全文获取类型
收费全文 | 369篇 |
免费 | 23篇 |
国内免费 | 1篇 |
专业分类
电工技术 | 3篇 |
化学工业 | 190篇 |
金属工艺 | 5篇 |
机械仪表 | 5篇 |
建筑科学 | 4篇 |
能源动力 | 10篇 |
轻工业 | 32篇 |
无线电 | 34篇 |
一般工业技术 | 61篇 |
冶金工业 | 21篇 |
自动化技术 | 28篇 |
出版年
2024年 | 1篇 |
2023年 | 6篇 |
2022年 | 41篇 |
2021年 | 67篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 20篇 |
2015年 | 8篇 |
2014年 | 20篇 |
2013年 | 12篇 |
2012年 | 15篇 |
2011年 | 17篇 |
2010年 | 11篇 |
2009年 | 7篇 |
2008年 | 15篇 |
2007年 | 15篇 |
2006年 | 11篇 |
2005年 | 8篇 |
2004年 | 3篇 |
2003年 | 5篇 |
2002年 | 6篇 |
2001年 | 5篇 |
1999年 | 3篇 |
1998年 | 5篇 |
1997年 | 4篇 |
1996年 | 7篇 |
1995年 | 2篇 |
1994年 | 6篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1991年 | 4篇 |
1990年 | 1篇 |
1989年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1984年 | 1篇 |
1983年 | 3篇 |
1982年 | 2篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1977年 | 5篇 |
1976年 | 4篇 |
排序方式: 共有393条查询结果,搜索用时 15 毫秒
51.
On image analysis by moments 总被引:28,自引:0,他引:28
Liao S.X. Pawlak M. 《IEEE transactions on pattern analysis and machine intelligence》1996,18(3):254-266
52.
A multidimensional classification procedure is examined derived from the multiple Hermite series estimate of probability density functions. Conditions for the almost sure convergence of the integrated square error for the estimate are presented and the rate of the convergence is studied. The probability of misclassification, conditioned on a learning sequence of length n, is shown to converge to the Bayes risk almost surely as rapidly as , δ positive. 相似文献
53.
Coals of different rank were treated with naphthalene anion in tetrahydrofuran. It was found that, as in the case of coal of 87.8% C (daf), large amounts of unreactive oxygen bonds, possibly of the ether type, were cleaved. Cleavage of these ether linkages led to a lowering of the melting point and, in some types of coals, to a large increase in dilatation and a substantial increase in Gieseler fluidity. 相似文献
54.
VAGUENESS AND UNCERTAINTY: A ROUGH SET PERSPECTIVE 总被引:36,自引:0,他引:36
Vagueness and uncertainty have attracted the attention of philosophers and logicians for many years. Recently, AI researchers contributed essentially to this area of research. Fuzzy set theory and the theory of evidence are seemingly the most appealing topics. On this note we present a new approach, based on the rough set theory, for looking to these problems. The theory of rough sets seems a suitable mathematical tool for dealing with problems of vagueness and uncertainty. This paper is a modified version of the author's lecture titled "An inquiry into vagueness and uncertainty," which was delivered at the AI Conference in Wigry (Poland), 1994. 相似文献
55.
J.?ZakrzewskiEmail author M.?Pawlak F.?Firszt S.?Legowski A.?Marasek H.?Meczynska M.?Malinski 《International Journal of Thermophysics》2005,26(1):285-293
This paper reports the results of photoacoustic measurements of Cd1-xBexSe mixed crystals grown by the high pressure Bridgman method with varying concentrations of Be (0.1 < x < 0.2). For examining continuous wave photoacoustic spectra, a piezoelectric transducer (PZT) and an open cell were used. An increase of the energy gap with increasing x has been observed. The thermal diffusivity values were estimated using the dependence of the amplitude and phase of the PA signal on the light modulation frequency.Paper presented at the Fifteenth Symposium on Thermophysical Properties, June 22–27, 2003, Boulder, Colorado, U.S.A. 相似文献
56.
57.
Pawlak M. 《IEEE transactions on information theory / Professional Technical Group on Information Theory》1993,39(3):979-988
Nonparametric kernel classification rules derived from incomplete (missing) data are studied. A number of techniques of handling missing observation in the training set are taken into account. In particular, the straightforward approach of designing a classifier only from available data (deleting missing values) is considered. The class of imputation techniques is also taken into consideration. In the latter case, one estimates missing values and then calculates classification rules from such a completed training set. Consistency and speed of convergence of proposed classification rules are established. Results of simulation studies are presented 相似文献
58.
In this study, the influence of pH on interfacial energy distributed over the phospholipids-bilayer surface model and the effect of hydrophobicity on coefficient of friction (f) were investigated by using microelectrophoresis. An important clinical implication of deficiency in hydrophobicity is the loss of phospholipids that is readily observed in osteoarthritis joints. This paper establishes the influence of pH on interfacial energy upon an increase f, which might be associated with a decrease of hydrophobicity of the articular surface. 相似文献
59.
Sylwia Czonka Agn Kairyt Karolina Miedziska Anna Strkowska 《International journal of molecular sciences》2021,22(14)
In the following study, polyurethane (PUR) composites were modified with 2 wt.% of walnut shell filler modified with selected mineral compounds–perlite, montmorillonite, and halloysite. The impact of modified walnut shell fillers on selected properties of PUR composites, such as rheological properties (dynamic viscosity, foaming behavior), mechanical properties (compressive strength, flexural strength, impact strength), dynamic-mechanical behavior (glass transition temperature, storage modulus), insulation properties (thermal conductivity), thermal characteristic (temperature of thermal decomposition stages), and flame retardant properties (e.g., ignition time, limiting oxygen index, heat peak release) was investigated. Among all modified types of PUR composites, the greatest improvement was observed for PUR composites filled with walnut shell filler functionalized with halloysite. For example, on the addition of such modified walnut shell filler, the compressive strength was enhanced by ~13%, flexural strength by ~12%, and impact strength by ~14%. Due to the functionalization of walnut shell filler with thermally stable flame retardant compounds, such modified PUR composites were characterized by higher temperatures of thermal decomposition. Most importantly, PUR composites filled with flame retardant compounds exhibited improved flame resistance characteristics-in all cases, the value of peak heat release was reduced by ~12%, while the value of total smoke release was reduced by ~23%. 相似文献
60.
Przemyslaw Bartnik Sylwia Jafra Magdalena Narajczyk Paulina Czaplewska Robert Czajkowski 《International journal of molecular sciences》2021,22(14)
Pectobacterium parmentieri is a Gram-negative plant-pathogenic bacterium able to infect potato (Solanum tuberosum L.). Little is known about lytic bacteriophages infecting P. parmentieri and how phage-resistance influences the environmental fitness and virulence of this species. A lytic phage vB_Ppp_A38 (ϕA38) has been previously isolated and characterized as a potential biological control agent for the management of P. parmentieri. In this study, seven P. parmentieri SCC 3193 Tn5 mutants were identified that exhibited resistance to infection caused by vB_Ppp_A38 (ϕA38). The genes disrupted in these seven mutants encoded proteins involved in the assembly of O-antigen, sugar metabolism, and the production of bacterial capsule exopolysaccharides. The potential of A38-resistant P. parmentieri mutants for plant colonization and pathogenicity as well as other phenotypes expected to contribute to the ecological fitness of P. parmentieri, including growth rate, use of carbon and nitrogen sources, production of pectinolytic enzymes, proteases, cellulases, and siderophores, swimming and swarming motility, presence of capsule and flagella as well as the ability to form biofilm were assessed. Compared to the wild-type P. parmentieri strain, all phage-resistant mutants exhibited a reduced ability to colonize and to cause symptoms in growing potato (S. tuberosum L.) plants. The implications of bacteriophage resistance on the ecological fitness of P. parmentieri are discussed. 相似文献