全文获取类型
收费全文 | 89275篇 |
免费 | 7424篇 |
国内免费 | 7215篇 |
出版年
2024年 | 215篇 |
2023年 | 1146篇 |
2022年 | 2527篇 |
2021年 | 4379篇 |
2020年 | 2865篇 |
2019年 | 3600篇 |
2018年 | 3459篇 |
2017年 | 2529篇 |
2016年 | 3574篇 |
2015年 | 5367篇 |
2014年 | 6313篇 |
2013年 | 6787篇 |
2012年 | 8038篇 |
2011年 | 7372篇 |
2010年 | 4619篇 |
2009年 | 4034篇 |
2008年 | 4777篇 |
2007年 | 4233篇 |
2006年 | 3768篇 |
2005年 | 3147篇 |
2004年 | 2683篇 |
2003年 | 2368篇 |
2002年 | 2000篇 |
2001年 | 1686篇 |
2000年 | 1463篇 |
1999年 | 1469篇 |
1998年 | 897篇 |
1997年 | 887篇 |
1996年 | 840篇 |
1995年 | 734篇 |
1994年 | 757篇 |
1993年 | 594篇 |
1992年 | 782篇 |
1991年 | 642篇 |
1990年 | 550篇 |
1989年 | 448篇 |
1988年 | 359篇 |
1987年 | 318篇 |
1986年 | 243篇 |
1985年 | 278篇 |
1984年 | 188篇 |
1983年 | 162篇 |
1982年 | 118篇 |
1981年 | 74篇 |
1980年 | 65篇 |
1979年 | 88篇 |
1978年 | 67篇 |
1977年 | 47篇 |
1976年 | 52篇 |
1973年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Genome‐wide detection of CNVs associated with beak deformity in chickens using high‐density 600K SNP arrays
下载免费PDF全文
![点击此处可从《Animal genetics》网站下载免费的PDF全文](/ch/ext_images/free.gif)
H. Bai Y. Sun N. Liu Y. Liu F. Xue Y. Li S. Xu A. Ni J. Ye Y. Chen J. Chen 《Animal genetics》2018,49(3):226-236
Beak deformity (crossed beaks) is found in several indigenous chicken breeds including Beijing‐You studied here. Birds with deformed beaks have reduced feed intake and poor production performance. Recently, copy number variation (CNV) has been examined in many species and is recognized as a source of genetic variation, especially for disease phenotypes. In this study, to unravel the genetic mechanisms underlying beak deformity, we performed genome‐wide CNV detection using Affymetrix chicken high‐density 600K data on 48 deformed‐beak and 48 normal birds using penncnv . As a result, two and eight CNV regions (CNVRs) covering 0.32 and 2.45 Mb respectively on autosomes were identified in deformed‐beak and normal birds respectively. Further RT‐qPCR studies validated nine of the 10 CNVRs. The ratios of six CNVRs were significantly different between deformed‐beak and normal birds (P < 0.01). Within these six regions, three and 21 known genes were identified in deformed‐beak and normal birds respectively. Bioinformatics analysis showed that these genes were enriched in six GO terms and one KEGG pathway. Five candidate genes in the CNVRs were further validated using RT‐qPCR. The expression of LRIG2 (leucine rich repeats and immunoglobulin like domains 2) was lower in birds with deformed beaks (P < 0.01). Therefore, the LRIG2 gene could be considered a key factor in view of its known functions and its potential roles in beak deformity. Overall, our results will be helpful for future investigations of the genomic structural variations underlying beak deformity in chickens. 相似文献
92.
Jianyong Wu 《Cytotechnology》1996,22(1-3):103-109
Animal cells in suspension culture can suffer severe mechanical damage from bursting gas bubbles or other hydrodynamic force sources. Certain chemical additives in the culture media, particularly some surface-active chemicals, can effectively protect animal cells against such damage. Previously we proposed that the protective effect is associated with the adsorption of the additives in the cell membrane through hydrophobic binding of the surface-active molecules to the membrane. Adsorption of the additives to the cell membrane may lead to decreased hydrophobicity of the cell surface, thus eliminating cell adhesion to bubbles and reducing cell damage from bursting bubbles. In this study, we measured the hydrophobicity of two insect cell lines based on cell adhesion to hydrocarbon phase and its influence by surface-active chemicals, Pluronic F68, a methylcellulose and a polyethylene glycol. The experimental results showed strong support for the aforecited cell protection mechanism. 相似文献
93.
This paper studies a Non-convex State-dependent Linear Quadratic Regulator (NSLQR) problem, in which the control penalty weighting matrix in the performance index is state-dependent. A necessary and sufficient condition for the optimal solution is established with a rigorous proof by Euler-Lagrange Equation. It is found that the optimal solution of the NSLQR problem can be obtained by solving a Pseudo-Differential-Riccati-Equation (PDRE) simultaneously with the closed-loop system equation. A Comparison Theorem for the PDRE is given to facilitate solution methods for the PDRE. A linear time-variant system is employed as an example in simulation to verify the proposed optimal solution. As a non-trivial application, a goal pursuit process in psychology is modeled as a NSLQR problem and two typical goal pursuit behaviors found in human and animals are reproduced using different control weighting . It is found that these two behaviors save control energy and cause less stress over Conventional Control Behavior typified by the LQR control with a constant control weighting , in situations where only the goal discrepancy at the terminal time is of concern, such as in Marathon races and target hitting missions. 相似文献
94.
95.
96.
Journal of Plant Growth Regulation - With the increasing popularity of urban landscaping, there is a greater need to address iron deficiency and chlorosis in Cinnamomum camphora. Beneficial... 相似文献
97.
98.
99.
100.