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991.
Wenmei Luo;Baojie Wei;Tianlin Luo;Baowen Li;Guimei Zhu; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(50):2406574
The rapid growth of flexible electronics has led to significant demand for relevant accessories, particularly highly efficient flexible heat dissipators. The fluidity of liquid metal (LM) makes it a candidate for realizing flexible thermal interface materials (TIMs). However, it is still challenging to combine LM with a conductive thermal network to achieve the synchronous improvement of thermal conductivity and flexibility. In this work, highly conductive flexible LM@GN/ANF films are made by coating LM nano-droplets with graphene nanosheets (GN) via sonication, and then they are combined with aramid nanofibers (ANF). The LM@GN/ANF film is found to have a thermal conductivity of 5.67 W m−1 K−1 and a 24.5% reduction in Young's modulus, making it suitable for various flexible electronic applications such as wearable devices and biosensors. 相似文献
992.
Jingxuan Zheng;Dapeng Meng;Junxin Guo;Anyu Zhang;Zhao Wang; 《Small (Weinheim an der Bergstrasse, Germany)》2024,20(49):2407177
Defect engineering is a promising approach to improve the conductivity and increase the active sites of transition metal oxides used as catalysts for the oxygen evolution reaction (OER). However, when metal defects and oxygen defects coexist closely within the same crystal, their compensating charges can diminish the benefits of both defect structures on the catalyst's local electronic structure. To address this limitation, a novel strategy that employs the heterostructure interface of ZnFe2O4–NiCo2O4 to spatially separate the metal defects from the oxygen defects is proposed. This configuration positions the two types of defects on opposite sides of the heterojunction interface, creating a unique structure termed the “metal-defect/oxygen-defect junction”. Physical characterization and simulations reveal that this configuration enhances electron transfer at the heterostructure interface, increases the oxidation state of Fe on the catalyst surface, and boosts bulk charge carrier concentration. These improvements enhance active site performance, facilitating hydroxyl adsorption and deprotonation, thereby reducing the overpotential required for the OER. 相似文献
993.
CHEN Qihan;ZHOU Jingzhi;ZHOU Guohui;CHENG Keyong;HUAI Xiulan;WEI Gaosheng 《热科学学报(英文版)》2024,33(2):625-647
Energy efficiency issues are being focused on the growing concern of global warming and environmental pollution.The high-temperature heat pipe(HTHP)is an effective and environmental-friendly heat transfer device employed in many industries,including solar power generation,high-temperature flue gas waste heat recovery,industrial furnaces,nuclear industries,and aviation.As a critical factor in HTHPs,thermal performance is mainly introduced in the entire paper.To date,most reviews have been published concerning one or several application scenarios.However,to the best of authors'knowledge,it is hard to find a review discussing how to improve the thermal performance of HTHPs comprehensively.First,the impact on the performance of three main components of HTHPs over the past 30 years is introduced:the working fluid,the HTHP structure,and the wick structure.Herein,it is a considerable review of the optimal operating conditions for each direction,and we expect this paper contribute to improving the thermal performance of HTHPs.Then,current numerical simulations and theoretical research on the heat transfer limit of HTHPs are recommended.The significant hypotheses used in numerical simulations and the present theoretical studies are compiled here.Finally,some potential future directions and tentative suggestions for HTHP research are put forward. 相似文献
994.
《Current Opinion in Solid State & Materials Science》2020,24(1):100805
With increasing human population, sustainable energy production has become one of the most persistent and significant problems of the current century. Hydrogen is considered to be the best clean fuel for future energy requirements. As a substitute of fossil fuels, hydrogen is readily provided by an electrocatalytic hydrogen evolution reaction that splits water molecules. Conventional electrocatalysts based on noble metals are scarce and considerably expensive for large-scale hydrogen production, necessitating the search for low-cost earth abundant alternatives. In this context, transition metal nitrides have gained considerable attention as competent electrocatalytic materials for water splitting. This review presents recent advancements and progress on transition metal nitrides as efficient and cost-effective electrocatalysts for hydrogen production. After overviewing the fundamental aspects of the hydrogen evolution reaction (HER), the review discusses various synthetic strategies for developing transition metal nitrides. Discussed herein are titanium nitrides, vanadium nitrides, iron nitrides, nickel nitrides, molybdenum nitrides, tungsten nitrides, and their composite electrocatalysts employed in HER applications. Some design viewpoints for improving the electrocatalytic activity are systematically proposed. Finally, the review discusses challenges and future perspectives for the advancement of non-noble metal-based electrocatalysts. 相似文献
995.
996.
997.
Yunok Kim Ji Hyun Um Hyunjoon Lee Woosung Choi Woon Ih Choi Hyo Sug Lee Ok‐Hee Kim Ji Man Kim Yong‐Hun Cho Won‐Sub Yoon 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(1)
Beyond a traditional view that metal nanoparticles formed upon electrochemical reaction are inactive against lithium, recently their electrochemical participations are manifested and elucidated as catalytic and interfacial effects. Here, ruthenium metal composed of ≈5 nm nanoparticles is prepared and the pure ruthenium as a lithium‐ion battery anode for complete understanding on anomalous lithium storage reaction mechanism is designed. In particular, the pure metal electrode is intended for eliminating the electrochemical reaction‐derived Li2O phase accompanied by catalytic Li2O decomposition and the interfacial lithium storage at Ru/Li2O phase boundary, and thereby focusing on the ruthenium itself in exploring its electrochemical reactivity. Intriguingly, unusual lithium storage not involving redox reactions with electron transfer but leading to lattice expansion is identified in the ruthenium electrode. Size‐dependent charge redistribution at surface enables additional lithium adsorption to occur on the inactive but more environmentally sensitive nanoparticles, providing innovative insight into dynamic electrode environments in rechargeable lithium chemistry. 相似文献
998.
Lu Shen Peiran Shi Xiaoge Hao Qiang Zhao Jiabin Ma Yan‐Bing He Feiyu Kang 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(26)
Lithium (Li) metal is promising for high energy density batteries due to its low electrochemical potential (?3.04 V) and high specific capacity (3860 mAh g?1). However, the safety issues impede the commercialization of Li anode batteries. In this work, research of hierarchical structure designs for Li anodes to suppress Li dendrite growth and alleviate volume expansion from the interior (by the 3D current collector and host matrix) to the exterior (by the artificial solid electrolyte interphase (SEI), protective layer, separator, and solid state electrolyte) is concluded. The basic principles for achieving Li dendrite and volume expansion free Li anode are summarized. Following these principles, 3D porous current collector and host matrix are designed to suppress the Li dendrite growth from the interior. Second, artificial SEI, the protective layer, and separator as well as solid‐state electrolyte are constructed to regulate the distribution of current and control the Li nucleation and deposition homogeneously for suppressing the Li dendrite growth from exterior of Li anode. Ultimately, this work puts forward that it is significant to combine the Li dendrite suppression strategies from the interior to exterior by 3D hierarchical structure designs and Li metal modification to achieve excellent cycling and safety performance of Li metal batteries. 相似文献
999.
Pengcheng Shi Fanfan Liu YueZhan Feng Jiafeng Zhou Xianhong Rui Yan Yu 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(30)
Fluorinated solid‐electrolyte interphase (SEI) derived from fluoroethylene carbonate (FEC) is particularly favored for dendrite suppression in lithium metal batteries because of the high Young's modulus (≈64.9 Gpa) and low electronic conductivity (10?31 S cm?1) of LiF. However, the transportation ability of Li+ in this fluorinated SEI under high current densities is limited by the low ionic conductivity of LiF (≈10?12 S cm?1). Herein, by rational design, 0.1 m lithium bisoxalatodifluorophosphate (LiDFBOP) is adopted to modify fluorinated SEI in FEC based electrolyte for fast charging lithium metal batteries. Benefiting from the synergetic effect of LiDFBOP and FEC, a fluorinated SEI rich in LiF and LixPOyFz species can be yielded, which can further improve the stability and ionic conductivity of SEI for fast Li+ transportation. Meanwhile, the average coulombic efficiency for Li plating/stripping is improved from 92.0% to 96.7%, thus promoting stable cycling of Li||Li symmetrical batteries with dendrite free morphologies, even at high current densities (3.0 mA cm?2) and high plating/stripping capacities (3.0 mAh cm?2). More attractively, in practical Li||LiNi0.6Co0.2Mn0.2O2 batteries, the cycling life at 1C and rate capacities at 6C are also significantly improved. Therefore, the synergetic effect of LiDFBOP and FEC provides great potential for achieving advanced lithium metal batteries with fast charging ability. 相似文献
1000.
Shuailong Guo Yunkun Zhao Hao Yuan Chengxiong Wang Haoqing Jiang Gary J. Cheng 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(18)
Supported metal nanoparticles (MNPs) undergo severe aggregation, especially when the interaction between MNPs and their supports are limited and weak where their performance deteriorates dramatically. This becomes more severe when catalysts are operated under high temperature. Here, it is reported that MNPs including Pt, Au, Rh, and Ru, with sub‐2 nm size can be stabilized on densely packed defective CeO2 nanoparticles with sub‐5 nm size via strong coupling by direct laser conversion of corresponding metal ions encapsulated cerous metal–organic frameworks (Ce‐MOFs). Ce‐MOF serves as an ideal dispersion precursor to uniformly encapsulate noble metal ions in their orderly arranged pores. Ultrafast laser vaporization and cooling forms uniform, ultrasmall, well‐mixed, and exceptionally dense nanoparticles of metal and metal oxide concurrently. The laser‐induced ultrafast reaction (within tens of nanoseconds) facilitates the precipitation of CeO2 nanoparticles with abundant surficial defects. Due to the well‐mixed ultrasmall Pt and CeO2 components with strong coupling, this catalyst exhibits exceptionally high stability and activity both at low and high temperatures (170–1100 °C) for CO oxidation in long‐term operation, significantly exceeding catalysts prepared by traditional methods. The scalable feature of laser and huge MOF family make it a versatile method for the production of MNP‐based nanocomposites in wide applications. 相似文献