全文获取类型
收费全文 | 240篇 |
免费 | 3篇 |
专业分类
化学工业 | 21篇 |
机械仪表 | 5篇 |
建筑科学 | 7篇 |
能源动力 | 3篇 |
轻工业 | 8篇 |
石油天然气 | 1篇 |
无线电 | 16篇 |
一般工业技术 | 32篇 |
冶金工业 | 121篇 |
原子能技术 | 3篇 |
自动化技术 | 26篇 |
出版年
2021年 | 2篇 |
2020年 | 1篇 |
2019年 | 1篇 |
2018年 | 1篇 |
2017年 | 1篇 |
2016年 | 1篇 |
2015年 | 1篇 |
2014年 | 1篇 |
2013年 | 5篇 |
2012年 | 6篇 |
2011年 | 13篇 |
2010年 | 4篇 |
2009年 | 4篇 |
2008年 | 13篇 |
2007年 | 9篇 |
2006年 | 9篇 |
2005年 | 9篇 |
2004年 | 8篇 |
2003年 | 11篇 |
2002年 | 2篇 |
2001年 | 3篇 |
2000年 | 4篇 |
1999年 | 1篇 |
1998年 | 21篇 |
1997年 | 8篇 |
1996年 | 9篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 11篇 |
1992年 | 2篇 |
1991年 | 5篇 |
1990年 | 8篇 |
1989年 | 9篇 |
1988年 | 3篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 2篇 |
1984年 | 3篇 |
1983年 | 2篇 |
1982年 | 1篇 |
1981年 | 5篇 |
1980年 | 2篇 |
1979年 | 4篇 |
1978年 | 2篇 |
1977年 | 6篇 |
1976年 | 5篇 |
1975年 | 2篇 |
1974年 | 1篇 |
1969年 | 1篇 |
1948年 | 1篇 |
排序方式: 共有243条查询结果,搜索用时 15 毫秒
1.
2.
A finite-difference numerical method of solution for the unsteady, incompressible Navier-Stokes equations using primitive variables is presented. The rate form of the equation of state is used for the calculation of pressure. This form of the equation of state is well-suited for use with the unsteady form of the conservation equations (mass, momentum and energy). An implicit algorithm is used for the time integration for greater numerical stability. This method is used to solve a known benchmark problem in steady-state natural convection as a test of steady-state accuracy. The results of the simulation are compared to the benchmark. 相似文献
3.
M. L. Trawick S. M. Ammirata C. D. Keener S. E. Hebboul J. C. Garland 《Journal of Low Temperature Physics》1996,105(5-6):1267-1272
The flux transformer geometry has been useful for studying vortex coupling in Bi2Sr2CaCu2O8+y crystals but is limited by the difficulty of controlling sample size. We have used an argon ion mill to etch two channels into the top face of a Bi2Sr2CaCu2O8+y crystal to reproduce the effects of the flux transformer geometry with more precise control over effective sample dimensions. The temperature dependence of the transformer voltage in such a crystal shows a pronounced peak between 87 K and 89 K which is linear with current. Application of a magnetic field (H c-axis) sharply suppresses the peak, broadens it, and shifts it to lower temperatures. The peak in the transformer voltage and its current and field dependence are consistent with interlayer Josephson coupling of thermally excited vortices. 相似文献
4.
5.
Lau Anna S.; McCabe Kristen M.; Yeh May; Garland Ann F.; Wood Patricia A.; Hough Richard L. 《Canadian Metallurgical Quarterly》2005,19(3):367
The authors tested the acculturation gap-distress hypothesis by examining whether parent-adolescent acculturation gaps were associated with greater conflict and youth conduct problems among 260 high-risk Mexican American families. The authors operationalized acculturation gaps in 2 ways: parent-youth mismatches in acculturation style, and parent-youth discrepancies in acculturation toward both mainstream and heritage cultures. Acculturation gaps were common, but results of hierarchical regression analyses indicated that parent-youth discrepancies in acculturation toward mainstream and heritage cultures were not related to increased conflict or youth conduct problems. Conduct problems were no higher in families in which the adolescent was more aligned with mainstream culture than the parent. Unexpectedly, the authors found more youth conduct problems in families in which the youth was more aligned with traditional culture than the parent. The results call into question the assumption that the more rapid acculturation of adolescents to American culture inevitably leads to distress in minority families. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
6.
Pouya Javadian Chao Xu Virginie Sjoelund Lindsay E. Borden Justin Garland Doris Mangiaracina Benbrook 《International journal of molecular sciences》2022,23(14)
Racial disparities in incidence and survival exist for many human cancers. Racial disparities are undoubtedly multifactorial and due in part to differences in socioeconomic factors, access to care, and comorbidities. Within the U.S., fundamental causes of health inequalities, including socio-economic factors, insurance status, access to healthcare and screening and treatment biases, are issues that contribute to cancer disparities. Yet even these epidemiologic differences do not fully account for survival disparities, as for nearly every stage, grade and histologic subtype, survival among Black women is significantly lower than their White counterparts. To address this, we sought to investigate the proteomic profiling molecular features of endometrial cancer in order to detect modifiable and targetable elements of endometrial cancer in different racial groups, which could be essential for treatment planning. The majority of proteins identified to be significantly altered among the racial groups and that can be regulated by existing drugs or investigational agents are enzymes that regulate metabolism and protein synthesis. These drugs have the potential to improve the worse outcomes of endometrial cancer patients based on race. 相似文献
7.
An amphoteric (cocamidopropylbetaine, CAPB) and a nonionic (alcohol polyethoxylate, AE) surfactant were characterized by electrospray ionization quadrupole ion trap mass spectrometry (ESI-MS) as to their homologue distribution and ionization/fragmentation chemistry. Quantitative methods involving reversed-phase gradient HPLC and (+)ESI-MSn were developed to directly determine these surfactants in hydroponic plant growth medium that received simulated graywater. The predominant homologues, 12 C alkyl CAPB and 9 EO AE, were monitored to represent the total amount of the respective surfactants. The methods demonstrated dynamic linear ranges of 0.5-250 ng (r2 > 0.996) for CAPB and 8-560 ng (r2 > 0.998) for AE homologue mixture, corresponding to minimum quantification limits of 25 ppb CAPB and 0.4 ppm AE with 20-microL injections. This translated into an even lower limit for individual components due to the polydispersive nature of the surfactants. The procedure was successfully employed for the assessment of CAPB and AE biodegradation in a hydroponic plant growth system used as a graywater bioreactor. 相似文献
8.
For a more accurate safety analysis for the McMaster nuclear reactor (MNR), local velocity measurements in a mock-up of the 18-plate fuel assembly were conducted in the low Reynolds number region with emphasis on edge effects. With modification of the curved plates in the assembly to flat ones, velocity in the narrow channels was measured by laser Doppler velocimetry (LDV). The velocity profile in individual channels and the channel-to-channel flow distribution were obtained. The effect of the sudden transition from the larger rectangular channel to the circular pipe on the velocity profile and the effect of the handle presence in the top end fitting on the flow distribution were investigated. The pressure drop along the assembly was measured and compared to a simple 1D correlation prediction. 相似文献
9.
Richard Garland 《建筑细部》2006,4(4):536-537
实施像这样的低成本预算并不是一件容易的事。另外一个复杂的因素是本地因工业的发展而被严重污染,并且在开发过程中,发现未爆炸的炮弹含有砷。此外,土地里含有大量泥煤而导致承重力较差。因此,建筑建在水泥柱和地梁上。一层楼板建在预制的混凝土块上。墙和地板是平行木框架结构,与楼梯、窗和门一样都是预制件。主要的技术问题来自南立面:大而重的玻璃如何与框架结构相协调。角窗和楼梯的开窗也存在同样的技术问题。 相似文献
10.
Collins Karen W.; Dansereau Donald F.; Garland John C.; Holley Charles D.; McDonald Barbara A. 《Canadian Metallurgical Quarterly》1981,73(1):122
Evaluated 3 strategies for controlling concentration during academic tasks. 82 undergraduates served as Ss. One strategy, self-initiated relaxation (SIR), required Ss to employ a combination of relaxation techniques to set and maintain constructive study and test-taking states. The 2nd strategy, self-coaching (SC), was an extension of the positive self-talk techniques developed by D. Meichenbaum (1972). Ss were taught to coach (talk) themselves into constructive states and to maintain these states during studying and test taking. Finally, a 3rd strategy that combined SIR and SC was created. Results indicate that the 3rd strategy, SIR plus SC, significantly facilitated some aspects of academic performance in comparison to a no-treatment control group. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献