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61.
62.
在自然或人为因素下容易出现鳗苗种质混杂的现象,由于鳗鲡苗种在形态上十分相似,难以区分。为了保障鳗农的合法利益和提高养殖效益,急需建立一种能够在现场快速、高效使用的鳗鲡种质鉴定方法。本研究通过比对找出5种常见鳗鲡养殖种类:日本鳗鲡(Anguilla japonica)、美洲鳗鲡(A.rostrata)、花鳗鲡(A.marmorata)、太平洋双色鳗鲡(A.bicolor pacifica)、欧洲鳗鲡(A.anguilla)线粒体细胞色素B(cytochrome b,cyt b)基因的差异序列,基于5个cyt b基因序列差异较大的片段,设计多对引物,分别经过PCR验证和条件优化,挑选出4对引物:aj S1/A1、r-a S1/A2、bp-m S5/A3和m-a S4/A4。将这4对引物组合在同一个反应体系中进行PCR扩增,进行条件优化,筛选出组合PCR的最优条件:退火温度为58oC;退火时间为45s;循环数为27。结果表明,通过扩增产物凝胶电泳中条带的有无及大小可快速准确的鉴定出五个鳗鲡种类。本研究建立的组合PCR方法在3小时内可完成整个种类鉴定过程,同时可使用便携式小型仪器完成操作,可满足现场快速、高效鉴定的要求。此外,通过MEGA5.0软件构建5种鳗鲡线粒体cyt b基因序列NJ进化树,发现花鳗鲡和太平洋双色鳗鲡先聚为一支,再与日本鳗鲡聚在一起,而欧洲鳗鲡和美洲鳗鲡聚在一起,进化树图显示的遗传距离和它们的地理分布的远近相似。  相似文献   
63.
This paper aims to qualify the behaviour of contributors to OpenStreetMap (OSM), a volunteered geographic information (VGI) project, through a multigraph approach. The main purpose is to reproduce contributor’s interactions in a more comprehensive way. First, we define a multigraph that combines existing spatial collaboration networks from the literature with new graphs that illustrate collaboration based on specific aspects of the VGI modes of contribution through semantics, geometry and topology. Indeed, the ways that contributors interact with one another through editing, completion, or even consumption may provide additional information on each user’s operation mode and therefore, on the quality of the contributed data. Social collaborations drawn from indirect criteria – for example, comparisons between contributors’ activity areas – can also be contemplated under another network. Second, the resulting multigraph is analysed using data mining approaches to characterise individuals and identify behavioural groups. The implementation of a multiplex network based on an OSM data sample and an initial analysis make it possible to identify useful behaviours for data qualification. The initial results characterise some contributors as pioneers, moderators and truthful contributors, according to their special roles in the graphs. Mapping elements that include these contributors’ participation are likely to be reliable data  相似文献   
64.
Assessing the Suitability of a Molecularbiological Method To Characterise the Microbial Populations in Groundwater A molecularbiological technique was used to characterise the bacterial community structure of groundwater habitats. This method consists of the isolation of bacterial DNA from the samples, amplification of 16S rDNA by PCR (polymerase chain reaction), and separation of the amplified DNA by DGGE (denaturing gradient gel electrophoresis). By using more specific primer combinations in the PCR instead of universal eubacterial primers, also groups of microorganisms (Proteobacteria, sulfate reducer, Archaea) were determined. The resulting DGGE patterns that reflect the microbial diversity are compared and differences or similarities evaluated. In the present studies, groundwater from different sites (bank filtrate, artificially recharged groundwater, and natural groundwater) and with changing redox milieus (aerobic, anaerobic) were investigated as well as the solid aquifer material. Besides, samples were taken from the different stages of artificial groundwater recharge, i.e., from surface water to the drain tile. Samples from groundwater derived from sites with different hydrogeochemical or hydrological conditions like bank filtrate and recharged groundwater revealed great differences in DGGE patterns indicating a characteristic species composition in these habitats, while samples taken at different times from the same groundwater showed only small seasonal variations. Clearly different patterns were also found for groundwater and the adjacent solid material as well as for anaerobic and aerobic groundwaters. Looking at artificial groundwater recharge, almost identical patterns were found in raw water and samples from gravel and sand filtration. DGGE patterns from the resulting groundwater indicated a total change in community structure during underground passage. By using group specific primers, Desulfovibrionaceae, Desulfobacteriaceae, and Archaea could be detected in anaerobic groundwaters.The molecularbiological approach described here gives an increasingly comprehensive and more precise picture of the microbial population of different environments. It is especially suitable to compare the community structure from different habitats or to analyse changes for example due to environmental stress at the same site.  相似文献   
65.
根据爱德华氏菌(Edwardsiella)的16S rDNA基因序列设计一对特异性引物,用二温式PCR对6株爱德华氏菌均扩增出与预期大小相一致的576 bp产物,而对嗜水气单胞菌(Aeromonas hydrophila)、温和气单胞菌(Aeromonas sobria)、荧光假单胞菌(Pseudcmonas fluoroscercs)、柱状屈挠杆菌(Cytophaga columnaris)、链球菌(Streptococcus)、葡萄球菌(Staphylococci)、弧菌(Vibrio)、大肠杆菌(Escherichia colibacillus)和沙门氏菌(Salmonella)等10种病原体的扩增,结果全为阴性。该二温式PCR可以检测到1 pg的爱德华氏菌DNA模板和48个菌体。本实验建立的二温式PCR为爱德华氏菌病的早期诊断与有效的防治提供了快速检测方法,对水产品的食品安全有重要的意义。  相似文献   
66.
东海原甲藻线粒体细胞色素b(Cytb)基因的定量检测   总被引:3,自引:0,他引:3  
建立了检测东海原甲藻线粒体细胞色素b(Cytb)基因mRNA含量的实时荧光定量PCR方法.以甲藻Cytb基因的简并引物扩增得到984 bp长的东海原甲藻Cytb基因片段,经克隆、测序,制备并纯化质粒.以光度法测定质粒浓度并作为标准品.对上述基因片段,利用PRIMER EXPRESS 3.0 设计引物,以梯度稀释的质粒标准品进行定量PCR反应,以SYBR Green I为荧光染料,制作标准曲线,得到基因拷贝数X与Ct值的关系为:Ct=-3.50 lg X+39.35(相关系数r为0.999).通过对不同生长时期的东海原甲藻样品的Cytb基因mRNA含量检测,发现该基因的表达量较稳定,平均值为(45.4±4.7)拷贝/细胞,受生长状态影响不大,可作为实时荧光定量PCR的内参基因.  相似文献   
67.
福建沿海巨蛎属牡蛎的主要种类及其分布   总被引:4,自引:0,他引:4  
杜玄  郭希明  钱鲁闽 《台湾海峡》2009,28(3):399-404
本实验采用了多重种类特异性PCR(multiplex species—specific PCR)技术,研究了巨蛎属(Crassostrea)牡蛎主要种类在福建沿海的分布.从沿海11个采样地点共采集了657个野生牡蛎样本,随机抽取了327个牡蛎样本进行基因组DNA的提取和线粒体COI基因的鉴定,结果发现200个个体为葡萄牙牡蛎(Crassostrea angulata),101个个体为近江牡蛎(Crassostrea ariakensis),20个个体为熊本牡蛎(Crassostrea sikamea),6个个体为香港巨牡蛎(Crassostrea hongkongensis).此次实验中未发现长牡蛎(Crassostrea gigas).结果表明,福建沿海有葡萄牙牡蛎、近江牡蛎、熊本牡蛎和香港巨牡蛎4种巨蛎属牡蛎分布.  相似文献   
68.
用PCR法成功制备了DIG标记探针,探针长度为547bp,探针的产量为21.6ng/μL。此探针与随机引物合成探针检测样品灵敏度相近。用此探针核酸斑点杂交法检测了54尾中国对虾。结果表明此探针在对白斑综合症病毒的检测、对虾暴发性流行病的诊断等方面具有很高的应用价值。  相似文献   
69.
为构建南极冰藻Chlamydomonassp.ICE-L的cDNA文库,提取对数生长期南极冰藻ICE-L的总RNA,以此为模板,通过PowerScript逆转录酶逆转录合成第一链cDNA;再以第一链cDNA产物为模板,用LD-PCR合成第二链cDNA。该cDNA产物经分级分离转入大肠杆菌中,即获得南极冰藻ICE-L的cDNA原始文库,其滴度为1.6×106cfu/mL。扩增后的cDNA文库的滴度为1.0×1010cfu/mL。用PCR方法测得文库的重组率大于97%,插入cDNA的长度为0.5~1.8 kb,0.9 kb以上插入片段占50%以上。取适量扩增文库稀释并铺平板,挑取72个独立菌落,对其中22个独立菌落所插入的cDNA进行测序,克隆到了一个具有5′和3′非编码区的40S ribosomalprotein S5全长基因序列,GenBank收录号为AM167929。  相似文献   
70.
RECENT DEVELOPMENTS IN MULTIVARIATE CALIBRATION   总被引:1,自引:0,他引:1  
With the goal of understanding global chemical processes,environmental chemists have some of the mostcomplex sample analysis problems.Multivariate calibration is a tool that can be applied successfully inmany situations where traditional univariate analyses cannot.The purpose of this paper is to reviewmultivariate calibration,with an emphasis being placed on the developments in recent years.The inverseand classical models are discussed briefly,with the main emphasis on the biased calibration methods.Principal component regression(PCR)and partial least squares(PLS)are discussed,along with methodsfor quantitative and qualitative validation of the calibration models.Non-linear PCR,non-linear PLSand locally weighted regression are presented as calibration methods for non-linear data.Finally,calibration techniques using a matrix of data per sample(second-order calibration)are discussed briefly.  相似文献   
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