全文获取类型
收费全文 | 1231篇 |
免费 | 99篇 |
国内免费 | 2篇 |
学科分类
工业技术 | 1332篇 |
出版年
2024年 | 4篇 |
2023年 | 17篇 |
2022年 | 13篇 |
2021年 | 104篇 |
2020年 | 39篇 |
2019年 | 41篇 |
2018年 | 38篇 |
2017年 | 40篇 |
2016年 | 52篇 |
2015年 | 52篇 |
2014年 | 51篇 |
2013年 | 101篇 |
2012年 | 73篇 |
2011年 | 93篇 |
2010年 | 77篇 |
2009年 | 84篇 |
2008年 | 73篇 |
2007年 | 51篇 |
2006年 | 35篇 |
2005年 | 24篇 |
2004年 | 28篇 |
2003年 | 19篇 |
2002年 | 16篇 |
2001年 | 18篇 |
2000年 | 13篇 |
1999年 | 13篇 |
1998年 | 15篇 |
1997年 | 12篇 |
1996年 | 9篇 |
1995年 | 10篇 |
1994年 | 8篇 |
1993年 | 12篇 |
1992年 | 10篇 |
1991年 | 9篇 |
1990年 | 8篇 |
1989年 | 5篇 |
1988年 | 4篇 |
1987年 | 6篇 |
1986年 | 4篇 |
1985年 | 7篇 |
1983年 | 6篇 |
1982年 | 5篇 |
1981年 | 9篇 |
1980年 | 5篇 |
1979年 | 5篇 |
1977年 | 4篇 |
1976年 | 3篇 |
1975年 | 2篇 |
1971年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有1332条查询结果,搜索用时 156 毫秒
1.
Casalaro Giuseppina Lucia Cattivera Giulio Ciccozzi Federico Malavolta Ivano Wortmann Andreas Pelliccione Patrizio 《Software and Systems Modeling》2022,21(1):19-49
Software and Systems Modeling - Mobile robots operate in various environments (e.g. aquatic, aerial, or terrestrial), they come in many diverse shapes and they are increasingly becoming parts of... 相似文献
2.
3.
The fission yeast Schizosaccharomyces pombe is an important model organism for the study of fundamental questions in eukaryotic cell and molecular biology. A plethora of cellular processes are membrane associated and/or dependent on the proper functioning of cellular membranes. Phospholipids are not only the basic building blocks of cellular membranes; they also serve as precursors to numerous signaling molecules. In this review, we describe the biosynthetic pathways leading to major S. pombe phospholipids, how these pathways are regulated, and what is known about degradation and turnover of fission yeast phospholipids. This review also addresses the synthesis, regulation and the role of water-soluble phospholipid precursors. The last chapter of the review is devoted to the use of S. pombe for the biotechnological production of value-added lipid molecules. 相似文献
4.
Non-pinched, minimum energy solutions are important class of distillation designs that offer the potential advantage of a better trade-off between capital investment and operating costs. In this paper, two important tasks associated with non-pinched distillation designs are studied. Thus the novel contributions of this work to the literature are
- (1) A comprehensive methodology for finding non-pinched minimum energy designs.
- (2) Understanding of the reasons for the existence of non-pinched distillation designs.
5.
In-Situ and Real-Time Investigation of Columnar-to-Equiaxed Transition in Metallic Alloy 总被引:1,自引:0,他引:1
H. Nguyen-Thi G. Reinhart N. Mangelinck-Noël H. Jung B. Billia T. Schenk J. Gastaldi J. Härtwig J. Baruchel 《Metallurgical and Materials Transactions A》2007,38(7):1458-1464
In this article, we present a review of observations during Al-3.5 wt pct Ni alloy solidi.cation experiments performed at
the European Synchrotron Radiation Facility (ESRF) in Grenoble. These experiments provide direct access to dynamical phenomena
during columnar growth (initial transient and breakdown of a planar solid-liquid interface), and for the first time to the
transition from columnar-to-equiaxed microstructure (nucleation ahead of a columnar front and blocking of a columnar front
by an equiaxed microstructure) and fully equiaxed growth (propagation of an effective front). Based on these experimental
observations, critical parameters such as columnar growth velocity variation during the transition or equiaxed-grain diameter
are measured and discussed.
This article is based on a presentation made in the symposium entitled “Solidi.cation Modeling and Microstructure Formation:
In Honor of Prof. John Hunt,” which occurred March 13–15, 2006, during the TMS Spring Meeting in San Antonio, Texas, under
the auspices of the TMS Materials Processing and Manufacturing Division, Solidification Committee. 相似文献
6.
Rafael Gallego Lucia Comino Alberto Ruiz‐Cabello 《International journal for numerical methods in engineering》2006,66(12):1913-1933
In this paper, the material constant sensitivity boundary integral equation is presented, and its numerical solution proposed, based on boundary element techniques. The formulation deals with plane problems with general rectilinear anisotropy. Expressions for the computation of sensitivities for displacements, tractions, strains and stresses are derived, both for boundary and interior points. The sensitivities can be computed with respect to the bulk material properties or to the properties of part of the domain (inclusions, coatings, etc.). To assess the accuracy of the proposed approach, the computed results are compared to analytical ones derived from exact solutions obtained by complex potential theory, when possible, or finite difference derivatives otherwise. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
7.
8.
Lucia RussoErasmo Mancusi Pier Luca MaffettoneSilvestro Crescitelli 《Chemical engineering science》2002,57(24):5065-5082
In this work, we discuss how periodic forcing may induce symmetry properties into mathematical models of chemical reactors. We define a class of reactors subjected to discontinuous periodic forcing, and show that all the reactors belonging to this class have spatio-temporal symmetry. This symmetry and its influence on the possible bifurcation scenarios are discussed. The bifurcation analysis is carried out with suitable discrete systems that exploit a property of the Poincaré map. In fact, it is shown that the spatio-temporal symmetry induced by the forcing makes the Poincaré map of the continuous system an iterate of another map. On this basis, a technique to implement parameter continuation methods is proposed. With such a technique, it is also possible to characterize symmetric and nonsymmetric regimes and unstable limit sets otherwise undetected with “bruteforce” approaches. Examples for reverseflow reactors and networks of n-reactors with periodically switched feed and discharge positions are presented. 相似文献
9.
L Riera Canals E Franco Miranda MA López Costea F Aguilo Lucia JM Caballero Gine J Serra Caner A Castelao N Serrallach Mila 《Canadian Metallurgical Quarterly》1993,17(8):492-496
Analysis of the indications for transplantectomy and its complications over a 12-year period. Over a total of 159 failure grafts, we performed 53 transplantectomies (33.3%). The percentage of complications was 16.9%. Three patients died (5.6%) during the more or less immediate post-operative period. In our experience, consistent and prolonged maintenance of immunosuppression should avoid the need for transplantectomy in a high percentage of grafts. Only 15 transplantectomies were made on 104 failure grafts after 6 months (14.4%). Our short but successful experience with embolization of 2 rejected grafts confirms the validity of this conservative alternative versus conventional surgical transplantectomy in selected cases. 相似文献
10.
This paper describes the present situation in Italy in the field of Acoustic Emission researches and applications.Information on the level of instrumentation development is given. Both multichannel and multiparameter systems for large structure examination in real time and data logging systems for continuous surveillance purposes are considered.The expertise accumulated in the application of AE to pressure vessel examination during hydrotest is mentioned, this being oriented to pressure components of conventional power stations and chemical plants.Particular attention is recently paid to mechanical fatigue tests. These were conducted on intermediate PWR nuclear pressure vessel, reduced scale offshore nodes and full scale prototype aircraft.A considerable activity has been carried out on application of AE technique to the detection of fluid leakages in power plant components. Both intrusive and non-intrusive methods have been considered. Many boilers and pre-heaters of thermal power plants have been instrumented for an on-line AE monitoring during operation. The problem of the loose part monitoring has been also considered.Several basic researches for material characterization by AE have been also conducted. Different composite material, carbon and austenitic steels, metal alloys have been studied. 相似文献