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991.
一种基于ARMA模型的目标极点提取新方法   总被引:2,自引:0,他引:2  
针对传统极点提取算法需要确定目标后时响应起点的不足,本文提出了一种提取目标极点的新方法,该方法使用ARMA模型逼近整个目标响应,并利用全局最小二乘技术求解模型参数获取目标极点。基于实测细导线和有限长柱体散射场数据的处理结果表明,本文新方法较之KT法和矩阵束法具有更高的极点提取精度。  相似文献   
992.
介绍一种双机双控实现高可靠容错系统,采用硬件冗余,结构简单可靠,应用灵活,现已开发出产品使用。  相似文献   
993.
网络并行计算的编程要求设计者对任务的分解、分配及子任务间的交互等问题有更高的技术。论文给出了在网络并行计算的一种新平台,用户只需提交数据和对它的操作即可。  相似文献   
994.
张信一  李代平  章文 《计算机工程》2004,30(5):161-163,166
通过构建PVM的网络并行计算平台,将并行计算的环境应用于勘探地球物理的计算中,利用互联网上的计算机资源实现大问题的并行计算,使得许多优秀的算法得以体现和广泛地应用。该文介绍了系统平台的构建、任务的划分和分派、处理结果的回收及对系统效果进行评价等内容。  相似文献   
995.
An extremely facile and up-scalable approach has been proposed to disperse ferric grains onto bacterial cellulose (BC) nanofibers. The BC-induced hydrolytic deposition can be performed at room temperature without using any organic solvents, toxic reagents, or complicated apparatuses, enabling a green pathway in realizing industrialization. After carbonization, the randomly oriented carbonized BC (CBC) nanofibers transmit the electrons throughout the electrode, while the inherited reticular morphology boosts the thorough penetration of electrolyte. Moreover, the sufficient space created by interconnected CBC nanofibers is able to accommodate the volume change of the nanosized Fe3O4 active materials during repeated Li+ intercalation and deintercalation. As a result, the as-prepared Fe3O4/CBC composites deliver the superior electrochemical performance as the free-standing anodes in Li-ion batteries (LIBs), including the impressive reversible capacity of 702 mAh g?1 after 400 cycles at 400 mA g?1, decent rate capability with capacity of 437 mAh g?1 at 2000 mA g?1, and a long cycling lifespan up to 1000 cycles at 800 mA g?1. This work provides a scalable and green approach to fabricate high-performance LIBs anode with the natural sustainable biomass.  相似文献   
996.
Puerarin, which is extracted from Chinese medicine, is widely used in China and mainly used as a therapeutic agent for the treatment of cardiovascular diseases. Owing to its short elimination half-life in human beings, frequently intravenous administration of high doses of puerarin may be needed, which possibly leads to severe and acute side effects. The development of an effective sustained-release drug delivery system is urgently needed. In this study, PEGylated mesoporous silica nanoparticles (PEG-MSNs) had become a preferred way to prolong the half-life and improve the bioavailability of drugs. The release of puerarin from PEG-MSNs was pH dependent, and the release rate was much faster at lower pH than that at higher pH. Moreover, the PEG-MSNs exhibited improved blood compatibility over the MSNs in terms of low hemolysis, and it could also reduce the side effect of hemolysis induced by PUE. Compared with puerarin, PUE-loaded PEG-MSNs showed a 2.3-fold increase in half-life of puerarin and a 1.47-fold increase in bioavailability. Thus, the PEG-MSNs hold the substantial potential to be further developed as an effective sustained-release drug delivery system.  相似文献   
997.
Chiral properties of nanoscale materials are of importance as they dominate interactions with proteins in physiological environments; however, they have rarely been investigated. In this study, a systematic investigation is conducted for the adsorption behaviors of bovine serum albumin (BSA) onto the chiral surfaces of gold nanoparticles (AuNPs), involving multiple techniques and molecular dynamic (MD) simulation. The adsorption of BSA onto both L‐ and D‐chiral surfaces of AuNPs shows discernible differences involving thermodynamics, adsorption orientation, exposed charges, and affinity. As a powerful supplement, MD simulation provides a molecular‐level understanding of protein adsorption onto nanochiral surfaces. Salt bridge interaction is proposed as a major driving force at protein–nanochiral interface interaction. The spatial distribution features of functional groups (? COO?, ? NH3+, and ? CH3) of chiral molecules on the nanosurface play a key role in the formation and location of salt bridges, which determine the BSA adsorption orientation and binding strength to chiral surfaces. Sequentially, BSA corona coated on nanochiral surfaces affects their uptake by cells. The results enhance the understanding of protein corona, which are important for biological effects of nanochirality in living organisms.  相似文献   
998.
A visible-light-driven g-C3N4/g-C3N4 isotype heterojunction photocatalyst was synthesized by one-step thermal treatment using urea and thiourea as the precursor. The photocatalytic activity of as-prepared photocatalyst was evaluated through the degradation of rhodamine B (RhB) and tetracycline hydrochloride (TC) under the visible light irradiation. The hybrid showed enhanced photocatalytic activity in photodegradating the applied pollutants as compared with single g-C3N4. When the ratio of urea to thiourea was 2:1, the prepared isotype heterojunction exhibited the highest photocatalytic activity and the photodegradation rates for RhB and TC were 99.8% and 95.1% after being visible light irradiated for 1 h and 4 h respectively. The enhanced photocatalytic performance of the isotype heterojunction is ascribed to the enhanced charge separation efficiency. After being reused for 5 times, the hybrid still showed excellent recyclability and chemical stability. Furthermore, NaI, BQ and IPA were used as the sacrificial agents for studying the surface reactions in the photocatalytic process. The method used in this work provides a new pathway to achieve more efficient degradation of antibiotics and to stimulate further studies in this important field.  相似文献   
999.
Advances in material design and applications are highly dependent on the development of particle surface engineering strategies. However, few universal methods can functionalize particles of different compositions, sizes, shapes, and structures. The amyloid‐like lysozyme assembly‐mediated surface functionalization of inorganic, polymeric or metal micro/nanoparticles in a unique amyloid‐like phase‐transition buffer containing lysozyme are described. The rapid formation of a robust nanoscale phase‐transitioned lysozyme (PTL) coating on the particle surfaces presents strong interfacial binding to resist mechanical and chemical peeling under harsh conditions and versatile surface functional groups to support various sequential surface chemical derivatizations, such as radical living graft polymerization, the electroless deposition of metals, biomineralization, and the facile synthesis of Janus particles and metal/protein capsules. Being distinct from other methods, the preparation of this pure protein coating under biocompatible conditions (e.g., neutral pH and nontoxic reagents) provides a reliable opportunity to directly modify living cell surfaces without affecting their biological activity. The PTL coating arms yeasts with a functional shell to protect their adhered body against foreign enzymatic digestion. The PTL coating further supports the surface immobilization of living yeasts for heterogeneous microbial reactions and the sequential surface chemical derivatization of the cell surfaces, e.g., radical living graft polymerization.  相似文献   
1000.
Driven by the intensified demand for energy storage systems with high‐power density and safety, all‐solid‐state zinc–air batteries have drawn extensive attention. However, the electrocatalyst active sites and the underlying mechanisms occurring in zinc–air batteries remain confusing due to the lack of in situ analytical techniques. In this work, the in situ observations, including X‐ray diffraction and Raman spectroscopy, of a heteroatom‐doped carbon air cathode are reported, in which the chemisorption of oxygen molecules and oxygen‐containing intermediates on the carbon material can be facilitated by the electron deficiency caused by heteroatom doping, thus improving the oxygen reaction activity for zinc–air batteries. As expected, solid‐state zinc–air batteries equipped with such air cathodes exhibit superior reversibility and durability. This work thus provides a profound understanding of the reaction principles of heteroatom‐doped carbon materials in zinc–air batteries.  相似文献   
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