全文获取类型
收费全文 | 973篇 |
免费 | 14篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 4篇 |
化学工业 | 130篇 |
金属工艺 | 26篇 |
机械仪表 | 11篇 |
建筑科学 | 18篇 |
矿业工程 | 3篇 |
能源动力 | 5篇 |
轻工业 | 55篇 |
水利工程 | 3篇 |
无线电 | 45篇 |
一般工业技术 | 73篇 |
冶金工业 | 565篇 |
原子能技术 | 9篇 |
自动化技术 | 42篇 |
出版年
2023年 | 5篇 |
2022年 | 6篇 |
2021年 | 5篇 |
2019年 | 6篇 |
2018年 | 4篇 |
2016年 | 10篇 |
2015年 | 10篇 |
2014年 | 13篇 |
2013年 | 14篇 |
2012年 | 19篇 |
2011年 | 16篇 |
2010年 | 18篇 |
2009年 | 13篇 |
2008年 | 12篇 |
2007年 | 23篇 |
2006年 | 13篇 |
2005年 | 16篇 |
2004年 | 20篇 |
2003年 | 20篇 |
2002年 | 25篇 |
2001年 | 15篇 |
2000年 | 13篇 |
1999年 | 17篇 |
1998年 | 172篇 |
1997年 | 92篇 |
1996年 | 72篇 |
1995年 | 44篇 |
1994年 | 38篇 |
1993年 | 45篇 |
1992年 | 17篇 |
1991年 | 7篇 |
1990年 | 5篇 |
1989年 | 6篇 |
1988年 | 9篇 |
1987年 | 5篇 |
1985年 | 10篇 |
1984年 | 9篇 |
1983年 | 9篇 |
1982年 | 8篇 |
1981年 | 12篇 |
1980年 | 8篇 |
1979年 | 3篇 |
1978年 | 6篇 |
1977年 | 18篇 |
1976年 | 38篇 |
1975年 | 4篇 |
1970年 | 3篇 |
1966年 | 3篇 |
1956年 | 4篇 |
1935年 | 3篇 |
排序方式: 共有989条查询结果,搜索用时 765 毫秒
1.
Cypriano G da Trindade Neto Ana LP Fernandes Ana IB Santos Waldenice A Morais Marcos VM Navarro Tereza NC Dantas Mrcia R Pereira Jos LC Fonseca 《Polymer International》2005,54(4):659-666
Complexation of chitosan in aqueous solutions by low molecular weight electrolytes is one of the simplest methods for the preparation of aqueous chitosan dispersions. In this work, the influence of storage time, sulfate concentration, method of preparation and surfactant content on some properties of the resultant chitosan dispersions (turbidity, viscosity and zeta potential) was analyzed. Turbidimetry was adequate to monitor the formation of particles, while viscometry was suitable to monitor changes in the dispersing phase. An analysis of the properties of these systems, mainly in terms of particle–particle and macromolecule–macromolecule interactions was carried out. Copyright © 2004 Society of Chemical Industry 相似文献
2.
3.
The authors describe their scientific and clinical interests in developing the panel Trauma, Dissociation, and Conflict: The Space Where Neuroscience, Cognitive Science, and Psychoanalysis Overlap, given at the 22nd Annual Spring Meeting of the Division of Psychoanalysis of the American Psychological Association. They cite the influence of the panelists, Philip M. Bromberg, Wilma Bucci, and Joseph LeDoux, on their own work. Specializing in the treatment of chronic pain, Anderson has developed a relational intersubjective technique informed by this interdisciplinary approach. Gold's work has focused on the distinction between dissociative processes and repression in traumatic memory. The relevance of trauma, dissociation, and conflict, heightened since September 11, 2001, could not have been anticipated in the planning of the panel. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
MD Goldberg JR Canvin P Freestone C Andersen D Laoudj PH Williams IB Holland V Norris 《Canadian Metallurgical Quarterly》1997,79(6):315-322
In the bacterium Escherichia coli, H-NS-(H1, H1a) is a heat-stable protein with a molecular mass of 15.5 kDa involved in nucleoid organisation and gene regulation linked to certain signal transduction pathways. We have shown that, following addition of preparations of everted inner membrane vesicles, heat-stable cleavage products of approximately 10 kDa of H-NS are formed in vitro from newly synthesised, radio-labelled H-NS and from purified H-NS. The 15.5 kDa protein and its cleavage products were also recovered from a minicell system. These results raised the possibility that cleavage of H-NS is physiologically significant. However, the cleavage of H-NS observed appears to occur during cell breakage and to depend on the method of protein extraction and the presence of the outer membrane protease, OmpT. Nevertheless, the results indicate that H-NS may contain at least two separate domains with cleavage occurring between these domains at a preferred OmpT site. Failure to take account of H-NS cleavage in sample preparation and analysis can lead to serious underestimation of H-NS levels. 相似文献
5.
The occurrence of fungi was investigated in the gut of 200 common garden lizards (Agama agama). The most important pathogenic fungus isolated was Basidiobolus haptosporus, an aetiological agent of subcutaneous zygomycosis. It was recovered from the intestinal contents of 112 (56%) lizards. Other important fungi isolated included Aspergillus spp. in 24 (12%) lizards, Candida spp. in 12 (6%), Penicillium spp. in 12 (6%) and Fusarium spp. in 12 (6%). Mucor spp. were isolated from eight (4%) male lizards only. Agamid lizards are plentiful in rural and urban areas of Nigeria. As they live in close vicinity to man, they are likely to play an important role in the spread of disease that may be caused by these fungi and its transmission to man. None of the animals investigated that yielded fungal cultures revealed any external fungal infection. 相似文献
6.
7.
8.
A prospective analysis of 69 patients who had been treated for nasopharyngeal carcinoma (NPC) by external radiotherapy was carried out. Biopsies from the posterior nasopharynx were performed and analyzed by in situ hybridization using an antisense Epstein-Barr Early RNA (EBER) radio-labelled riboprobe. None of the patients had evidence of disease in the nasopharynx. One patient was found to have nasopharyngeal carcinoma detected only by in situ hybridization. In the subsequent 18-month follow-up of these clinically- and biopsy-negative patients, only one patient developed relapse in the nasopharynx. In situ hybridization is a valuable tool for the detection of NPC and should be routinely available in histopathology laboratories where NPC is regularly diagnosed. 相似文献
9.
10.