全文获取类型
收费全文 | 727篇 |
免费 | 35篇 |
国内免费 | 2篇 |
专业分类
电工技术 | 5篇 |
化学工业 | 156篇 |
金属工艺 | 68篇 |
机械仪表 | 15篇 |
建筑科学 | 34篇 |
矿业工程 | 2篇 |
能源动力 | 13篇 |
轻工业 | 94篇 |
石油天然气 | 2篇 |
无线电 | 23篇 |
一般工业技术 | 138篇 |
冶金工业 | 117篇 |
自动化技术 | 97篇 |
出版年
2023年 | 6篇 |
2022年 | 27篇 |
2021年 | 31篇 |
2020年 | 23篇 |
2019年 | 25篇 |
2018年 | 32篇 |
2017年 | 16篇 |
2016年 | 31篇 |
2015年 | 13篇 |
2014年 | 29篇 |
2013年 | 49篇 |
2012年 | 27篇 |
2011年 | 50篇 |
2010年 | 45篇 |
2009年 | 34篇 |
2008年 | 36篇 |
2007年 | 29篇 |
2006年 | 13篇 |
2005年 | 17篇 |
2004年 | 21篇 |
2003年 | 19篇 |
2002年 | 9篇 |
2001年 | 10篇 |
2000年 | 9篇 |
1999年 | 12篇 |
1998年 | 12篇 |
1997年 | 11篇 |
1996年 | 8篇 |
1995年 | 4篇 |
1994年 | 8篇 |
1993年 | 11篇 |
1992年 | 4篇 |
1990年 | 4篇 |
1989年 | 6篇 |
1988年 | 5篇 |
1987年 | 5篇 |
1986年 | 5篇 |
1985年 | 9篇 |
1984年 | 4篇 |
1982年 | 3篇 |
1981年 | 3篇 |
1980年 | 5篇 |
1979年 | 3篇 |
1978年 | 4篇 |
1977年 | 3篇 |
1976年 | 3篇 |
1973年 | 3篇 |
1971年 | 5篇 |
1969年 | 3篇 |
1943年 | 3篇 |
排序方式: 共有764条查询结果,搜索用时 234 毫秒
11.
Iris Ribitsch Andrea Bileck Alexander D. Aldoshin Maciej M. Kadua Rupert L. Mayer Monika Egerbacher Simone Gabner Ulrike Auer Sinan Gültekin Johann Huber David P. Kreil Christopher Gerner Florien Jenner 《International journal of molecular sciences》2021,22(11)
Tendinopathies are painful, disabling conditions that afflict 25% of the adult human population. Filling an unmet need for realistic large-animal models, we here present an ovine model of tendon injury for the comparative study of adult scarring repair and fetal regeneration. Complete regeneration of the fetal tendon within 28 days is demonstrated, while adult tendon defects remained macroscopically and histologically evident five months post-injury. In addition to a comprehensive histological assessment, proteome analyses of secretomes were performed. Confirming histological data, a specific and pronounced inflammation accompanied by activation of neutrophils in adult tendon defects was observed, corroborated by the significant up-regulation of pro-inflammatory factors, neutrophil attracting chemokines, the release of potentially tissue-damaging antimicrobial and extracellular matrix-degrading enzymes, and a response to oxidative stress. In contrast, secreted proteins of injured fetal tendons included proteins initiating the resolution of inflammation or promoting functional extracellular matrix production. These results demonstrate the power and relevance of our novel ovine fetal tendon regeneration model, which thus promises to accelerate research in the field. First insights from the model already support our molecular understanding of successful fetal tendon healing processes and may guide improved therapeutic strategies. 相似文献
12.
Omar Hatamleh Iris V. Rivero Jed Lyons 《Journal of Materials Engineering and Performance》2007,16(5):549-553
The effects of laser, and shot peening on the residual stresses in friction stir welds (FSW) has been investigated. The surface
residual stresses were measured at five different locations across the weld in order to produce an adequate residual stress
profile. The residual stresses before and after sectioning the coupon from the welded plate were also measured, and the effect
of coupon size on the residual stress relaxation was determined and characterized. Measurements indicate that residual stresses
were not uniform along the welded plate, and large variation in stress magnitude could be exhibited at various locations along
the FSW plate. Sectioning resulted in significant residual stress relaxation in the longitudinal direction attributed to the
large change in dimensions in this direction. Overall, laser and shot peening resulted in a significant reduction in tensile
residual stresses at the surface of the specimens. 相似文献
13.
H. Mughrabi H. Biermann T. Ungar 《Journal of Materials Engineering and Performance》1993,2(4):557-564
The γ-γ lattice mismatch of specimens of the monocrystalline nickel-base superalloy SRR 99 has been measured by a high-resolution
X-ray diffraction technique for the undeformed state and after high-tem-perature creep deformation. During creep deformation
beyond the minimum creep rate (total strain =0.5%), the lattice mismatches, measured in and perpendicular to the [001] stress
axis, respectively, un-dergo changes in opposite directions. This reflects the buildup of a complex deformation-induced triaxial
state of internal stress in the phases y and γ. The overall resolved shear stresses that act in γ and y due to the combined
action of the external and internal stresses are estimated, and the conditions under which cutting of the γ phase by dislocations
should occur are discussed. 相似文献
14.
Software Product Line Engineering (SPLE) deals with developing artifacts that capture the common and variable aspects of software product families. Domain models are one kind of such artifacts. Being developed in early stages, domain models need to specify commonality and variability and guide the reuse of the artifacts in particular software products. Although different modeling methods have been proposed to manage and support these activities, the assessment of these methods is still in an inceptive stage. In this work, we examined the comprehensibility of domain models specified in ADOM, a UML-based SPLE method. In particular, we conducted a controlled experiment in which 116 undergraduate students were required to answer comprehension questions regarding a domain model that was equipped with explicit reuse guidance and/or variability specification. We found that explicit specification of reuse guidance within the domain model helped understand the model, whereas explicit specification of variability increased comprehensibility only to a limited extent. Explicit specification of both reuse guidance and variability often provided intermediate results, namely, results that were better than specification of variability without reuse guidance, but worse than specification of reuse guidance without variability. All these results were perceived in different UML diagram types, namely, use case, class, and sequence diagrams and for different commonality-, variability-, and reuse-related aspects. 相似文献
15.
Nadia Plata Iris Hofer Stephane Roudier Jean-Pierre Schaller 《Journal of aerosol science》2006,37(12):1871-1875
A new cryogenic instrument was designed for the trapping of aerosols such as cigarette mainstream smoke at low temperature. The technique enabled the trapping of the mainstream smoke of a single cigarette and the particulate and vapor phases were trapped simultaneously. 2R4F reference cigarettes were smoked under International Standard Organization (ISO) regime and trapped at low temperature using the cryogenic instrument. After trapping, the mainstream smoke of the 2R4F reference cigarette was diluted with a solvent and selected smoke components could be quantified using gas-mass spectrometry (GCMS) and high-performance liquid chromatography (HPLC). The capability of the instrument for trapping the mainstream smoke was demonstrated. The feasibility of the procedure for the detection and the quantification of a large range of smoke components including carbonyls, alkaloids and organic volatile compounds (VOC) in the mainstream of a single cigarette was also shown. 相似文献
16.
Jürgen o. Metzger Ursula Biermann 《European Journal of Lipid Science and Technology》1994,96(9):321-323
Products of the Thermal Ene-Reaction of Unsaturated Fatty Compounds and Maleic Anhydride The thermal ene reaction of the methylates of unsaturated fatty acids 10-undecenoic acid, oleic acid and (E)-10-eicosendioic acid with maleic anhydride was carried out at 190°C. The mono addition products were isolated and their stereochemistry was deduced from 1HNMR- and 13C-NMR-spectroscopy. 相似文献
17.
Iris Reinbacher Marc Benkert Marc van Kreveld Joseph S. B. Mitchell Jack Snoeyink Alexander Wolff 《Algorithmica》2008,50(3):386-414
In geographic information retrieval, queries often name geographic regions that do not have a well-defined boundary, such
as “Southern France.” We provide two algorithmic approaches to the problem of computing reasonable boundaries of such regions
based on data points that have evidence indicating that they lie either inside or outside the region. Our problem formulation
leads to a number of subproblems related to red-blue point separation and minimum-perimeter polygons, many of which we solve
algorithmically. We give experimental results from our implementation and a comparison of the two approaches.
This research is supported by the EU-IST Project No. IST-2001-35047 (SPIRIT) and by grant WO 758/4-2 of the German Research
Foundation (DFG). 相似文献
18.
Iris Binyamin Eitan Grossman Matanel Gorodnitsky Doron Kam Shlomo Magdassi 《Advanced functional materials》2023,33(24):2214368
High-performance polymers are an important class of materials that are used in challenging conditions, such as in aerospace applications. Until now, 3D printing based on stereolithography processes can not be performed due to a lack of suitable materials. There is report on new materials and printing compositions that enable 3D printing of objects having extremely high thermal resistance, with Tg of 283 °C and excellent mechanical properties. The printing is performed by a low-cost Digital Light Processing printer, and the formulation is based on a dual-cure mechanism, photo, and thermal process. The main components are a molecule that has both epoxy and acrylate groups, alkylated melamine that enables a high degree of crosslinking, and a soluble precursor of silica. The resulting objects are made of hybrid materials, in which the silicon is present in the polymeric backbone and partly as silica enforcement particles. 相似文献
19.
The combination of building information modeling (BIM) and integrated project delivery (IPD) has been widely supported in the literature as a solution to the problems of limited collaboration in the construction industry. BIM and IPD have been described as cooperative means of achieving sustainable benefit to stakeholders. However, most studies focused on the technological challenges involved, with reference mainly to the sustainable economic and environmental benefits of the combination, while the sustainable sociocultural benefits have not been extensively explored. In this study, these issues are addressed by highlighting the importance of implementing BIM as a social system, using BIM corporate social responsibility (CSR) application model, in a BIM-based IPD project. This CSR model of BIM application (CSR-BIM model) serves as a benchmark for examining the achievement of a sociocultural benefits from the project. Social network analysis (SNA) was employed as an analytical method for examining the inter-organizational communication network during the design stage in relation to the CSR-BIM model. The SNA studies were conducted to compare the optimal model findings and the actual findings, focusing on clusters, ego-network clusters and the centrality of the players. The comparison—which related only to the BIM communication platform, in the context of the professionals—found a distinction between the BIM manager and the project team and its management, presenting separate and partial clusters. The evaluation also identified the low centrality of the BIM manager relative to the optimal option. In response, recommendations are made to implement the CSR-BIM model as a management measure to better support a sustainable sociocultural project. 相似文献
20.