全文获取类型
收费全文 | 9275篇 |
免费 | 408篇 |
国内免费 | 10篇 |
专业分类
电工技术 | 110篇 |
综合类 | 8篇 |
化学工业 | 1896篇 |
金属工艺 | 200篇 |
机械仪表 | 141篇 |
建筑科学 | 482篇 |
矿业工程 | 8篇 |
能源动力 | 282篇 |
轻工业 | 996篇 |
水利工程 | 61篇 |
石油天然气 | 14篇 |
武器工业 | 1篇 |
无线电 | 759篇 |
一般工业技术 | 1723篇 |
冶金工业 | 1585篇 |
原子能技术 | 89篇 |
自动化技术 | 1338篇 |
出版年
2023年 | 63篇 |
2022年 | 49篇 |
2021年 | 180篇 |
2020年 | 129篇 |
2019年 | 149篇 |
2018年 | 183篇 |
2017年 | 176篇 |
2016年 | 237篇 |
2015年 | 225篇 |
2014年 | 270篇 |
2013年 | 446篇 |
2012年 | 445篇 |
2011年 | 529篇 |
2010年 | 476篇 |
2009年 | 411篇 |
2008年 | 454篇 |
2007年 | 385篇 |
2006年 | 363篇 |
2005年 | 287篇 |
2004年 | 272篇 |
2003年 | 261篇 |
2002年 | 228篇 |
2001年 | 185篇 |
2000年 | 185篇 |
1999年 | 177篇 |
1998年 | 427篇 |
1997年 | 306篇 |
1996年 | 230篇 |
1995年 | 143篇 |
1994年 | 141篇 |
1993年 | 129篇 |
1992年 | 86篇 |
1991年 | 75篇 |
1990年 | 86篇 |
1989年 | 81篇 |
1988年 | 50篇 |
1987年 | 66篇 |
1986年 | 68篇 |
1985年 | 53篇 |
1984年 | 57篇 |
1983年 | 59篇 |
1982年 | 67篇 |
1981年 | 55篇 |
1980年 | 50篇 |
1979年 | 63篇 |
1978年 | 47篇 |
1977年 | 90篇 |
1976年 | 104篇 |
1975年 | 36篇 |
1974年 | 30篇 |
排序方式: 共有9693条查询结果,搜索用时 15 毫秒
1.
2.
3.
Nicholas Caffes David B. Kurland Volodymyr Gerzanich J. Marc Simard 《International journal of molecular sciences》2015,16(3):4973-4984
Ischemic and hemorrhagic strokes are associated with severe functional disability and high mortality. Except for recombinant tissue plasminogen activator, therapies targeting the underlying pathophysiology of central nervous system (CNS) ischemia and hemorrhage are strikingly lacking. Sur1-regulated channels play essential roles in necrotic cell death and cerebral edema following ischemic insults, and in neuroinflammation after hemorrhagic injuries. Inhibiting endothelial, neuronal, astrocytic and oligodendroglial sulfonylurea receptor 1–transient receptor potential melastatin 4 (Sur1–Trpm4) channels and, in some cases, microglial KATP (Sur1–Kir6.2) channels, with glibenclamide is protective in a variety of contexts. Robust preclinical studies have shown that glibenclamide and other sulfonylurea agents reduce infarct volumes, edema and hemorrhagic conversion, and improve outcomes in rodent models of ischemic stroke. Retrospective studies suggest that diabetic patients on sulfonylurea drugs at stroke presentation fare better if they continue on drug. Additional laboratory investigations have implicated Sur1 in the pathophysiology of hemorrhagic CNS insults. In clinically relevant models of subarachnoid hemorrhage, glibenclamide reduces adverse neuroinflammatory and behavioral outcomes. Here, we provide an overview of the preclinical studies of glibenclamide therapy for CNS ischemia and hemorrhage, discuss the available data from clinical investigations, and conclude with promising preclinical results that suggest glibenclamide may be an effective therapeutic option for ischemic and hemorrhagic stroke. 相似文献
4.
5.
Previous experimental results indicate that the humidification conditions at the anode have an impact on the liquid water distribution in the cathode gas diffusion layer. Numerical simulations are developed to reproduce and analyze this effect. Results consistent with the experimental results are first obtained by playing with the partition coefficients of an advanced pore network model computing the liquid water formation and transfer in the cathode gas diffusion layer (GDL) for a large range of operating conditions. Then, a model for the full anode – cathode assembly is developed by combining the pore network model of the cathode GDL and a 1D model describing the heat and water transfer in the various components of the anode-cathode assembly. This enables one to generalize the dry – wet regime diagram introduced in a previous work by incorporating the effect of the humidity condition at the anode. 相似文献
6.
Shamila Vibhushan Manuela Bratti Juan Eduardo Montero-Hernndez Alaa El Ghoneimi Marc Benhamou Nicolas Charles Eric Daugas Ulrich Blank 《International journal of molecular sciences》2021,22(1)
A sizable part (~2%) of the human genome encodes for proteases. They are involved in many physiological processes, such as development, reproduction and inflammation, but also play a role in pathology. Mast cells (MC) contain a variety of MC specific proteases, the expression of which may differ between various MC subtypes. Amongst these proteases, chymase represents up to 25% of the total proteins in the MC and is released from cytoplasmic granules upon activation. Once secreted, it cleaves the targets in the local tissue environment, but may also act in lymph nodes infiltrated by MC, or systemically, when reaching the circulation during an inflammatory response. MC have been recognized as important components in the development of kidney disease. Based on this observation, MC chymase has gained interest following the discovery that it contributes to the angiotensin-converting enzyme’s independent generation of angiotensin II, an important inflammatory mediator in the development of kidney disease. Hence, progress regarding its role has been made based on studies using inhibitors but also on mice deficient in MC protease 4 (mMCP-4), the functional murine counterpart of human chymase. In this review, we discuss the role and actions of chymase in kidney disease. While initially believed to contribute to pathogenesis, the accumulated data favor a more subtle view, indicating that chymase may also have beneficial actions. 相似文献
7.
8.
High‐intensity sweeteners in espresso coffee: ideal and equivalent sweetness and time–intensity analysis 下载免费PDF全文
Bruna M. Azevedo Flávio L. Schmidt Helena M. A. Bolini 《International Journal of Food Science & Technology》2015,50(6):1374-1381
The efficient substitution of sucrose by a sweetener in beverages requires the application of some sensory techniques. First, one must determine the concentrations of the sweeteners under study, equivalent in sweetness to the ideal sucrose concentration. In addition, it is fundamental to determine which is most similar to sucrose. The objectives of this study were to determine the ideal sweetness for espresso coffee and the equivalent concentrations in sweetness of different sweeteners, as well as characterise the time–intensity profile of each sweetener in relation to sweetness. The sweeteners evaluated were sucralose, aspartame, neotame, a cyclamate/saccharin mixture (2:1) and stevia. The sucrose concentration considered ideal by consumers was 12.5% (w/v), and the equivalent concentrations of the sweeteners were 0.0159% for sucralose, 0.0549% for aspartame, 0.0016% for neotame, 0.0359% for the cyclamate/saccharin mixture and 0.0998% for stevia. The time–intensity analysis indicated that possibly the sweeteners neotame, aspartame and sucralose would be the best substitutes for sucrose. 相似文献
9.
Freddy A. Bernal Dr. Marcel Kaiser Prof. Dr. Bernhard Wünsch Prof. Dr. Thomas J. Schmidt 《ChemMedChem》2020,15(1):68-78
Protozoal infections are still a global health problem, threatening the lives of millions of people around the world, mainly in impoverished tropical and sub-tropical regions. Thus, in view of the lack of efficient therapies and increasing resistances against existing drugs, this study describes the antiprotozoal potential of synthetic cinnamate ester analogues and their structure-activity relationships. In general, Leishmania donovani and Trypanosoma brucei were quite susceptible to the compounds in a structure-dependent manner. Detailed analysis revealed a key role of the substitution pattern on the aromatic ring and a marked effect of the side chain on the activity against these two parasites. The high antileishmanial potency and remarkable selectivity of the nitro-aromatic derivatives suggested them as promising candidates for further studies. On the other hand, the high in vitro potency of catechol-type compounds against T. brucei could not be extrapolated to an in vivo mouse model. 相似文献
10.