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   1737篇
  免费   82篇
  国内免费   3篇
电工技术   11篇
综合类   1篇
化学工业   354篇
金属工艺   11篇
机械仪表   11篇
建筑科学   81篇
矿业工程   1篇
能源动力   25篇
轻工业   303篇
水利工程   18篇
石油天然气   4篇
无线电   77篇
一般工业技术   294篇
冶金工业   451篇
原子能技术   1篇
自动化技术   179篇
  2023年   24篇
  2022年   50篇
  2021年   70篇
  2020年   43篇
  2019年   45篇
  2018年   41篇
  2017年   45篇
  2016年   39篇
  2015年   54篇
  2014年   61篇
  2013年   77篇
  2012年   78篇
  2011年   120篇
  2010年   85篇
  2009年   85篇
  2008年   107篇
  2007年   115篇
  2006年   95篇
  2005年   86篇
  2004年   82篇
  2003年   62篇
  2002年   47篇
  2001年   22篇
  2000年   26篇
  1999年   24篇
  1998年   27篇
  1997年   23篇
  1996年   38篇
  1995年   20篇
  1994年   18篇
  1993年   18篇
  1992年   8篇
  1991年   7篇
  1990年   8篇
  1989年   6篇
  1988年   3篇
  1987年   10篇
  1986年   6篇
  1985年   7篇
  1984年   4篇
  1983年   6篇
  1982年   7篇
  1981年   5篇
  1980年   4篇
  1978年   3篇
  1977年   2篇
  1976年   3篇
  1975年   2篇
  1974年   1篇
  1973年   1篇
排序方式: 共有1822条查询结果,搜索用时 15 毫秒
41.
Emotional labor theory has conceptualized emotional display rules as shared norms governing the expression of emotions at work. Using a sample of registered nurses working in different units of a hospital system, we provided the first empirical evidence that display rules can be represented as shared, unit-level beliefs. Additionally, controlling for the influence of dispositional affectivity, individual-level display rule perceptions, and emotion regulation, we found that unit-level display rules are associated with individual-level job satisfaction. We also showed that unit-level display rules relate to burnout indirectly through individual-level display rule perceptions and emotion regulation strategies. Finally, unit-level display rules also interacted with individual-level dispositional affectivity to predict employee use of emotion regulation strategies. We discuss how future research on emotional labor and display rules, particularly in the health care setting, can build on these findings. (PsycINFO Database Record (c) 2011 APA, all rights reserved)  相似文献   
42.
Maternal obesity predisposes for hepato-metabolic disorders early in life. However, the underlying mechanisms causing early onset dysfunction of the liver and metabolism remain elusive. Since obesity is associated with subacute chronic inflammation and accelerated aging, we test the hypothesis whether maternal obesity induces aging processes in the developing liver and determines thereby hepatic growth. To this end, maternal obesity was induced with high-fat diet (HFD) in C57BL/6N mice and male offspring were studied at the end of the lactation [postnatal day 21 (P21)]. Maternal obesity induced an obese body composition with metabolic inflammation and a marked hepatic growth restriction in the male offspring at P21. Proteomic and molecular analyses revealed three interrelated mechanisms that might account for the impaired hepatic growth pattern, indicating prematurely induced aging processes: (1) Increased DNA damage response (γH2AX), (2) significant upregulation of hepatocellular senescence markers (Cdnk1a, Cdkn2a); and (3) inhibition of hepatic insulin/insulin-like growth factor (IGF)-1-AKT-p38-FoxO1 signaling with an insufficient proliferative growth response. In conclusion, our murine data demonstrate that perinatal obesity induces an obese body composition in male offspring with hepatic growth restriction through a possible premature hepatic aging that is indicated by a pathologic sequence of inflammation, DNA damage, senescence, and signs of a possibly insufficient regenerative capacity.  相似文献   
43.
Patients with advanced thyroid cancer harboring NTRK rearrangements can be treated with highly effective selective inhibitors. Immunohistochemistry (IHC) analysis, to detect Trk protein expression, represents an appealing screening strategy for NTRK rearrangements, but its efficacy has been poorly explored in thyroid cancer. The aim of this study is to investigate the diagnostic utility of Trk IHC in the identification of NTRK rearrangements. A series of 26 follicular-derived thyroid tumors, positive for NTRK rearrangements, and 28 NTRK fusion-negative controls were retrospectively analyzed by IHC using the pan-Trk monoclonal antibody (clone EPR17341) on the Ventana system. Area under the curve (AUC), sensitivity and specificity were calculated by ROC analysis. Trk expression was detected in 25 samples, including 22 out of the 26 NTRK-rearranged (84.6%) and three out of 28 NTRK-negative samples (10.7%). Four out of twenty-six NTRK-rearranged thyroid tumors were negative for Trk expression (15.4%), all carrying the ETV6/NTRK3 fusion. The AUC, sensitivity and specificity were 0.87, 0.85 and 0.89, respectively. A screening based on IHC analysis showed limited sensitivity and specificity in the identification of NTRK-rearranged tumors. Since falsely negative results could preclude the administration of effective targeted drugs, alternative detection strategies should be considered for thyroid cancer.  相似文献   
44.
It has been accepted for decades that T lymphocytes and metastasising tumour cells traverse basement membranes (BM) by deploying a battery of degradative enzymes, particularly proteases. However, since many redundant proteases can solubilise BM it has been difficult to prove that proteases aid cell migration, particularly in vivo. Recent studies also suggest that other mechanisms allow BM passage of cells. To resolve this issue we exploited heparanase-1 (HPSE-1), the only endoglycosidase in mammals that digests heparan sulfate (HS), a major constituent of BM. Initially we examined the effect of HPSE-1 deficiency on a well-characterised adoptive transfer model of T-cell-mediated inflammation. We found that total elimination of HPSE-1 from this system resulted in a drastic reduction in tissue injury and loss of target HS. Subsequent studies showed that the source of HPSE-1 in the transferred T cells was predominantly activated CD4+ T cells. Based on bone marrow chimeras, two cellular sources of HPSE-1 were identified in T cell recipients, one being haematopoiesis dependent and the other radiation resistant. Collectively our findings unequivocally demonstrate that an acute T-cell-initiated inflammatory response is HPSE-1 dependent and is reliant on HPSE-1 from at least three different cell types.  相似文献   
45.
46.
47.
We prove the consistency of the averaged periodogram estimator (APE) in two new cases. First, we prove that the APE is consistent for negative memory parameters, after suitable tapering. Second, we prove that the APE is consistent for a power law in the cross‐spectrum and therefore for a power law in the coherency, provided that sufficiently many frequencies are used in estimation. Simulation evidence suggests that the lower bound on the number of frequencies is a necessary condition for consistency. For a Taylor series approximation to the estimator of the power law in the cross‐spectrum, we consider the rate of convergence and obtain a central limit theorem under suitable regularity conditions.  相似文献   
48.
Monetite is a promising biomaterial for restoring the function of the compromised skeletal structures due to its superior osteoconductive and resorption properties. However, its potential as a coating for orthopaedic implants in load bearing applications has not yet been investigated. The aim of this study was to prepare monetite coating on Ti substrate in mild conditions, which may allow incorporation of protein-based drugs during the coating deposition. Coatings were prepared using chemical deposition of monetite on Ti substrate in acidic conditions at 75 °C for 24 h. Coatings were characterised by scanning electron microscope (SEM), energy-dispersive X-ray spectroscopy (EDS), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR). Adhesion of the coatings to Ti substrate was measured using tensile tests. EDS confirmed the calcium phosphate nature of the coating and XRD and FTIR confirmed the monetite phase of the coatings. SEM revealed that the coatings were formed of densely packed plate-like monetite crystals, with the crystal size approximately 20 × 10 × 5 μm. Adhesion tests showed cohesive failure of the monetite coatings and the tensile strength of the coating was in the range of 15.43 ± 0.20 MPa. Mechanical tests showed that monetite coatings were stable and could be considered for use with Ti orthopaedic implants.  相似文献   
49.
50.
Rebecca Shawcross 《Costume》2013,47(1):130-132
Abstract

This paper examines the influence that the costume designers of the Ballets Russes, many of whom were important artists from significant art movements of the day, had on contemporaneous fashion. It looks at why in particular the 'Ballets Russes' artists Leon Bakst and Natalia Goncharova went on to involve themselves in actual fashion production and the similarities between their work and the fashion designers producing work at the same time, principally Paul Poiret, Mariano Fortuny and Coco Chanel. Overall, this paper investigates the significance of the cultural times and of the distinct characteristics of the separate art forms, that may have encouraged avant-garde art and fashion to crossover and collaborate so unreservedly.  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