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   940篇
  免费   1篇
化学工业   4篇
金属工艺   1篇
轻工业   1篇
石油天然气   1篇
一般工业技术   5篇
冶金工业   929篇
  2016年   1篇
  2015年   1篇
  2007年   1篇
  2005年   2篇
  2004年   1篇
  2003年   1篇
  2000年   1篇
  1999年   22篇
  1998年   282篇
  1997年   121篇
  1996年   126篇
  1995年   68篇
  1994年   55篇
  1993年   43篇
  1992年   6篇
  1991年   22篇
  1990年   10篇
  1989年   21篇
  1988年   11篇
  1987年   14篇
  1986年   13篇
  1985年   17篇
  1982年   6篇
  1981年   5篇
  1980年   7篇
  1978年   5篇
  1977年   24篇
  1976年   52篇
  1975年   2篇
  1958年   1篇
排序方式: 共有941条查询结果,搜索用时 10 毫秒
861.
Community support programs are increasingly establishing paid service positions designated exclusively for consumers. Project WINS (Work Incentives and Needs Study), a hybrid case management-vocational program for individuals with severe mental illness, used consumers as peer support specialists (PSSs) to supplement professional roles. Semistructured interviews were conducted with PSSs about 12 months after their employment ended. They identified substantial personal benefits specific to consumer-designated roles (e.g., a "safe" employment setting with accommodations) and general benefits from employment. Problems described were just as numerous, encompassing attitudes toward assigned peers and costs to their own well-being. Critical commentary addressed program operations (structure, supervision, and training needs) and problems in the mental health system. The authors discuss the changed sense of self that service provider roles can create for consumers and suggest that mental health administrators provide anticipatory socialization for this service innovation throughout their agencies and ongoing supports for consumers in their new roles.  相似文献   
862.
INTRODUCTION: Previous studies have demonstrated a high prevalence of "white coat" hypertension (20%), but it is still controversial if it implies an increase in cardiovascular risk. PATIENTS: Between 1992 and 95 we prospectively studied 175 untreated hypertensive patients aged over 18 years (V Joint National Committee's stage I-II), and 91 controls. DESIGN AND METHODS: The subjects were submitted to clinical evaluation, ambulatory blood pressure monitoring, 24-hour Holter monitoring, signal-averaged ECG, echocardiography/Doppler and ergometry. "White coat" hypertension was defined as mean daytime (6.00-22.00 H) ambulatory blood pressure < 136/87 mm Hg (males) and < 131/86 mm Hg (females). RESULTS: "White coat" hypertension was present in 29 patients (18%). "White coat" hypertension patients had an identical prevalence of smoking, family history of cardiovascular disease, abnormal ECG and retinopathy (> Keith-Wagener II) as patients with daytime hypertension. Ambulatory blood pressure values (24 hour, 6.00-22.00 h, 22.00-6.00 h, sleep, blood pressure load, heart rate) were all significantly different from controls (p < 0.03 to 0.0007). In patients with daytime hypertension, only 24 hour and daytime diastolic ambulatory blood pressure (p < 0.005) were different from "white coat" hypertension patients. Exercise testing blood pressure values (6 min exercise, maximal, 3 min recovery) were significantly different between "white coat" hypertension patients and the control group (n = 70) (p varying from 0.05 to 0.005) but not between "white coat" hypertension and daytime hypertension (n = 33) patients. Diastolic function was studied only in 39 daytime hypertension patients, 10 individuals with "white coat" hypertension and 34 controls (for technical reasons and because we only analyzed individuals younger than 55 years). E velocity and E/A ratio were similar in "white coat" hypertension and daytime hypertension, but only in daytime hypertension patients they reached a significant difference from controls (p = 0.04; p = 0.01), probably due to the small number of patients. CONCLUSIONS: These data (clinical, ambulatory blood pressure, ergometric, diastolic function) suggest that "white coat" hypertension might not be a benign entity.  相似文献   
863.
Today a "just" health policy is balanced between the problem of the allocation of scarce resources and the priority setting of services, care and cures. Despite technologies and molecular medicine, with their tendency to reach absolute prediction of disease or absence of disease and to cure with predicted efficacy, a large portion of the public refuse the results of experimental procedures and prefer to place trust in so-called alternative medicine or in drugs which are not in the official guide-lines following the principles of evidence-based medicine according to DL Sackett. Juridical problems arise between the rights of free choice of cure and social dimension of Governmental care programs, which include the maximum of benefits (i.e. effective therapies) for a pre-fixed total budget. An explicit rationing only on budgetary bases without rationalisation of medical procedures reduces the rights to care of citizens-patients. Thus, an explicit rationing-rationalisation seems to be the only procedure compatible with the interest of patients in a social security system allocating "scarce" resources.  相似文献   
864.
OBJECTIVE: This study examined the reliability of the three-cluster model for chronic low back pain patients found using the Integrated Psychosocial Assessment Model (IPAM). A replication study using a sample of patients from a different country was completed. PATIENTS: Seventy patients (average age = 47.05 years, SD = 16.11) with chronic low back pain of noncancer origin participated in the study. Sixty-two of these patients were attending The Auckland New Zealand Regional Pain Service, while a further eight were attending a private practice pain service in Auckland. OUTCOME MEASURES: Subjects were assessed on the IPAM, which measures pain intensity, disability, coping strategies, attitudes towards and beliefs about pain, depression and illness behaviour, the Medical Examination and Diagnostic Information Coding System, and the Multidimensional Pain Inventory. RESULTS: Cluster analyses using the kappa-means algorithm were performed on the IPAM data. The three-cluster solution was preferred according to both the Variance Ratio Criterion and cluster interpretability. Two of the three clusters correlated highly with clusters retrieved in the original study (r = 0.78, r = 0.71), while the third cluster showed partial resemblance (correlation of r = 0.31). Clusters were named "In Control," "Depressed and Disabled," and "High Deniers and Somatizisers." No differences were found on the physical pathology scores between clusters. Decision rules for cluster assignation resulted in 68% of the sample being correctly assigned. CONCLUSIONS: Support for this cluster model from two countries suggests its value in providing a multidimensional picture of patients with chronic low back pain. The possibility of using such cluster groups for determining treatment type is discussed.  相似文献   
865.
郑景翔  常学军 《石油仪器》2000,14(3):32-36,39
文件管理器是SN388应用程序中的一个子菜单。它提供了一些直观处理文件的方法。在SN388操作与维护中经常应用到,特别是在补钉软件的安装过程中。文章简单的介绍了常规的窗口使用方法,重点介绍了文件查看、编辑、查找、修改等方法,最后列举了一个利用文件管理器排除一个实际故障的方法。  相似文献   
866.
867.
868.
869.
870.
The straight portion (S3) of the proximal tubule lies in close proximity to the thick ascending limbs (TALs) at the cortico-medullary junction. Since a delicate balance exists between oxygen demand and the limited oxygen supply in this region, we hypothesized that reduction of thick limb metabolic activity might augment oxygen availability to S3 segments, which depend heavily upon aerobic metabolism, and prevent hypoxic damage. The degree of functional deterioration and morphological damage to S3 was assessed in isolated rat kidneys perfused with an erythrocyte-free medium. Bumetanide (10(-5) M) and furosemide (10(-4) M) reduced S3 fragmentation from 9.8 +/- 3.9% of tubules in controls to 0 and 1.4 +/- 0.9%, respectively (P < 0.0005). Tubular glucose reabsorption was better preserved in kidneys exposed to loop diuretics than in control kidneys (P < 0.01), and urinary alkaline phosphatase (P < 0.05) and the total amount of LDH released into the perfusate and urine (P < 0.01) were lower in the treatment groups. Morphological damage to S3 was closely correlated with medullary TAL necrosis (r = 0.66, P < 0.001), urinary alkaline phosphatase excretion (r = 0.89, P < 0.001) and glycosuria (r = 0.83, P < 0.001). We conclude that under hypoxic conditions TALs and S3 segments may compete with each other for a limited oxygen supply. Reduction of active transport in the mTAL might augment oxygen availability to S3 segments and improve their survival.  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