全文获取类型
收费全文 | 1979篇 |
免费 | 13篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 40篇 |
金属工艺 | 3篇 |
机械仪表 | 2篇 |
建筑科学 | 6篇 |
能源动力 | 4篇 |
轻工业 | 60篇 |
石油天然气 | 1篇 |
无线电 | 22篇 |
一般工业技术 | 21篇 |
冶金工业 | 1804篇 |
自动化技术 | 28篇 |
出版年
2023年 | 3篇 |
2022年 | 3篇 |
2021年 | 4篇 |
2020年 | 6篇 |
2019年 | 8篇 |
2018年 | 4篇 |
2017年 | 8篇 |
2016年 | 5篇 |
2015年 | 4篇 |
2014年 | 5篇 |
2013年 | 17篇 |
2012年 | 9篇 |
2011年 | 9篇 |
2010年 | 6篇 |
2009年 | 9篇 |
2008年 | 10篇 |
2007年 | 5篇 |
2006年 | 10篇 |
2005年 | 12篇 |
2004年 | 6篇 |
2003年 | 6篇 |
2002年 | 5篇 |
2001年 | 3篇 |
2000年 | 8篇 |
1999年 | 61篇 |
1998年 | 555篇 |
1997年 | 327篇 |
1996年 | 222篇 |
1995年 | 117篇 |
1994年 | 103篇 |
1993年 | 112篇 |
1992年 | 12篇 |
1991年 | 25篇 |
1990年 | 19篇 |
1989年 | 27篇 |
1988年 | 24篇 |
1987年 | 22篇 |
1986年 | 17篇 |
1985年 | 25篇 |
1983年 | 1篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1980年 | 9篇 |
1979年 | 2篇 |
1978年 | 4篇 |
1977年 | 32篇 |
1976年 | 89篇 |
1975年 | 3篇 |
1966年 | 1篇 |
1955年 | 3篇 |
排序方式: 共有1992条查询结果,搜索用时 8 毫秒
121.
122.
123.
124.
EW Ling FJ Noya G Ricard K Beharry EL Mills JV Aranda 《Canadian Metallurgical Quarterly》1995,38(6):981-987
The meningeal inflammatory response to a heat-killed mutant unencapsulated strain of type III group B Streptococcus (GBS) was studied in a newborn piglet model. GBS (10(9) colony-forming unit equivalents) or saline (control) was inoculated intraventricularly. Serial cerebrospinal fluid measurements were done at baseline and over the course of the next 24 h for cytochemical changes and production of tumor necrosis factor (TNF) and prostaglandins. In separate experiments, we defined the time course of early changes during the first 6 h and dose response relationship over a range of inocula 10(6) to 10(9) colony-forming unit equivalents. The intraventricular inoculation of the heat-killed unencapsulated GBS induced marked leukocytosis and increased protein by 6 h. These changes were preceded by a several hundredfold increase in TNF (maximum at 2 h) and prostaglandins (maximum at 2-4 h). The early and sharp rise in TNF suggests its pivotal role in initiating the inflammatory cascade. The magnitude of the inflammatory response increased with increasing bacterial dose over the range studied. To study the effect of encapsulation of GBS in the induction of meningeal inflammation, we compared the response to the unencapsulated mutant strain with that to the encapsulated parent strain. The encapsulated strain produced much smaller inflammatory changes, and only with high doses of bacteria. The GBS cell wall appeared to be the primary bacterial product triggering inflammation. Intraventricular injection of the heat-killed unencapsulated GBS with exposed cell wall can serve as a valid model for studying neonatal meningitis. 相似文献
125.
126.
127.
128.
129.
Molecular modeling of immunoglobulin light chains implicates hydrophobic residues in non-amyloid light chain deposition disease 总被引:3,自引:0,他引:3
Deret S; Chomilier J; Huang DB; Preud'homme JL; Stevens FJ; Aucouturier P 《Protein engineering, design & selection : PEDS》1997,10(10):1191-1197
Light chain deposition disease is a severe complication of certain
immunoproliferative disorders, due to the secretion of a monoclonal light
chain which precipitates close to basement membranes of several tissues. A
kappa isotype restriction and an unusual frequency of a variable region
subgroup (VkappaIV) suggest that precise structural features govern the
propensity of pathogenic light chains to precipitate in extracellular
spaces. We studied primary structures of light chains from six patients
with light chain deposition disease in comparison with light chains from
other pathological conditions. Sequence alignment revealed the presence of
certain amino acids only in light chain deposition disease, in particular
non-polar replacing hydrophilic residues. To determine the role of these
residues, structures of the variable domain from four kappa chains
belonging to VkappaI and VkappaIV subgroups responsible for deposition
disease were modeled using known immunoglobulins as templates. The most
evident structural features shared by all pathogenic light chains were
hydrophobic residues exposed to the solvent in complementarity determining
regions 1 or 3. In contrast to immunoglobulin light chain- related
amyloidosis, where deposition of organized material might be due to
electrostatic interactions between light chain dimers, hydrophobic
interactions could enhance amorphous precipitation in non- amyloid light
chain deposition disease.
相似文献
130.
This study has shown that orthodontists and their patients share a common pool of diffuse esthetic values of the same smile. Profile and frontal views of the same smile were not similarly rated for esthetic pleasantness: the profile views were rated higher than the frontal views of the same smile. This finding suggests that orthodontists should consider both frontal and lateral views during evaluation of their patient when planning and assessing orthodontic treatment. More research is needed to determine the generalizability of the finding that orthodontists and patients have similar facial esthetic preferences. Future studies should expand the range of smiles that are evaluated by including both genders, people of different ethnic backgrounds, and people of a variety of ages. Research is also needed to evaluate facial esthetics and smiles in dynamic motion. 相似文献