首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   754篇
  免费   1篇
工业技术   755篇
  2017年   1篇
  2013年   2篇
  2011年   3篇
  2010年   1篇
  2008年   1篇
  2005年   1篇
  2003年   1篇
  2002年   1篇
  1999年   29篇
  1998年   235篇
  1997年   118篇
  1996年   101篇
  1995年   38篇
  1994年   37篇
  1993年   39篇
  1992年   5篇
  1991年   3篇
  1990年   4篇
  1989年   3篇
  1988年   7篇
  1987年   8篇
  1986年   7篇
  1985年   4篇
  1984年   1篇
  1983年   1篇
  1982年   5篇
  1981年   4篇
  1980年   7篇
  1979年   1篇
  1978年   1篇
  1977年   21篇
  1976年   42篇
  1975年   2篇
  1974年   2篇
  1973年   2篇
  1972年   2篇
  1971年   1篇
  1970年   2篇
  1968年   3篇
  1966年   1篇
  1965年   1篇
  1964年   1篇
  1962年   2篇
  1961年   1篇
  1960年   1篇
  1959年   1篇
  1958年   1篇
排序方式: 共有755条查询结果,搜索用时 15 毫秒
751.
752.
Tested the proposal that comparability in life-styles exists between normal college males who have adopted closed and open styles of coping with aversive maternal control (i.e., perceived high control, low nurturance) and the life-styles of process and reactive schizophrenics. Breadth of internal scanning behavior, defined in terms of the availability of alternate word meanings, was studied with the expectation that closed-style males would be broader internal scanners in keeping with the adaptive-style model and with the limited evidence on process-reactive schizophrenics. 56 white male undergraduates completed the Parental Attitude Research Instrument, A. Heilbrun's parent-child interaction rating scales, A. Willner's unusual meanings vocabulary test, and the Stroop Color-Word Test. Closed-style males were superior to open-style males on a test of nondominant word namings and also provided more remote free word associations. No differences were found on a word-meaning test not requiring extended meanings. (24 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
753.
754.

ABSTRACT

This study examined the effects of different salt contents (3, 6 and 9%) during process stages on physicochemical, lipid oxidation and microbial quality of a dry‐cured meat product, past?rma, throughout 21 days of processing. Significant changes in moisture content, NaCl content, pH and water activity (aw) were observed in past?rma after the third drying and pasting stages. There were significant decreases (P < 0.05) in objective color characteristics (L*, a* and b*) between raw material and final product for all past?rma samples. However, no significant effect of salt level (P > 0.05) was detected on L* and a*. Salt level significantly (P < 0.05) affected thiobarbituric acid‐reactive substances (TBARS) formation, which was lower in low‐salt past?rma samples, while the combination of salting, drying and pressing stages increased TBARS values in high‐salt past?rma samples. Higher salt content (6% and 9%) and last drying resulted in reduction of microbial count.

PRACTICAL APPLICATIONS

Salt (NaCl) is an important agent in inhibiting microbial growth, reducing water activity and imparting a salty taste to dry‐cured meat products such as ham and past?rma. Salt content in past?rma varies from 5% to 10% in the final product and has an impact on product quality parameters. The effects of different NaCl contents (3, 6 and 9%) and processing stages on pH, water activity (aw), color parameters, lipid oxidation and microbial count were studied during processing of past?rma. Low‐salt concentration had some negative impacts on past?rma characteristics, giving high aw, pH and microbial count, but low Thiobarbituric acid‐reactive substances value and NaCl content. Drying, pressing and pasting with çemen mixture during past?rma processing had a positive impact on reduction of moisture, aw and microbial count.
  相似文献   
755.
All retroviruses (except the spumaretroviruses) contain a nucleocapsid (NC) protein that encodes one or two copies of the Zn2+-finger sequence -Cys-X2-Cys-X4-His-X4-Cys-. This region has been shown to be essential for recognition and packaging of the genomic RNA during virion particle assembly. Additionally, this region has been shown to be involved in early infection events in a wide spectrum of retroviruses, including mammalian type C [e.g., murine leukemia virus (MuLV)], human immunodeficiency virus type 1 (HIV-1), Rous sarcoma virus, and other retroviruses. Mutations in the two Zn2+-fingers of the NC protein of simian immunodeficiency virus strain Mne [SIV(Mne)] have been generated. The resulting virions contained the normal complement of processed viral proteins with densities indistinguishable from wild-type SIV(Mne). All of the mutants had electron micrograph morphologies similar to those of immature particles observed in wild-type preparations. RNA packaging was less affected by mutations in the NC protein of SIV(Mne) than has been observed for similar mutants in the MuLV and HIV-1 systems. Nevertheless, in vitro replication of SIV(Mne) NC mutants was impaired to levels comparable to those observed for MuLV and HIV-1 NC mutants; replication defective NC mutants are typically 10(5)- to 10(6)-fold less infectious than similar levels of wild-type virus. One mutant, DeltaCys33-Cys36, was also found to be noninfectious in vivo when mutant virus was administered intravenously to a pig-tailed macaque. NC mutations can therefore be used to generate replication defective virions for candidate vaccines in the SIV macaque model for primate lentiviral diseases.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号