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   156篇
  免费   2篇
电工技术   1篇
化学工业   33篇
金属工艺   2篇
机械仪表   15篇
建筑科学   1篇
能源动力   1篇
轻工业   7篇
石油天然气   1篇
无线电   11篇
一般工业技术   27篇
冶金工业   32篇
原子能技术   1篇
自动化技术   26篇
  2023年   3篇
  2021年   3篇
  2020年   4篇
  2019年   5篇
  2018年   2篇
  2017年   3篇
  2016年   4篇
  2015年   1篇
  2014年   2篇
  2013年   8篇
  2012年   1篇
  2011年   2篇
  2010年   2篇
  2009年   5篇
  2008年   4篇
  2007年   1篇
  2006年   5篇
  2005年   4篇
  2004年   2篇
  2003年   3篇
  2002年   3篇
  2001年   2篇
  2000年   1篇
  1999年   2篇
  1998年   12篇
  1997年   7篇
  1996年   6篇
  1995年   6篇
  1994年   1篇
  1993年   4篇
  1992年   2篇
  1991年   3篇
  1990年   4篇
  1989年   2篇
  1988年   1篇
  1987年   1篇
  1986年   1篇
  1985年   7篇
  1984年   5篇
  1983年   2篇
  1982年   2篇
  1981年   2篇
  1979年   3篇
  1978年   2篇
  1977年   2篇
  1976年   4篇
  1975年   2篇
  1973年   2篇
  1972年   1篇
  1971年   1篇
排序方式: 共有158条查询结果,搜索用时 9 毫秒
51.
On industrially produced particle boards and MDF, the influence of wood moisture on bending MOE, bending strength and shear modulus Gzx and Gzy was determined. The equilibrium moisture content and the differential swelling of thickness proved to be smaller for MDF than for particle boards. Tensile strength and tensile MOE, shear modulus and bending strength decrease likewise with increasing wood moisture content. Furthermore the Poisson ratio μ12 decreases with increasing wood moisture content.  相似文献   
52.
Nondestructive near-infrared spectroscopy (NIRS) between 400 and 1100 nm regions was employed directly on surimi using a surface interactance fibre optic accessory, to investigate the potential of NIRS as a fast method to determine water and protein contents. The reason why NIRS is well suited when assessing the presence of water or protein is due to the specificity of O–H and N–H bindings. At 980 nm only one broad peak in the original spectra can be seen due to the absorption of water since it contained nearly 80% of surimi. Predictive equations were developed using partial least squares (PLS) regression where excellent predictions for protein and water are noticed. Regression coefficients are higher than 0.98, errors are small and RPD value for protein is well over 8 and that for water is very close to it which can be used for any analytical purpose.  相似文献   
53.
OBJECTIVE: It is not clear whether obsessive-compulsive disorder (OCD) in the context of Tourette's syndrome (TS) is the same as that disorder found in patients with OCD alone. This study evaluated the severity and characteristics of the obsessive-compulsive symptoms in adult patients with OCD and TS compared to adult patients with OCD alone. METHOD: Thirteen subjects with both DSM-III-R TS and OCD and 13 subjects with OCD alone were recruited. Obsessive-compulsive severity was determined by using the Yale-Brown Obsessive Compulsive Scale. The Tourette Syndrome Association Unified Tic Rating Scale was administered to determine tic severity, and the adult version of the Attention Deficit and Hyperactivity Checklist was used to detect a history of childhood attention-deficit hyperactivity disorder (ADHD). RESULTS: Subjects with OCD alone had very few obsessions and compulsions that were not also experienced by subjects with both TS and OCD. In contrast, subjects with TS and OCD were significantly more likely to report obsessions involving nonviolent images, excessive concern with appearance, and need for symmetry. Touching, blinking or staring, and counting compulsions were also significantly more common in this group. Eight subjects with OCD and TS had a childhood history of ADHD, compared to none of the pure OCD subjects. CONCLUSION: There are subtle but definite differences in symptomatology of subjects with pure OCD compared to those with OCD and TS consistent with putative differences in pathophysiology between the 2 groups, i.e., abnormalities in the serotonergic system in OCD patients and serotonergic and dopaminergic abnormalities in those with OCD and TS. These observations may be consistent with genetic heterogeneity within both OCD and TS.  相似文献   
54.
Recent user interface concepts, such as multimedia, multimodal, wearable, ubiquitous, tangible, or augmented-reality-based (AR) interfaces, each cover different approaches that are all needed to support complex human–computer interaction. Increasingly, an overarching approach towards building what we call ubiquitous augmented reality (UAR) user interfaces that include all of the just mentioned concepts will be required. To this end, we present a user interface architecture that can form a sound basis for combining several of these concepts into complex systems. We explain in this paper the fundamentals of DWARFs user interface framework (DWARF standing for distributed wearable augmented reality framework) and an implementation of this architecture. Finally, we present several examples that show how the framework can form the basis of prototypical applications.  相似文献   
55.
A thermoelasticity theory for damage in anisotropic materials is developed. This theory can be applied to evaluate the damage parameter D, the normalized effective mess density ρe/ρ, and the effective modulus Ee quantitatively in some metals and composites by incorporating the thermographic stress analysis method (TSA; also, SPATE method). The effective moduli due to fatigue damage and static loads in a glass fiber/epoxy laminate obtained by the TSA method are compared with the values measured by an extensometer. The correlation between the measurements using the two methods is very good.  相似文献   
56.
57.
58.
This paper presents the experimental justification of two previously published formulas, Eqs. 2) and 6), for the estimation of the complete stress-strain diagram of concrete. Eq. 2) combined with Eq. 3) differs from the other formulas offered in the literature for similar purpose in that provides more relative curvature in the diagram for concretes of lower strengths. Also, with Eq. 6), it can take the fact into consideration that the value of Σ0 increases with increasing concrete strength. The result of these refinements is that the stress-strain diagrams calculated by these formulas fit better the experimentally obtained diagrams and within wider limits than the similar formulas available in the literature. (Figs. 5a through 5d, 8a through 8d, and 9.)  相似文献   
59.
In this paper, theory of kinematics analysis of planar higher pair mechanisms is presented. It has been found that the analysis procedure will be analytical or numerical depending on whether the geometry of the contacting surface(s) is given in an analytical form or in terms of coordinates of discrete points on the surface(s). For either of these options, solution procedures have been described. For the case when profile data is given in numerical form, a numerical scheme of kinematic analysis using cubic spline curve fitting technique has been developed. Two examples are presented: one to illustrate the analytical procedure and the other to illustrate the numerical technique.  相似文献   
60.
Ion beams can be used to permanently bend and re-align nanowires after growth. We have irradiated ZnO nanowires with energetic ions, achieving bending and alignment in different directions. Not only the bending of single nanowires is studied in detail, but also the simultaneous alignment of large ensembles of ZnO nanowires. Computer simulations reveal how the bending is initiated by ion beam induced damage. Detailed structural characterization identifies dislocations to relax stresses and make the bending and alignment permanent, even surviving annealing procedures.  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