全文获取类型
收费全文 | 471篇 |
免费 | 23篇 |
专业分类
电工技术 | 11篇 |
化学工业 | 68篇 |
金属工艺 | 25篇 |
机械仪表 | 10篇 |
建筑科学 | 7篇 |
矿业工程 | 2篇 |
能源动力 | 6篇 |
轻工业 | 50篇 |
水利工程 | 1篇 |
无线电 | 36篇 |
一般工业技术 | 98篇 |
冶金工业 | 88篇 |
原子能技术 | 24篇 |
自动化技术 | 68篇 |
出版年
2021年 | 5篇 |
2020年 | 6篇 |
2019年 | 4篇 |
2018年 | 8篇 |
2017年 | 11篇 |
2016年 | 9篇 |
2015年 | 7篇 |
2014年 | 12篇 |
2013年 | 21篇 |
2012年 | 12篇 |
2011年 | 15篇 |
2010年 | 16篇 |
2009年 | 18篇 |
2008年 | 17篇 |
2007年 | 14篇 |
2006年 | 12篇 |
2005年 | 7篇 |
2004年 | 10篇 |
2003年 | 11篇 |
2002年 | 10篇 |
2001年 | 11篇 |
2000年 | 4篇 |
1999年 | 10篇 |
1998年 | 25篇 |
1997年 | 19篇 |
1996年 | 24篇 |
1995年 | 14篇 |
1994年 | 16篇 |
1993年 | 8篇 |
1992年 | 7篇 |
1991年 | 6篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 3篇 |
1987年 | 3篇 |
1986年 | 6篇 |
1985年 | 8篇 |
1984年 | 9篇 |
1980年 | 5篇 |
1977年 | 9篇 |
1976年 | 3篇 |
1975年 | 4篇 |
1972年 | 6篇 |
1971年 | 4篇 |
1967年 | 5篇 |
1966年 | 3篇 |
1955年 | 2篇 |
1941年 | 4篇 |
1940年 | 10篇 |
1939年 | 6篇 |
排序方式: 共有494条查询结果,搜索用时 15 毫秒
1.
This paper examines the relationship between self-efficacy and social power (expert and referent) and how the application of this relationship, leads to client adherence and compliance. Referent power is defined, including methods that health care professionals may use to develop and apply referent power. Expert power is defined and addressed in the context of referent power, self-esteem and self-efficacy as a means of promoting adherence. Self-efficacy as a concept is defined and explored in the context of social power. The relationships between self-efficacy and social power (expert and referent) are shown as important determinants of adherence and compliance. The theory of the application of referent and expert power in relationship with self-efficacy has been compared with an effective programme, yielding high compliance, at Western Psychiatric Institute and Clinic, showing the theory's relevance and applicability in determining compliance. Explored are the reasons for non-compliance in the elderly population and how the theory model can remedy these detriments for compliance. The empowerment of elderly patients through the application of this theory to medication compliance is examined. The determination of adherence and compliance is shown by the application of the relationship between self-efficacy and both expert and referent power. 相似文献
2.
The neuronal cytoskeleton is one of the most profoundly altered organelles in late life neuro-degenerative disorders that are characterized by progressive impairments in cognitive abilities. The elucidation of the protein building blocks of these organelles as well as advances in understanding how these proteins become altered in Alzheimer's disease (AD) and other less common dementing illnesses, i.e., diffuse Lewy body disease (DLBD) or the Lewy body variant of AD (LBVAD), will provide insights into the molecular basis of these disorders. Within, we review evidence that normal adult human tau is abnormally phosphorylated and converted into the subunits of AD paired helical filaments (PHFs), and that Lewy bodies (LBs) represent accumulation of altered neurofilament (NF) triplet subunits. Although the precise biological consequences of PHF and LB formation in neurons is unknown, growing evidence suggests that the formation of PHFs and LBs from normal neuronal cytoskeletal proteins could have deleterious effects on neuronal function and survival. Finally, insights into the composition of PHFs and LBs could lead to the development of novel strategies for the timely and accurate diagnosis of AD, DLBD and the LBVAD. 相似文献
3.
The structural properties and hydrogen bonding of undoped and phosphorous doped polycrystalline silicon produced by step-by-step laser dehydrogenation and crystallization technique were investigated using Raman spectroscopy and hydrogen effusion measurements. At low laser fluences, EL, a two-layer system is created. This is accompanied by the change in hydrogen bonding. The intensity of the Si–H vibration mode at 2000 decreases faster than the one at 2100 cm−1. This is even more pronounced in phosphorous-doped specimens. The laser crystallization results in an increase of the hydrogen binding energy by approximately 0.2–0.3 eV compared to the amorphous starting materials. 相似文献
4.
F. -U. Gast P. S. Dittrich P. Schwille M. Weigel M. Mertig J. Opitz U. Queitsch S. Diez B. Lincoln F. Wottawah S. Schinkinger J. Guck J. Käs J. Smolinski K. Salchert C. Werner C. Duschl M. S. Jäger K. Uhlig P. Geggier S. Howitz 《Microfluidics and nanofluidics》2006,2(1):21-36
We describe a novel microfluidic perfusion system for high-resolution microscopes. Its modular design allows pre-coating of
the coverslip surface with reagents, biomolecules, or cells. A poly(dimethylsiloxane) (PDMS) layer is cast in a special molding
station, using masters made by photolithography and dry etching of silicon or by photoresist patterning on glass or silicon.
This channel system can be reused while the coverslip is exchanged between experiments. As normal fluidic connectors are used,
the link to external, computer-programmable syringe pumps is standardized and various fluidic channel networks can be used
in the same setup. The system can house hydrogel microvalves and microelectrodes close to the imaging area to control the
influx of reaction partners. We present a range of applications, including single-molecule analysis by fluorescence correlation
spectroscopy (FCS), manipulation of single molecules for nanostructuring by hydrodynamic flow fields or the action of motor
proteins, generation of concentration gradients, trapping and stretching of live cells using optical fibers precisely mounted
in the PDMS layer, and the integration of microelectrodes for actuation and sensing. 相似文献
5.
S Kriwanek P Beckerhinn W Blauensteiner K Dittrich C Armbruster 《Canadian Metallurgical Quarterly》1995,380(2):70-74
BACKGROUND: Although gastric bypass is an effective treatment for morbid obesity, the postoperative results are unsatisfactory in 10% of all patients. Therapeutic failures after an operation performed with the sole purpose of reducing the risk of obesity-associated diseases have to be taken seriously. The goal of this study was to investigate the causes of these failures. METHOD: From 1979 to 1993, 165 gastric bypass operations (technique: Mason-Griffen) were performed. Long-term results were obtained in 60 patients after an average of 6.6 years (range 3-13). On follow-up all patients were examined and asked about their level of satisfaction with the weight loss achieved and changes in eating habits. RESULTS: In 6 patients the weight reduction was regarded as insufficient (BMI > 35 and reduction of BMI < 10). The causes of these failures were technical in 3 cases (gastric pouch to 0 large in 1, dilatation of gastrojejunostomy in 2). Three patients had a high calorie intake through an intact gastric bypass by snacking. Three patients regarded the operation as a failure although they had achieved significant weight loss, because they could no longer eat the usual amounts of food. CONCLUSION: Correct surgical technique and preoperative information on the changes in eating habits after a gastric bypass operation are the most important steps in preventing therapeutic failures. 相似文献
6.
Three-dimensional, turbulent fluid flow analysis with computational methods has emerged as a viable tool in the design process
of engine components for passenger cars. If applied in the early stages of the component development such analysis can help
reduce the product development time drastically, and may support the design engineer to evaluate several competing design
aspects before product completion. However the grid generation for complex geometries still poses a difficult and time consuming
taks which strongly influences the accuracy of the numerical solution. The present paper studies the numerical solution of
the flow in an inlet-manifold of a five-cylinder engine with two intake-ports for each cylinder. A fast and reliable grid
generation technique is discussed in detail. The finite volume based Navier-Stokes solver with schemes of first and second
order accuracy for the convective terms is used. Numerical results at several mass flow rates and different boundary conditions
at the intake ports are compared with measurements. Finally, the computational results are discussed with respect to their
applicability to support the design process of an inlet-manifold. 相似文献
7.
8.
In order to characterize the protein binding of a drug, it is necessary to have a method which is close to in vivo conditions and fast in the course of measurement. The continuous ultrafiltration fulfils both requirements for substances with a high extent of protein binding. In this study, 18 gyrase inhibitors in clinical practice, characterized by a lower extent of protein binding, were subjected to the titration procedure of the continuous ultrafiltration using bovine and human serum albumin (BSA, HSA), and human plasma. The results of the continuous ultrafiltration were found to be similar to those obtained by means of the 'classical' discontinuous ultrafiltration using plasma (correlation between continuous and discontinuous ultrafiltration r2 = 0.87). In the cases of pipemidic acid, enoxacin and rufloxacin, the continuous method gave approximately 20% lower degrees of protein binding than the discontinuous procedure, which utilizes plasma having the full range of proteins. It is likely that these drugs bind mainly to other proteins in plasma than HSA. This finding proves that this fast method is worthwhile in the whole range of protein binding. 相似文献
9.
10.
Serge Bilger Emmanuel Syskakis Aristides Naoumidis Hubertus Nickel 《Journal of the American Ceramic Society》1992,75(4):964-970
Strontium-doped lanthanum manganite powders were prepared using a peroxide acetate salt based solution. The stable sol was peptized by reacting ammonium hydroxide with the precursor solution. The amorphous dried gel powders exhibit a high energy level, due to their high cations coordination and small particles, to develop the perovskite phase. This crystalline phase development from powders containing monocarboxylate ligands was characterized by thermal analysis (TG, DTG, DTA), X-ray diffraction, and IR spectroscopy. The transformation from amorphous powders into a crystallized homogeneous oxycarbonate phase in a first stage corresponds to an exothermal DTA peak at 270°C. X-ray diffraction patterns and IR spectra showed similar behavior of the powders after complete organic removal, during the conversion into perovskite phase starting at approximately 630°C and achieved about 700°C and achieved about 700°C, as well as during the sintering process. 相似文献