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141.
电网的大规模互联成为世界范围内电力系统发展的必然趋势。现代电力系统的强非线性和高维等复杂特性,使得传统的理论分析方法已不能较好地分析复杂电网的动态行为及由电网连锁反应故障造成的大面积停电事故的成因。作为科学的方法论,综合集成方法论综合了计算机网络技术、数据融合技术、知识与信息及专家群体智能的各方面优势,其应用在研究方式和工作方式上都突破了传统还原论思想的束缚。从复杂性科学的角度,介绍了复杂电力系统的特征,并着重论述了应用研究复杂系统的方法论——从定性到定量综合集成方法进行电力系统灾变防治研究的方法。 相似文献
142.
143.
A. Srivastava K. Hacker K. Lewis T.W. Simpson 《Structural and Multidisciplinary Optimization》2004,28(2-3):146-155
Despite a steady increase in computing power, the complexity of engineering analyses seems to advance at the same rate. Traditional parametric design analysis is inadequate for the analysis of large-scale engineering systems because of its computational inefficiency; therefore, a departure from the traditional parametric design approach is required. In addition, the existence of legacy data for complex, large-scale systems is commonplace. Approximation techniques may be applied to build computationally inexpensive surrogate models for large-scale systems to replace expensive-to-run computer analysis codes or to develop a model for a set of nonuniform legacy data. Response-surface models are frequently utilized to construct surrogate approximations; however, they may be inefficient for systems having with a large number of design variables. Kriging, an alternative method for creating surrogate models, is applied in this work to construct approximations of legacy data for a large-scale system. Comparisons between response surfaces and kriging are made using the legacy data from the High Speed Civil Transport (HSCT) approximation challenge. Since the analysis points already exist, a modified design-of-experiments technique is needed to select the appropriate sample points. In this paper, a method to handle this problem is presented, and the results are compared against previous work. 相似文献
144.
Today, they are students in colleges and universities. Tomorrow, they will be engineers in various industrial sectors. One of the primary goals of education is to prepare people for successful careers in the real world. As in every course, students want to obtain the maximum value of a CAD related course for their future careers. They want to obtain knowledge and skills that are most practical and useful to them when they become engineers. College professors and teachers also want to provide the maximum value for students in their CAD courses. The question is: what should be included in such a CAD curriculum. This paper tries to answer some critical questions related to developing such a curriculum, from an industrial perspective, based on the authors' survey results and the first author's own (rather limited) experiences as a R&D staff for a CAD vendor. It focuses on issues related to teaching and training students on CAD systems. These include, for different roles, how much underlying mathematical foundations in CAD systems should be taught, how much computer skills and engineering knowledge the students should know, how much design methodologies related to CAD systems should be taught, and how much ability the students should develop in order to specify their CAD needs and to evaluate and choose the CAD systems most suitable for their specific applications. The paper then shares some personal experiences and suggestions from long-term CAD veterans on the essential topics of CAD education. Based on the survey results, last section concludes the paper by authors' suggestions on what should be included in CAD curriculums for different levels of students. 相似文献
145.
《电子商务概论》教学方法探讨 总被引:4,自引:0,他引:4
吴凌娇 《常州信息职业技术学院学报》2004,3(3):54-56,60
《电子商务概论》是一门广泛涉及多种学科的电子商务专业基础课程。为提高该课程的教学质量,本文从培养学生学习兴趣、提高课堂教学效率、教学文档透明化、课内课外学习有效结合四个方面,对该课程的教学方法进行了积极探讨。 相似文献
146.
战略规划方法比较研究 总被引:1,自引:0,他引:1
分析总结了我国现阶段出现的大量战略规划,归纳了问题导引法、目标论证法、综合竞争力要素分析法、多平台研究法、实施策略研究法及战略环境评价法等六种战略规划的基本方法.对各种方法进行了比较与分析,提出战略规划的方法应随着城市发展的推进不断更新和系统化. 相似文献
147.
Wang YunliXiao TianyuanDuan GuanghongWang XiankuiNational CIMS EngineeringResearch Center Tsinghua University Beijing China 《机械工程学报(英文版)》2003,16(4):348-351
A design methodology fOr multi-agent systems is proposed. The systemic framework ofCAPP and scheduling integrated multi-agent system according to design methodology is researched.Agent model, composition model and cooperation model are discussed respectively in the multi-agentsystem.Static composition model and dynamic running model of CAPP and scheduling integrated 相似文献
148.
Influence of konjac flour on foaming properties of milk protein concentrate and quality characteristics of gluten‐free cookie
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Adisak Akesowan 《International Journal of Food Science & Technology》2016,51(7):1560-1569
The effects of konjac flour (KF) for modifying the foaming properties of milk protein concentrate (MPC) and characteristics of gluten‐free rice cookies were investigated. The three variables of konjac concentration (0.1–0.4%), pH (pH 5–9) and NaCl concentration (0.2–0.6 м) were studied. Both KF and pH had considerable effects on the foaming capacity (FC) and foaming stability (FS) of MPC. The NaCl had a negligible effect. Lowered FC and FS observed at pH 9 and pH 5 were increased with the increase in KF addition. Batter characteristics (flowability and consistency), cookie quality (moisture, yield, spread ratio, specific volume, hardness and colour) and sensory acceptance were evaluated in gluten‐free cookies with 0%, 0.25% and 0.4% KF. Konjac supplementation increased batter characteristics, yield, specific volume and hardness, but decreased lightness. Panellist acceptance, especially regarding texture and overall acceptability, increased in gluten‐free cookies with 0.4% KF. A higher purchasing decision was found for cookies with added KF. 相似文献
149.
Response surface methodology was advantageously used to optimally immobilise a β-galactosidase from chick pea onto alkylamine glass using Box–Behnken experimental design, resulting in an overall 91% immobilisation efficiency. Analysis of variance was performed to determine the adequacy and significance of the quadratic model. Immobilised enzyme showed a shift in the optimum pH; however, optimum temperature remained unaffected. Thermal denaturation kinetics demonstrated significant improvement in thermal stability of the enzyme after immobilisation. Galactose competitively inhibits the enzyme in both soluble and immobilised conditions. Lactose in milk whey was hydrolysed at comparatively higher rate than that of milk. Immobilised enzyme showed excellent reusability with retention of more than 82% enzymatic activity after 15 uses. The immobilised enzyme was found to be fairly stable in both dry and wet conditions for three months with retention of more than 80% residual activity. 相似文献
150.
Reactive extraction was experimentally investigated for recovery of gallic acid (GA) from the aqueous solution using tri-n-octylamine (TOA) as extractant in hexanol. All experiments were carried out according to statistical design in order to develop a regression model used to optimize the extraction of GA. Two independent variables were selected as: initial concentration of GA (CGA0) in aqueous phase and concentration of TOA (CTOA) in organic phase. The statistical analysis showed that both the independent variables had significant effect on response value, followed by the quadratic and interactive effect on response. A five-level central composite rotatable design (CCRD) was employed. Analysis of variance (ANOVA) showed a high coefficient of determination (R2?=?99.0%). The optimal extraction conditions of GA were determined as: CGA0?=?2.01?g/L, CTOA?=?6.8% v/v. At the optimum conditions, the experimental yield of GA was 91.9%, which was in close agreement with the predicted value of 93.2%. 相似文献