全文获取类型
收费全文 | 1238篇 |
免费 | 124篇 |
国内免费 | 49篇 |
专业分类
林业 | 99篇 |
农学 | 73篇 |
基础科学 | 32篇 |
172篇 | |
综合类 | 521篇 |
农作物 | 14篇 |
水产渔业 | 92篇 |
畜牧兽医 | 377篇 |
园艺 | 16篇 |
植物保护 | 15篇 |
出版年
2024年 | 9篇 |
2023年 | 32篇 |
2022年 | 39篇 |
2021年 | 39篇 |
2020年 | 51篇 |
2019年 | 63篇 |
2018年 | 42篇 |
2017年 | 63篇 |
2016年 | 85篇 |
2015年 | 55篇 |
2014年 | 79篇 |
2013年 | 98篇 |
2012年 | 116篇 |
2011年 | 121篇 |
2010年 | 83篇 |
2009年 | 76篇 |
2008年 | 56篇 |
2007年 | 61篇 |
2006年 | 60篇 |
2005年 | 28篇 |
2004年 | 19篇 |
2003年 | 21篇 |
2002年 | 18篇 |
2001年 | 14篇 |
2000年 | 10篇 |
1999年 | 16篇 |
1998年 | 6篇 |
1997年 | 11篇 |
1996年 | 15篇 |
1995年 | 7篇 |
1994年 | 2篇 |
1993年 | 3篇 |
1992年 | 5篇 |
1991年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1985年 | 1篇 |
1974年 | 1篇 |
1956年 | 1篇 |
排序方式: 共有1411条查询结果,搜索用时 15 毫秒
1.
2.
Lactate Kinetics in veterinary Critical Care: A Review 总被引:3,自引:0,他引:3
Michael S. Lagutchik DVM Gregory K. Ogilvie DVM Wayne E. Wingfield MS DVM Timothy B. Hackett DVM MS 《Journal of Veterinary Emergency and Critical Care》1996,6(2):81-95.
Elevation in blood lactate concentration, with or without accompanying metabolic acidosis, is a hallmark finding in patients with circulatory compromise, and is also consistently noted in other conditions affecting critically ill or injured individuals. Little is reported in a veterinary literature regarding lactate measurement in the emergency and critical care setting, despite impressive reports of the clinical usefulness of lactate measurement in people. The purpose of this article is to review lactate kinetics and the clinical utility of lactate measurement. Limitations to lactate evaluation will also be discussed. 相似文献
3.
Joyce D'SILVA 《Integrative zoology》2006,1(1):53-58
Industrial animal agriculture is grounded in the concept of maximizing productivity and profit. Selective breeding for maximum productivity in one characteristic of the animal (e.g. milk yield in cows, or breast meat in broiler chickens) has resulted in genotypes and phenotypes that may predispose the animals to poor health and welfare. The conditions in which these individuals are kept may also frustrate many inherited behaviors that they are strongly motivated to perform. In order to curb the resulting harmful aberrant behaviors, such as feather‐pecking in chickens, we sometimes resort to mutilating the animals. In many places chickens are routinely de‐beaked by means of a hot metal guillotine. Compassion in World Farming (an international organization that promotes the humane treatment of farm animals) believes that it is unethical to treat sentient beings in such ways. We have a duty to respect farm animals' sentience by providing them with housing conditions that take their needs and wants into account, and by reverting to the use of dual‐purpose, slower‐growing breeds that have the potential for good welfare. Alternatives to current farming practices are available, and we owe it to the animals, and to our consciences, to pursue them. 相似文献
4.
5.
马耘秀 《山西农业大学学报(自然科学版)》2014,(1):34-38
对高速公路用地进行集约用地评价,可以为未来区域土地利用提供决策依据。从高速公路的用地结构、用地功能和与外部因素的协调性出发,对山西高速公路建设用地的集约利用程度作出评价。结果表明:2001~2010年,山西省高速公路用地数量有所增长,其结构不断调整,功能不断增强,与人口、社会经济的协调性也不断加强,集约度不断提高。未来10年,山西省高速公路将迅速发展,必须加大集约利用力度,以尽可能少的用地满足人类社会发展对公路交通运输的需求。 相似文献
6.
7.
Dandan Zhu Jianglin Zhang Zheng Wang Rizwan Khan Muhammad Jianwei Lu Xiaokun Li 《Soil Use and Management》2019,35(3):503-510
Data from 147 field trials were collected to study the influence of straw incorporation on soil potassium (K) under an intensive rice–oilseed rape rotation system, while pot experiments were conducted to evaluate the effects of rice straw incorporation on soil K availability. A significant correlation was observed between the soil available K and the relative yield (RRY) and the relative K uptake (RKU) of oilseed rape, with R2 values ranging from 0.07 to 0.08 and from 0.10 to 0.11, respectively, when data were fitted to a logarithmic equation model. In approximately 30% of trials, RRY reached 90%, while soil test available K values were below the critical limit, indicating that soil K values at the time of sampling (within 1 week of rice harvest) underestimated the actual soil K supply capacity. The pot experiment results showed that soil available K was affected by straw incorporation and soil type in the fallow period. The NH4OAc‐K and NaBPh4‐K concentrations of soils increased at first, and then, plateaued after 28 days. Straw incorporation significantly influenced the critical soil K concentration, which is important for making accurate K fertilizer recommendation. These results suggested that straw K should be seriously considered in making K fertilizer recommendations. Extending the sampling time from 1 to 3 weeks after the harvesting of rice to stabilize the effects of straw incorporation may help achieve a more accurate evaluation of soil available K. 相似文献
8.
张旭 《农业图书情报学刊》2011,23(2):93-95
报纸是一种形式普及、内容广泛、报道及时的信息资源,是研究某一地区、某一国家,特定历史时期社会状态不可或缺的文献资料。对报纸实行人文管理不仅仅是高校图书馆提高自身水平的要求,也是报纸自身特点的要求,更是满足广大师生对信息收集的要求。如何针对性地满足读者的各种信息需求,加大对报纸人文管理和利用,是高校图书馆最根本的职责。 相似文献
9.
10.