首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   44篇
  免费   6篇
电工技术   1篇
化学工业   19篇
金属工艺   2篇
机械仪表   2篇
建筑科学   3篇
矿业工程   1篇
能源动力   3篇
轻工业   3篇
水利工程   1篇
石油天然气   1篇
无线电   6篇
一般工业技术   5篇
冶金工业   1篇
自动化技术   2篇
  2022年   1篇
  2021年   3篇
  2020年   1篇
  2019年   5篇
  2018年   1篇
  2017年   3篇
  2016年   3篇
  2015年   2篇
  2014年   3篇
  2013年   7篇
  2012年   6篇
  2011年   5篇
  2010年   4篇
  2008年   3篇
  2007年   1篇
  2006年   1篇
  1999年   1篇
排序方式: 共有50条查询结果,搜索用时 515 毫秒
1.
2.
The Quantitative Strategic Planning Matrix (QSPM) is a useful tool to prioritize strategies at any level including corporate, business and functional. The ratings and attractive scores used in QSPM, however, require judgmental decisions and should be based on expert's opinion to ensure the applicability of chosen strategies. Application of a fuzzy multi-criteria decision making method is proposed in this paper with the goal of improving the output of conventional QSPM by allowing the experts to employ linguistic terms (qualitative data) in their judgments. Namely, a multi-criteria decision making index via the technique for Order Preference by Similarity to Ideal Solution (TOPSIS) is adapted to the fuzzy QSPM in finding the sum total attractive scores of strategies. As a case study, the proposed method has been applied for strategy prioritization in a Tile Company. The results have been verified with expert knowledge and showed an improvement compared to the non-fuzzy QSPM.  相似文献   
3.
A novel monomer containing a triaryl imidazole pendent group was successfully synthesized by nucleophilic substitution of bisphenol A with 2-(2-chloro-5-nitrophenyl)-4,5-diphenyl-1H-imidazole (I). A series of new polyamides (PAs) with inherent viscosities of 0.95–1.2 dL/g was prepared by direct polycondensation of the diamine with various dicarboxylic acids. These PAs were readily soluble in many organic solvents and gave tough and flexible films by solution casting. These PAs exhibited Tgs between 189 °C and 252 °C, and 10% weight loss temperatures in excess of 400 °C with up to 68% char yield at 600 °C in air. All of the PAs emitted a greenish-yellow light in dilute THF solution, with photoluminescence (PL) quantum yields in the range of 10–25%. The chemiluminescent activity and electrochemical oxidation of the PAs were also investigated.  相似文献   
4.
Geoelectrical surveys were conducted in Area 3 of the Gol-e-Gohar iron ore mine to provide geological and hydrogeological information. Open pit mining is currently underway in the northern part of the Area, and underground mining operations are planned for the southern section. Groundwater has already been encountered in the open pit mine. Twenty five resistivity soundings were first performed in the mine area; then, induced polarization (IP) measurements were carried out to remove ambiguities between clay and water-bearing layers. To investigate fault zones as water conduits, combined resistivity profiling surveys were also carried out. These measurements provided a detailed structural map of the pit area. Resistivity and IP results have subsequently been confirmed by observations at three monitoring wells and the mine pit wall. Monitoring and piezometric wells will be drilled at locations suggested by the results of the geoelectrical surveys. Drainage galleries may be developed to dewater the open pit mine. However, another option being considered is to start the underground mining with the idea that it will initially simply serve as a dewatering mechanism.  相似文献   
5.
计算高频RF电路中的负载阻抗与功耗是一件繁琐的任务。这里介绍的设计实例描述了利用VI(虚拟仪器)简单、迅速而有效地测量这些参数。可以测量并显示各种类型负载(如电阻回路或串联/并联谐振回路)在任何特定频率下的功耗和阻抗。使用National Instruments公司(www.ni.com)的LabView可以轻松修改Ⅵ,以适应任何复杂程度的各类负载。虚拟RF发生器由电源、放大器及负载选择/测量显示模块构成。  相似文献   
6.
The deposition of aerosol particles in laminar mixed-convection flow in a lid-driven cavity with two heated obstacles is investigated numerically by an Eulerian–Lagrangian method. Lagrangian particle transport calculations are carried out to track 2000 particles that initially exerted with random distribution in flow regime and also assumed that the effect of particles on the fluid is neglected. All the affecting forces on particle equation of motion, such as Brownian, thermophoresis, drag, lift and gravity are considered. The main goal is to study the effective parameter on deposition of particles such as free convection, distance and size variation of obstacles. Numerical results showed that free convection is an effective parameter that affected the deposition. As a main result, it is observed that deposition decreases with increasing in the Richardson number. Results showed that by increasing obstacles distance, deposition increases. Finally, it is revealed that the size of obstacles has a great effect on particle deposition, such that by increasing the obstacles size, the deposition increases.  相似文献   
7.
Highly selective molecularly imprinted polymer (MIP) was synthesized by using methacrylic acid as functional monomer, trimethylolpropane trimethacrylate as cross-linker, chloroform as porogen and penicillin G potassium as template molecule. These imprinted polymers were used as solid-phase extraction sorbent for the selective extraction of penicillin G from the fermentation broth samples. Various parameters affecting the extraction efficiency of the MIP particles such as; effects of pH, wash and eluent solutions were evaluated. Molecular recognition properties and selectivity of these MIPs were estimated and the obtained results revealed high affinity for the target antibiotic. Equilibrium binding experiments were done to assess the performance of the MIP relative to non imprinted polymer (NIP). After optimizing the extraction parameters in molecularly imprinted solid-phase extraction (MISPE), successful imprinting was confirmed by comparison of the recoveries from the fermentation broth, ranging between 24–26% (RSD 4.1–4.5%, n = 4) for the NIPs and 83–88% (RSD 3.1–3.4%, n = 4) for the MIPs.  相似文献   
8.
In this paper, an efficient method is developed for the formation of null bases of four-node quadrilateral plate bending finite element models, corresponding to highly sparse and banded flexibility matrices. This is achieved by introducing a new four-node quadrilateral plate bending element, and using special graphs associated with the finite element models. The results are compared to those of the previously developed graph theoretical and algebraic force methods, and also the displacement approach.  相似文献   
9.
This article investigates the effect of nanoparticles on mass transfer in the liquid–liquid extraction for the chemical system of n-butanol–succinic acid–water. For this purpose, nanofluids containing various concentrations of ZnO, carbon nanotubes (CNT), and TiO2 nanoparticles in water, as base fluid, were prepared. To examine the flow mode effect on mass transfer rate, different fluid modes including dropping and jetting were employed in the process. Results show that mass transfer rate enhancement depends on the kinds and the concentration of nanoparticles and the modes of flow. It was observed that after adding nanoparticles, the mass transfer rate significantly increases up to two-fold for ZnO nanoparticles. Furthermore, the results indicate that under the circumstances in which the mass flow rate is high enough, the effect of nanoparticles on the mass transfer phenomenon is too slight.  相似文献   
10.
In this paper, we investigate the performance assessment of a bidirectional relaying system using energy harvesting techniques. We assume independent and nonidentically distributed (i.n.i.d.) Nakagami‐m fading channels where the amplify‐and‐forward relay is subject to co‐channel interference (CCI) due to transmissions of other transmitters. Two different scenarios, namely, scenario I and scenario II are evaluated. In scenario I, both end‐sources provide the required energy for the relay, whereas the relay also harvests energy from the co‐channel interferes. Then, in the first phase of cooperation, both end‐sources send the information to the relay, and after amplifying the received signal, relay transfers information to the appropriate destination in the second time‐slot. In the scenario II, both end‐sources harvest energy from the relay. After that, the information cooperative transmission is done similar to the first scenario. For both considered scenarios, tight closed‐form expressions of outage probability, symbol error probability, ergodic capacity, and throughput are obtained at arbitrary signal‐to‐noise‐ratios (SNRs). To get more insights, simplified high SNR results for both scenarios are also deduced where the diversity orders are obtained. Monte Carlo simulation results are presented to validate the correctness of our proposed analysis. Our results explicitly demonstrate that the first scenario has a better performance than the second one in the medium and high SNR region, whereas the second scenario outperforms the first one in the low SNR regime.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号