全文获取类型
收费全文 | 121篇 |
免费 | 5篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 1篇 |
化学工业 | 56篇 |
金属工艺 | 2篇 |
机械仪表 | 3篇 |
建筑科学 | 2篇 |
能源动力 | 8篇 |
轻工业 | 4篇 |
水利工程 | 1篇 |
石油天然气 | 3篇 |
无线电 | 9篇 |
一般工业技术 | 22篇 |
冶金工业 | 5篇 |
原子能技术 | 2篇 |
自动化技术 | 11篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 2篇 |
2021年 | 8篇 |
2020年 | 5篇 |
2019年 | 11篇 |
2018年 | 9篇 |
2017年 | 8篇 |
2016年 | 8篇 |
2015年 | 7篇 |
2014年 | 3篇 |
2013年 | 15篇 |
2012年 | 12篇 |
2011年 | 8篇 |
2010年 | 5篇 |
2009年 | 4篇 |
2008年 | 4篇 |
2007年 | 4篇 |
2006年 | 1篇 |
2001年 | 1篇 |
1999年 | 1篇 |
1995年 | 2篇 |
1994年 | 2篇 |
1993年 | 1篇 |
1992年 | 1篇 |
1990年 | 2篇 |
1987年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有129条查询结果,搜索用时 17 毫秒
101.
Transparent heat mirrors based on tungsten oxide/silver three-layer structures were fabricated using thermal evaporation. The optical and morphological properties of the single layers were first investigated to serve as a basis for the fabrication of the heat mirrors. Only silver films with a thickness higher than 18 nm were found to be continuous. Subsequently, WO3/Ag/WO3 multilayers were deposited, where the WO3 layers thickness was fixed at 35 nm, and the thickness of the silver layer was varied from 18 to 39 nm. The optical properties of the multilayers were measured over the visible and near infrared ranges. These multilayers exhibited the desired heat mirror behavior, namely the transmittance was largely confined to the visible range and the reflectance was diminished in that range. The maximum visible transmittance was 88.3% at 554 nm. Increasing the thickness of the silver films resulted in a decrease of the visible transmittance, with a corresponding increase in the infrared reflectance. Optimization of these two opposing trends was evaluated using a figure of merit, from which the best performance was obtained for multilayers with a silver layer of thickness of 24 nm. 相似文献
102.
Ghasem Bakhtiari Hamid Ghassabzadeh Sayed Javid Royaee Majid Abdouss Mansour Bazmi 《石油科学(英文版)》2019,(2):417-427
This paper summarizes the results of a study of adsorption of sulfur compounds from a high-sulfur feed on improved spherical-shaped nano-AgX zeolite. For this purpose, the nano-AgX zeolite was initially synthesized and improved with silver compounds such as silver nitrate, and then it was utilized in the adsorption process. In order to investigate the equilibrium and dynamics of the adsorption process, adsorptive desulfurization of real feed(i.e., sour gas condensate from the South Pars gas field) was carried out in batch and continuous processes under several operating conditions; a temperature-dependent Langmuir isotherm model was used to fit the equilibrium data. The value of monolayer adsorption capacity(q_m) and adsorption enthalpy(ΔH) were calculated to be 1.044 mmol/g and 16.8 kJ/mol, respectively. Furthermore, a detailed theoretical model was employed in order to model the breakthrough experiments. The results revealed that an increase in the feed flow rate and 1/T values will cause linear and exponential increase in the total mass transfer coefficient(ks). Isotherm and dynamic breakthrough models were found to be in agreement with the experimental data. 相似文献
103.
Bahram Kamarehie Ali Jafari Mohammad Amin Karami Khadijeh Mousavi Afshin Ghaderpoury 《Chemical Engineering Communications》2019,206(7):898-908
In the catalytic ozonation process used in this study, adsorption and chemical reactions were performed at the catalyst surface. This process can increase the efficiency of plain ozonation. The main aim of this study was to investigate the efficiency of the catalytic ozonation process in removing Alizarin Red S dye from colored water by Fe2O3 coated on PAC. In this work, activated carbon powder/γ-Fe2O3 nano-composite was modified. The BET results showed that the surface area in PAC and PAC-γ-Fe2O3 nano-composite was 654 and 450?m2 g?1, respectively. In this study, the best pH for removal of ARS was found to be 9. At a higher pH, the efficiency of the process decreased gradually. According to studies, catalysts increase surface area and active sites for more ozone degradation. Also, the characterization of the catalyst will play a very important role in the COP. Also, the maximum removal efficiency was observed in catalyst dose 1.1?g l?1. The study results showed that the highest mineralization rate in ARS degradation was related to O3/PAC/γ-Fe2O3. The amount of mineralization in the SOP, O3-PAC, and O3/PAC/γ-Fe2O3 was 13, 25, and 40%, respectively. The finding of mineralization of ARS using the SOP reflected the low power of the ozonation process for the mineralization of pollutants. 相似文献
104.
Chemical stability and reactivity of organic pollutants is dependent to their formation enthalpies. The main objective of this study is to provide simple straightforward strategy for prediction of the formation enthalpies of wide range organic pollutants only from their structural functional groups. Using such an extended dataset comprising 1694 organic chemicals from 77 diverse material classes benefits the generalizability and reliability of the study. The new suggested collection of 12 functional groups and a simple linear regression lead to promising statistics of R2=0.958, QLoo2=0.956, and δAEE=57 kJ·mol-1 for the whole dataset. Moreover, unknown experimental formation enthalpies for 27 organic pollutants are estimated by the presented approach. The resultant model needs no technical software/calculations, and thus can be easily applied by a non-specialist user. 相似文献
105.
Mehrdad Bakhtiari Aouni A. Lakis Youcef Kerboua 《Journal of Mechanical Science and Technology》2020,34(4):1375-1388
A numerical model was developed to investigate the flutter instability of truncated conical shells subjected to supersonic flows. The exact solution of Sanders’ best firstorder approximation was used to develop the finite elements model of the shell. Nonlinear kinematics of Donnell’s, Sanders’ and Nemeth’s theories, in conjunction with the generalized coordinates method, were used to formulate the nonlinear strain energy of the shell. A pressure field was formulated using the piston theory with the correction term for the curvature. Lagrangian equations of motion based on Hamilton’s principle were obtained. A variation of the harmonic balance method was used for developing the amplitude equations of the shell, and a numerical method was used for solving these equations. Results of linear and nonlinear flutter of truncated conical shells were validated against the existing data in the literature. It was observed that geometrical nonlinearities have a softening effect on the stability of the shell in supersonic flows. 相似文献
106.
Sample calculations were performed with a three-dimensional (3D) finite-element model to describe the response of an eddy current (EC) probe to defects in steam generator (SG) tubing. Such calculations could be very helpful in understanding and interpreting EC probe response to complex tube/defect geometries associated with the inservice inspection (ISI) of SG tubes. The governing field equations are in terms of coupled magnetic vector and electric scalar potentials in conducting media and of total or reduced scalar potentials in nonconducting regions. To establish the validity of the model, comparisons of the theoretical and experimental responses of an absolute bobbin probe are given for two types of calibration standard defects. Simulation results are also presented on the effect of ligament size in axial cracks on bobbin probe response. 相似文献
107.
108.
Zeolitic imidazolate frameworks (ZIF‐8) nanoparticles were successfully synthesized and embedded into a chitosan (CS) polymeric matrix to prepare CS/ZIF‐8 mixed‐matrix membranes (MMMs) in order to investigate the effect of ZIF‐8 addition as novel filler on the dehydration performance of the CS polymeric membrane. MMMs were evaluated using pervaporation (PV) dehydration of isopropanol (IPA). The synthesized ZIF‐8 nanoparticles and MMMs were characterized by X‐ray diffraction, scanning electron microscopy, energy‐dispersive X‐ray spectroscopy, Fourier transform infrared spectroscopy, and a swelling study. The PV performance of the prepared MMMs with different ZIF‐8 loadings for IPA dehydration was investigated. For the ZIF‐8/CS MMMs, at the optimum loading the total flux increases significantly with low separation factor reduction. The good PV performance of the ZIF‐8‐incorporated CS membranes for dehydration of IPA is demonstrated. 相似文献
109.
The efficient delivery of daunorubicin loaded poly (lactic acid) (PLA)/multiwalled carbon nanotubes (MWCNT)/Fe3O4 composite nanofibers was investigated. The synthesized nanofibers were characterized using SEM, TEM, and XRD analysis. The proliferation inhibition effect of PLA/MWCNT/Fe3O4 nanofibrous scaffolds on leukemia K562 cell lines was investigated. The effect of nanofiber concentration on the daunorubicin delivery in the absence and presence of external magnetic field was also evaluated. The results indicated that the incorporation of daunorubicin into the prepared nanofibrous scaffold under applied magnetic field could have synergistic cytotoxic effect on leukemia cancer cells. The drug release mechanism followed the non-Fickian transport. 相似文献
110.