首页 | 本学科首页   官方微博 | 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   1333篇
  免费   2篇
  国内免费   1篇
综合类   1篇
化学工业   20篇
金属工艺   1篇
机械仪表   3篇
能源动力   4篇
轻工业   6篇
石油天然气   5篇
无线电   10篇
一般工业技术   37篇
冶金工业   1227篇
原子能技术   1篇
自动化技术   21篇
  2023年   1篇
  2022年   2篇
  2021年   2篇
  2020年   1篇
  2019年   3篇
  2018年   4篇
  2017年   1篇
  2016年   1篇
  2014年   1篇
  2013年   9篇
  2012年   4篇
  2011年   2篇
  2010年   1篇
  2009年   8篇
  2008年   5篇
  2007年   1篇
  2006年   4篇
  2005年   5篇
  2004年   2篇
  2003年   3篇
  2002年   1篇
  2000年   1篇
  1999年   41篇
  1998年   372篇
  1997年   238篇
  1996年   140篇
  1995年   87篇
  1994年   56篇
  1993年   74篇
  1992年   10篇
  1991年   21篇
  1990年   16篇
  1989年   19篇
  1988年   13篇
  1987年   25篇
  1986年   21篇
  1985年   24篇
  1984年   2篇
  1983年   7篇
  1982年   4篇
  1981年   7篇
  1980年   10篇
  1979年   4篇
  1978年   6篇
  1977年   26篇
  1976年   47篇
  1975年   2篇
  1965年   1篇
  1955年   1篇
排序方式: 共有1336条查询结果,搜索用时 453 毫秒
71.
72.
73.
74.
This pilot study constitutes the first exploration of the impact of breast cancer on Asian American women. Three hypotheses guided this study: (1) Asian American women would choose breast conserving therapy and breast reconstruction at a lower rate than the Anglo American women due to cultural differences in body image, (2) Asian American women with breast cancer would express psychological distress somatically and Anglo American women would express distress emotionally, and acculturation levels of the Asian American women would modify the expressions of distress such that women with high acculturation will express distress more emotionally and less acculturated women would express distress more somatically, and (3) Asian American women would seek assistance for psychosocial problems at a significantly lower rate than Anglo women. Ethnicity, age, and levels of acculturation were found to be significant variables that had to be considered simultaneously. The three hypotheses were only partially supported: (1) Asian American women chose breast conserving therapy and adjuvant therapy at a significantly lower rate than the Anglo American women, (2) Contrary to the hypothesis, somatization did not appear to be a dominant form of symptom presentation for Asian American women regardless of level of acculturation, and (3) Asian American women sought professional assistance for psychosocial problems at a significantly lower rate than Anglo women. Asian American women reported using different modes of help-seeking behavior for emotional concerns and receiving different sources of social support than the Anglo American women. Cultural interpretations of the findings are offered to explain the differences in the physical, emotional, and social responses to the breast cancer experience of Asian American women compared with the Anglo Americans, and notably between the Chinese- and Japanese Americans as well. The findings of this study warrant more refined exploration in order to improve the medical, psychological and social outcomes for Asian American women with breast cancer.  相似文献   
75.
DK 《电声技术》2009,33(3):91-91
UK10-A系列适用于各种固定安装的高档演艺吧、慢摇吧及现场表演。该系列采用高功率扬声器单元和轻巧的箱体搭配,通过计算机优化设计,达到平滑的特性、展宽的频响特点和良好的控制覆盖性能。  相似文献   
76.
77.
78.
The glnA gene from the human pathogen Streptococcus agalactiae was cloned from a genomic library prepared with the lambda phage vector lambdaDASHII. A 4.6-kb DNA fragment of one of the recombinant phages was subcloned in pUC18. This Escherichia coli clone expressed a 52-kDa protein encoded by a 1,341-bp open reading frame. The nucleotide sequence of the open reading frame and the deduced amino acid sequence shared a significant degree of homology with the sequences of other glutamine synthetases (GS). The highest homology was between our deduced protein and GS of gram-positive bacteria such as Bacillus subtilis, Bacillus cereus, and Staphylococcus aureus. Plasmids with the cloned streptococcal glnA were able to complement E. coli glnA mutants grown on minimal media. Rabbit antisera to streptococcal GS recombinant protein recognized not only the recombinant protein but also a similar-sized band in mutanolysin extracts of all group B streptococcal strains tested, regardless of polysaccharide type or surface protein profile. The amino acid sequence of the deduced protein had similarities to other streptococcal cell-surface-bound proteins. The possible functional role of the immunological features of streptococcal GS is discussed.  相似文献   
79.
Expression of parathyroid hormone-related protein (PTHrP) messenger RNA (mRNA) and protein was investigated throughout the developmental progression of endochondral bone formation in mouse and intramembranous bone formation in an in vivo model in rabbit, using in situ hybridization and immunohistochemistry. Endochondral bone formation was investigated in a developing embryo, newborn, and adult mouse. In fetal long bones through to newborn (day 7), PTHrP mRNA and protein were consistently expressed in chondrocytes within the proliferative, transitional, and hypertrophic zones. In addition, high levels of PTHrP were also detected in osteoblasts on the surface of trabecular bone surfaces. Similarly, at the adult stage (week 7), PTHrP mRNA and protein were consistently expressed in chondrocytes at epiphyseal ends of the subarticular cartilage, within cortical periosteum, as well as in osteoblasts located at the metaphyseal trabecular bone surfaces. Using an in vivo intramembranous bone formation model in rabbits, expression of PTHrP mRNA and protein was demonstrated in preosteoblasts prior to trabecular bone formation (1-week bone harvest). As bone formed (2-, 3-, and 4-week bone tissue harvests), PTHrP mRNA and protein were highly expressed in actively synthesizing osteoblasts and in those osteocytes embedded within the superficial layers of the bone matrix. Lining osteoblasts and osteocytes buried deeply in the bone matrix displayed weak or no signal for PTHrP. The pattern of spatial and temporal expression of PTHrP demonstrated in cartilage cells and osteoblasts in the two systems suggests an important role of PTHrP in both endochondral and intramembranous bone formation.  相似文献   
80.
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