全文获取类型
收费全文 | 600篇 |
免费 | 12篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 47篇 |
金属工艺 | 4篇 |
机械仪表 | 21篇 |
建筑科学 | 13篇 |
矿业工程 | 2篇 |
能源动力 | 12篇 |
轻工业 | 187篇 |
水利工程 | 8篇 |
石油天然气 | 1篇 |
无线电 | 23篇 |
一般工业技术 | 49篇 |
冶金工业 | 179篇 |
原子能技术 | 8篇 |
自动化技术 | 57篇 |
出版年
2024年 | 2篇 |
2023年 | 2篇 |
2022年 | 3篇 |
2021年 | 9篇 |
2019年 | 11篇 |
2018年 | 13篇 |
2017年 | 12篇 |
2016年 | 6篇 |
2015年 | 9篇 |
2014年 | 12篇 |
2013年 | 29篇 |
2012年 | 22篇 |
2011年 | 22篇 |
2010年 | 14篇 |
2009年 | 18篇 |
2008年 | 21篇 |
2007年 | 31篇 |
2006年 | 13篇 |
2005年 | 22篇 |
2004年 | 16篇 |
2003年 | 21篇 |
2002年 | 13篇 |
2001年 | 10篇 |
2000年 | 12篇 |
1999年 | 11篇 |
1998年 | 38篇 |
1997年 | 23篇 |
1996年 | 39篇 |
1995年 | 14篇 |
1994年 | 16篇 |
1993年 | 16篇 |
1992年 | 14篇 |
1991年 | 8篇 |
1990年 | 11篇 |
1989年 | 6篇 |
1988年 | 6篇 |
1987年 | 3篇 |
1986年 | 10篇 |
1985年 | 7篇 |
1984年 | 4篇 |
1983年 | 5篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1979年 | 2篇 |
1978年 | 3篇 |
1977年 | 7篇 |
1976年 | 6篇 |
1975年 | 2篇 |
1972年 | 4篇 |
1956年 | 1篇 |
排序方式: 共有612条查询结果,搜索用时 15 毫秒
51.
Heparin (HE) exhibited a protective effect on liposome peroxidation induced by Fe2+ and Cu2+, decreasing the formation of both conjugated dienes and thiobarbituric acid reactive substances (TBARS) in a dose-dependent manner. The antioxidant activity was more relevant in the oxidizing system employing Fe2+ and H2O2 and generating the highly reactive OH radical. The analysis of liposome size distribution by quasielastic laser light scattering showed that: (1) the native structure of the particles was completely lost after exposure to Fenton reagent; (2) the presence of HE in the reaction mixture completely prevented the peroxidative damage on liposomes. Thus, HE acts as an antioxidant factor on membrane lipid bilayer. This suggests that HE, released from mast-cell granules during inflammatory processes, might locally protect the cell membrane from the oxidative injuries. 相似文献
52.
Ruiz Mark A.; Drake Evan B.; Glass Aviva; Marcotte David; van Gorp Wilfred G. 《Canadian Metallurgical Quarterly》2002,33(3):294
Although the Internet may be beneficial to clinical practice, its potential for misuse cannot be overlooked. The current probe identified Internet Web sites that contained information that violated the test security of psychological assessment instruments. Five individuals, using multiple search engines, conducted Internet searches to evaluate samples of Web sites. Sites were classified into 1 of 3 levels according to the degree of threat they posed to test security. A small number (2-5%) appeared to be a direct threat to test security. The findings are discussed and recommendations for promoting more ethical use of the Internet are made. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
53.
Granda M. Drake J.M. Gregorio J.A. 《IEEE transactions on pattern analysis and machine intelligence》1992,18(1):55-71
Methods of calculating efficiently the performance measures of parallel systems by using unbounded generalized stochastic Petri nets are presented. An explosion in the number of states to be analyzed occurs when unbounded places appear in the model. The state space of such nets is infinite, but it is possible to take advantage of the natural symmetries of the system to aggregate the states of the net and construct a finite graph of lumped states which can easily be analyzed. With the methods developed, the unbounded places introduce a complexity similar to that of safe places of the net. These methods can be used to evaluate models of open parallel systems in which unbounded places appear; systems which are k -bounded but are complex and have large values of k can also be evaluated in an appropriate way. From the steady-state solution of the model, it is possible to obtain automatically the performance measures of parallel systems represented by this type of net 相似文献
54.
AM O''Connor ER Drake VJ Fiset J Page D Curtin HA Llewellyn-Thomas 《Canadian Metallurgical Quarterly》1997,29(3):113-120
As the size of the older population grows and mortality rates continue to decline, an unprecedented number of women will live to very old age. Recent research has provided a better understanding of the impact of disability in the older population, risk factors for disability, and the consequences of disability. Older women have consistently been found to have higher prevalence rates of disability than men of the same age. This difference does not result from women developing disability more often than men, but rather surviving longer with their disabilities. This effect may be explained at least in part by the differences in the diseases underlying disability in older women and men. Interventions that can reduce the burden of disability in the aging population are now being explored. In the next century, it will be increasingly important to develop new prevention and treatment strategies that address the functional consequences of chronic disease in the population of women living to older and older ages. 相似文献
55.
56.
Design of a Beverage from Whey Permeate 总被引:1,自引:0,他引:1
57.
58.
Ryan G. McClarren D. RyuR. Paul Drake Michael GrosskopfDerek Bingham Chuan-Chih ChouBruce Fryxell Bart van der HolstJames Paul Holloway Carolyn C. KuranzBani Mallick Erica RutterBen R. Torralva 《Reliability Engineering & System Safety》2011,96(9):1194-1207
This work discusses the uncertainty quantification aspect of quantification of margin and uncertainty (QMU) in the context of two linked computer codes. Specifically, we present a physics based reduction technique to deal with functional data from the first code and then develop an emulator for this reduced data. Our particular application deals with conditions created by laser deposition in a radiating shock experiment modeled using the Lagrangian, radiation-hydrodynamics code Hyades. Our goal is to construct an emulator and perform a sensitivity analysis of the functional output from Hyades to be used as an initial condition for a three-dimensional code that will compute the evolution of the radiating shock at later times. Initial attempts at purely statistical data reduction techniques, were not successful at reducing the number of parameters required to describe the Hyades output. We decided on an alternate approach using physical arguments to decide what features/locations of the output were relevant (e.g., the location of the shock front or the location of the maximum pressure) and then used a piecewise linear fit between these locations. This reduced the number of outputs needed from the emulator to 40, down from the O(1000) points in the Hyades output. Then, using Bayesian MARS and Gaussian process regression, we were able to build emulators for Hyades and study sensitivities to input parameters. 相似文献
59.
Eight cases of hydatid disease of the abdomen and thorax were diagnosed by fine-needle aspiration (FNA) cytology under ultrasound guidance. The age of the patients ranged from 28 to 60 yr with a median of 34.5 yr; the male to female ratio was 2:6. None of the cases were diagnosed clinically as hydatid diseases but following ultrasonography suspicion of hydatid cyst was raised in two cases. The locations of cysts were the liver in six cases, the lung in one case, and the mediastinum in one case. FNA yielded clear fluid in five cases and turbid fluid in three cases. Laminated cyst wall, scolices, and hooklets were observed in one case, scolices and hooklets were present in two cases, and laminated cyst wall along with hooklets were seen in two cases. The remaining three cases showed only laminated cyst walls which yielded positive reaction with periodic acid-Schiff reaction. Inflammatory cell reaction in the form of neutrophils was observed in four cases, including the three cases where turbid fluid was aspirated. Epithelioid cell reaction was present in one case. None of our eight cases showed any untoward allergic reaction following FNA. 相似文献
60.
We describe different models of community care for persons with severe mental illness and review the research literature on case management, including the results of 75 studies. Most research has been conducted on the assertive community treatment (ACT) or intensive case management (ICM) models. Controlled research on ACT and ICM indicates that these models reduce time in the hospital and improve housing stability, especially among patients who are high service users. ACT and ICM appear to have moderate effects on improving symptomatology and quality of life. Most studies suggest little effect of ACT and ICM on social functioning, arrests and time spent in jail, or vocational functioning. Studies on reducing or withdrawing ACT or ICM services suggest some deterioration in gains. Research on other models of community care is inconclusive. We discuss the implications of the findings in terms of the need for specialization of ACT or ICM teams to address social and vocational functioning and substance abuse. We suggest directions for future research on models of community care, including evaluating implementation fidelity, exploring patient predictors of improvement, and evaluating the role of the helping alliance in mediating outcome. 相似文献