全文获取类型
收费全文 | 589篇 |
免费 | 26篇 |
国内免费 | 23篇 |
专业分类
电工技术 | 6篇 |
综合类 | 19篇 |
化学工业 | 116篇 |
金属工艺 | 12篇 |
机械仪表 | 27篇 |
建筑科学 | 26篇 |
矿业工程 | 8篇 |
能源动力 | 37篇 |
轻工业 | 13篇 |
水利工程 | 7篇 |
石油天然气 | 48篇 |
武器工业 | 2篇 |
无线电 | 92篇 |
一般工业技术 | 57篇 |
冶金工业 | 6篇 |
原子能技术 | 17篇 |
自动化技术 | 145篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 5篇 |
2021年 | 7篇 |
2020年 | 13篇 |
2019年 | 13篇 |
2018年 | 7篇 |
2017年 | 17篇 |
2016年 | 17篇 |
2015年 | 16篇 |
2014年 | 38篇 |
2013年 | 28篇 |
2012年 | 29篇 |
2011年 | 56篇 |
2010年 | 35篇 |
2009年 | 41篇 |
2008年 | 46篇 |
2007年 | 36篇 |
2006年 | 30篇 |
2005年 | 30篇 |
2004年 | 27篇 |
2003年 | 22篇 |
2002年 | 17篇 |
2001年 | 15篇 |
2000年 | 17篇 |
1999年 | 9篇 |
1998年 | 4篇 |
1997年 | 13篇 |
1996年 | 8篇 |
1995年 | 13篇 |
1994年 | 5篇 |
1993年 | 1篇 |
1992年 | 10篇 |
1991年 | 2篇 |
1990年 | 2篇 |
1988年 | 2篇 |
1987年 | 1篇 |
1986年 | 1篇 |
排序方式: 共有638条查询结果,搜索用时 8 毫秒
631.
Prediction of scaling in geothermal systems is important in order to be able to take preventive action. Scaling and corrosion processes are correlated in geothermal systems so that the factors influencing both processes are discussed in this paper. Pilot-scale equipment to model dissolution and scaling, and investigate corrosion, has been constructed. The construction of the pilot-scale equipment and the design of the experiments were based on the results of earlier laboratory model experiments. In order to check the measurement results we used a computer programe that was developed earlier, and which is suitable for the calculation of the equilibrium solubilities. Based on the results of the equilibrium experiments, we developed a modelling method for scaling in the pilot-scale equipment, and studied corrosion during scaling on the surfaces of five different structural materials. 相似文献
632.
633.
《Journal of the European Ceramic Society》2023,43(12):5319-5329
The cold sintering process (CSP) densifies ceramics below 300 °C by utilizing a transient phase and applied pressure. Although CSP has been employed for densifying a variety of functional systems, their structural integrity does not always reach that of conventionally sintered parts. On the example of ZnO, this study aims to eliminate processing-induced defects that compromise the strength of cold sintered materials. Ultrasonic evaluation was employed for nondestructive detection of flaws prior to mechanical testing. Load transfer misalignments and fast heating rates were found as major sources of defects, impairing the mechanical strength. Based on these findings, multiple disc-shaped samples (13 mm diameter and ∼1.3 mm thickness) were cold sintered simultaneously using precisely aligned punches and slow heating rates. The obtained homogeneous densification, high relative density (>97%) and relatively high strength (∼120 MPa), i.e. two times superior to previously reported values, demonstrates the feasibility of scaling up the CSP towards industrial implementation. 相似文献
634.
In this work a new method of Scaling Factor Regula Falsi type is developed, by using parabolic interpolation. It has global convergence and a high computational efficiency for simple roots. The method, not being a hybrid one, allows changing the function used for calculating the scaling factor at every iteration, making possible to switch to other more adequate methods for multiple roots (e.g., a generalised Illinois one). As an important feature of the method, it allows determining with no additional calculations, whether the root is simple or multiple. The developed algorithm has been tested with numerous functions extracted from the bibliography, performing, in most cases, better than some routines (like brentq, brenth and toms748) found in common numerical libraries. Fully operative routines of the new method are provided as supplementary files in four different programming languages: python, lua, C and Fortran90. 相似文献
635.
《International Journal of Hydrogen Energy》2023,48(71):27450-27463
Understanding multiphase flow close to the electrode surface is crucial to the design of electrolyzers, such as alkaline water electrolyzers for the production of green hydrogen. Vertical electrodes develop a narrow gas plume near their surface. We apply the integral method to the mixture model. Considering both exponentially varying and step-function gas fraction profiles, we derive analytical relations for plume thickness, velocity profile, and gas fraction near the electrode as a function of height and current density. We verify these analytical relations with the numerical solutions obtained using two-dimensional mixture model simulations. We find that for low gas fractions, the plume thickness decreases with an increase in current density for an exponentially varying gas fraction profile. In contrast, the plume thickness increases with increasing current density at high gas fractions for an approximately step-function-shaped gas fraction profile, in agreement with experiments from the literature. 相似文献
636.
The schedule of divisible loads is one of the most typical problems in the research and application of parallel and distributed systems. For these large‐scale systems, the energy consumption problem has drawn great attention in recent years because of falling hardware costs and the growing concern of energy costs. In computing‐intensive systems, energy is primarily consumed by CPUs, and dynamic voltage‐frequency scaling technology is capable of adjusting CPUs' speed as well as saving energy. In this paper, we focus on computing‐intensive applications and study the energy‐aware scheduling problem for divisible loads in a bus network. The energy‐speed model is introduced to characterize the problem based on dynamic voltage scaling, and the energy‐aware scheduling problem is analyzed in the application layer above the operating system. The problem can be formulated mathematically as a nonlinear programming problem, and the solution is achieved using the Lagrange multiplier method under Kuhn–Tucker conditions. Based on the analytical results, an energy‐aware scheduling scheme called ENERG for divisible loads is presented. Finally, the energy‐aware scheme is compared with two other schemes to show the effectiveness and efficiency of the energy savings of our algorithm. Additionally, the experimental results illustrate the influence of network transmission delay on energy consumption. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
637.
638.
应用Davis 和Stiff 等预测CaCO3 结垢趋势和结垢严重程度的公式以及带压力注水系统中pH 值计算方法,对陈堡油田陈2 、陈3 块混合污水进行了CaCO3 结垢理论预测,通过库尔特粒径分析证实了理论预测结果。 相似文献