全文获取类型
收费全文 | 470篇 |
免费 | 17篇 |
国内免费 | 5篇 |
专业分类
电工技术 | 7篇 |
综合类 | 1篇 |
化学工业 | 93篇 |
金属工艺 | 11篇 |
机械仪表 | 17篇 |
建筑科学 | 23篇 |
矿业工程 | 1篇 |
能源动力 | 25篇 |
轻工业 | 44篇 |
水利工程 | 7篇 |
石油天然气 | 3篇 |
无线电 | 52篇 |
一般工业技术 | 99篇 |
冶金工业 | 15篇 |
原子能技术 | 3篇 |
自动化技术 | 91篇 |
出版年
2024年 | 3篇 |
2023年 | 8篇 |
2022年 | 23篇 |
2021年 | 25篇 |
2020年 | 20篇 |
2019年 | 21篇 |
2018年 | 27篇 |
2017年 | 16篇 |
2016年 | 21篇 |
2015年 | 14篇 |
2014年 | 22篇 |
2013年 | 38篇 |
2012年 | 33篇 |
2011年 | 39篇 |
2010年 | 19篇 |
2009年 | 18篇 |
2008年 | 21篇 |
2007年 | 15篇 |
2006年 | 14篇 |
2005年 | 14篇 |
2004年 | 7篇 |
2003年 | 2篇 |
2002年 | 13篇 |
2001年 | 4篇 |
2000年 | 1篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 11篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 4篇 |
1991年 | 3篇 |
1990年 | 1篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 2篇 |
1983年 | 3篇 |
1982年 | 3篇 |
1981年 | 2篇 |
1980年 | 2篇 |
1979年 | 1篇 |
1974年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有492条查询结果,搜索用时 15 毫秒
131.
Marco Montemurro Yao Koutsawa Salim Belouettar Angela Vincenti Paolo Vannucci 《Composite Structures》2012
In this paper a global optimisation technique for the design of damping properties of hybrid elastomer/composite laminates is presented. The goal of the procedure is to maximise the first N modal loss factors of the laminate subject to constraints on the in-plane and out-of-plane stiffness along with a constraint on the weight of the plate. The problem is considered in the most general case: no simplifying hypotheses are made on the behaviour of the hybrid laminate, thus allowing us to consider as design variables the number of layers (both of the elastic and viscoelastic layers), their thickness and orientations as well as the position of the viscoelastic plies within the stacking sequence. The proposed approach relies on one hand, upon the dynamic response of the structure in terms of natural undamped frequencies and modal loss factors which are evaluated using the well-known Iterative Modal Strain Energy (IMSE) method, and on the other hand on the use of genetic algorithms as optimisation tool to perform the solution’s search. As an example, the method is applied to a rectangular plate and the results demonstrate the effectiveness of the proposed strategy. 相似文献
132.
The objective of study was to evaluate some of the physical and mechanical properties of medium density fiberboard (MDF) panels laminated with veneer sheets compressed at different levels of pressure and temperature. Rotary peeled veneer samples of European beech (Fagus orientalis Lipsky) were compressed at temperatures of 150 °C, 180 °C, and 200 °C using 4 MPa and 6 MPa pressure for 8 min. Commercially produced MDF samples also were laminated with such compressed veneer sheets. Both modulus of elasticity (MOE) and modulus of rupture (MOR) of the specimens increased with increasing pressure and press temperature. Bending characteristics of the samples tested parallel to the grain orientation resulted in significantly higher values than that perpendicular to the grain orientation for each manufacturing parameter. Thickness swelling of the samples also was influenced by increased pressure but variation in press temperature did not result in any influence on dimensional stability. The findings of this work provide potential to produce sandwich type panels with improved properties. Initial results found in this study could be used to manufacture laminated panels with a fixed rate of adhesive while controlling press parameters as a function of the magnitude of pressure and temperature. 相似文献
133.
Bakhtyar Baher Qi Zhang Azam Muhammad Rashid Salim 《Clean Technologies and Environmental Policy》2023,25(1):21-34
Clean Technologies and Environmental Policy - Universal environmental policies adopt strategies that enhance and encourage the production and usage of electric vehicles (EVs). Universal cooperation... 相似文献
134.
135.
136.
Alaya Bechir Khan Rehanullah Moulahi Tarek Khediri Salim El 《Wireless Personal Communications》2021,118(4):2175-2207
Wireless Personal Communications - Vehicular Ad Hoc Network (VANET) is a particular type of MANET providing various wireless communications such as infrastructure communications and inter-vehicle... 相似文献
137.
Matthew L. Hammill Lidya Salim Kouta Tsubaki Andrew J. Varley Mitsuru Kitamura Tatsuo Okauchi Jean-Paul Desaulniers 《Chembiochem : a European journal of chemical biology》2021,22(20):2981-2985
Cubane molecules hold great potential for medicinal chemistry applications due to their inherent stability and low toxicity. In this study, we report the synthesis of a cubane derivative phosphoramidite for the incorporation of cubane into small interfering RNAs (siRNAs). Synthetic siRNAs rely on chemical modifications to improve their pharmacokinetic profiles. However, they are still able to mediate sequence-specific gene silencing via the endogenous RNA interference pathway. We designed a library of siRNAs bearing cubane at different positions within the sense and antisense strands. All siRNAs showed excellent gene-silencing activity, with IC50 values ranging from 45.4 to 305 pM. Incorporating the cubane modification in both the sense and antisense strand led to viable duplexes with good biological activity. To the best of our knowledge, this is the first report of siRNAs bearing a cubane derivative within the backbone. 相似文献
138.
Francesca Desiderio Salim Bourras Elisabetta Mazzucotelli Diego Rubiales Beat Keller Luigi Cattivelli Giampiero Val 《International journal of molecular sciences》2021,22(6)
Leaf rust and powdery mildew are two important foliar diseases in wheat. A recombinant inbred line (RIL) population, obtained by crossing two bread wheat cultivars (‘Victo’ and ‘Spada’), was evaluated for resistance to the two pathogens at seedling stage. Upon developing a genetic map of 8726 SNP loci, linkage analysis identified three resistance Quantitative Trait Loci (QTLs), with ‘Victo’ contributing the resistant alleles to all loci. One major QTL (QPm.gb-7A) was detected in response to Blumeria graminis on chromosome 7A, which explained 90% of phenotypic variation (PV). The co-positional relationship with known powdery mildew (Pm) resistance loci suggested that a new source of resistance was identified in T. aestivum. Two QTLs were detected in response to Puccinia triticina: a major gene on chromosome 5D (QLr.gb-5D), explaining a total PV of about 59%, and a minor QTL on chromosome 2B (QLr.gb-2B). A positional relationship was observed between the QLr.gb-5D with the known Lr1 gene, but polymorphisms were found between the cloned Lr1 and the corresponding ‘Victo’ allele, suggesting that QLr.gb-5D could represent a new functional Lr1 allele. Lastly, upon anchoring the QTL on the T. aestivum reference genome, candidate genes were hypothesized on the basis of gene annotation and in silico gene expression analysis. 相似文献
139.
140.