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195.
植物乳杆菌G8菌株产细菌素最佳条件的研究 总被引:3,自引:1,他引:3
对甘蓝泡菜的一株产细菌素植物乳杆菌LactobacillusplantarumG8进行研究,确定了在MRS液体培养其中细菌素产生的条件。通过L93^4正交试验,筛选出其最佳产细菌素的组合为C2D2A1B2即起始PH值为6.0;培养温度为30℃,葡萄糖浓度为0.5%,蛋白胨浓度为1%。 相似文献
196.
Miao Luo Juan Zhao Yanyan Liu Zhu Mao Sheng Wang Zhenguo Chi 《Advanced functional materials》2023,33(9):2211009
Developing new all-visible-light driven fluorescent molecular switches has attracted much interests due to their important application prospects in materials science and life science. Herein, three novel all-visible-light triggered fluorescent molecular photoswitches ( 2P3 , 4F , and 4Cl ) are designed and prepared, which are realized by prolonging π-conjugation length with aggregated-induced emission units. These photoswitches show reversible photochromic and fluorescent switching in dilute solutions and films under 420 nm and 560 nm irradiations. Meanwhile, upon alternating irradiations with 450 nm/560 nm light, effective photochromic and fluorescent switching in powder states are also achieved. More interestingly, two distinct conformations with different photochromic abilities can be altered by solvents polarity. The size difference of the two conformations is over 5 Å in the vertical direction which is one of the largest changes among photochromic molecules based on dithienylethene. The accompanying conformational changes are analysed to understand the relationship between solvent characteristics and crystal structure, as well as the intermolecular interaction in solid state for all-visible-light triggered photoswitching molecules. 相似文献
197.
Beibei Fan Zhaozheng Wang Guoxu Liu Zheng Wang Xianpeng Fu Likun Gong Chi Zhang 《Advanced functional materials》2023,33(33):2301821
The tribovoltaic effect can convert semiconductor interfacial frictional mechanical energy into direct current (DC) electricity, but the flexibility and durability of semiconductor materials limit its application in wearable electronic. Herein, a robust flexible textile tribovoltaic nanogenerator is presented based on a 2D dynamic heterojunction of 2H-MoS2/Ta4C3 (MTNG). During the friction process, a built-in electric field (Eb) and an additional interfacial electric field (ECE) are generated in a continuous dynamic contact of 2H-MoS2/Ta4C3, and through the 2H-MoS2/Ta4C3 dynamic heterojunction, a significant number of electron-hole pairs are excited and move directionally to generate a DC. The influences of mechanical pressure and sliding speed on output performance of MTNGs are systematically investigated. The MTNGs deliver excellent output power density (39.15 mW m2) and outstanding robustness (43 000 cycles). Ten MTNGs can be connected in series to obtain a DC voltage of 3.3 V and in parallel to obtain a DC current of 75 µA. Furthermore, the MTNGs can effectively power a variety of commercial electronic watches and calculators by harvesting human kinetic energy. A 2D dynamic heterojunction 2H-MoS2/Ta4C3 DC nanogenerator is described and offers a workable option for the creation of flexible DC power sources and self-powered wearable electronics. 相似文献
198.
该文报导以天然香茅醇为原料,采用光敏氧化法合成外消旋玫瑰醚。通过的氧化还、还原、环化三个单元的影响因素的探讨,筛选出合理的工艺条件,产品纯度〉98%;茯理化指标,香气均达到国外同类产品的水平。 相似文献
199.
Chun‐Chuan Yang Yi‐Ting Mai Liang‐Chi Tsai 《International Journal of Communication Systems》2009,22(12):1543-1562
IEEE 802.16 (WiMax) technology is designed to support broadband speeds over wireless networks for the coming era of broadband wireless access (BWA). IEEE 802.16 is expected to provide transmission of high‐rate and high‐volume multimedia data streams for fixed and mobile applications. As an extension of point‐to‐multipoint (PMP) configuration, the IEEE 802.16 mesh mode provides a quicker and more flexible approach for network deployment. Multimedia networking requires quality‐of‐service (QoS) support, which demands elaborate mechanisms in addition to the four service types defined in the specification. By examining standard centralized and distributed scheduling/routing schemes in the mesh mode from QoS aspect, a BS‐controlled and delay‐sensitive scheduling/routing scheme is proposed in the paper. Associate mechanisms including admission control, flow setup and link state monitoring are also proposed. Integration of the proposed mechanisms is presented as a complete QoS framework. Simulation study has demonstrated that the average delay as well as the delay jitters per hop in the proposed scheme is smaller than that of the distributed scheme and much smaller than that of the centralized scheme. Furthermore, proposed mechanisms can also achieve higher throughput than the contrasts and generate much smaller signaling overhead, making the proposed framework a promising scheme for multimedia support in the IEEE 802.16 mesh network. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
200.
Woo‐Seok Cheong Jeong‐Min Lee Jong‐Ho Lee Sang‐Hee Ko Park Sung Min Yoon Chun‐Won Byun Shinhyuk Yang Sung Mook Chung Kyoung Ik Cho Chi‐Sun Hwang 《ETRI Journal》2009,31(6):660-666
We investigate the effects of interfacial dielectric layers (IDLs) on the electrical properties of top‐gate In‐Ga‐Zn‐oxide (IGZO) thin film transistors (TFTs) fabricated at low temperatures below 200°C, using a target composition of In:Ga:Zn = 2:1:2 (atomic ratio). Using four types of TFT structures combined with such dielectric materials as Si3N4 and Al2O3, the electrical properties are analyzed. After post‐annealing at 200°C for 1 hour in an O2 ambient, the sub‐threshold swing is improved in all TFT types, which indicates a reduction of the interfacial trap sites. During negative‐bias stress tests on TFTs with a Si3N4 IDL, the degradation sources are closely related to unstable bond states, such as Si‐based broken bonds and hydrogen‐based bonds. From constant‐current stress tests of Id = 3 µA, an IGZO‐TFT with heat‐treated Si3N4 IDL shows a good stability performance, which is attributed to the compensation effect of the original charge‐injection and electron‐trapping behavior. 相似文献