全文获取类型
收费全文 | 9422篇 |
免费 | 155篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 89篇 |
综合类 | 4篇 |
化学工业 | 1226篇 |
金属工艺 | 164篇 |
机械仪表 | 227篇 |
建筑科学 | 281篇 |
矿业工程 | 55篇 |
能源动力 | 164篇 |
轻工业 | 692篇 |
水利工程 | 69篇 |
石油天然气 | 19篇 |
武器工业 | 1篇 |
无线电 | 747篇 |
一般工业技术 | 1340篇 |
冶金工业 | 3663篇 |
原子能技术 | 81篇 |
自动化技术 | 766篇 |
出版年
2022年 | 48篇 |
2021年 | 55篇 |
2020年 | 40篇 |
2019年 | 55篇 |
2018年 | 78篇 |
2017年 | 73篇 |
2016年 | 85篇 |
2015年 | 78篇 |
2014年 | 99篇 |
2013年 | 354篇 |
2012年 | 194篇 |
2011年 | 252篇 |
2010年 | 252篇 |
2009年 | 236篇 |
2008年 | 254篇 |
2007年 | 251篇 |
2006年 | 214篇 |
2005年 | 237篇 |
2004年 | 175篇 |
2003年 | 195篇 |
2002年 | 189篇 |
2001年 | 158篇 |
2000年 | 172篇 |
1999年 | 193篇 |
1998年 | 1003篇 |
1997年 | 695篇 |
1996年 | 486篇 |
1995年 | 338篇 |
1994年 | 295篇 |
1993年 | 319篇 |
1992年 | 123篇 |
1991年 | 117篇 |
1990年 | 135篇 |
1989年 | 142篇 |
1988年 | 135篇 |
1987年 | 105篇 |
1986年 | 96篇 |
1985年 | 114篇 |
1984年 | 113篇 |
1983年 | 88篇 |
1982年 | 75篇 |
1981年 | 74篇 |
1980年 | 90篇 |
1979年 | 79篇 |
1978年 | 90篇 |
1977年 | 153篇 |
1976年 | 266篇 |
1975年 | 65篇 |
1974年 | 63篇 |
1973年 | 58篇 |
排序方式: 共有9588条查询结果,搜索用时 15 毫秒
1.
Thin Film Thermoelectric Metal–Organic Framework with High Seebeck Coefficient and Low Thermal Conductivity 下载免费PDF全文
2.
3.
Dr. Hui Qiu Richard Caldwell Dr. Lesley Liu-Bujalski Dr. Andreas Goutopoulos Reinaldo Jones Justin Potnick Dr. Brian Sherer Dr. Andrew Bender Dr. Roland Grenningloh Dr. Daigen Xu Dr. Anna Gardberg Dr. Igor Mochalkin Dr. Theresa Johnson Dr. Ariele Viacava Follis Jared Head Dr. Federica Morandi 《ChemMedChem》2019,14(2):217-223
Bruton's tyrosine kinase (Btk) is an attractive target for the treatment of a wide array of B-cell malignancies and autoimmune diseases. Small-molecule covalent irreversible Btk inhibitors targeting Cys481 have been developed for the treatment of such diseases. In clinical trials, probe molecules are required in occupancy studies to measure the level of engagement of the protein by these covalent irreversible inhibitors. The result of this pharmacodynamic (PD) activity provides guidance for appropriate dosage selection to optimize inhibition of the drug target and correlation of target inhibition with disease treatment efficacy. This information is crucial for successful evaluation of drug candidates in clinical trials. Based on the pyridine carboxamide scaffold of a novel solvent-accessible pocket (SAP) series of covalent irreversible Btk inhibitors, we successfully developed a potent and selective affinity-based biotinylated probe 12 (2-[(4-{4-[5-(1-{5-[(3aS,4S,6aR)-2-oxo-hexahydro-1H-thieno[3,4-d]imidazol-4-yl]pentanamido}-3,6,9,12-tetraoxapentadecan-15-amido)pentanoyl]piperazine-1-carbonyl}phenyl)amino]-6-[1-(prop-2-enoyl)piperidin-4-yl]pyridine-3-carboxamide). Compound 12 has been used in Btk occupancy assays for preclinical studies to determine the therapeutic efficacy of Btk inhibition in two mouse lupus models driven by TLR7 activation and type I interferon. 相似文献
4.
5.
Dyspnea may be easily appreciated during exercise with dyspneic scales, but methodological standardisation still needs to be specified. Authors review the basic physiological mechanism relating dyspnea to indices obtained during a stress test. They propose to use the dyspnea/VE relationship. With the concept of dyspneic threshold (close to the ventilatory threshold) and the ramp that both could be modified (for instance by rehabilitation programmes including exercise training). Interpretation of dyspnea during an exercise test obviously needs to be integrated with other parameters studied during exercise. 相似文献
6.
7.
Capers Jones 《Information Systems Management》1994,11(4):28-33
If you don't know the current productivity rates, usage volumes, and other quantitative baseline data for your software operations, then software might not be a key component of the company's core business. The evaluation criteria in this article can help the IS executive determine the outsourcing options for software operations. 相似文献
8.
9.
Current cementing techniques of distal plugging, pulsatile water cleaning of the canal, and retrograde filling with PMMA in a low-viscous state prepared using porosity reduction techniques and then pressurized have been shown to give excellent results at 10 or more years after operation. However, physical and aging characteristics of PMMA do not guarantee that those results will hold up in the 20- to 30-year time frame. Fifteen-year experience with bony ingrowth systems indicate the development of a durable interface without PMMA, although the interface does appear more vulnerable to attack by the biologic reaction to HMWPE debris. Bone remodeling appears more favorable around proximally fixed bone ingrowth prostheses than around distally fixed prostheses. Softening of the physical characteristics of the stem tip may reduce the incidence of thigh pain. Patients with high activity potential and a life expectancy of greater than 25 years should be strongly considered for a proximally fixed bone ingrowth or ongrowth prosthesis. 相似文献
10.
LM Sayre RT Naismith MA Bada WS Li ME Klein MD Tennant 《Canadian Metallurgical Quarterly》1996,1296(2):250-256
Horseradish peroxidase (HRP) is well known for mediating the electron-transfer oxidation of electron-rich aromatic 'donors' such as phenols and anilines, but has not been described to oxidize aliphatic amines. We here confirm the inability of HRP to oxidize typical aliphatic amines, even those which would exist significantly as free bases at the operative pH. In contrast, trans-2-phenylcyclopropylamine (2-PCPA) is both a substrate (turnover product is cinnamaldehyde) and a time-dependent inactivator of HRP. These activities of 2-PCPA are consistent with either a concerted or rapid sequential one-electron-oxidation/ring-opening to give an intermediate capable of covalent binding to the enzyme. 2-PCPA is the first known example of a simple aliphatic amine which serves as a substrate for HRP under turnover conditions. 相似文献