全文获取类型
收费全文 | 146篇 |
免费 | 13篇 |
专业分类
化学工业 | 42篇 |
金属工艺 | 2篇 |
机械仪表 | 2篇 |
建筑科学 | 3篇 |
能源动力 | 13篇 |
轻工业 | 11篇 |
水利工程 | 2篇 |
石油天然气 | 4篇 |
无线电 | 5篇 |
一般工业技术 | 49篇 |
冶金工业 | 3篇 |
自动化技术 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 14篇 |
2020年 | 8篇 |
2019年 | 14篇 |
2018年 | 12篇 |
2017年 | 13篇 |
2016年 | 7篇 |
2015年 | 5篇 |
2014年 | 11篇 |
2013年 | 16篇 |
2012年 | 16篇 |
2011年 | 10篇 |
2010年 | 3篇 |
2009年 | 5篇 |
2008年 | 2篇 |
2007年 | 5篇 |
2006年 | 2篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1997年 | 1篇 |
1995年 | 1篇 |
1992年 | 1篇 |
1984年 | 1篇 |
排序方式: 共有159条查询结果,搜索用时 0 毫秒
151.
Aamir Saghir Subhabrata Chakraborti Ishfaq Ahmad 《Quality and Reliability Engineering International》2017,33(3):637-656
A phase‐I study is generally used when population parameters are unknown. The performance of any phase‐II chart depends on the preciseness of the control limits obtained from the phase‐I analysis. The performance of phase‐I bivariate dispersion charts has mainly been investigated for bivariate normal distribution. However, this assumption is seldom fulfilled in reality. The current work develops and studies the performance of phase‐I |S| and |G| charts for monitoring the process dispersion of bivariate non‐normal distributions. The necessary control charting constants are determined for the bivariate non‐normal distributions at nominal false alarm probability (FAP0). The performance of these charts is evaluated and compared in a situation when samples are generated by bivariate logistic, bivariate Laplace, bivariate exponential, or bivariate t5 distribution. The analysis shows that the proper consideration to underlying bivariate distribution in the construction of phase‐I bivariate dispersion charts is very important to give a real picture of in or out of control process status. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
152.
In this paper, we consider the (k+1)-order rational difference equation
153.
154.
Mohammad Fahiminia Narges Sadat Shamabadi Mahmoud Nasrollahzadeh S. Mohammad Sajadi 《IET nanobiotechnology / IET》2019,13(2):202
For the first time, copper nanoparticles (Cu NPs) superficially deposited on reduced graphene oxide (rGO) using Euphorbia cheiradenia Boiss leaf aqueous media. A beneficial series of analytical methods was used to characterise E. cheiradenia Boiss leaf extract and involved nanostructures. The Cu/rGO nanocomposite (NC) obtained from the conversion of Cu2+ ions to Cu NPs and GO to rGO undergoes the plant extract and used as a heterogeneous and reusable nanocatalyst for the destruction of 4‐nitrophenol, rhodamine B, methylene blue, methyl orange and congo red using sodium borohydride at ambient temperature. In addition, Cu/rGO NC has reusability for many times in the reduction reactions with no decreasing of its catalytic capability.Inspec keywords: catalysts, nanofabrication, nanocomposites, dyes, nanoparticles, reduction (chemical), copper, graphene compoundsOther keywords: phytosynthesis, organic dyes, reusable nanocatalyst, Euphorbia cheiradenia Boiss extract, 4‐nitrophenol, nanoparticles, graphene oxide, nanocomposites, methylene blue, methyl orange, congo red, sodium borohydride, catalytic capability, Cu‐CO 相似文献
155.
Mohammad Ali Karambeigi Narges Fallah Manouchehr Nikazar Riyaz Kharrat 《Petroleum Science and Technology》2019,37(11):1238-1242
Asphaltene deposits can reduce the productivity of the reservoir as well as foul piping and surface equipment. Current chemical and mechanical methods for treating deposition are only partially effective partly because the deposition process is poorly understood. The most commonly way to asphaltene precipitation reduction is applying an asphaltene inhibitor. In order to investigate the extent of formation damage by asphaltenes in crude oil this work has used electro kinetic technique to study the adsorption of asphaltenes in rock pores. Most researchers investigate the kinetics of adsorption by monitoring changes in the concentration of asphaltene or polymer in a dispersion of adsorbent particles or capillaries. This study is a coherent approach to measure amount of asphaltene adsorption on rock surface and survey effect of asphaltene inhibitors on precipitation reduction in porous media. 相似文献
156.
Elder EJ Evans JC Scherzer BD Hitt JE Kupperblatt GB Saghir SA Markham DA 《Drug development and industrial pharmacy》2007,33(7):755-765
Many new molecular entities targeted for pharmaceutical applications face serious development challenges because of poor water solubility. Although particle engineering technologies such as controlled precipitation have been shown to enhance aqueous dissolution and bioavailability of poorly water soluble active pharmaceutical ingredients, the data available are the results of laboratory-scale experiments. These technologies must be evaluated at larger scale to ensure that the property enhancement is scalable and that the modified drugs can be processed on conventional equipment.
In experiments using ketoconazole as the model drug, the controlled precipitation process was shown to produce kg-scale modified drug powder with enhanced dissolution comparable to that of lab-scale powder. Ketoconazole was demonstrated to be stable throughout the controlled precipitation process, with a residual methanol level below the ICH limit. The modified crystalline powder can be formulated, and then compressed using conventional high-speed tableting equipment, and the resulting tablets showed bioavailability more than double that of commercial tablets. When appropriately protected from moisture, both the modified powder and tablets prepared from the modified powder showed no change in dissolution performance for at least 6 months following storage at accelerated conditions and for at least 18 months following storage at room temperature. 相似文献
In experiments using ketoconazole as the model drug, the controlled precipitation process was shown to produce kg-scale modified drug powder with enhanced dissolution comparable to that of lab-scale powder. Ketoconazole was demonstrated to be stable throughout the controlled precipitation process, with a residual methanol level below the ICH limit. The modified crystalline powder can be formulated, and then compressed using conventional high-speed tableting equipment, and the resulting tablets showed bioavailability more than double that of commercial tablets. When appropriately protected from moisture, both the modified powder and tablets prepared from the modified powder showed no change in dissolution performance for at least 6 months following storage at accelerated conditions and for at least 18 months following storage at room temperature. 相似文献
157.
Amir Abdolmaleki Hamidreza Gharibi Mohammad Reza Molavian Mohammad-Reza Norouzi Narges Asefifeyzabadi 《应用聚合物科学杂志》2021,138(32):50778
Due to the unique biophysicochemical characteristics of synthesized superhydrophilic poly[N-[tris(hydroxymethyl)methyl] acrylamide] (PTHMMA) and poly(vinyl alcohol) (PVA), in this study, we investigated the preparation of physically and chemically crosslinked thermosensitive double network (DN) hydrogels with superior mechanical properties. The effect of the combination of PTHMMA with PVA was further explored experimentally and theoretically. Moreover, adjusting the lower critical solution temperature (LCST) of PTHMMA/PVA DN hydrogels in the phosphate buffer was achieved by chemical alteration and crosslinking of water-soluble polymers. Changing the composition and the extent of ether/acetal linkages altered the LCST based on hydrophilic/hydrophobic composition, which decreased the complexity of adjusting hydrogels' temperature sensitivity. PTHMMA-comprising hydrogels were found to have non-Fickian and super case ΙΙ transport characters. Moreover, the construction of shrunken PVA at high temperature was tailored by introducing PTHMMA into the network to permit a relaxed drug release of indomethacin (IND) at 37°C and pH 7.4. Finally, the tensile strength, the equilibrium water content, thermo-sensitivity, and cell viability behaviors suggest that these materials can be tailored for potential applications as biomaterials. 相似文献
158.
Narges Hadjesfandiari Mona Khorshidfar Dana V. Devine 《International journal of molecular sciences》2021,22(8)
While differences among donors has long challenged meeting quality standards for the production of blood components for transfusion, only recently has the molecular basis for many of these differences become understood. This review article will examine our current understanding of the molecular differences that impact the quality of red blood cells (RBC), platelets, and plasma components. Factors affecting RBC quality include cytoskeletal elements and membrane proteins associated with the oxidative response as well as known enzyme polymorphisms and hemoglobin variants. Donor age and health status may also be important. Platelet quality is impacted by variables that are less well understood, but that include platelet storage sensitive metabolic parameters, responsiveness to agonists accumulating in storage containers and factors affecting the maintenance of pH. An increased understanding of these variables can be used to improve the quality of blood components for transfusion by using donor management algorithms based on a donors individual molecular and genetic profile. 相似文献
159.
This paper attempts to identify origins of inefficient used resource for greenhouse strawberry production in Tehran. A nonparametric method, data envelopment analysis (DEA), was used to study the technical efficiency of producers with regard to effective energy utilization on strawberry yield. Data for the production of strawberries were collected from 25 greenhouses by using a face-to-face questionnaire method. Both constant and variable returns to scale DEA models were used to evaluate and rank technical efficiency of greenhouses based on four energy inputs: fertilizer, human labor, diesel fuel, and electricity. Pure technical efficiency specification shows that 10 greenhouses are producing at an efficient scale. The study has also helped to segregate efficient greenhouses from inefficient ones to get insights into the performance of individual producers, to identify wasteful uses of energy, and to suggest reasonable savings in energy uses from different sources. The results reveal that, on an average, about 16% of the total input energy could be saved if the producers follow the input package recommended by the study. The results of analysis show that DEA is a pivotal tool for analyzing productive efficiency of agricultural units. 相似文献