全文获取类型
收费全文 | 297篇 |
免费 | 17篇 |
专业分类
电工技术 | 7篇 |
综合类 | 2篇 |
化学工业 | 100篇 |
金属工艺 | 1篇 |
机械仪表 | 10篇 |
建筑科学 | 10篇 |
矿业工程 | 3篇 |
能源动力 | 3篇 |
轻工业 | 50篇 |
水利工程 | 5篇 |
石油天然气 | 2篇 |
无线电 | 12篇 |
一般工业技术 | 40篇 |
冶金工业 | 22篇 |
原子能技术 | 4篇 |
自动化技术 | 43篇 |
出版年
2023年 | 4篇 |
2022年 | 3篇 |
2021年 | 19篇 |
2020年 | 6篇 |
2019年 | 12篇 |
2018年 | 7篇 |
2017年 | 10篇 |
2016年 | 8篇 |
2015年 | 12篇 |
2014年 | 10篇 |
2013年 | 24篇 |
2012年 | 30篇 |
2011年 | 22篇 |
2010年 | 9篇 |
2009年 | 12篇 |
2008年 | 14篇 |
2007年 | 17篇 |
2006年 | 11篇 |
2005年 | 13篇 |
2004年 | 8篇 |
2003年 | 7篇 |
2002年 | 8篇 |
2001年 | 2篇 |
2000年 | 4篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 3篇 |
1996年 | 3篇 |
1995年 | 2篇 |
1994年 | 3篇 |
1993年 | 2篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1986年 | 2篇 |
1985年 | 2篇 |
1984年 | 1篇 |
1983年 | 1篇 |
1982年 | 2篇 |
1981年 | 4篇 |
1980年 | 1篇 |
1979年 | 2篇 |
1978年 | 1篇 |
1976年 | 2篇 |
1975年 | 1篇 |
1965年 | 1篇 |
排序方式: 共有314条查询结果,搜索用时 15 毫秒
21.
Thermal and elastic properties of poly(vinyl chloride) (PVC) + chlorinated polyethylene (CPE) blends
Robert?D.?MaksimovEmail author Tatjana?Ivanova Janis?Zicans Sophia?N.?Negreeva Egils?Plume 《Materials Research Innovations》2003,7(5):326-330
Eight types of PVC + CPE blends with different weight ratios (PVC/CPE = 100/0, 90/10, 80/20, 60/40, 40/60, 20/80, 10/90, and 0/100) are tested. Data on the heat conductivity, thermal diffusivity, and heat capacity of the blends investigated are reported. Primary attention is paid to the structural approach for effective elastic constants: bulk, shear, and Young's modulae. The blends are considered as random mixtures of two isotropic constituents. It is found that the elastic moduli may be well represented by the Kerner and Budiansky equations. 相似文献
22.
Katarina Vojisavljević Goran Branković Tatjana Srećković Aleksander Rečnik Zorica Branković 《Journal of the European Ceramic Society》2010,30(2):485-488
Ultrathin PZT film was prepared using a chemical solution deposition method from polymeric citrate precursors. The PZT solution was spin-coated on an amorphous silica layer formed on a Si(1 0 0) substrate. The films were thermally treated from the substrate side with a low heating rate (1°/min) up to 700 °C and finally annealed for 10 h. Ultrathin PZT films without microstructural instability were prepared in spite of high temperature and long annealing time. AFM and HRTEM investigations revealed the formation of a well-developed dense microstructure consisting of spherical crystallites (4–7 nm). Low roughness (2.2 nm) of a ~26 nm thick layer was obtained for a two-layered PZT film. The grazing incidence X-ray diffraction (GIXRD) measurements confirmed the polycrystalline structure of ultrathin PZT films. Also, GIXRD and electron energy dispersive X-ray (EDS) analysis showed that compositional variations were smaller than expected, in spite of the long annealing time. 相似文献
23.
The crystal-melt equilibria in complex 15-component-simulated high-level waste (HLW) glass melts are modeled based on quasicrystalline concepts that are discussed in Part I. A pseudobinary phase diagram between a transition metal ferrite spinel (an incongruent melt product of a transition metal iron-rich acmite) and nepheline is defined based on calculation of the quasicrystalline melt precursors calculated by a freezing point depression approach. The pseudobinary lies within the Al2 O3 –Fe2 O3 –Na2 O–SiO2 quaternary system that defines the crystallization of basalt glass melts. The modeling provides the partitioning of species between the melt and the primary liquidus phases. The medium-range order of the melt and the melt-crystal exchange equilibria are defined based on a constrained mathematical treatment that considers the crystallochemical coordination of the elemental species in acmite and nepheline. The liquidus phases that form are shown to be governed by the melt polymerization (Part II) and the thermodynamic octahedral site preference energies (Part I). The liquidus model developed based on these concepts has been used to prevent unwanted crystallization in the world's largest HLW melter for the past 4 years while allowing >10 wt% higher waste loadings to be processed. 相似文献
24.
25.
Ljubinko?Levi? Julianna?Gyura Mirjana?Djuri?Email author Tatjana?Kuljanin 《European Food Research and Technology》2005,220(1):70-73
The aim of this investigation was to find the optimal working conditions for the chemical treatment of molasses that guarantee coagulation and precipitation of undesired macromolecules. Twenty experiments were performed, within the limits: 3.5pH8.5 and 0.1 mol Al/lc0.5 mol Al/l, on samples of molasses treated with Al2(SO4)3 as a precipitant. The efficiency of the treatment was controlled through measuring both the zeta potential and solution absorbance at 560 nm. By analysing the experimental results, it was concluded that the optimum lies within reduced limits of: 4pH7 and 0.2 mol Al/lc0.4 mol Al/l, which covers nine experimental points. Based on these measurements, a mathematical model of absorbance changes was defined, in terms of pH and Al2(SO4)3 quantity. The model was taken as the objective function, and the optimal calculated values were obtained: pH=5.3 and c=0.34 mol Al/l. They guarantee a minimal absorbance value of: 0.124 at 560 nm. 相似文献
26.
Marina M. Radišić Tatjana M. Vasiljević Nikolina N. Dujaković Mila D. Laušević 《Food Analytical Methods》2013,6(2):648-657
This study presents an application of rapid and sensitive multiresidue method for the analysis of acephate, acetamipride, atrazine, carbendazim, carbaryl, carbofuran, dimethoate, imidacloprid, linuron, malathion, monocrotophos, monuron, propazine, simazine, and tebufenozide in fruits. The method involves an extraction procedure based on matrix solid-phase dispersion using diatomaceous earth as a dispersant and dichloromethane as the eluent. The target pesticides were determined using liquid chromatography–ion trap mass spectrometry. Quantification of the analytes was carried out using the most sensitive ion transition. Ion trap parameters, like activation q and time, were found to have a prominent influence on method sensitivity for some pesticides and they were optimized accordingly. The confirmation of residues detected in real samples was performed by repeated injection and acquiring additional ion transitions besides the ones used for quantification. The method was validated for accuracy, linearity, reproducibility, and sensitivity. Mean values for recoveries were in the range of 70–120 % for all tested matrices. Repeatability of the method, expressed as the relative standard deviation, was in general lower than 20 %. The applicability of the method to routine analysis was tested in real fruit samples with good performance. 相似文献
27.
Wolfgang Augustin Tatjana Fuchs Henning Föste Martin Schöler Jens-Peter Majschak Stephan Scholl 《Food and Bioproducts Processing》2010,88(4):384-391
The use of slow (~1 Hz) flow oscillation imposed on a stationary flow of liquid has been shown to enhance shear stresses imposed on a surface and to mitigate fouling or enhance cleaning. Examples of the application of pulsed flow are presented in this paper. A new measuring technique in combination with tailored CFD simulations was developed for monitoring the cleaning of complex piping equipment with pulsed flow. A time-independent and isotropic approach to model the wall shear stress is introduced. The optical monitoring procedure uses a model food soil consisting of starch as matrix material and phosphorescent zinc sulfide crystals as optical tracer. Investigations of pulsed flow cleaning published prior to this work focused on tests with straight pipes, whereas difficulties in industrial cleaning operations more often arise while operating piping systems and plant components with complex geometries. Therefore cleaning experiments were performed in a CIP test rig simulating industrial cleaning processes. The results with pulsed flow show an enhancement of cleaning efficiency at locations difficult to access using stationary flow. 相似文献
28.
29.
Tatjana V. Sibalija Sanja Z. Petronic Vidosav D. Majstorovic Radica Prokic-Cvetkovic Andjelka Milosavljevic 《The International Journal of Advanced Manufacturing Technology》2011,54(5-8):537-552
This paper presents a hybrid design strategy for the determination of the optimum laser drilling parameters which simultaneously meets the requirements for seven quality characteristics (responses) of the holes produced during pulsed Nd:YAG laser drilling of a thin sheet of nickel-based superalloy Nimonic 263. The process was designed using two approaches based on the experimental data. In the first approach, the quality losses of seven correlated responses were uncorrelated into a set of components using the principal component analysis; then the grey relational analysis was applied to synthesise components into a synthetic performance measure. Since this approach considered only parameter values used in the experiment, the second approach was developed to find the global optimal parameters solution using an artificial neural network to model the relation between parameters and a synthetic performance measure, and a genetic algorithm to perform a search for the global optimum in a continual multidimensional space. The analysis of the application indicated that the proposed approaches gave a better result, in terms of the optimal parameter settings that yield the maximal synthetic performance measure, than several commonly used methods for multi-response process parameters design. The results demonstrated that the robust Nd:YAG laser drilling of Ni-based superalloy sheets was designed with respect to the requirements for seven quality characteristics of the drilled holes, by using the proposed strategy. 相似文献
30.
Data from total synchronous fluorescence spectroscopy (TSFS) measurements of normal and malignant breast tissue samples are introduced in supervised self-organizing maps, a type of artificial neural network (ANN), to obtain diagnosis. Three spectral regions in both TSFS patterns and first-derivative TSFS patterns exhibited clear differences between normal and malignant tissue groups, and intensities measured from these regions served as inputs to neural networks. Histology findings are used as the gold standard to train self-organizing maps in a supervised way. Diagnostic accuracy of this procedure is evaluated with sample test groups for two cases, when the neural network uses TSFS data and when the neural network uses data from first-derivative TSFS. In the first case diagnostic sensitivity of 87.1% and specificity of 91.7% are found, while in the second case sensitivity of 100% and specificity of 94.4% are achieved. 相似文献