全文获取类型
收费全文 | 30699篇 |
免费 | 2755篇 |
国内免费 | 1541篇 |
专业分类
电工技术 | 2044篇 |
技术理论 | 2篇 |
综合类 | 2105篇 |
化学工业 | 4952篇 |
金属工艺 | 1540篇 |
机械仪表 | 2006篇 |
建筑科学 | 3082篇 |
矿业工程 | 839篇 |
能源动力 | 831篇 |
轻工业 | 2480篇 |
水利工程 | 552篇 |
石油天然气 | 1380篇 |
武器工业 | 233篇 |
无线电 | 3725篇 |
一般工业技术 | 3569篇 |
冶金工业 | 1202篇 |
原子能技术 | 404篇 |
自动化技术 | 4049篇 |
出版年
2024年 | 152篇 |
2023年 | 571篇 |
2022年 | 1061篇 |
2021年 | 1453篇 |
2020年 | 1051篇 |
2019年 | 870篇 |
2018年 | 933篇 |
2017年 | 1051篇 |
2016年 | 972篇 |
2015年 | 1198篇 |
2014年 | 1573篇 |
2013年 | 1804篇 |
2012年 | 2034篇 |
2011年 | 2157篇 |
2010年 | 2026篇 |
2009年 | 1902篇 |
2008年 | 1756篇 |
2007年 | 1665篇 |
2006年 | 1579篇 |
2005年 | 1349篇 |
2004年 | 904篇 |
2003年 | 838篇 |
2002年 | 827篇 |
2001年 | 744篇 |
2000年 | 676篇 |
1999年 | 704篇 |
1998年 | 497篇 |
1997年 | 475篇 |
1996年 | 468篇 |
1995年 | 381篇 |
1994年 | 317篇 |
1993年 | 215篇 |
1992年 | 163篇 |
1991年 | 114篇 |
1990年 | 84篇 |
1989年 | 86篇 |
1988年 | 64篇 |
1987年 | 45篇 |
1986年 | 36篇 |
1985年 | 24篇 |
1984年 | 14篇 |
1983年 | 14篇 |
1982年 | 11篇 |
1981年 | 8篇 |
1980年 | 10篇 |
1979年 | 10篇 |
1977年 | 4篇 |
1962年 | 42篇 |
1961年 | 39篇 |
1960年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
81.
82.
83.
电能计量领域的多功能低功耗设计 总被引:1,自引:0,他引:1
电力用户是我国电工仪器仪表最大的用户群体,需求量占整个市场的90%。电能表是我国电工仪表行业中产量最大的产品。本文讨论了电能表的低功耗设计需求以及Maxim 提供的 MAXQ3180低功耗电表设计方案。 相似文献
84.
Network traffic classification is essential in supporting network measurement and management.Many existing traffic classification approaches provide application-level results regardless of the network quality of service(QoS) requirements. In practice,traffic flows from the same application may have irregular network behaviors that should be identified to various QoS classes for best network resource management. To address the issues, we propose to conduct traffic classification with two newly de... 相似文献
85.
86.
As the most recent melanocortin receptor (MCR) identified, melanocortin-5 receptor (MC5R) has unique tissue expression patterns, pharmacological properties, and physiological functions. Different from the other four MCR subtypes, MC5R is widely distributed in both the central nervous system and peripheral tissues and is associated with multiple functions. MC5R in sebaceous and preputial glands regulates lipid production and sexual behavior, respectively. MC5R expressed in immune cells is involved in immunomodulation. Among the five MCRs, MC5R is the predominant subtype expressed in skeletal muscle and white adipose tissue, tissues critical for energy metabolism. Activated MC5R triggers lipid mobilization in adipocytes and glucose uptake in skeletal muscle. Therefore, MC5R is a potential target for treating patients with obesity and diabetes mellitus. Melanocortin-2 receptor accessory proteins can modulate the cell surface expression, dimerization, and pharmacology of MC5R. This minireview summarizes the molecular and pharmacological properties of MC5R and highlights the progress made on MC5R in energy metabolism. We poInt. out knowledge gaps that need to be explored in the future. 相似文献
87.
Xiaosu Huang Junhua Yang Renyue Zhang Lianbao Ye Ming Li Weiqiang Chen 《International journal of molecular sciences》2022,23(15)
Globally, wound infection is considered to be one of the major healthcare problems, with bacterial infections being the most critical threat, leading to poor and delayed wound healing, and even death. As a superbug, methicillin-resistant Staphylococcus aureus (MRSA) causes a profound hazard to public health safety, prompting us to search for alternative treatment approaches. Herein, the MTT test and Hoechst/propidium iodide (PI) staining demonstrated that PD was slightly less toxic to human fibroblasts including Human keratinocytes (HaCaT) cell line than Silver sulfadiazine (SSD), and Vancomycin (Van). In the MRSA-infected wound model, PD hydrogel (1%, 2.5%) was applied with for 14 days. The wound healing of PD hydrogel groups was superior to the SSD, Van, and control groups. Remarkably, the experimental results showed that PD reduced the number of skin bacteria, reduced inflammation, and upregulated the expression of PCNA (keratinocyte proliferation marker) and CD31 (angiogenesis manufacturer) at the wound site by histology (including hematoxylin–eosin (HE) staining, Masson staining) and immunohistochemistry. Additionally, no toxicity, hemocompatibility or histopathological changes to organs were observed. Altogether, these results suggested the potential of PD hydrogel as a safe, effective, and low toxicity hydrogel for the future clinical treatment of MRSA-infected wounds. 相似文献
88.
Ye Yunguang Sun Yu Dongfang Shiping Shi Dachuan Hecht Markus 《Multibody System Dynamics》2021,51(1):91-122
Multibody System Dynamics - The selection of a wheel profile is a topic of great interest as it can affect running performances and wheel wear, which needs to be determined based on the actual... 相似文献
89.
90.