全文获取类型
收费全文 | 2375篇 |
免费 | 112篇 |
国内免费 | 6篇 |
专业分类
电工技术 | 12篇 |
综合类 | 1篇 |
化学工业 | 388篇 |
金属工艺 | 30篇 |
机械仪表 | 38篇 |
建筑科学 | 130篇 |
矿业工程 | 11篇 |
能源动力 | 35篇 |
轻工业 | 424篇 |
水利工程 | 13篇 |
石油天然气 | 15篇 |
无线电 | 112篇 |
一般工业技术 | 301篇 |
冶金工业 | 631篇 |
原子能技术 | 5篇 |
自动化技术 | 347篇 |
出版年
2023年 | 16篇 |
2022年 | 23篇 |
2021年 | 36篇 |
2020年 | 26篇 |
2019年 | 44篇 |
2018年 | 39篇 |
2017年 | 43篇 |
2016年 | 45篇 |
2015年 | 38篇 |
2014年 | 63篇 |
2013年 | 179篇 |
2012年 | 79篇 |
2011年 | 143篇 |
2010年 | 112篇 |
2009年 | 97篇 |
2008年 | 129篇 |
2007年 | 129篇 |
2006年 | 113篇 |
2005年 | 94篇 |
2004年 | 76篇 |
2003年 | 81篇 |
2002年 | 79篇 |
2001年 | 46篇 |
2000年 | 49篇 |
1999年 | 46篇 |
1998年 | 44篇 |
1997年 | 39篇 |
1996年 | 48篇 |
1995年 | 32篇 |
1994年 | 52篇 |
1993年 | 42篇 |
1992年 | 24篇 |
1991年 | 13篇 |
1990年 | 35篇 |
1989年 | 34篇 |
1988年 | 27篇 |
1987年 | 29篇 |
1986年 | 31篇 |
1985年 | 23篇 |
1984年 | 27篇 |
1983年 | 22篇 |
1982年 | 13篇 |
1981年 | 15篇 |
1980年 | 13篇 |
1979年 | 12篇 |
1978年 | 13篇 |
1977年 | 16篇 |
1976年 | 11篇 |
1975年 | 11篇 |
1974年 | 7篇 |
排序方式: 共有2493条查询结果,搜索用时 41 毫秒
1.
Nitsa Buaron Antonella Mangraviti Francesco Volpin Ann Liu Mariangela Pedone Eric Sankey Dina Aranovich Itay Adar Fausto J. Rodriguez Abraham Nyska Riki Goldbart Tamar Traitel Henry Brem Betty Tyler Joseph Kost 《Advanced functional materials》2021,31(44):2100643
Treating neuroinflammation-related injuries and disorders through manipulation of neuroinflammation functions is being heralded as a new therapeutic strategy. In this study, a novel pectic galactan (PG) polysaccharide based gene therapy approach is developed for targeting reactive gliosis in neuroinflammation. Galectin-3 (Gal-3) is a cell protein with a high affinity to β-galactoside sugars and is highly expressed in reactive gliosis. Since PG carries galactans, it can target reactive gliosis via specific carbohydrate interaction between galactan and Gal-3 on the cell membrane, and therefore can be utilized as a carrier for delivering genes to these cells. The carrier is synthesized by modifying quaternary ammonium groups on the PG. The resulting quaternized PG (QPG) is found to form complexes with plasmid DNA with a mean diameter of 100 nm and have the characteristics required for targeted gene therapy. The complexes efficiently condense large amounts of plasmid per particle and successfully bind to Gal-3. The in vivo study shows that the complexes are biocompatible and safe for administration and can selectively transfect reactive glial cells of an induced cortical lesion. The results confirm that this PG-based delivery system is a promising platform for targeting Gal-3 overexpressing neuroinflammation cells for treating neuroinflammation-related injuries and neurodegenerative diseases. 相似文献
2.
3.
We have improved the electronic properties of narrow-bandgap (Tauc gap below 1.5 eV) amorphous-silicon germanium alloys (a-SiGe:H) grown by hot-wire chemical vapor deposition (HWCVD) by lowering the substrate temperature and deposition rate. Prior to this work, we were unable to grow a-SiGe:H alloys with bandgaps below 1.5 eV that had photo-to-dark conductivity ratios comparable with our plasma-enhanced CVD (PECVD) grown materials [B.P. Nelson et al., Mater. Res. Soc. Symp. 507 (1998) 447]. Decreasing the filament diameter from our standard configuration of 0.5 mm to 0.38 or 0.25 mm provides first big improvements in the photoresponse of these alloys. Lowering the substrate temperature from our previous optimal temperatures (Tsub starting at 435 °C) to at 250 °C provides additional photo-to-dark conductivity ratio increasing by two orders of magnitude for growth conditions containing 20–30% GeH4 in the gas phase (relative to the total GeH4+SiH4 flow). 相似文献
4.
Cured samples of a nitrogen-containing acetylene-terminated resin, N,N′-(1,3-phenylene-dimethylidene)bis(3-ethynylaniline), have been heated at 10°C/min up to 900°C in a pyroprobe attached to a gas chromatograph/mass spectrometer (GC/MS). Analysis of the volatiles evolved during heating identified both gases and higher boiling compounds. The major higher boiling compounds are benzene, toluene, xylene, aniline, benzonitrile, m-methylaniline, and m-methylbenzonitrile; the gases include ammonia, methane, and traces of carbon dioxide. Correlations between sample temperature and the evolution of each of these compounds have been made. The onset of all volatile formation occurs between 450 and 500°C. The higher boiling volatiles peak, then end by approximately 700°C, while the gases peak then fall off but are still being evolved at 900°C. Average weight loss measurements of 13.6% at 700°C and 15.7% at 900°C agree with previously published thermogravimetric analysis (TGA) data. © 1993 John Wiley & Sons, Inc. 相似文献
5.
A historical review of licensing among industrial/organizational (I/O) psychologists demonstrates that the American Psychological Association (APA) policy on such licensing is inconsistent. Arguments for and against licensure for this group are presented. Job analysis and APA data are drawn upon to show that few I/O activities may pose the personal risk that would seem to require the protection of a license. Alternatives are discussed for changes in present APA policy and state licensing requirements. (16 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
7.
Mark Sherman Jonathan Rosenberg Ann Marks Jaap Akkerhuis 《Computer Standards & Interfaces》1991,11(3):177-182
Many advanced document systems provide a formatting mechanism called ‘style sheets’ Style sheets provide a great deal of flexibility in describing a document's format, and allow easy maintenance of different house styles for a collection of documents. In this paper, we describe the basics of general style sheet systems, argue that successful document interchange must include the exchange of style sheet information, and evaluate ODA's style mechanism against this requirement. 相似文献
8.
Due to their small size, mammalian oocytes and embryos pose unique problems during preparation for transmission electron microscopy. This paper outlines a method which combines protein embedding with centrifugation to locate the specimens on the face of a Beem capsule mould. This method facilitates both the processing of oocytes with minimal loss and rapid location of the specimens within the block for simultaneous sectioning, staining and examination. 相似文献
9.
Reviews available research on the meaning and measurement of denial and strategies for treating maladaptive denial, with special reference to its occurrence in traumatic head injuries. Questionnaire or interview measures, rather than behavioral indices, are used to assess denial. Denial may be manifested with respect to past, present, or future status; and it may have both positive and negative consequences for coping, motivation, and rehabilitation. Where denial limits a patient's functioning or recovery, several treatment strategies are possible. Intervention should involve a balance between supportive and confrontational elements, with a focus on behaviors rather than verbalizations. Computer feedback, videotaping, focused group therapy, and supervised activities are possible interventions for confronting maladaptive forms of denial. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
This study investigated jurors' reactions to judges' nonverbal communication in mock trials. Participants in 80 mock juries viewed taped segments of direct and cross examination that varied the judges' level of nonverbal involvement. Comments about the judge were solicited in predeliberation questionnaires and unsolicited comments obtained from dialogue that occurred during mock jury deliberations. The investigation found that jurors are aware of nonverbal cues from judges, particularly negative behaviors. Although the high- and low-involved judges solicited roughly the same number of comments, more negative comments were made about the judge displaying low than high nonverbal involvement. The results also revealed that jurors made more negative comments than positive ones. Overall, jurors are most aware of a judge's lack of involvement and apparent bias. Discussion focuses on ways to minimize the influence of judge nonverbal communication on jurors. 相似文献