全文获取类型
收费全文 | 2359篇 |
免费 | 91篇 |
国内免费 | 17篇 |
专业分类
耳鼻咽喉 | 1篇 |
儿科学 | 23篇 |
妇产科学 | 1篇 |
基础医学 | 53篇 |
口腔科学 | 21篇 |
临床医学 | 94篇 |
内科学 | 444篇 |
皮肤病学 | 16篇 |
神经病学 | 14篇 |
特种医学 | 33篇 |
外科学 | 41篇 |
综合类 | 111篇 |
预防医学 | 1443篇 |
眼科学 | 8篇 |
药学 | 126篇 |
1篇 | |
中国医学 | 17篇 |
肿瘤学 | 20篇 |
出版年
2024年 | 2篇 |
2023年 | 25篇 |
2022年 | 197篇 |
2021年 | 212篇 |
2020年 | 62篇 |
2019年 | 49篇 |
2018年 | 49篇 |
2017年 | 41篇 |
2016年 | 44篇 |
2015年 | 97篇 |
2014年 | 187篇 |
2013年 | 171篇 |
2012年 | 131篇 |
2011年 | 165篇 |
2010年 | 131篇 |
2009年 | 132篇 |
2008年 | 67篇 |
2007年 | 112篇 |
2006年 | 116篇 |
2005年 | 77篇 |
2004年 | 71篇 |
2003年 | 52篇 |
2002年 | 42篇 |
2001年 | 48篇 |
2000年 | 33篇 |
1999年 | 18篇 |
1998年 | 19篇 |
1997年 | 21篇 |
1996年 | 18篇 |
1995年 | 9篇 |
1994年 | 9篇 |
1993年 | 6篇 |
1992年 | 9篇 |
1991年 | 12篇 |
1990年 | 7篇 |
1989年 | 6篇 |
1988年 | 4篇 |
1987年 | 8篇 |
1986年 | 1篇 |
1985年 | 5篇 |
1983年 | 1篇 |
1974年 | 1篇 |
排序方式: 共有2467条查询结果,搜索用时 15 毫秒
1.
M. Zamparas V.C. Kapsalis G.L. Kyriakopoulos K.G. Aravossis A.E. Kanteraki A. Vantarakis I.K. Kalavrouziotis 《Sustainable Chemistry and Pharmacy》2019
At this study a multi-criteria model was developed to examine the available procedures, techniques and methods of handling infectious waste in the large healthcare unit of University Regional General Hospital of Patras, Western Greece. Particularly, this study examined the: a) current legislation and Directives issued for medical waste management at Greece and among the other EU-members, b) contribution of healthcare wastes (HCW) generation rate on social and economic parameters in selected European countries, c) available procedures, techniques, and methods upon the disposal of infectious wastes at the healthcare studied, and, d) propositions for integrated management of such hazardous wastes. Specifically, the Analytic Hierarchy Process (AHP) methodology was applied under pair wise comparison matrices in two stages: 1) the scale factors and the indicators, and 2) the criteria and their sub–criteria. The assessment of these pair wise matrices included the indicators and the sub–criteria. Subsequently, two pair wise comparison matrices, upon a) the “Fulfillment of environmental objectives” indicator and b) the “Energy consumption” sub criterion, were denoted. The AHP methodology yielded good results; however there is still space of improving the environmental performance. The normalized relative weights obtained for the criteria and sub criteria motivated specific actions that have to be handled. Particularly, the results indicated a very good value in environmental management criteria due the values obtained for the commitment towards the environmental policy standards and the waste management procedures. However, further improvements on staff awareness (such as development programs to enhance sensitivity) and more green purchasing suppliers, should be further addressed. 相似文献
2.
通过历时2 a的现场监测,揭示了大面积堆场逐级增高情况下软土地基变形特性的规律,总结了固结沉降的规律,为软土地基的固结沉降分析计算提供依据. 相似文献
3.
介绍了一种从谷朊粉废水中提取戊聚糖的工艺,由此工艺得到的产品(戊聚糖质量分数约70%,蛋白质质量分数约20%)能较好地保持戊聚糖的特性.研究了其它添加剂(卡拉胶)对戊聚糖的乳化性,戊聚糖对肉制品持油、持水性以及其质构的影响.谷朊粉废弃水提取物与卡拉胶的复配产品在添加量(质量分数)为6%时能使肉制品有较好的持油性和相应的质构. 相似文献
4.
5.
6.
G. M. Price A. A. Paul F. B. Key A. C. Harter T. J. Cole K. C. Day M. E. J. Wadsworth 《Journal of human nutrition and dietetics》1995,8(6):417-428
A diary method using household measures was employed to obtain dietary records in a large national prospective survey and a computer program, DIDO (Diet In Data Out), was designed for direct entry of the diaries. The accuracy of this computerized coding system was examined alongside that of the manual coding used for a similar diary in a previous wave, 7 years earlier, of the same survey. Accuracy was assessed by analysis of the errors in the coded and checked records by stringent re-checking of nominal 2% random subsamples of the diet diaries coded by each method. The mean time to code and check each of the 2086 7-day records in the whole survey using DIDO was 58 minutes (SD 30) compared with reported results of 1–4 hours for manual methods. The mean error rate of computerized coding and checking with DIDO was 2.3% (SD 2.1; range 0–8.9) per diary in the subsample. Correcting these mistakes made insignificant changes to the calculated mean energy and nutrient intakes for the subsample. The percentage of individuals changing to an adjacent third of nutrient distribution after correcting unambiguous errors ranged from none (for alcohol) to 11% (for carbohydrate and calcium intake). The mean error rate on a similar subsample of diaries from the earlier survey which had been coded manually was significantly higher at 5.9% (SD 4.1; range 0–17) per diary. Emphasis is laid on the importance, in coding, of dealing with ambiguities in the subjects' records, since this can affect the accuracy and the precision of the nutrient results obtained. We conclude that the DIDO coding method has the advantages of greater accuracy, speed, consistency and efficient data handling, and affords greater data accessibility for checking, compared with manual systems. 相似文献
7.
张震宇 《天津中医药大学学报》2002,21(4):45-45
1 临床资料 本组62例中,男38例,女24例;年龄最大67岁,最小21岁,平均36岁;病程最长8 a,最短2个月,平均15个月.全部病例均有眩晕症状,常在颈部旋转或屈伸时出现或加重,伴颈枕部不适或疼痛,颈肌僵硬.伴耳鸣32例,伴恶心或呕吐23例,伴上肢麻木感15例. 相似文献
8.
以苏州七子山垃圾填埋场为背景,采用理论分析的方法,探讨山谷型垃圾填埋场合理的渗滤液收集系统的形式和定量计算方法。 相似文献
9.
新建废物处理和处置设施的选址是一项综合性很强的工作,涉及自然环境,社会政治和经济、安全和技术等诸多方面,选址的主要目标通过一系列的选址技术的步骤来具体体现。 相似文献
10.
介绍了香港环保署通过10年努力的完整的固体废弃物收运,处理及处置系统,以及他们为实现废弃物减量化和资源化所采取的策略与行动。由此提出上海浦东新区在固体废弃物管理和环卫设施建设上应加强关注;逐步按规划实施;采用多种形式设计,建造,营运环卫设施以及开展全方位宣传教育活动的建议。 相似文献