全文获取类型
收费全文 | 613篇 |
免费 | 7篇 |
国内免费 | 12篇 |
专业分类
电工技术 | 18篇 |
综合类 | 3篇 |
化学工业 | 244篇 |
金属工艺 | 13篇 |
机械仪表 | 4篇 |
矿业工程 | 2篇 |
能源动力 | 248篇 |
无线电 | 16篇 |
一般工业技术 | 78篇 |
冶金工业 | 3篇 |
原子能技术 | 1篇 |
自动化技术 | 2篇 |
出版年
2023年 | 28篇 |
2022年 | 47篇 |
2021年 | 51篇 |
2020年 | 37篇 |
2019年 | 43篇 |
2018年 | 38篇 |
2017年 | 23篇 |
2016年 | 18篇 |
2015年 | 17篇 |
2014年 | 30篇 |
2013年 | 13篇 |
2012年 | 13篇 |
2011年 | 83篇 |
2010年 | 61篇 |
2009年 | 37篇 |
2008年 | 28篇 |
2007年 | 25篇 |
2006年 | 17篇 |
2005年 | 9篇 |
2004年 | 6篇 |
2003年 | 5篇 |
2002年 | 3篇 |
排序方式: 共有632条查询结果,搜索用时 11 毫秒
1.
《International Journal of Hydrogen Energy》2022,47(3):1954-1964
Recently, researchers have devoted more attention to supercapacitors (SCs) to integrate with batteries in energy storage systems (ESSs) for vehicle applications. In this study, we attempted to characterize the use of SCs in the ESS for a PEM fuel cell vehicle equipped with an alternator to maximize the performance of regenerative braking. We applied lithium-ion batteries (LIBs) and SCs as energy storage devices to examine their effect on ESS. Then we used a hysteresis brake to apply controllable braking force on the flywheel to form hybrid braking (HB) and made efforts to study its behavior to suggest a braking control strategy. We also ran the whole system over the rotational speed to cover the range of driving speed. At last, we sized the SCs for the most commonly used fuel cell electric vehicle (FCEV) in Korea, i.e., Hyundai NEXO, based on the results obtained from the above study by alternator efficiencies. 相似文献
2.
《International Journal of Hydrogen Energy》2022,47(26):12829-12840
In the present work, nitrogen doped hierarchically activated porous carbon (APC) samples have been synthesized via single step scalable method using ethylene di-amine tetra acetic acid (EDTA) as precursor and KOH as activating agent. Activated porous carbons with different pore sizes have been developed by varying the activation temperature. SEM, TEM and SAXS analysis suggest that with variation of activation temperature, a hierarchical porous structure with interconnected meso-pore and micro pores has been achieved. The sufficiently high surface area of the synthesized materials provides active sites to enhance the diffusion of ions between the electrolyte and the carbon electrodes. The electrode prepared at 800 °C activated sample exhibited highest specific capacitance of 274 Fg-1 in two electrode setup, at a current density of 0.1 Ag-1 in 1 M aqueous H2SO4. Along with this, it showed maximum energy density of 9.5 Whkg?1 at a power density of 64.5 Wkg-1. The remarkable electrochemical performance reveals that the synthesized nitrogen doped activated carbon electrodes derived from EDTA can be tuned to have optimum pore structure and pore size distribution for better electrochemical performance, so it can be considered as a potential electrode material for applications in electrochemical energy storage. 相似文献
3.
The relatively low capacitance of negative electrodes, as compared to the capacitance of advanced positive electrodes, poses a serious problem, since this limits the development of asymmetric supercapacitor (SC) devices with a large voltage window and enhanced power-energy characteristics. We fabricate negative SC electrodes with a high capacitance that match the capacitance of advanced positive electrodes at similar active mass loadings, as high as 37?mg?cm?2. Cyclic voltammetry, impedance spectroscopy, galvanostatic charge-discharge data and the power-energy characteristics of the asymmetric SC device exhibit good electrochemical performance for a voltage window of 1.6?V. Our approach involves the development and application of particle extraction through liquid-liquid interface (PELLI) methods, new extraction mechanisms and efficient extractors to synthesize α-FeOOH and β-FeOOH electrode materials. The use of PELLI allows agglomerate-free processing of powders, which facilitates their efficient mixing with multiwalled carbon nanotubes (MWCNT) and allows improved electrolyte access to the particle surface. Experiments to determine the properties of FeOOH-MWCNT composites provided insight into the influence of the electrode material and the structure of extractor molecules on the composite properties. The highest capacitance of 5.86?F?cm?2 for negative electrodes and low impedance were achieved using α-FeOOH-MWCNT composites and a 16-phosphonohexadecanoic acid (PHDA) extractor. This extractor allows adsorption on particles, not only at the liquid-liquid interface, but also in the bulk aqueous phase and can potentially be used as a capping agent for particle synthesis and as an extractor in the PELLI method. 相似文献
4.
《The Electricity Journal》2020,33(5):106763
While wind and solar generation has increased dramatically over the past decade, there has been a much larger increase in gas generation (eia, 2019). This is driven in part by low gas prices but also in part by how electricity markets are organized. The intermittent nature of wind and solar generation increases the need for more flexible and reliable generation; a role gas plants fill well. However, current market structures and rules unfairly tip the balance in their favor compared to energy storage systems. They have created market barriers restrictive enough to prevent market participation of a technology key to a 100 % renewable grid: supercapacitors. Adjusting markets to remove the market barriers to supercapacitor and other energy storage systems will allow for increased renewable penetration while simultaneously improving grid performance and reducing costs. 相似文献
5.
A novel high power symmetric ZnO/carbon aerogel composite electrode for electrochemical supercapacitor 总被引:1,自引:0,他引:1
We present, for the first time, a new material of symmetric electrochemical supercapacitor in which zinc oxide (ZnO) with carbon aerogel (CA) was used as active material. Physical properties of ZnO/CA composite were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). It was found that ZnO has single hexagonal structure and the grain size increases with increase of ZnO compository. The result of cyclic voltammetry indicates that the specific capacitance of ZnO/CA composite in 6 M KOH electrolyte was approximately 25 F/g at 10 mV/s for 2:1 composition. AC impedance analysis reveals that ZnO with carbon aerogel powder enhanced the conductivity by reducing the internal resistance. Galvanostatic charge/discharge measurements were done at various current densities, namely 25, 50, 75, and 100 mA/cm2. It was found that the cells have excellent electrochemical reversibility and capacitive characteristics in KOH electrolyte. The maximum capacitance of the ZnO/CA supercapacitor was 500 F/g at 100 mA/cm2. It has been observed that the specific capacitance is constant up to 500 cycles at all current densities, which implies that the dendrite formation was controlled. 相似文献
6.
New energy storage devices such as batteries and supercapacitors are widely used in various felds because of their
irreplaceable excellent characteristics. Because there are relatively few monitoring parameters and limited understanding of their operation, they present problems in accurately predicting their state and controlling operation, such
as state of charge, state of health, and early failure indicators. Poor monitoring can seriously afect the performance of
energy storage devices. Therefore, to maximize the efciency of new energy storage devices without damaging the
equipment, it is important to make full use of sensing systems to accurately monitor important parameters such as
voltage, current, temperature, and strain. These are highly related to their states. Hence, this paper reviews the sensing
methods and divides them into two categories: embedded and non-embedded sensors. A variety of measurement
methods used to measure the above parameters of various new energy storage devices such as batteries and supercapacitors are systematically summarized. The methods with diferent innovative points are listed, their advantages
and disadvantages are summarized, and the application of optical fber sensors is emphasized. Finally, the challenges
and prospects for these studies are described. The intent is to encourage researchers in relevant felds to study the
early warning of safety accidents from the root causes. 相似文献
7.
《Advanced Powder Technology》2023,34(1):103838
Manganese sulfide (MnS) with high specific capacitance and low-cost merits, has been investigated as a potential electroactive material for supercapacitor. However, in practical application, MnS has been suffering from some disadvantageous issues such as insufficient electrical conductivity, serious particle agglomeration as well as huge volume change during continuous charges and discharges, which resulted in a limited specific capacitance, shortened working life and inferior rate performance. Engineering electrode materials with controlled nanostructure and composition is pivotal to improve electrichemical performance of supercapacitors. This paper introduces a facile in situ sulfuration method to fabricate MnS/NSC composite with Mn-hexamethylene tetramine coordination framework as precursor. The results indicated that MnS nanoparticles were highly dispersed and incorporated into nitrogen, sulfur-doped carbon microsheets in MnS/NSC composite. Carbon matrix effectively dispersed and confined the MnS nanoparticles, thus inhibiting aggregation, relieving volume change and retaining structural integrity. Moreover, the 2D conductive carbon matrix reduced the diffusion distance for ions and ensured fast electron delivery. As a result, MnS/NSC electrode delivered a tremendously boosted electrochemical performance for supercapacitor. A large capacitance value about 1881.8F/g was achieved at 1A/g. Even cycling for 3000 loops at 40 A/g, MnS/NSC electrode retained a large capacitance of 404.3F/g. Furthermore, an asymmetric capacitor based on assembly of MnS/NSC composite cathode and activated carbon anode was fabricated. As tested under a current density of 0.1 A/g, it delivered a capacitance of ~ 110.1F/g and achieved an energy density of 12.4 Wh kg?1 along with a power density of 3.03 kW kg?1. These results demonstrate the potential utilization of MnS/NSC composite as electrodes for energy conversion and storage devices and open up a route for material design for future energy storage devices. 相似文献
8.
为合理调节电磁储能,在实现电网运动运行基础上加强新能源电能利用率,提出基于电磁储能的电网新能源消纳能力仿真分析方法.为准确地反映出电容器在工作过程中不同时间段内特征动态变化过程,采用改进后三支路模型对超级电容储能系统精确建模,根据超级电容恒流放电曲线完成三支路模型中等效电容值、串联电阻值和并联电阻值的辨识.对超级电容电... 相似文献
9.
Hierarchical Co3O4@NiCoLDH nanosheets(NSs)were prepared on carbon cloth through a multistep method,containing Metal-organic frameworks(MOF)-templated thermal annealing and electrodeposition.The triangle-shaped Co3O_(4 NSs)were firstly obtained by thermal treatment of MOF templates in air.Then,ultrathin NiCoLDHNSswere in-situ electrodeposited on the surface of Co3O4NSs,constructing a core-shell structure.Benefiting the unique hierarchical structure,high conductivity of Co3O_(4 NSs)core and large surface area of NiCoLDHNSs shell,the Co3O4@NiCoLDHNSsarray served as supercapacitor electrode exhibits excellent electrochemical properties,such as high specific capacitance of 1708 F g-1(850 C g-1)at a current density of 1 A g-1,good rate capability,and excellent cycling stability.Further,the asymmetric supercapacitor assembled by Co3O4@NiCoLDHNSsand activated carbon,also displays superior electrochemical perfo rmance with high energy density and power density.Remarkably,the strategy of constructing core-shell structure based on MOF templates could be extended to other electrochemical fields. 相似文献
10.
Herein, macroporous carbon sheets (MCS) was synthesized by a re-assembly engineering. In this process, surfactant is combined with oligomeric resin to form micelles, which are re-assembled on the pre-prepared hybrid sheet through hydrogen bonding and electrostatic action, resulting in the reconstruction of relatively regular macropores on the sheet. The obtained MCS maintains the morphology of nanosheet with obvious circular macropores, high specific surface area and pore volume, which improves the charge transfer efficiency and is favorable electrochemical energy storage. As the electrode material for a supercapacitor, the MCS exhibits a high specific capacitance, excellent rate performance and long-term stability, which make the MCS an ideal electrode material for electrochemical energy storage. 相似文献