全文获取类型
收费全文 | 121407篇 |
免费 | 6218篇 |
国内免费 | 9970篇 |
专业分类
林业 | 12293篇 |
农学 | 10183篇 |
基础科学 | 5414篇 |
15542篇 | |
综合类 | 59501篇 |
农作物 | 6042篇 |
水产渔业 | 5312篇 |
畜牧兽医 | 12738篇 |
园艺 | 3785篇 |
植物保护 | 6785篇 |
出版年
2024年 | 599篇 |
2023年 | 1590篇 |
2022年 | 2669篇 |
2021年 | 2987篇 |
2020年 | 3050篇 |
2019年 | 3829篇 |
2018年 | 2246篇 |
2017年 | 3955篇 |
2016年 | 5151篇 |
2015年 | 4499篇 |
2014年 | 5354篇 |
2013年 | 5960篇 |
2012年 | 9037篇 |
2011年 | 9223篇 |
2010年 | 7472篇 |
2009年 | 7269篇 |
2008年 | 7154篇 |
2007年 | 8664篇 |
2006年 | 7729篇 |
2005年 | 6259篇 |
2004年 | 4861篇 |
2003年 | 3934篇 |
2002年 | 3088篇 |
2001年 | 2757篇 |
2000年 | 2486篇 |
1999年 | 1970篇 |
1998年 | 1676篇 |
1997年 | 1522篇 |
1996年 | 1450篇 |
1995年 | 1447篇 |
1994年 | 1339篇 |
1993年 | 1213篇 |
1992年 | 1119篇 |
1991年 | 942篇 |
1990年 | 844篇 |
1989年 | 710篇 |
1988年 | 564篇 |
1987年 | 376篇 |
1986年 | 239篇 |
1985年 | 91篇 |
1984年 | 42篇 |
1983年 | 34篇 |
1982年 | 23篇 |
1981年 | 28篇 |
1980年 | 29篇 |
1979年 | 31篇 |
1978年 | 18篇 |
1976年 | 12篇 |
1962年 | 10篇 |
1955年 | 11篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
991.
992.
Thromboelastographic evidence of inhibition of fibrinolysis after ε‐aminocaproic acid administration in a dog with suspected acute traumatic coagulopathy
下载免费PDF全文
![点击此处可从《Journal of Veterinary Emergency and Critical Care》网站下载免费的PDF全文](/ch/ext_images/free.gif)
993.
994.
ASVCP guidelines: quality assurance for portable blood glucose meter (glucometer) use in veterinary medicine
下载免费PDF全文
![点击此处可从《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Karen L. Gerber Kathleen P. Freeman 《Veterinary clinical pathology / American Society for Veterinary Clinical Pathology》2016,45(1):10-27
Portable blood glucose meters (PBGM, glucometers) are a convenient, cost effective, and quick means to assess patient blood glucose concentration. The number of commercially available PBGM is constantly increasing, making it challenging to determine whether certain glucometers may have benefits over others for veterinary testing. The challenge in selection of an appropriate glucometer from a quality perspective is compounded by the variety of analytic methods used to quantify glucose concentrations and disparate statistical analysis in many published studies. These guidelines were developed as part of the ASVCP QALS committee response to establish recommendations to improve the quality of testing using point‐of‐care testing (POCT) handheld and benchtop devices in veterinary medicine. They are intended for clinical pathologists and laboratory professionals to provide them with background knowledge and specific recommendations for quality assurance (QA) and quality control (QC), and to serve as a resource to assist the provision of advice to veterinarians and technicians to improve the quality of results obtained when using PBGM. These guidelines are not intended to be all‐inclusive; rather they provide a minimum standard for management of PBGM in the veterinary setting. 相似文献
995.
996.
随着植物新品种权的申请授权量急剧增长,品种权的"数量多、质量差"的问题引起了全社会的普遍关注。如何评价品种权质量成为重要的理论和现实问题。为了科学合理地判断我国品种权的综合质量水平,首先从竞争力的角度界定植物新品种权质量的定义,然后从品种权的法律、技术和经济三大属性建立品种权质量评价指标体系,并利用均值差异法验证品种权质量指标的有效性,最后采用逻辑回归模型构建品种权质量综合指数,以便全面、快捷地综合评价品种权质量。植物新品种权质量评估研究不仅有利于解决品种权质量判断标准问题,对提高品种权质量水平提供了理论依据,而且为我国品种权的价值评估、许可转让、融资、抵押等交易活动提供重要参考。 相似文献
997.
998.
999.
Akihito TAKAHASHI Ajalli RAHIM Miki TAKEUCHI Emiko FUKUI Midori YOSHIZAWA Kuniaki MUKAI Makoto SUEMATSU Hidetoshi HASUWA Masaru OKABE Hiromichi MATSUMOTO 《The Journal of reproduction and development》2016,62(1):43-49
Tubulointerstitial nephritis antigen-like 1 (Tinagl1, also known as adrenocortical zonation factor 1 [AZ-1]
or lipocalin 7) is a matricellular protein. Previously, we demonstrated that Tinagl1 expression was restricted
to extraembryonic regions during the postimplantation period and detected marked expression in mouse
Reichert’s membranes. In uteri, Tinagl1 is markedly expressed in the decidual endometrium during the
postimplantation period, suggesting that it plays a physical and physiological role in embryo development
and/or decidualization of the uterine endometrium during pregnancy. In the present study, in order to
determine the role of Tinagl1 during embryonic development and pregnancy, we generated
Tinagl1-deficient mice. Although Tinagl1–/– embryos were not
lethal during development to term, homologous matings of Tinagl1–/– females and
Tinagl1–/– males showed impaired fertility during pregnancy, including failure
to carry pregnancy to term and perinatal lethality. To examine ovarian function, ovulation was induced with
equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG); the number of ovulated oocytes did
not differ between Tinagl1–/– and Tinagl1flox/flox.
In vitro fertilization followed by embryo culture also demonstrated the normal
developmental potential of Tinagl1-null embryos during the preimplantation period. Our
results demonstrate that Tinagl1 deficiency affects female mice and results in subfertility phenotypes, and
they suggest that although the potential of Tinagl1–/– oocytes is normal, Tinagl1
is related to fertility in adult females but is not essential for either fertilization or preimplantation
development in vitro. 相似文献
1000.
J. Xiao E. Sakaguchi X. Min K. Kawasaki 《Journal of animal physiology and animal nutrition》2016,100(4):715-722
The effect of mannitol on bone‐related mineral absorption and retention and the mechanism was investigated in this study. Fourteen 8‐week‐old male Wistar rats in experiment 1 and same number and age cecectomized Wistar male rats in experiment 2 were divided into two subgroups of seven animals, respectively, fed diets containing 0 or 4% mannitol for 28 days. Mineral balance tests were determined twice during days 8–12 and days 22–26, and the rats were slaughtered on day 28 both in experiment 1 and experiment 2. The whole caecum and colon were collected with the content to analyse tissue weight, content weight, content's pH and moisture, organic acids' concentration and mineral levels. In experiment 1, Ca absorption and retention and Mg absorption were significantly increased by mannitol feeding during days 8–12. Caecal total weight, tissue weight and content weight were increased, the pH of caecum and colon was reduced, and the concentrations of caecal short‐chain fatty acids (SCFAs) were modified by mannitol feeding. In experiment 2, during days 8–12 and days 22–26, Ca absorption and retention were significantly lowered by mannitol feeding in cecectomized rats; however, mannitol feeding decreased Mg absorption during days 8–12, but did not impact Mg retention. Colonic total weight, tissue weight and content weight were significantly increased, and colonic pH was reduced by mannitol feeding. In conclusion, dietary mannitol increased the absorption of Ca and Mg and the caecum markedly contributed to this promoting effect of mannitol. 相似文献