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1.
《International Journal of Hydrogen Energy》2022,47(83):35423-35436
The gas diffusion substrate (GDS) is essential in the proton exchange membrane fuel cells. Its fabrication techniques affect the performance significantly and are worthy of investigation. In this study, a manufacturing process of the GDS is proposed to understand the formation process of GDS and promote its structure and performance more pertinently. Different states during the preparation process, raw carbon paper, pre-curing, curing, carbonation, and graphitization, are characterized and measured. Experimental and numerical methods are employed to determine the relationships between microstructure, transport, and mechanical performance variation with the fabricating processes. The results show that its porosity, average pore size, and effective diffusivity decrease first and increase after curing. These parameters after graphitization are lower than that of the carbon paper (CP). The electrical resistivity increases dramatically while pre-curing and decreases gradually after curing, carbonation, and graphitization, and it is much reduced after graphitization. Moreover, mechanical measurement results show that both the picks of tensile strength and flexural modulus occur after curing. Its tensile strength shows little change after graphitization compared to the initial paper's. In contrast, the flexural modulus is improved significantly. 相似文献
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《International Journal of Hydrogen Energy》2022,47(61):25769-25779
Gas diffusion layer (GDL) is one of the most important components of fuel cells. In order to improve the fuel cell performance, GDL has developed from single layer to dual layers, and then to multiple layers. However, dual or multi layers in GDL are usually prepared by layer-by-layer methods, which cost too much time, energy, and resources. In this work, we successfully developed a facile one-step method to prepare a GDL with three functional layers by utilizing the different sedimentation rates and filtration rates of short carbon fiber (CF) and carbon nanotube (CNT). The treatment temperature for this GDL is much lower than that of traditional method. The thickness of the GDL can be effectively controlled from as thin as 50 μm to more than 200 μm by simply adjusting the content of CF. The GDL with high flexibility is suitable to develop high performance flexible electronics. The fuel cell with the GDL has the maximum power density 1021 mW cm?2, which shows 19% improvement comparing to the conventional one. Therefore, this work breaks the traditional concept that GDL for fuel cells only can be prepared by very complex and high-cost procedure. 相似文献
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《International Journal of Hydrogen Energy》2022,47(36):16121-16131
Ammonia is considered as a promising hydrogen or energy carrier. Ammonia absorption or adsorption is an important aspect for both ammonia removal, storage and separation applications. To these ends, a wide range of solid and liquid sorbents have been investigated. Among these, the deep eutectic solvent (DES) is emerging as a promising class of ammonia absorbers. Herein, we report a novel type of DES, i.e., metal-containing DESs for ammonia absorption. Specifically, the NH3 absorption capacity is enhanced by ca. 18.1–36.9% when a small amount of metal chlorides, such as MgCl2, MnCl2 etc., are added into a DES composed of resorcinol (Res) and ethylene glycol (EG). To our knowledge, the MgCl2/Res/EG (0.1:1:2) DES outperforms most of the reported DESs. The excellent NH3 absorption performances of metal–containing DESs have been attributed to the synergy of Lewis acid–base and hydrogen bonding interactions. Additionally, good reversibility and high NH3/CO2 selectivity are achieved over the MgCl2/Res/EG (0.1:1:2) DES, which enables it to be a potential NH3 absorber for further investigations. 相似文献
4.
《International Journal of Hydrogen Energy》2022,47(61):25511-25521
Metal/carbon composite materials are highly promising electrocatalysts for water electrolysis. In this work, three composites of metal cobalt nanoparticles highly dispersed in N-doped carbon materials were facilely constructed by pyrolysis of different phenylenediamine based Schiff base-Co complexes (PDBs). Interestingly, the composites derived from PDBs based on different phenylenediamine exhibited different morphologies. The superior case is that rodlike composite catalyst was derived from o-phenylenediamine based PDBs. The obtained catalyst exhibited remarkable performances for both cathodic hydrogen evolution reaction (HER) and anodic oxygen evolution reaction (OER), as well as overall water electrolysis. Only 172 and 289 mV of overpotentials and 1.57 V of cell voltage were exhibited at 10 mA cm?2 for HER, OER and water splitting in 1.0 M KOH, respectively. The catalyst also displayed robust stability and high Faraday efficiency, and thus are potential high-performance catalyst for commercial water electrolysis. 相似文献
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分别采用共沉淀法、清洁法制备焙烧态水铝钙石,通过低温N2吸脱附法、CO2-TPD、XRD、DTA和FT-IR表征结构,并将其作为大豆油与甲醇酯交换合成生物柴油的催化剂,探讨制备方法对焙烧态水铝钙石催化合成生物柴油的影响。此外,考察了Ca/Al摩尔比、焙烧温度、甲醇与大豆油摩尔比(醇油比)、催化剂用量和反应时间对酯交换合成生物柴油的影响。结果表明,清洁法制备的焙烧态水铝钙石具有更高的比表面积,强碱中心的表面碱量更大,催化活性更高。当Ca/Al摩尔比为2∶1,焙烧温度为600℃时,制备的Ca2Al O-2-600催化剂的催化活性最高,在醇油比8∶1、催化剂用量3%、反应温度65℃、反应时间4 h的条件下,大豆油转化率达到98. 0%。催化剂经重复使用3次后仍保持较高催化活性。 相似文献
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制浆造纸行业水污染全过程控制技术理论与实践 总被引:1,自引:0,他引:1
制浆造纸行业是我国水污染防治的重点,减排任务艰巨。在环境倒逼下,造纸行业加快淘汰落后产能和完善末端治理技术,污染控制取得了初步成效。但随着国家和地方环境治理由浓度控制走向总量控制、质量控制,原有技术的局限性难以满足解决水污染的更高要求,必须创新污染防治方法。本文介绍了制浆造纸行业水污染全过程控制的基本理论和内涵,并结合化学法制浆、化学机械法制浆、废纸制浆与造纸过程水污染防治工程实践,提出了解决制浆造纸行业水污染的对策,为推动行业绿色转型升级和高质量发展提供了支撑。 相似文献