全文获取类型
收费全文 | 488篇 |
免费 | 8篇 |
国内免费 | 36篇 |
专业分类
系统科学 | 35篇 |
丛书文集 | 5篇 |
教育与普及 | 2篇 |
理论与方法论 | 13篇 |
现状及发展 | 57篇 |
研究方法 | 4篇 |
综合类 | 412篇 |
自然研究 | 4篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 14篇 |
2021年 | 9篇 |
2020年 | 19篇 |
2019年 | 10篇 |
2018年 | 18篇 |
2017年 | 17篇 |
2016年 | 24篇 |
2015年 | 41篇 |
2014年 | 46篇 |
2013年 | 30篇 |
2012年 | 31篇 |
2011年 | 26篇 |
2010年 | 14篇 |
2009年 | 12篇 |
2008年 | 15篇 |
2007年 | 16篇 |
2006年 | 22篇 |
2005年 | 19篇 |
2004年 | 13篇 |
2003年 | 10篇 |
2002年 | 20篇 |
2001年 | 18篇 |
2000年 | 15篇 |
1999年 | 19篇 |
1998年 | 15篇 |
1997年 | 14篇 |
1996年 | 4篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 3篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1980年 | 1篇 |
排序方式: 共有532条查询结果,搜索用时 296 毫秒
431.
神经网络直接自适应控制器的设计与实现 总被引:2,自引:0,他引:2
柔性机器人在受限运动时由于控制对象极其复杂而难以控制。为了解决受限柔性机器人机械臂难以精确定位问题提出并设计了一种神经网络直接自适应控制器。其控制效果在研究的受限柔性机器人控制实验上作了仿真与实验。结果表明该控制器能经较高精度控制受限柔性机器人的机械臂精确定位。本文是深入研究受限柔性机器人控制问题的基础。 相似文献
432.
The heavy chain Fd genes and K chain genes of immunoglobulin were amplified by RT-PCR from PBL of three volunteer donors with HIV-positive. Phage antibody library was constructed with the Fd genes and K chain genes using pComb3 as vector. Three-round selection against coated gp120 showed specific enrichment of phage antibodies. After the third round selection, 40 out of 50 clones exhibited gp120 binding capacity. The specificity of the clones was verified by ELISA and competition inhibition ELISA. The VH was derived from subgroups VH Ⅱ and VHⅢ, VL belonged to subgroups VKⅠ and VK Ⅲ with DNA sequencing. These results suggest that the antibodies obtained are specific to gp120. 相似文献
433.
Born WK Zhang L Nakayama M Jin N Chain JL Huang Y Aydintug MK O'Brien RL 《Cellular and molecular life sciences : CMLS》2011,68(14):2335-2343
γδ T cells express adaptive antigen receptors encoded by rearranging genes. Their diversity is highest in the small region
of TCR V–J junctions, especially in the δ chain, which should enable the γδ TCRs to distinguish differences in small epitopes.
Indeed, recognition of small molecules, and of an epitope on a larger protein has been reported. Responses to small non-peptides
known as phospho-antigens are multi-clonal yet limited to a single γδ T cell subset in humans and non-human primates. Responses
to small peptides are multi-clonal or oligo-clonal, include more than one subset of γδ T cells, and occur in rodents and primates.
However, less effort has been devoted to investigate the peptide responses. To settle the questions of whether peptides can
be ligands for the γδ TCRs, and whether responses to small peptides might occur normally, peptide binding will have to be
demonstrated, and natural peptide ligands identified. 相似文献
434.
Marco Ventura Paul W. O’Toole Willem M. de Vos Douwe van Sinderen 《Cellular and molecular life sciences : CMLS》2018,75(1):81-82
The gut microbiota represents a highly complex assembly of microbes, which interact with each other and with their host. These interactions have various implications in terms of health and disease, and this multi-author review issue will address a number of selected aspects pertaining to gut microbiota research. 相似文献
435.
Genome-wide microRNA profiling of human temporal lobe epilepsy identifies modulators of the immune response 总被引:1,自引:1,他引:0
436.
437.
海上浮式风电具有广阔的发展前景,而高昂的建造成本是阻碍其发展的关键因素。拖曳锚因其制造和安装成本低廉成为浮式风电锚固基础的一种选择。本文以黏土场地为背景,通过采用经验图表法,理论计算方法以及有限元方法对黏土场地拖曳锚的贯入深度以及承载力进行了计算。结果表明厂家提供的经验方法的计算精度较低,适用于拖曳锚的初始选型;理论计算方法对土体计算参数敏感;有限元分析显示,拖曳锚的埋深是控制拖曳锚承载力的关键因素,根据上述计算结果提出了浮式风机拖曳锚设计计算的流程。计算结果显示,在进行拖曳锚设计计算时需要根据流程并谨慎选择计算参数,以保证工程的安全可靠。 相似文献
438.
Baud'huin M Lamoureux F Duplomb L Rédini F Heymann D 《Cellular and molecular life sciences : CMLS》2007,64(18):2334-2350
1997 saw the identification of a novel set of proteins within the tumor necrosis factor (TNF)/TNF receptor families that are
required for the control of bone remodeling. Therefore, these receptors, receptor activator of nuclear factor kappa B (RANK),
osteoprotegerin (OPG) and their ligand RANK ligand (RANKL) became the critical molecular triad controlling osteoclastogenesis
and pathophysiologic bone remodeling. However, the establishment of the corresponding knock-out and transgenic mice revealed
unexpected results, most particularly, the involvement of these factors in the vascular system and immunity. Thus, the OPG/RANK/RANKL
molecular triad appears to be associated with vascular calcifications and plays a pivotal function in the development of the
immune system through dendritic cells. OPG/RANK/RANKL thus constitute a molecular bridge spanning bone metabolism, vascular
biology and immunity. This review summarizes recent knowledge of OPG/RANK/RANKL interactions and activities as well as the
current evidence for their participation in osteoimmunology and vascular diseases. In fine, the targeting of the OPG/RANK/RANKL
axis as novel therapeutic approaches will be discussed.
Received 27 February 2007; accepted 4 April 2007 相似文献
439.
Morrison BE Majdzadeh N D'Mello SR 《Cellular and molecular life sciences : CMLS》2007,64(17):2258-2269
Neurodegenerative disease strikes millions worldwide and there is mounting evidence suggesting that underlying the onset and
progression of these debilitating diseases is inappropriate neuronal apoptosis. Recent reports have implicated a family of
proteins known as histone deacetylases (HDACs) in various neuronal processes including the neuronal death program. Initial
headway in this field has been made largely through the use of broad-spectrum HDAC inhibitors. In fact, pharmacological inhibition
of HDAC activity has been shown to protect neurons in several models of neurodegeneration. The observation that HDAC inhibitors
can have opposing effects in different paradigms of neurodegeneration suggests that individual members of the HDAC protein
family may play distinct roles that could depend on the specific cell type under study. The purpose of this review is to detail
work involving the use of HDAC inhibitors within the context of neurodegeneration and examine the roles of individual HDAC
members in the nervous system with specific focus on neuronal cell death.
Received 25 January 2007; received after revision 3 April 2007; accepted 26 April 2007 相似文献
440.
Peacock CS Seeger K Harris D Murphy L Ruiz JC Quail MA Peters N Adlem E Tivey A Aslett M Kerhornou A Ivens A Fraser A Rajandream MA Carver T Norbertczak H Chillingworth T Hance Z Jagels K Moule S Ormond D Rutter S Squares R Whitehead S Rabbinowitsch E Arrowsmith C White B Thurston S Bringaud F Baldauf SL Faulconbridge A Jeffares D Depledge DP Oyola SO Hilley JD Brito LO Tosi LR Barrell B Cruz AK Mottram JC Smith DF Berriman M 《Nature genetics》2007,39(7):839-847
Leishmania parasites cause a broad spectrum of clinical disease. Here we report the sequencing of the genomes of two species of Leishmania: Leishmania infantum and Leishmania braziliensis. The comparison of these sequences with the published genome of Leishmania major reveals marked conservation of synteny and identifies only approximately 200 genes with a differential distribution between the three species. L. braziliensis, contrary to Leishmania species examined so far, possesses components of a putative RNA-mediated interference pathway, telomere-associated transposable elements and spliced leader-associated SLACS retrotransposons. We show that pseudogene formation and gene loss are the principal forces shaping the different genomes. Genes that are differentially distributed between the species encode proteins implicated in host-pathogen interactions and parasite survival in the macrophage. 相似文献