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   77篇
  免费   0篇
电工技术   2篇
化学工业   2篇
建筑科学   31篇
能源动力   1篇
轻工业   7篇
水利工程   3篇
无线电   2篇
一般工业技术   4篇
冶金工业   24篇
自动化技术   1篇
  2022年   1篇
  2021年   2篇
  2016年   1篇
  2015年   2篇
  2014年   1篇
  2013年   1篇
  2012年   2篇
  2011年   2篇
  2010年   4篇
  2009年   3篇
  2008年   1篇
  2007年   2篇
  2006年   3篇
  2004年   2篇
  2003年   1篇
  2002年   1篇
  2000年   3篇
  1999年   4篇
  1998年   15篇
  1997年   8篇
  1996年   5篇
  1995年   4篇
  1994年   1篇
  1993年   4篇
  1984年   1篇
  1978年   1篇
  1977年   1篇
  1972年   1篇
排序方式: 共有77条查询结果,搜索用时 15 毫秒
1.
2.
Measurements of carotid artery wall thickness are often used as a surrogate for atherosclerosis. However, few studies have performed these measurements in populations of Mexican origin. Since Mexicans in Mexico City consume high-carbohydrate diets and have carbohydrate-induced dyslipidemia (high triglyceride and low HDL cholesterol levels) compared with Mexican Americans living in San Antonio, Tex, we questioned whether they also had more atherosclerosis than San Antonio Mexican Americans. Mean maximum intimal-medial thickness (IMT) of the common (CCA) and internal (ICA) carotid arteries were measured in 867 subjects aged 35 to 64 years (40% men) in two Mexican-origin populations, one from San Antonio (n = 202) and the other from Mexico City (n = 665). IMT's in the two cities were compared, and their associations with cardiovascular risk factors were analyzed. Older age, male sex, high levels of total cholesterol, low levels of HDL cholesterol, and high systolic blood pressure were positively associated with both CCA IMT and ICA IMT. Cigarette smoking was significantly associated with ICA IMT. CCA and ICA IMTs in diabetic subjects were thicker than in nondiabetic subjects in both men and women (all P < = .05). CCA IMT was thicker in the San Antonio than the Mexico City subjects after adjustment for cardiovascular risk factors (0.81 versus 0.76 mm in men and 0.77 versus 0.71 mm in women; P < .001 for city difference). San Antonio men also had thicker ICA IMT than their counterparts in Mexico City (0.88 versus 0.83 mm), but the reverse was true for women (0.73 versus 0.77 mm; interaction between sex and city, P < .05). Our results indicate that men had higher carotid IMTs than women. CCA IMT was thicker in San Antonio Mexican Americans than in Mexico City residents. The differences in ICA IMTs between San Antonio and Mexico City were inconsistent. Thus, since Mexico City residents consume high-carbohydrate diets, the data do not support an atherogenic effect of such diets. The interaction between sex and city on ICA IMT deserves further study.  相似文献   
3.
We report polarization-dependent angle-resolved photoemission studies of single crystalline Ba2Cu3O4Cl2. This antiferromagnet adopts a layered body-centered tetragonal structure related to that of the cuprates, but with anextra copper site resulting in a plane with Cu3O4 stoichiometry. For the -M direction of the Brillouin zone we observe a dispersive feature with a bandwidth of 400 ±80 meV, which approaches to within 0.9 eV of the Fermi level at (/2,/2). The magnitude of the observed dispersion and its polarization dependence are consistent with its origin as a purely antibonding combination of O2px,y and atomic orbitals from the cuprate-like CuO2 sub-system, i.e. Zhang-Rice singlets.  相似文献   
4.
5.
In an era of population ageing, the primary home is increasingly viewed as a personal resource that can perform a pension role in retirement. This article assesses the extent to which Australians aged 45 years and over withdraw housing equity through in situ mortgage equity withdrawal (MEW), downsizing and selling up. We find that the incidence of housing equity withdrawal has increased over the last decade despite a global financial crisis. MEW is the dominant form of equity release among those under pension age, while downsizing or selling up is more frequent among those above pension age. Downsizing and selling up are more likely to be prompted by adverse life events than MEW. Selling up is typically an option of last resort. Our findings offer insights into important debates around homeownership societies and the welfare role performed by owner-occupied housing in mid-to-late life.  相似文献   
6.
7.
8.
9.
In this paper the impact of taxation and arrangements for owner occupiers on household finance expenses are compared. The countries included are the Netherlands, Belgium, Denmark, France, the UK and (West) Germany. To achieve this comparison, taxation, subsidies and prevalent financing possibilities for owner occupiers are discussed. The comparison is made on a micro‐level: four representative fictitious owner occupiers in each country are taken into account. Conclusions are concerned firstly with a comparison among countries on the extent to which government intervention influences mortgage expenditure. Secondly, differences in effects of instruments on different income groups are described.  相似文献   
10.
OBJECTIVE: To assess whether people with impaired glucose tolerance (IGT) exhibit an increased risk of atherosclerosis as measured by the thickness of the carotid artery. RESEARCH DESIGN AND METHODS: We examined the relationship between glucose tolerance status and subclinical atherosclerosis in the Insulin Resistance Atherosclerosis Study (IRAS). The IRAS is an epidemiological study of 1,625 Hispanic, African-American, and white men and women, with approximately equal numbers of subjects with normal glucose tolerance (NGT), IGT, and type 2 diabetes as assessed by an oral glucose tolerance test. Half of those with diabetes were previously unaware of their condition and were defined as having new diabetes. Persons using insulin were excluded. The intima-media thickness (IMT) of the common carotid artery (CCA) and internal carotid artery (ICA) was measured as an index of subclinical atherosclerosis using B-mode ultrasonography. RESULTS: Adjusted for demographics and smoking, CCA-IMT increased most notably at the level of established diabetes (802, 822, 831, and 896 microm for NGT, IGT, new diabetes, and established diabetes, respectively). Adjustment for coronary heart disease (CHD) risk factors, which tended to worsen across glucose tolerance category, further minimized the slightly graded relationship. The relationship with the ICA-IMT was steeper and again suggested that the increased wall thickness is associated with diabetes, not with IGT. The relationship between glucose tolerance category and IMT was similar in men and women. CONCLUSIONS: We observed considerably greater IMT among persons with established diabetes but no significant increase in persons with IGT. These data suggest that the increased risk of CHD observed in persons with diabetes may largely develop after the onset of overt diabetes.  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