全文获取类型
收费全文 | 6831篇 |
免费 | 1535篇 |
国内免费 | 218篇 |
专业分类
电工技术 | 1202篇 |
综合类 | 217篇 |
化学工业 | 1504篇 |
金属工艺 | 361篇 |
机械仪表 | 71篇 |
建筑科学 | 33篇 |
矿业工程 | 104篇 |
能源动力 | 1057篇 |
轻工业 | 24篇 |
水利工程 | 1篇 |
石油天然气 | 6篇 |
武器工业 | 10篇 |
无线电 | 1442篇 |
一般工业技术 | 2299篇 |
冶金工业 | 185篇 |
原子能技术 | 4篇 |
自动化技术 | 64篇 |
出版年
2024年 | 74篇 |
2023年 | 810篇 |
2022年 | 297篇 |
2021年 | 576篇 |
2020年 | 685篇 |
2019年 | 561篇 |
2018年 | 482篇 |
2017年 | 488篇 |
2016年 | 426篇 |
2015年 | 337篇 |
2014年 | 334篇 |
2013年 | 276篇 |
2012年 | 247篇 |
2011年 | 498篇 |
2010年 | 341篇 |
2009年 | 287篇 |
2008年 | 273篇 |
2007年 | 346篇 |
2006年 | 248篇 |
2005年 | 210篇 |
2004年 | 192篇 |
2003年 | 126篇 |
2002年 | 139篇 |
2001年 | 74篇 |
2000年 | 44篇 |
1999年 | 67篇 |
1998年 | 32篇 |
1997年 | 31篇 |
1996年 | 32篇 |
1995年 | 18篇 |
1994年 | 10篇 |
1992年 | 4篇 |
1990年 | 1篇 |
1989年 | 1篇 |
1988年 | 2篇 |
1987年 | 2篇 |
1986年 | 1篇 |
1984年 | 1篇 |
1983年 | 2篇 |
1954年 | 1篇 |
1951年 | 8篇 |
排序方式: 共有8584条查询结果,搜索用时 15 毫秒
141.
Congcong Cai Xinyuan Li Ping Hu Ting Zhu Jiantao Li Hao Fan Ruohan Yu Tianyi Zhang Sungsik Lee Liang Zhou Liqiang Mai 《Advanced functional materials》2023,33(24):2215155
Introducing anionic redox in layered oxides is an effective approach to breaking the capacity limit of conventional cationic redox. However, the anionic redox reaction generally suffers from excessive oxidation of lattice oxygen to O2 and O2 release, resulting in local structural deterioration and rapid capacity/voltage decay. Here, a Na0.71Li0.22Al0.05Mn0.73O2 (NLAM) cathode material is developed by introducing Al3+ into the transition metal (TM) sites. Thanks to the strong Al–O bonding strength and small Al3+ radius, the TMO2 skeleton and the holistic TM–O bonds in NLAM are comprehensively strengthened, which inhibits the excessive lattice oxygen oxidation. The obtained NLAM exhibits a high reversible capacity of 194.4 mAh g-1 at 20 mA g-1 and decent cyclability with 98.6% capacity retention over 200 cycles at 200 mA g−1. In situ characterizations reveal that the NLAM experiences phase transitions with an intermediate OP4 phase during the charge–discharge. Theoretical calculations further confirm that the Al substitution strategy is beneficial for improving the overlap between Mn 3d and O 2p orbitals. This finding sheds light on the design of layered oxide cathodes with highly reversible anionic redox for sodium storage. 相似文献
142.
Thanh Hai Nguyen Phan Khanh Linh Tran Van An Dinh Duy Thanh Tran Nam Hoon Kim Joong Hee Lee 《Advanced functional materials》2023,33(7):2210101
Development of multifunctional electrocatalysts with high efficiency and stability is of great interest in recent energy conversion technologies. Herein, a novel heteroelectrocatalyst of molecular iron complex (FeMC)-carbide MXene (Mo2TiC2Tx) uniformly embedded in a 3D graphene-based hierarchical network (GrH) is rationally designed. The coexistence of FeMC and MXene with their unique interactions triggers optimum electronic properties, rich multiple active sites, and favorite free adsorption energy for excellent trifunctional catalytic activities. Meanwhile, the highly porous GrH effectively promotes a multichannel architecture for charge transfer and gas/ion diffusion to improve stability. Therefore, the FeMC–MXene/GrH results in superb performances towards oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and hydrogen evolution reaction (HER) in alkaline medium. The practical tests indicate that Zn/Al–air batteries derived from FeMC–MXene/GrH cathodic electrodes produce high power densities of 165.6 and 172.7 mW cm−2, respectively. Impressively, the liquid-state Zn–air battery delivers excellent cycling stability of over 1100 h. In addition, the alkaline water electrolyzer induces a low cell voltage of 1.55 V at 10 mA cm−2 and 1.86 V at 0.4 A cm−2 in 30 wt.% KOH at 80 °C, surpassing recent reports. The achievements suggest an exciting multifunctional electrocatalyst for electrochemical energy applications. 相似文献
143.
Zhuoran Lv Baixin Peng Ximeng Lv Yusha Gao Keyan Hu Wujie Dong Gengfeng Zheng Fuqiang Huang 《Advanced functional materials》2023,33(16):2214370
Alloying-type metal sulfides with high theoretical capacities are promising anodes for sodium-ion batteries, but suffer from sluggish sodiation kinetics and huge volume expansion. Introducing intercalative motifs into alloying-type metal sulfides is an efficient strategy to solve the above issues. Herein, robust intercalative In S motifs are grafted to high-capacity layered Bi2S3 to form a cation-disordered (BiIn)2S3, synergistically realizing high-rate and large-capacity sodium storage. The In S motif with strong bonding serves as a space-confinement unit to buffer the volume expansion, maintaining superior structural stability. Moreover, the grafted high-metallicity Indium increases the bonding covalency of Bi S, realizing controllable reconstruction of Bi S bond during cycling to effectively prevent the migration and aggregation of atomic Bi. The novel (BiIn)2S3 anode delivers a high capacity of 537 mAh g−1 at 0.4 C and a superior high-rate stability of 247 mAh g−1 at 40 C over 10000 cycles. Further in situ and ex situ characterizations reveal the in-depth reaction mechanism and the breakage and formation of reversible Bi S bonds. The proposed space confinement and bonding covalency enhancement strategy via grafting intercalative motifs can be conducive to developing novel high-rate and large-capacity anodes. 相似文献
144.
145.
为了保证电动汽车和储能系统的安全运行,电池组的故障诊断研究备受关注。针对目前面向电池组故障诊断方法相对匮乏且实用性不佳的问题,提出了一种基于主成分分析(PCA)的故障诊断实用方法,以准确地区分组内的电池单体故障和连接故障。首先,提出了非硬件冗余的交叉测量拓扑,分别用不同数量的传感器测量电池和连接板;然后,分析组内测量电压的变化特点,引入PCA对故障特征进行提取,为了保证PCA模型适配,提出了PCA实时建模与故障诊断一体化的思路,并基于此设计了完整的故障诊断方案;最后,利用实验对所提方法进行验证,结果表明所提方法能够可靠区分电池单体故障和连接故障,准确检测阈值法无法检测的电池单体故障,且强鲁棒于荷电状态、健康状态和温度差异的影响。现场运行数据也证实了所提方法能够有效避免发生虚警。 相似文献
146.
147.
针对储能锂离子电池热失控引发的安全问题,开发一种高效锂离子软包电池内部温度压力模拟方法,为储能系统提供电池状态实时监测工具。首先,通过融合化学反应模型、热路模型和膨胀模型,将软包电池内部生热、产气、传热、膨胀等过程集成到统一的计算框架中。其次,建立基于微分方程组的软包电池温度、压力计算模型,反应模型和热路模型通过温度、生热率等状态参数彼此耦合。再次,将该方法应用于4款电池样本进行温度、压力模拟。计算值和实测值对比表明,该方法能高效计算锂离子软包电池内部温度和压力,最大模拟误差小于4%,具有良好的计算精度。并且,该方法求解过程无需调用耗时的多物理场耦合仿真,计算效率高。 相似文献
148.
Ziyang Jia Rui Ding Wujiang Yu Yi Li Ailin Wang Miao Liu Feng Yang Xiujuan Sun Enhui Liu 《Advanced functional materials》2022,32(1):2107674
Herein, a trimetallic Ni–Co–Zn perovskite fluoride (ABF3) (denoted as KNCZF) electrode material is explored for advanced aqueous supercabatteries (ASCBs), with KNCZF and activated carbon–FeBiCu@reduced graphene oxides (AC–FeBiCu@rGO) as cathode and anode, respectively, which outperform aqueous supercapacitors (ASCs) and batteries (ABs) with AC and FeBiCu@rGO anodes because of the synergistic effect of pseudocapacitive (KNCZF), capacitive (AC), and faradaic (FeBiCu@rGO) responses. One of the important findings is that the KNCZF shows a typical bulk phase conversion mechanism for charge storage in the alkaline media with the transition of ABF3 perovskite nanocrystals into amorphous metal oxides/(oxy)hydroxides nanosheets, showing the redox-active and redox-inert roles for the Ni/Co and Zn species, respectively, which can be deduced by various ex-situ techniques. Another interesting finding is that the redox-inert Zn species largely enhance the activity of Ni/Co redox-active species in the ABF3 materials, mainly owing to the promotion of surface electroactive sites, adsorption of OH?, and charge transfer of surface Ni/Co atoms by Zn-doping, which can be proved by ex-situ characterizations and theoretical calculations. Overall, this study reveals the structure–activity relationship and charge storage mechanisms of Zn-doping ABF3 materials for advanced ASCBs, showing a great impact on developing advanced electrochemical energy storage. 相似文献
149.
Zhonghai Song Ning Cao Xuejiao Gao Qiu Liang 《Fullerenes, Nanotubes and Carbon Nanostructures》2017,25(2):65-70
Ultrathin Co3O4 nanosheets grown on the reduced graphene oxide (Co3O4/rGO) was synthesized by a simple hydrothermal method and was investigated as a cathode in a Li-O2 battery. Benefited from the synergistic effect between Co3O4 and rGO, the hybrid exhibits a high initial capacity of 10,528 mAh g?1 along with a high coulombic efficiency (84.4%) at 100 mA g?1. In addition, the batteries show an enhanced cycling stability and after 113 cycles, the cut-off discharge voltage remains above 2.5 V. The outstanding performance is intimately related to the high surface area of rGO, which not only provide carbon skeleton for the uniform distribution of Co3O4 nanosheets but also facilitate the reversible formation and decomposition of insoluble Li2O2. The results of electrochemical tests confirm that the Co3O4/rGO hybrid is a promising candidate for the Li-O2 batteries. 相似文献
150.
Phase Separation Derived Core/Shell Structured Cu11V6O26/V2O5 Microspheres: First Synthesis and Excellent Lithium‐Ion Anode Performance with Outstanding Capacity Self‐Restoration
下载免费PDF全文
![点击此处可从《Small (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Jian Pei Gang Chen Qiang Zhang Changfeng Bie Jingxue Sun 《Small (Weinheim an der Bergstrasse, Germany)》2017,13(17)
Novel amorphous vanadium oxide coated copper vanadium oxide (Cu11V6O26/V2O5) microspheres with 3D hierarchical architecture have been successfully prepared via a microwave‐assisted solution method and subsequent annealing induced phase separation process. Pure Cu11V6O26 microspheres without V2O5 coating are also obtained by an H2O2 solution dissolving treatment. When evaluated as an anode material for lithium‐ion batteries (LIBs), the as‐synthesized hybrid exhibits large reversible capacity, excellent rate capability, and outstanding capacity self‐recovery. Under the condition of high current density of 1 A g?1, the 3D hierarchical Cu11V6O26/V2O5 hybrid maintains a reversible capacity of ≈1110 mA h g?1. Combined electrochemical analysis and high‐resolution transmission electron microscopy observation during cycling reveals that the amorphous V2O5 coating plays an important role on enhancing the electrochemical performances and capacity self‐recovery, which provides an active amorphous protective layer and abundant grain interfaces for efficient inserting and extracting of Li‐ion. As a result, this new copper vanadium oxide hybrid is proposed as a promising anode material for LIBs. 相似文献