立心材与树木各生长量之间的回归模型。结果表明:楸树年轮宽度在10~15年达到峰值,可持... 为系统了解珍贵阔叶树楸树心材与边材的生长特征及边心材转化规律,采用树木年轮分析仪对5株楸树不同树高处的圆盘进行年轮数、宽度等生长特征测定,建立心材与树木各生长量之间的回归模型。结果表明:楸树年轮宽度在10~15年达到峰值,可持续10年左右;心材起始树龄为5.26a,心材形成速率为0.90轮/a;属于生长收获周期短、心材形成时期较早且形成速率较快的树种。 展开更多
关键词 楸树 心材 边材 生长特征 变异规律
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Characteristics of volatile organic compounds,NO2, and effects on ozone formation at a site with high ozone level in Chengdu
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作者 Yuanyuan Deng Jing Li +2 位作者 Yaqi Li Rongrong Wu Shaodong Xie 《环境科学学报:英文版》 SCIE EI CAS CSCD 2019年第1期334-345,共12页
Chengdu is a megacity in the southwest of China with high ozone (O3) mixing ratio. Observation of volatile organic compounds (VOCs),NO2 and O3 with high temporal resolution was conducted in Chengdu to investigate the ... Chengdu is a megacity in the southwest of China with high ozone (O3) mixing ratio. Observation of volatile organic compounds (VOCs),NO2 and O3 with high temporal resolution was conducted in Chengdu to investigate the chemical processes and causes of high O3 levels.The hourly mixing ratios of VOCs,NO2,and Os were monitored by an online system from 28 August to 7 October,2016.According to meteorological conditions, Chengdu,with relative warm weather and low wind speed,is favorable to O3 formation. Part of the O3 in Chengdu may be transported from the downtown area.In O3 episodes, the average mixing ratios of NO2 and O3 were 20.20 ppbv and 47.95ppbv,respectively.In non-O3 episodes,the average mixing ratios of NO2 and O3 were 16.38 ppbv and 35.15 ppbv, respectively.The average mixing ratio of total VOCs (TVOCs)was 40.29ppbv in non-O3 episodes,which was lower than that in O3 episodes (53.19ppbv).Alkenes comprised 51.7% of the total O3formation potential (OFP)in Chengdu,followed by aromatics which accounted for 24.2%.Ethylene,trans-pentene,propene,and BTEX (benzene,ethylbenzene, toluene,rn/p-xylene,o-xylene)were also major contributors to the OFP in Chengdu.In O3 episodes,intensive secondary formations were observed during the campaign.Oxygenated VOCs (OVOCs),such as acetone,Methylethylketone (MEK),and Methylvinylketone (MVK) were abundant.Isoprene rapidly converted to MVK and Methacrolein (MACR)during O3 episodes.Acetone was mainly the oxidant of C3-C5 hydrocarbons. 展开更多
关键词 OZONE FORMATION VOCs NO2 OFP DIURNAL VARIATION
广西10年生杂交桉无性系木材纤维特征及变异研究 预览
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作者 兰俊 覃林波 +3 位作者 黎巍 陆珍先 施东强 刘鑫 《桉树科技》 2019年第2期16-20,共5页
对10个10a生桉树杂交桉无性系木材纤维特征进行检测分析,结果表明:10a生无性系木材纤维长度变化范围为878.24~1068.75μm,变异系数为5.09%,均值为981.05μm。纤维长度最大的无性系为GL9,最小的无性系为SH1;木材纤维宽度变化范围为14.26~... 对10个10a生桉树杂交桉无性系木材纤维特征进行检测分析,结果表明:10a生无性系木材纤维长度变化范围为878.24~1068.75μm,变异系数为5.09%,均值为981.05μm。纤维长度最大的无性系为GL9,最小的无性系为SH1;木材纤维宽度变化范围为14.26~17.94μm,均值为16.20μm,变异系数为7.15%,木材纤维宽度最大的无性系为DH33-27,最小无性系为SH1;纤维双壁厚变化范围为6.47~7.58μm,均值为6.98μm,变异系数为5.22%,最大的无性系为DH32-13,最小无性系为SH1。各无性系3个不同部位纤维长、宽度、双壁厚径向变异上整体表现为:边材>中材>心材。木材纤维3个指标对应的无性系重复力和单株重复力均在0.96以上,稳定性极高。 展开更多
关键词 杂交桉无性系 纤维特征 变异 重复力
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区域气候变化对西藏扎布耶、当雄错、班戈湖变化的影响
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作者 王云生 郑绵平 +2 位作者 闫丽娟 卜令忠 齐文 《地理学报:英文版》 SCIE CSCD 2019年第11期1895-1907,共13页
The lake hydrological and meteorological data of the Tibetan Plateau are not rich.This research reports the observed climatic data and measured water levels of saline lakes from the local meteorological stations in th... The lake hydrological and meteorological data of the Tibetan Plateau are not rich.This research reports the observed climatic data and measured water levels of saline lakes from the local meteorological stations in the Zabuye salt lake,the Dangqiong Co salt lake and the Bankog Co salt lake in recent two decades.Combining with satellite remote sensing maps,we have analyzed the changes of the water level of these three lakes in recent years and discussed the origins of the changes induced by the meteorological factors.The results show that the annual mean temperature and the water level reflect a general ascending trend in these three lakes during the observation period.The rising rates of the annual mean temperature were 0.08℃/yr during 1991–2014 and 0.07℃/yr during 2004–2014,and of the water level,were 0.032 m/yr and 0.24 m/yr,respectively.Analysis of changes of the meteorological factors shows the main cause for the increase of lake water quantity are the reduced lake evaporation and the increased precipitation in the lake basins by the rise of average temperature.Seasonal variation of lake water level is powered largely by the supply of lake water types and the seasonal change of regional climate. 展开更多
关键词 TIBETAN PLATEAU SALINE LAKE CLIMATE variation LAKE change
变异肝动脉的解剖学特点及其临床意义
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作者 侯燕红 崔爱玲 +3 位作者 刘学敏 李建斌 李明 曹靖 《中国临床解剖学杂志》 CSCD 北大核心 2019年第4期366-370,共5页
目的观察变异肝动脉的解剖学特点,为临床相关血管影像学检查、手术及介入治疗等提供形态学资料。方法按常规方法解剖25例成人尸体标本,沿肝总动脉追踪、寻找肝固有动脉的分支并观察分布情况。结果本组肝固有动脉及其分支变异率为28%。... 目的观察变异肝动脉的解剖学特点,为临床相关血管影像学检查、手术及介入治疗等提供形态学资料。方法按常规方法解剖25例成人尸体标本,沿肝总动脉追踪、寻找肝固有动脉的分支并观察分布情况。结果本组肝固有动脉及其分支变异率为28%。其中有2例属Hitta分型外的变异肝动脉,肝固有动脉右侧壁未见胃右动脉,而是在左侧壁发出1支动脉主干,远端分支分布于肝和胃,本文称为"肝胃动脉(HGA)";其中标本2从HGA主干后壁发出1分支,远端也分布于肝和胃,本文称为"肝胃副动脉"。结论本组2例起于肝固有动脉左侧壁的HGA,是胃小弯右侧的主要动脉来源,并有分支营养肝和胃的其他部位。此种变异补充了变异肝动脉的形态学资料,对临床有一定的指导价值。 展开更多
关键词 肝固有动脉 变异肝动脉 肝胃动脉 胃右动脉 变异
猪仿生消化中消化酶活性随消化时间变化的研究 预览
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作者 王亚 赵峰 +5 位作者 张虎 党方昆 高庆涛 于耀 杜中原 萨仁娜 《畜牧兽医学报》 CAS CSCD 北大核心 2019年第7期1412-1423,共12页
旨在探讨猪仿生消化过程中胃、小肠阶段消化酶的衰减以及补加消化酶后活性变化的规律,为仿生消化法评定猪饲料养分消化率提供参考。本研究中,试验一采用单因素完全随机设计,评价以玉米、大豆粕、小麦麸、玉米-大豆粕型饲粮为底物,在仿... 旨在探讨猪仿生消化过程中胃、小肠阶段消化酶的衰减以及补加消化酶后活性变化的规律,为仿生消化法评定猪饲料养分消化率提供参考。本研究中,试验一采用单因素完全随机设计,评价以玉米、大豆粕、小麦麸、玉米-大豆粕型饲粮为底物,在仿生消化中一次性注入模拟胃液和小肠液后,消化酶活性随消化时间的变化规律。胃阶段消化时间设0、1、 2、 3、4 h,测定消化液中胃蛋白酶的比活性及总活性。小肠消化时间设0、2、4、6、8、12、16 h,分析消化液中胰蛋白酶、糜蛋白酶和淀粉酶的活性。试验二根据试验一结果,在小肠消化4 h补加消化酶,评价补加酶后小肠消化4、6、8 h消化液中消化酶活性。每个时间点为一个处理,每个处理5个重复,每个重复1根消化管。结果表明:1)当模拟胃液与玉米、大豆粕、小麦麸或玉米-大豆粕型饲粮混合后,消化液中胃蛋白酶的比活性迅速降低(为模拟胃液活性的28.8%~59.1%),但在模拟消化1~4 h时,胃蛋白酶的比活性和总活性呈二次曲线增加(P<0.05),最终可达到模拟胃液比活性的78.0%~96.1%和总活性的87.2%~102.7%;在小肠消化阶段,模拟消化液中淀粉酶、胰蛋白酶、糜蛋白酶的活性均有不同程度的衰减(P<0.05),其中淀粉酶和糜蛋白酶活性的变化规律因消化底物不同而呈二次或其它非线性变化(P<0.05),而胰蛋白酶的活性均呈二次曲线下降(P<0.05)。胰蛋白酶的活性下降速度最快。2)补加消化酶后消化液中淀粉酶、胰蛋白酶、糜蛋白酶的活性均可恢复到初始值,但仍随消化时间而衰减(P<0.05),其中胰蛋白酶活性依然快速下降。综上所述,在仿生消化过程中,胃消化阶段无需补充胃蛋白酶;小肠消化阶段需要补充消化酶。 展开更多
关键词 仿生消化 消化酶活性 变异
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不同辐射强度对大豆M1代重要农艺性状的影响 预览
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作者 齐波 汝玄玄 +5 位作者 贾召召 霍晴 曹宇鹏 吴润之 李曙光 杨加银 《中国农学通报》 2019年第12期40-45,共6页
为研究不同强度的60Coγ射线对大豆重要农艺性状的辐照效应,明确适宜辐照剂量,本研究以‘淮豆13’为材料,选取3种60Coγ射线辐照剂量(200 Gy、300 Gy和400 Gy)进行诱变处理。结果表明,不同辐照剂量均明显地降低了M1代群体的田间出苗率... 为研究不同强度的60Coγ射线对大豆重要农艺性状的辐照效应,明确适宜辐照剂量,本研究以‘淮豆13’为材料,选取3种60Coγ射线辐照剂量(200 Gy、300 Gy和400 Gy)进行诱变处理。结果表明,不同辐照剂量均明显地降低了M1代群体的田间出苗率和成活率,且随着剂量的增加,出苗率和成活率不断降低。与对照(CK)相比,出苗率和成活率的变化幅度分别为18.07%~44.34%和0.89%~24.45%,其中400 Gy降幅最大;不同剂量处理对大豆始花期均有不同程度的延迟作用,比对照推迟3~5天开花,其中400 Gy对开花期影响最大;不同剂量处理对M1代群体株高、主茎节数、有效分枝数、单株荚数等重要农艺性状表现为剂量越高,表型差异越大;3种剂量中,300 Gy处理的M1代群体大小适中,且各种极端分化类型均具有一定的比例,表型变异较为丰富,获得目标性状的几率较大,适宜大豆突变体库构建。本研究结果为进一步构建不同类型的大豆突变体库以及深入开展功能基因组学研究提供了重要参考。 展开更多
关键词 大豆 60Coγ辐射 突变体库 诱变育种 变异
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猪瘟病毒GZA株的分离鉴定及遗传变异分析
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作者 胡玲玲 汤德元 +6 位作者 曾智勇 王彬 黄涛 龙冬梅 石远菊 杨伟 叶丽 《中国兽医学报》 CAS CSCD 北大核心 2019年第2期204-208,共5页
本研究收集贵州规模化猪场猪瘟净化过程中RT-PCR检测阳性病料,采用细胞接毒技术、病毒的形态结构观察和间接免疫荧光试验等分离鉴定了1株猪瘟病毒(CSFV),命名为CSFV GZA株,并对GZA株E2基因的核苷酸和氨基酸序列进行差异性分析。分离鉴... 本研究收集贵州规模化猪场猪瘟净化过程中RT-PCR检测阳性病料,采用细胞接毒技术、病毒的形态结构观察和间接免疫荧光试验等分离鉴定了1株猪瘟病毒(CSFV),命名为CSFV GZA株,并对GZA株E2基因的核苷酸和氨基酸序列进行差异性分析。分离鉴定结果表明:接种PK-15细胞后连传7代RT-PCR均能扩增出CSFV特异性条带;病毒粒子在电镜下呈椭圆形或圆形,直径30~80nm;该毒株E2基因与参考毒株E2基因的核苷酸同源性82.8%~83.4%,氨基酸相似度88.7%~90.6%,并在713,725,729,734,738氨基酸位点发生改变;遗传进化树分析还得出GZA株E2基因与参考毒株遗传距离较远。说明本次分离株与其他流行株存在一定的差异,可为以后CSFV病原学的研究提供参考。 展开更多
关键词 猪瘟病毒 GZA株 分离鉴定 遗传 变异
腋动脉分支类型的解剖学研究及意义
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作者 杨晓霞 张永馨 +3 位作者 尤琳 孟冰冰 龙润雨 李京 《解剖学研究》 CAS 2019年第3期217-221,共5页
目的对腋动脉分支形成的动脉干进行分型,为血管造影、外科干预提供解剖学基础。方法 90例(左侧47例,右侧43例)经10%福尔马林溶液灌注固定的人体上肢标本,解剖腋动脉各段分支及其形成的动脉干;采用游标卡尺,测量各段分支起点管径。结果... 目的对腋动脉分支形成的动脉干进行分型,为血管造影、外科干预提供解剖学基础。方法 90例(左侧47例,右侧43例)经10%福尔马林溶液灌注固定的人体上肢标本,解剖腋动脉各段分支及其形成的动脉干;采用游标卡尺,测量各段分支起点管径。结果①经典型腋动脉46例(51.1%),即各段分支均直接从腋动脉分出,未形成动脉干;②肩胛下-旋肱后动脉干28例(31.1%),此干最终分支为旋肩胛动脉、胸背动脉、旋肱后动脉;③有胸外侧动脉参与形成的动脉干10例(11.1%),分别有胸外侧-肩胛下动脉干、胸外侧-胸背动脉干及胸外侧-胸肩峰动脉干;④多分支型(≥4)动脉干6例(6.7%),根据其分支是否含有肱动脉的分支,进一步分为腋-胸动脉干及腋-肱动脉干;⑤右侧胸肩峰动脉起点管径显著高于左侧(P=0.015,t=-2.542)。结论对腋动脉分支所形成的动脉干尝试进行解剖学类型划分,是对既往研究的补充。在腋动脉造影时,有助于识别其变异,减少误诊;掌握这些动脉干的解剖学特征,对于腋血管损伤的外科治疗也具有积极意义。 展开更多
关键词 腋动脉 变异 应用解剖 血管造影
同一种源锥连栎的种子形态特征及变异 预览
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作者 常恩福 肖桂英 +5 位作者 李品荣 李娅 张清 丁玉雄 黄春良 景跃波 《西部林业科学》 CAS 北大核心 2019年第2期159-164,共6页
以建水县5个锥连栎种群的34个家系为研究材料,通过种长、种宽、种形指数、单粒重及千粒重5个性状指标的测定,分析锥连栎不同家系间及种群间种子形态特征及变异。结果表明,锥连栎种子的5个性状指标在家系内、家系间及种群间均存在着显著... 以建水县5个锥连栎种群的34个家系为研究材料,通过种长、种宽、种形指数、单粒重及千粒重5个性状指标的测定,分析锥连栎不同家系间及种群间种子形态特征及变异。结果表明,锥连栎种子的5个性状指标在家系内、家系间及种群间均存在着显著差异(P<0.05)或极显著差异(P<0.01)。不同家系及种群间种子性状的变异均以单粒重及千粒重最大,种长、种宽及种形指数3个性状更趋于稳定,种群间变异小于家系间的变异。其种子的形状主要受遗传控制,受环境影响较小,种子大小及质量则受分布区海拔的影响而存在一定的垂直变异。基于聚类分析结果,可优先选择格安、双剑峰、红田、燕子洞4个种群的4号、8号、9号、10号、15号、19号、20号、21号和34号共9个种子质量优良的家系作为锥连栎的采种母树。就种群而言,则是红田种群和双剑峰种群作为采种林分。 展开更多
关键词 喀斯特 锥连栎 种子 形态 变异
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Variation-Aware Task Mapping on Homogeneous Fault-Tolerant Multi-Core Network-on-Chips 预览
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作者 Chengbo Xue Yougen Xu +1 位作者 Yue Hao Wei Gao 《北京理工大学学报:英文版》 EI CAS 2019年第3期497-509,共13页
A variation-aware task mapping approach is proposed for a multi-core network-on-chips with redundant cores, which includes both the design-time mapping and run-time scheduling algorithms. Firstly, a design-time geneti... A variation-aware task mapping approach is proposed for a multi-core network-on-chips with redundant cores, which includes both the design-time mapping and run-time scheduling algorithms. Firstly, a design-time genetic task mapping algorithm is proposed during the design stage to generate multiple task mapping solutions which cover a maximum range of chips. Then, during the run, one optimal task mapping solution is selected. Additionally, logical cores are mapped to physically available cores. Both core asymmetry and topological changes are considered in the proposed approach. Experimental results show that the performance yield of the proposed approach is 96% on average, and the communication cost, power consumption and peak temperature are all optimized without loss of performance yield. 展开更多
关键词 process VARIATION TASK mapping FAULT-TOLERANT network-on-chips MULTI-CORE
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