全文获取类型
收费全文 | 365篇 |
免费 | 2篇 |
国内免费 | 4篇 |
专业分类
系统科学 | 59篇 |
丛书文集 | 1篇 |
教育与普及 | 8篇 |
现状及发展 | 7篇 |
研究方法 | 50篇 |
综合类 | 246篇 |
出版年
2020年 | 3篇 |
2019年 | 1篇 |
2016年 | 1篇 |
2014年 | 1篇 |
2013年 | 2篇 |
2012年 | 21篇 |
2011年 | 28篇 |
2010年 | 10篇 |
2009年 | 11篇 |
2008年 | 11篇 |
2007年 | 15篇 |
2006年 | 5篇 |
2005年 | 9篇 |
2004年 | 61篇 |
2003年 | 31篇 |
2002年 | 38篇 |
2001年 | 17篇 |
2000年 | 5篇 |
1999年 | 10篇 |
1998年 | 13篇 |
1997年 | 13篇 |
1996年 | 3篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 13篇 |
1991年 | 12篇 |
1990年 | 3篇 |
1989年 | 3篇 |
1987年 | 12篇 |
1976年 | 1篇 |
1975年 | 1篇 |
1974年 | 1篇 |
1973年 | 1篇 |
1972年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有371条查询结果,搜索用时 375 毫秒
11.
IntroductionTheappraisementofenterprisehumanresourcehaspositiveinfluenceonenterpriseandstaff.Throughtheappraisement,anenterprisecanmakegooduseofitsstaff.Meanwhile,thestaffcanfindthepositionfitforhim.Nevertheless,thereisagreatamountoflinguisticinformationintheappraisementofenterprisehumanresource,whichbringsmanydifficultiesforappraisement.Ifthelinguisticvalueinthecourseofappraisementisnotprocessedproperly,thereasonabilityandusefulnessofappraisementresultwillbelargelyreduced.Whatevernumericalap… 相似文献
12.
呼和浩特市80余年气温序列的小波分析 总被引:6,自引:0,他引:6
利用小波变换时域局部性的特点,对呼和浩特市1915~2000年冬季和全年的平均气温时间序列资料进行了小波分析。研究了呼和浩特市在不同时间尺度上的气温状况,指出气温变化的阶段性、周期性和突变性等特征,揭示了长期的气温变化规律,呼和浩特市冬季气温时间序列主要存在7年左右和2~3年左右的周期振荡,在较大的时间尺度上,较为明显的气温突变点位于1933年、1955年、1975年和1993年左右;全年平均气温时间序列主要存在13年左右和5年左右的周期振荡,在较大的时间尺度上,气温突变点位于1930年和1970年左右,有一个明显的偏冷期。预测呼和浩特市冬季和全年气温在较大的时间尺度上将继续维持偏暖的趋势。 相似文献
13.
一种新的预测PID控制器 总被引:1,自引:0,他引:1
提出了一种新的预测PID控制器 ,通过将广义预测控制的控制律写成PID的形式 ,使PID控制器具有预测的功能。同时 ,在广义预测控制的性能指标中引入稳态误差加权项 ,用较小的预测时域和稳态条件代替较大的预测时域 ,从而减小了在线计算量。在连续搅拌反应釜 (CSTR)上进行的仿真试验验证了该技术的可行性 ,新控制器的控制性能优于普通的预测PID控制器。 相似文献
14.
面向微装配机器人的TSB分级智能控制结构 总被引:1,自引:0,他引:1
提出了一种面向微装配机器人的TSB(任务 策略 行为 )分级智能控制结构 ,该结构自上而下有三个控制层组成 :任务层、策略层和行为层 .操作者在任务层通过人机交互接口进行微装配任务规划 ,策略层将抽象的装配规划分解为具体的显微视觉伺服策略控制微装配机械手的运动 ,行为层则涉及微装配机器人基本行为的生成与执行监督 .TSB控制结构通过人机交互的方式将操作者的任务规划能力和机器人显微视觉伺服策略结合起来 ,实现了微装配机器人的半自主控制 . 相似文献
15.
提出了一种基于扫描线种子填充的二值图像快速聚类算法 .该算法步骤为 :对二值图像进行扫描 ,如果检测到了目标点 ,则将该点作为新的聚类的种子 ,将该种子扩展到整个目标区域 ,形成一个包含目标区域的聚类 .该算法的特点为 :只需一次扫描即可动态生成所有聚类 ,聚类总数动态生成 ,每一时刻只有一个聚类被处理 ,可提前进行一些后续处理 ,算法描述简单 ,易于编程实现 . 相似文献
16.
多传感器机器人数据采集与融合系统研究 总被引:1,自引:1,他引:1
根据多传感器机器人控制器数据采集量大、数据融合算法复杂、系统实时性强的特点 ,提出了基于ADμC812和TMS32 0F2 0 6的双CPU结构的机器人信息采集与数据融合系统结构 .介绍了该系统的硬件组成、基本工作原理以及接口电路 ,并给出了ADμC812子系统程序流程图 . 相似文献
17.
阐述了在PowerBuilder的应用程序中 ,实现嵌入电子邮件的一般原理、方法及具体的程序实现 ,使PowerBuilder应用程序能够访问与MAPI兼容的电子邮件系统 .该邮件应用的特点在于能在应用软件系统中自动发送和接收电子邮件 ,同时还能获得地址薄的信息 .该邮件应用模块可挂接在任意PowerBuilder应用软件中 ,具有一定实用价值 . 相似文献
18.
A second generation human haplotype map of over 3.1 million SNPs 总被引:2,自引:0,他引:2
International HapMap Consortium Frazer KA Ballinger DG Cox DR Hinds DA Stuve LL Gibbs RA Belmont JW Boudreau A Hardenbol P Leal SM Pasternak S Wheeler DA Willis TD Yu F Yang H Zeng C Gao Y Hu H Hu W Li C Lin W Liu S Pan H Tang X Wang J Wang W Yu J Zhang B Zhang Q Zhao H Zhao H Zhou J Gabriel SB Barry R Blumenstiel B Camargo A Defelice M Faggart M Goyette M Gupta S Moore J Nguyen H Onofrio RC Parkin M Roy J Stahl E Winchester E Ziaugra L Altshuler D Shen Y Yao Z Huang W Chu X He Y Jin L Liu Y 《Nature》2007,449(7164):851-861
We describe the Phase II HapMap, which characterizes over 3.1 million human single nucleotide polymorphisms (SNPs) genotyped in 270 individuals from four geographically diverse populations and includes 25-35% of common SNP variation in the populations surveyed. The map is estimated to capture untyped common variation with an average maximum r2 of between 0.9 and 0.96 depending on population. We demonstrate that the current generation of commercial genome-wide genotyping products captures common Phase II SNPs with an average maximum r2 of up to 0.8 in African and up to 0.95 in non-African populations, and that potential gains in power in association studies can be obtained through imputation. These data also reveal novel aspects of the structure of linkage disequilibrium. We show that 10-30% of pairs of individuals within a population share at least one region of extended genetic identity arising from recent ancestry and that up to 1% of all common variants are untaggable, primarily because they lie within recombination hotspots. We show that recombination rates vary systematically around genes and between genes of different function. Finally, we demonstrate increased differentiation at non-synonymous, compared to synonymous, SNPs, resulting from systematic differences in the strength or efficacy of natural selection between populations. 相似文献
19.
Genome-wide detection and characterization of positive selection in human populations 总被引:3,自引:0,他引:3
Sabeti PC Varilly P Fry B Lohmueller J Hostetter E Cotsapas C Xie X Byrne EH McCarroll SA Gaudet R Schaffner SF Lander ES;International HapMap Consortium Frazer KA Ballinger DG Cox DR Hinds DA Stuve LL Gibbs RA Belmont JW Boudreau A Hardenbol P Leal SM Pasternak S Wheeler DA Willis TD Yu F Yang H Zeng C Gao Y Hu H Hu W Li C Lin W Liu S Pan H Tang X Wang J Wang W Yu J Zhang B Zhang Q Zhao H Zhao H Zhou J Gabriel SB Barry R Blumenstiel B Camargo A Defelice M Faggart M Goyette M Gupta S Moore J 《Nature》2007,449(7164):913-918
With the advent of dense maps of human genetic variation, it is now possible to detect positive natural selection across the human genome. Here we report an analysis of over 3 million polymorphisms from the International HapMap Project Phase 2 (HapMap2). We used 'long-range haplotype' methods, which were developed to identify alleles segregating in a population that have undergone recent selection, and we also developed new methods that are based on cross-population comparisons to discover alleles that have swept to near-fixation within a population. The analysis reveals more than 300 strong candidate regions. Focusing on the strongest 22 regions, we develop a heuristic for scrutinizing these regions to identify candidate targets of selection. In a complementary analysis, we identify 26 non-synonymous, coding, single nucleotide polymorphisms showing regional evidence of positive selection. Examination of these candidates highlights three cases in which two genes in a common biological process have apparently undergone positive selection in the same population:LARGE and DMD, both related to infection by the Lassa virus, in West Africa;SLC24A5 and SLC45A2, both involved in skin pigmentation, in Europe; and EDAR and EDA2R, both involved in development of hair follicles, in Asia. 相似文献
20.
Genome-wide association study of 14,000 cases of seven common diseases and 3,000 shared controls 总被引:2,自引:0,他引:2
Wellcome Trust Case Control Consortium 《Nature》2007,447(7145):661-678
There is increasing evidence that genome-wide association (GWA) studies represent a powerful approach to the identification of genes involved in common human diseases. We describe a joint GWA study (using the Affymetrix GeneChip 500K Mapping Array Set) undertaken in the British population, which has examined approximately 2,000 individuals for each of 7 major diseases and a shared set of approximately 3,000 controls. Case-control comparisons identified 24 independent association signals at P < 5 x 10(-7): 1 in bipolar disorder, 1 in coronary artery disease, 9 in Crohn's disease, 3 in rheumatoid arthritis, 7 in type 1 diabetes and 3 in type 2 diabetes. On the basis of prior findings and replication studies thus-far completed, almost all of these signals reflect genuine susceptibility effects. We observed association at many previously identified loci, and found compelling evidence that some loci confer risk for more than one of the diseases studied. Across all diseases, we identified a large number of further signals (including 58 loci with single-point P values between 10(-5) and 5 x 10(-7)) likely to yield additional susceptibility loci. The importance of appropriately large samples was confirmed by the modest effect sizes observed at most loci identified. This study thus represents a thorough validation of the GWA approach. It has also demonstrated that careful use of a shared control group represents a safe and effective approach to GWA analyses of multiple disease phenotypes; has generated a genome-wide genotype database for future studies of common diseases in the British population; and shown that, provided individuals with non-European ancestry are excluded, the extent of population stratification in the British population is generally modest. Our findings offer new avenues for exploring the pathophysiology of these important disorders. We anticipate that our data, results and software, which will be widely available to other investigators, will provide a powerful resource for human genetics research. 相似文献