全文获取类型
收费全文 | 639篇 |
免费 | 2篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 110篇 |
金属工艺 | 23篇 |
机械仪表 | 2篇 |
建筑科学 | 29篇 |
矿业工程 | 2篇 |
能源动力 | 8篇 |
轻工业 | 8篇 |
水利工程 | 2篇 |
石油天然气 | 55篇 |
无线电 | 33篇 |
一般工业技术 | 202篇 |
冶金工业 | 90篇 |
原子能技术 | 13篇 |
自动化技术 | 63篇 |
出版年
2014年 | 9篇 |
2013年 | 8篇 |
2010年 | 14篇 |
2009年 | 15篇 |
2008年 | 18篇 |
2007年 | 13篇 |
2006年 | 8篇 |
2005年 | 7篇 |
2004年 | 11篇 |
2003年 | 12篇 |
2002年 | 10篇 |
2001年 | 12篇 |
1999年 | 7篇 |
1998年 | 20篇 |
1997年 | 10篇 |
1996年 | 12篇 |
1995年 | 11篇 |
1994年 | 9篇 |
1993年 | 12篇 |
1992年 | 7篇 |
1991年 | 7篇 |
1990年 | 7篇 |
1989年 | 7篇 |
1987年 | 13篇 |
1986年 | 9篇 |
1985年 | 9篇 |
1984年 | 8篇 |
1983年 | 7篇 |
1982年 | 7篇 |
1981年 | 10篇 |
1980年 | 10篇 |
1979年 | 16篇 |
1978年 | 18篇 |
1977年 | 19篇 |
1976年 | 22篇 |
1975年 | 16篇 |
1974年 | 23篇 |
1973年 | 9篇 |
1972年 | 16篇 |
1971年 | 10篇 |
1970年 | 14篇 |
1969年 | 11篇 |
1968年 | 13篇 |
1967年 | 12篇 |
1966年 | 13篇 |
1965年 | 14篇 |
1964年 | 7篇 |
1963年 | 10篇 |
1962年 | 10篇 |
1961年 | 9篇 |
排序方式: 共有641条查询结果,搜索用时 15 毫秒
1.
2.
Michael Rabinovich Kate L. Olsavsky Burr Leach Mauricio Cabrera‐Ríos José M. Castro 《应用聚合物科学杂志》2008,109(4):2465-2471
Sheet molding compound (SMC) is a fiber‐reinforced polymeric composite. It is often used in automotive, marine, and industrial applications over other materials because of its high strength to density ratio, resistance to corrosion, and low cost. There is a demand in the SMC industry to be able to characterize SMC processability. This is particularly true for heavy truck body panels, one of the fastest growing applications of SMC. Because of their large size and high strength requirement, the molding forces have a major influence in the molding cycle. Also because of the long flow paths involved, the ability of the paste to carry glass needs to be properly characterized when developing new SMC materials. In this article, we demonstrate the benefits of using spiral flow as a processability tester. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008 相似文献
3.
I. G. Rabinovich Yu. A. Bagdasarov A. G. Chakhvadze G. I. D'yachenko E. A. Bozhko 《Soil Mechanics and Foundation Engineering》1989,26(5):197-203
Translated from Osnovaniya, Fundamenty i Mekhanika Gruntov, No. 5, pp. 12–15, September–October, 1989. 相似文献
4.
M. Kh. Rabinovich V. G. Kudryashov M. V. Markushev 《Metal Science and Heat Treatment》1988,30(8):609-612
1. | The characteristics of strength (u, o 2), plasticity (, ) in the longitudinal and transverse directions, impact toughness in the transverse direction, and also the nominal stress intensity factor K c * are practically independent of the grain size of the alloy AMg6. |
2. | The ultrafine-grained structure somewhat reduces the endurance of the alloy AMg6 in the region of low cycle fatigue and increases endurance and fatigue limit in the region of multicycle fatigue. |
3. | Reduced grain size is accompanied by increased resistance to fatigue crack nucleation in alloy AMg6. |
4. | Alloy AMg6 with ultrafine-grained structure is isotropic in crack resistance, and with coarse-grained structure it is anisotropic. The highest fatigue crack growth rate is found in transverse speciment of coarse-grained material. |
5. | The effect of the grain size on crack resistance depends on the change of the ratio of resistance to crack nucleation and growth at high and low stress levels under conditions of variable loading. |
5.
This work presents experimental results on pickup velocity (critical velocity) measurements for a variety of particulate solids. The present experiments together with previously published experiments of a number of researchers encompass about 100 measurements of 24 materials for a wide range of particle sizes, shapes and densities. Based on the experimental results, three zones are defined by establishing simple relationships between the Reynolds and Archimedes numbers. The empirical relationships were further modified by taking into account the pipe diameter and particle shape (sphericity). The three-zone model was shown to reasonably correlate to Geldart's classification groups. 相似文献
6.
Helmut Alt Esther M. Arkin Alon Efrat George Hart Ferran Hurtado Irina Kostitsyna Alexander Kröller Joseph S. B. Mitchell Valentin Polishchuk 《Theory of Computing Systems》2014,54(4):689-714
We show how to compute the smallest rectangle that can enclose any polygon, from a given set of polygons, in nearly linear time; we also present a PTAS for the problem, as well as a linear-time algorithm for the case when the polygons are rectangles themselves. We prove that finding a smallest convex polygon that encloses any of the given polygons is NP-hard, and give a PTAS for minimizing the perimeter of the convex enclosure. We also give efficient algorithms to find the smallest rectangle simultaneously enclosing a given pair of convex polygons. 相似文献
7.
Efrat Blumenfeld-Lieberthal 《Networks and Spatial Economics》2009,9(3):427-458
This paper presents an analysis of the topology of transportation networks within different systems of cities. Urban entities
and their components are complex systems by their nature; there is no central force that affects their spatial structure.
Thus, we study transportation networks within different countries as complex networks. Based on the above, we consider cities
as nodes, while direct air and railways routes represent the links. We present characteristics of these networks including
their degree and clustering coefficient. Transportation networks can be used as an indicator of economic activity between
cities. Cities with strong economic relationship are characterized by high volume of connectivity. Our findings suggest that
the topology of the analyzed transportation networks can be used to classify the countries they belong to based on their economic
development.
相似文献
Efrat Blumenfeld-LieberthalEmail: |
8.
Alexander Rabinovich 《Information and Computation》1996,124(2):154
We consider the problem of determining when two dataflow networks with uninterpreted nodes always have the same input-output behavior. We define a set of behavior-preserving transformations on networks and show that this set is “schematologically complete”; i.e., networks have the same input-output behavior under all interpretations if and only if they can be transformed into isomorphic networks. As a by product, we obtain a polynomial algorithm for deciding schematological equivalence of dataflow networks. 相似文献
9.
Towards capacity and profit optimization of video-on-demand services in a peer-assisted IPTV platform 总被引:1,自引:0,他引:1
Yih-Farn Chen Yennun Huang Rittwik Jana Hongbo Jiang Michael Rabinovich Jeremy Rahe Bin Wei Zhen Xiao 《Multimedia Systems》2009,15(1):19-32
This paper studies the conditions under which peer-to-peer (P2P) technology may be beneficial in providing IPTV services over
typical network architectures. It has three major contributions. First, we contrast two network models used to study the performance
of such a system: a commonly used logical “Internet as a cloud” model and a “physical” model that reflects the characteristics
of the underlying network. Specifically, we show that the cloud model overlooks important architectural aspects of the network
and may drastically overstate the benefits of P2P technology. Second, we propose an algorithm called Zebra that pre-stripes
content across multiple peers during idle hours to speed up P2P content delivery in an IPTV environment with limited upload
bandwidth. We also perform simulations to measure Zebra’s effectiveness at reducing load on the content server during peak
hours. Third, we provide a cost-benefit analysis of P2P video content delivery, focusing on the profit trade-offs for different
pricing/incentive models rather than purely on capacity maximization. In particular, we find that under high volume of video
demand, a P2P built-in incentive model performs better than any other model, while the conventional no-P2P model generates
more profits when the request rate is low. The flat-reward model generally falls in between the usage-based model and the
built-in model in terms of profitability except for low request rates. We also find that built-in and flat-reward models are
more profitable than the usage-based model for a wide range of subscriber community sizes.
Funding for J. Rahe’s research has been provided by AT&T Labs, the State of California under the MICR Oprogram, and by the
Toshiba Corporation.
Zhen Xiao is partially supported by China MOST project (2006BAH02A10). 相似文献
10.
Daniel Rabinovich Dan Givoli Jacobo Bielak Thomas Hagstrom 《Computer Methods in Applied Mechanics and Engineering》2011,200(23-24):2048-2066
A high-order absorbing boundary condition (ABC) is devised on an artificial boundary for time-dependent elastic waves in unbounded domains. The configuration considered is that of a two-dimensional elastic waveguide. In the exterior domain, the unbounded elastic medium is assumed to be isotropic and homogeneous. The proposed ABC is an extension of the Hagstrom–Warburton ABC which was originally designed for acoustic waves, and is applied directly to the displacement field. The order of the ABC determines its accuracy and can be chosen to be arbitrarily high. The initial boundary value problem including this ABC is written in second-order form, which is convenient for geophysical finite element (FE) analysis. A special variational formulation is constructed which incorporates the ABC. A standard FE discretization is used in space, and a Newmark-type scheme is used for time-stepping. A long-time instability is observed, but simple means are shown to dramatically postpone its onset so as to make it harmless during the simulation time of interest. Numerical experiments demonstrate the performance of the scheme. 相似文献