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991.
文章从FPCB生产案例金裂问题出发,研究讨论了耐电镀光致抗蚀干膜对化学镀镍药水pH值、镀层厚度、表面形貌和脆性的影响,并采用弯折法定性研究了干膜对化学镀镍镀层脆性的影响。结果显示干膜在化学镀镍药水中长时间浸泡使溶出物大量积累会增大化学镀镍镀层脆性。  相似文献   
992.
RPC溢出漏洞成为Windows系统安全的巨大威胁。介绍了RPC的原理,研究了RPC中Stub的数据构造和标准,分析了堆结构和堆溢出原理,总结了堆溢出漏洞的利用方法,针对一个RPC堆溢出漏洞分析了利用过程,提出了RPC堆溢出漏洞攻击的防范措施。  相似文献   
993.
Highly-active single-atom nanoenzymes (SAzymes) with biomimetic geometric and electronic coordination structures are highly highlighted to exhibit greatly-increased catalysis activity. Despite various SAzymes, superoxide dismutase (SOD)-like SAzymes for scavenging superoxide anions to treat osteoarthritis are still absent. In this report, a graphene-supported Cl Cu N4-centered SAzyme (Cu N4ClG) is engineered that carries out SOD-like reactions. Various synchrotron radiation-based X-ray valence/structural analyses reveal that the geometric and electronic structures of such Cl Cu N4 active centers are validated to atomically match natural SOD enzyme after precisely manipulating coordinated N and Cl atoms via the unprecedented pre-coordination orientation and preservation of copper-phthalocyanine structure. Cu-N4ClG SAzymes are endowed with unparalleled catalytic activities and kinetics to degrade O2¯ into H2O2 and O2, and further exhibit catalase (CAT)-like activity to sequentially decompose H2O2 and OH into H2O and O2, wherein the origin of sequential SOD-like and CAT-like catalysis routes is uncovered. Impressively, nitroxide radical scavenging and photothermally-enhanced catalytic activity are reached, synergistically protecting chondrocytes from oxidative stress-induced apoptosis and alleviating osteoarthritis via re-programming or normalizing osteoarthritis microenvironments. Cu-N4ClG SAzymes are competent for other reactive oxygen species (ROS)-arised lesions, and their rationales provide guidance to design other SAzymes.  相似文献   
994.
Aqueous ammonium ion hybrid supercapacitor (A-HSC) combines the charge storage mechanisms of surface adsorption and bulk intercalation, making it a low-cost, safe, and sustainable energy storage candidate. However, its development is hindered by the low capacity and unclear charge storage fundamentals. Here, the strategy of phosphate ion-assisted surface functionalization is used to increase the ammonium ion storage capacity of an α-MoO3 electrode. Moreover, the understanding of charge storage mechanisms via structural characterization, electrochemical analysis, and theoretical calculation is advanced. It is shown that NH4+ intercalation into layered α-MoO3 is not dominant in the A-HSC system; rather, the charge storage mainly depends on the adsorption energy of surface “O” to NH4+. It is further revealed that the hydrogen bond chemistry of the coordination between “O” of surface phosphate ion and NH4+ is the reason for the capacity increase of MoO3. This study not only advances the basic understanding of rechargeable aqueous A-HSC but also demonstrates the promising future of surface engineering strategies for energy storage devices.  相似文献   
995.
An ideal craniofacial bone repair graft shall not only focus on the repair ability but also the regeneration of natural architecture with occlusal loads-related function restoration. However, such functional bone tissue engineering scaffold has rarely been reported. Herein, a hierarchical 3D graft is proposed for rebuilding craniofacial bone with both natural structure and healthy biofunction reconstruction. Inspired by the bone healing process, an organic–inorganic nanoink with ultrasmall calcium phosphate oligomers and bone morphogenetic protein-2 incorporated is developed for spatiotemporal guidance of new bone. Based on such homogeneous nanoink, a biomimetic graft, including a cortical layer containing Haversian system, and a cancellous layer featured with triply periodic minimum surface macrostructures, is fabricated via projection-based 3D printing method, and the layers are loaded with distinct concentrations of bioactive factors for regenerating new bone with gradient density. The graft exhibits excellent osteogenic and angiogenic potential in vitro, and accelerates revascularization and reconstructs neo-bone with original morphology in vivo. Benefiting from such natural architecture, loading force is widely transferred with reduced stress concentration around the inserted dental implant. Taken from native physiochemical and structural cues, this wstudy provides a novel strategy for functional tissue engineering through designing function-oriented biomaterials.  相似文献   
996.
Artificial interface layer engineering is an efficacious modification strategy for protecting zinc anode from dendrite growth and byproducts formation. However, the high bulk ionic conductivity of most artificial interfacial layers is mainly contributed by the movement of anions (SO42−), which is the source of parasitic reactions on zinc anode. Herein, a high zinc ion donor transition (σZn2+ = 3.89 × 10−2 S cm−1) imidazole polymeric ionic liquid interface layer (1-carboxymethyl-3-vinylimidazolium bromide monomer, CVBr) for Zn metal protection is designed. The N+ atom of imidazole rings is connected by chains to form the cavities and the anions are confined within these cavities. Thus, the hindering effect of surrounding units on the anions leads to the subdiffusive regime, which inhibits the diffusion of SO42− in interface and increases Zn2+ transference number. Besides, the polycation-anion coordination mechanism of PolyCVBr ensures accelerated Zn2+ transition and realizes rapid internal Zn2+ migration channel. As a result, the Zn@CVBr||AM symmetry cells deliver high bulk ionic conductivity (4.42 × 10−2 S cm−1) and high Zn2+ transference number (tZn2+ = 0.88) simultaneously. The Zn@CVBr||AM-NaV3O8 pouch cells display the capacity retention of 88.9% after 190 cycles under 90° bending, verifying their potential practical application.  相似文献   
997.
In this work, the effects of growth pressure and growth rate on electrical and structural properties of Mg-doped GaN were investigated. It has been shown that enhanced growth rates induced by higher growth pressures may lead to decreased structural and electrical properties of p-type GaN layers. If the growth rate is kept unchanged, higher growth pressures will be beneficial for the quality of Mg-doped GaN due to the enhanced NH3 overpressure.  相似文献   
998.
Low-loss materials Li2ZnTi3+x O8+2x (LZT) (x = 0, 0.10, 0.17, 0.25, 1.00) were prepared by the conventional solid-state route. The effect of TiO2 ratio on phase composition, microstructure, and the microwave dielectric properties of Li2ZnTi3+x O8+2x ceramics were investigated using x-ray diffraction, scanning electron microscopy, energy-dispersive x-ray spectroscopy, and Vector Network Analyzer. The results revealed that a two-phase system Li2ZnTi3O8-TiO2 was formed. The appropriate content of TiO2 ratio can effectively adjust the temperature coefficient of the resonant frequency (τ f) value from ?14.5 to 0 ppm/ °C without obvious degradation of the microwave dielectric properties. The microwave dielectric properties of the Li2ZnTi3+x O8+2x materials were characterized at microwave frequencies. Typically, the Li2ZnTi3+x O8+2x (x = 0.17) ceramic sintered at 1,160 °C for 5 h showed excellent microwave dielectric properties with ε r = 28.51, Q × f = 58,511 GHz, and τ f = + 2.3 ppm/ °C.  相似文献   
999.
赵建宜  陈鑫  周宁  黄晓东  刘文 《半导体学报》2014,35(11):114008-7
使用纳米压印技术制作了用于1.3um CWDM系统的四通道单片集成折射率耦合DFB半导体激光器。得到了符合设计的20nm通道间隔激射波长。结果显示纳米压印技术在制作DFB半导体激光器方面是成熟可靠的。  相似文献   
1000.
Wearable strain sensors with the ability of detecting physiological activities play an important role in personalized healthcare. Electrospun fibers have become a popular building block for wearable strain sensors due to their excellent mechanical properties, breathability, and light weight. In this review, the structure and preparation process of electrospun fibers and the conductive layer are systematically introduced. The impact of materials and structures of electrospun fibers on the wearable strain sensors with a following discussion of sensing performance optimization strategies is outlined. Furthermore, the applications of electrospun fiber-based wearable strain sensors in biomonitoring, motion detection, and human-machine interaction are presented. Finally, the challenges and promising future directions for the community of wearable strain sensors based on electrospun fibers are pointed out.  相似文献   
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