全文获取类型
收费全文 | 388篇 |
免费 | 29篇 |
国内免费 | 10篇 |
专业分类
综合类 | 1篇 |
化学工业 | 107篇 |
金属工艺 | 4篇 |
机械仪表 | 21篇 |
建筑科学 | 11篇 |
能源动力 | 33篇 |
轻工业 | 40篇 |
水利工程 | 2篇 |
石油天然气 | 5篇 |
无线电 | 28篇 |
一般工业技术 | 100篇 |
冶金工业 | 9篇 |
原子能技术 | 5篇 |
自动化技术 | 61篇 |
出版年
2024年 | 4篇 |
2023年 | 7篇 |
2022年 | 17篇 |
2021年 | 25篇 |
2020年 | 21篇 |
2019年 | 21篇 |
2018年 | 30篇 |
2017年 | 29篇 |
2016年 | 22篇 |
2015年 | 19篇 |
2014年 | 21篇 |
2013年 | 41篇 |
2012年 | 28篇 |
2011年 | 19篇 |
2010年 | 19篇 |
2009年 | 13篇 |
2008年 | 12篇 |
2007年 | 18篇 |
2006年 | 5篇 |
2005年 | 4篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 7篇 |
2001年 | 2篇 |
2000年 | 5篇 |
1999年 | 2篇 |
1998年 | 3篇 |
1997年 | 2篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 1篇 |
1987年 | 1篇 |
1985年 | 1篇 |
1982年 | 1篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 1篇 |
1978年 | 1篇 |
1975年 | 1篇 |
1972年 | 1篇 |
排序方式: 共有427条查询结果,搜索用时 15 毫秒
81.
82.
Hannes M. Findeisen Vivienne C. Voges Laura C. Braun Jannik Sonnenberg Dennis Schwarz Helena Krner Holger Reinecke Yahya Sohrabi 《International journal of molecular sciences》2022,23(11)
Reprogramming of metabolic pathways in monocytes and macrophages can induce a proatherosclerotic inflammatory memory called trained innate immunity. Here, we have analyzed the role of the Liver X receptor (LXR), a crucial regulator of metabolism and inflammation, in oxidized low-density lipoprotein (oxLDL)-induced trained innate immunity. Human monocytes were incubated with LXR agonists, antagonists, and oxLDL for 24 h. After five days of resting time, cells were restimulated with the TLR-2 agonist Pam3cys. OxLDL priming induced the expression of LXRα but not LXRβ. Pharmacologic LXR activation was enhanced, while LXR inhibition prevented the oxLDL-induced inflammatory response. Furthermore, LXR inhibition blocked the metabolic changes necessary for epigenetic reprogramming associated with trained immunity. In fact, enrichment of activating histone marks at the IL-6 and TNFα promotor was reduced following LXR inhibition. Based on the differential expression of the LXR isoforms, we inhibited LXRα and LXRβ genes using siRNA in THP1 cells. As expected, siRNA-mediated knock-down of LXRα blocked the oxLDL-induced inflammatory response, while knock-down of LXRβ had no effect. We demonstrate a specific and novel role of the LXRα isoform in the regulation of oxLDL-induced trained immunity. Our data reveal important aspects of LXR signaling in innate immunity with relevance to atherosclerosis formation. 相似文献
83.
Samer Yahya M. Moghavvemi Haider A.F. Mohamed 《Simulation Modelling Practice and Theory》2011,19(1):406-422
A new method for inverse kinematics for hyper-redundant manipulators is proposed in this paper to plan the path of the end-effector. The basic idea is that for a given smooth path consisting of points close enough to each other; computing the inverse kinematics for these points is carried out geometrically using the proposed method. In this method, the angles between the adjacent links are set to be the same, which makes lining up of two or more joint axes impossible; therefore, avoiding singularities. The manipulability index has been used to show how far the manipulator from the singularity configuration is. The determination of the workspace of the manipulator using the proposed method has been presented in this paper. The simulation results have been carried out on a planar and a three dimensional manipulators. The effectiveness of the proposed method is clearly demonstrated by comparing its result with results calculated by the well-known method of measuring manipulability which is used for singularity avoidance for the last two decades. 相似文献
84.
This article studies the effect of transpiration on a fully developed natural convection MHD flow in a vertical annulus with heat generation/absorption. The governing coupled differential equations are solved by an estimated analytical method identified as the Adomian decomposition method with initial conditions and an appropriate initial guess condition. Furthermore, the effect of several parameters illustrating the flow phenomena is considered through graphs and the numerical computations are obtained and presented through tables. However, it is observed that there is a decrease in velocity due to the effect of the suction of fluid on the heated porous wall with concurrent injection. Also, heat generation parameter enhances the temperature of the fluid on both the isothermal and constant heat flux. 相似文献
85.
Mohamed Saad Bala Husain Basma Yahya Alashwal Swati Sharma 《Energy Sources, Part A: Recovery, Utilization, and Environmental Effects》2018,40(20):2388-2393
The composition and synthesis of hydrogel were developed by using Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP). Polyvinyl alcohol (PVA) and Polyvinylpyrrolidone (PVP) based hydrogels are the most popular water-soluble, biodegradable, biocompatible, non-carcinogenic, and extremely low cytotoxicity synthetic polymers due to their good biocompatibility have been used in numerous biomedical applications, such as implants, artificial organs, drug delivery devices, and wound dressings. In this review paper, details of synthetic of hydrogel formulations with PVA and PVP for biomedical applications. 相似文献
86.
Omed Gh. Abdullah Rawad R. Hanna Yahya A. K. Salman Shujahadeen B. Aziz 《Journal of Inorganic and Organometallic Polymers and Materials》2018,28(4):1432-1438
Lithium ion-conducting polymer blend electrolytes based on chitosan and methylcellulose complexed with lithium tetrafluoroborate (LiBF4) were prepared by a solution-casting method. The features of complexation of the solid polymer electrolytes were studied using X-ray diffraction techniques. Electrical conductivity of the prepared films was measured as a function of frequency at a different temperature. The increased trend of the electrical conductivity with increasing temperature and salt concentration can be attributed to increasing the mobility and number of lithium ions, respectively. The polymer electrolyte system exhibited Arrhenius-type, temperature-dependence ion conductivity behavior. Optical properties such as optical band gap, tail due to localized states and complex refractive index were estimated for present polymer electrolyte system from optical absorption measurement in the wavelength region 190–1100 nm. It was found that the optical direct band gap values shifted to lower energies upon addition of LiBF4 salt up to 40 wt% dopant concentration, and showed an increasing tendency for a further increase in dopant concentration. The high refractive index for this composition (2.44–2.63) at visible wavelengths eminently suitable for optical applications. 相似文献
87.
Control of Grid Connected Photovoltaic Systems with Microinverters: New Theoretical Design and Numerical Evaluation
下载免费PDF全文
![点击此处可从《Asian journal of control》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Abdelhafid Yahya Hassan El Fadil Mustapha Oulcaid Leila Ammeh Fouad Giri Josep M. Guerrero 《Asian journal of control》2018,20(2):906-918
This paper addresses the problem of controlling grid connected photovoltaic (PV) systems that are driven with microinverters. The systems to be controlled consist of a solar panel, a boost dc–dc converter, a DC link capacitor, a single‐phase full‐bridge inverter, a filter inductor, and an isolation transformer. We seek controllers that are able to simultaneously achieve four control objectives, namely: (i) asymptotic stability of the closed loop control system; (ii) maximum power point tracking (MPPT) of the PV module; (iii) tight regulation of the DC bus voltage; and (iv) unity power factor (PF) in the grid. To achieve these objectives, a new multiloop nonlinear controller is designed using the backstepping design technique. A key feature of the control design is that it relies on an averaged nonlinear system model accounting, on the one hand, for the nonlinear dynamics of the underlying boost converter and inverter and, on the other, for the nonlinear characteristic of the PV panel. To achieve the MPPT objective, a power optimizer is designed that computes online the optimal PV panel voltage used as a reference signal by the PV voltage regulator. It is formally shown that the proposed controller meets all the objectives. This theoretical result is confirmed by numerical simulation tests. 相似文献
88.
This paper investigates the problem of stability analysis for switched complex dynamical networks with mixed time-varying delays and parameter uncertainties. The switched complex dynamical networks are composed of m modes that are switched from one to another based on time, state, etc. Although, the active subsystem is known in any instance, but the switching law such as transition probabilities are not known. The model for each mode is considered affine with matched and unmatched perturbations. The main purpose of the addressed problem is to design a filter error for the switched complex dynamical networks such that the dynamics of the error converges to the asymptotically irrespective of the admissible parameter variations with the gains. Then, by utilizing the Lyapunov functional method, the stochastic analysis combined with the matrix inequality techniques, a sufficient condition in terms of linear matrix inequalities is presented to ensure the
$$H_\infty $$
performance of the complex dynamical system models. Finally, a numerical example is presented to illustrate the effectiveness of the proposed design method. 相似文献
89.
In this paper we proposed a new de-noising technique based on combination of isotropic diffusion model, anisotropic diffusion (PM) model, and total variation model. The proposed model is able to be adaptive in each region depending on the information of the image. More precisely, the model performs more diffusion in the flat areas of the image, and less diffusion in the edges of the image. And so we can get rid of the noise, and preserve the edges of the image simultaneously. To verify that, we did several experiments, which showed that our algorithm is the best method for edge preserving and noise removing, compared with the isotropic diffusion, anisotropic diffusion, and total variation methods. 相似文献
90.
Salabat Khan Abdul Rauf Baig Armughan Ali Bilal Haider Farman Ali Khan Mehr Yahya Durrani Muhammad Ishtiaq 《中国科学:信息科学(英文版)》2014,57(9):1-15
In this article,a novel unordered classification rule list discovery algorithm is presented based on Ant Colony Optimization(ACO). The proposed classifier is compared empirically with two other ACO-based classification techniques on 26 data sets,selected from miscellaneous domains,based on several performance measures. As opposed to its ancestors,our technique has the flexibility of generating a list of IF-THEN rules with unrestricted order. It makes the generated classification model more comprehensible and easily interpretable.The results indicate that the performance of the proposed method is statistically significantly better as compared with previous versions of AntMiner based on predictive accuracy and comprehensibility of the classification model. 相似文献