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排序方式: 共有204条查询结果,搜索用时 375 毫秒
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By using diphenyliodonium salts with different counterions as photo acid generators (PAGs), theeffect of acidity on ring-opening polymerization of epoxy monomers and polycondensation of polyol withhexamethoxymethyl melamine (HMMM) was studied. The result shows that the rate of ring-openingpolymerization is evidently dependent on the acidity of the acid and strong photo-generated acid is required.However, there is a leveling effect in the polycondensation system; if the photo-generated acid is strongerthan protonated HMMM, the acidity does not obviously affect the polycondensation rate. 相似文献
113.
利用Nd/YAG激光器的三倍频激光脉冲(355nm),对双环戊二烯的光敏化反应进行了CIDNP方面的研究,结合CIDNP理论模拟谱的计算,证实了Roth等人所推测的此光敏化反应自由基中间体结构为双重的烯丙基物种,通过计算,确定了自由基各质子的超精细偶合常数hfc的相对大小和绝对符号以及各碳原子上的未偶电子自旋密度,从而对这个特殊的自由基中间体结构有了更清晰的认识. 相似文献
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T. Watanabe M. Akiyama K. Totani S.M. Kuebler F. Stellacci W. Wenseleers K. Braun S.R. Marder J.W. Perry 《Advanced functional materials》2002,12(9):611-614
A photoresponsive polymeric hydrogel cantilever that deflects under illumination has been fabricated by using two‐photon three‐dimensional lithography. The hydrogel was prepared from a comonomer solution containing acryloylacetone, acrylamide, and N,N′‐methylene bisacrylamide. The photoresponse of the cantilever was activated by photoexcitation of acetylacetone groups at 244 nm. Deflection of the cantilever by ∼ 45° was effected upon UV irradiation for 20 min. 相似文献
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JIN Tongzheng JIANG Xinyi YANG Yumeng ZHU Benfeng LIU Jiao JIANG Li WEI Guoying ZHANG Zhao 《高等学校化学研究》2021,37(3):696-703
In this paper, the early stages of nucleation and photoirradiation growth of CeO2 thin films have been studied. Cyclic voltammetry, chronoamperometry and scanning electron microscopy were used to analyze the nucleation process of CeO2 thin films deposited on the anode with photo irradiation. Experimental results show that the anodic deposition process with photo illumination is controlled by diffusion. Compared with the dark state, photo illumination mainly contributed to increase the current density of the three-dimensional nucleation process, because photo illumination is helpful to create active sites and accelerate the nucleation progress on the surface that a thin ceria film has been formed. Two-dimensional nucleation process mainly exists within the initial 2 s, and then only three-dimensional instantaneous nucleation process continues, which may be the main reason why the thickness of the CeO2 film can continue to grow with photo illumination but not in the dark state. Increasing the deposition overpotential can promote two-dimensional nucleation and growth rate, whilst when the potential exceeds 0.65 V, three-dimensional current density decreases. The li-miting factor at that time may be the diffusion rate of cerium ions in the solution towards the electrode substrate. 相似文献
118.
《中国化学快报》2021,32(11):3364-3367
High responsivity and sensitivity play essential roles in the development of organic field-effect transistors (OFETs)-based biosensors with regard to biological detections, particularly for disease diagnosis. Nonetheless, how to design a biosensor which improves these two outstanding properties while achieving low cost, easy processing, and time saving is a daunting challenge. Herein, a novel biosensor based on OFET with copolymer thin film, whose surface is illuminated with a suitable light beam is reported. This film can be used as both an organic semiconductor material and as a photoelectric active material. Due to amplification of signals as a result of the film’s strong response to light, the biosensor possesses higher responsivity and sensitivity compared to dark condition and even realizes a maximum responsivity of up to 103 for alpha-fetoprotein (AFP) detection. The simple combination of light and transistor builds a bridge between photoelectric effect and biological system. In addition, the emergence of more excellent photoelectric active materials is expected to pave a way for ultrasensitive bio-chemical diagnostic tools. 相似文献
119.
Robert Wagner Claudia Linke Martin Schnaiter Martin Gangl 《Journal of Quantitative Spectroscopy & Radiative Transfer》2009,110(11):930-949
This paper provides a survey of recent studies on the optical properties of aerosol and cloud particles that have been conducted at the AIDA facility of Forschungszentrum Karlsruhe (Aerosol Interactions and Dynamics in the Atmosphere). Reflecting the broad accessible temperature range of the AIDA chamber which extends from ambient temperature down to 183 K, the investigations feature a broad diversity of research topics, such as the wavelength-dependence of the specific absorption cross sections of soot and mineral dust aerosols at room temperature, depolarization and infrared extinction measurements of ice crystal clouds generated at temperatures below 235 K, and the optical properties of polar stratospheric cloud constituents whose formation was studied in chamber experiments at temperatures well below 200 K. After reviewing the AIDA research activity of the past decade and introducing the optical instrumentation of the AIDA facility, this paper presents illustrative examples of ongoing and already published work on optical measurements of soot aerosols, mineral dust particles, and ice crystal clouds. 相似文献
120.
Self-assembled monolayers(SAMs) of thiol-derivatized porphyrin molecules on Au substrate have attracted extensively interest for use in sensing,optoelectronic devices and molecular electronics.In this paper,tetra-[p-(3-mercaptopropyloxy)-phenyl]porphyrin was synthesized and self-assembled with thiol on Au substrate for porphyrin SAMs(PPS 4).The electrochemical results demonstrated that PPS 4 could form excellent SAMs on gold surface.Self-assembled nanojunctions of PPS 4 were fabricated by using gold nanogap electrodes(gap width:ca.100 nm).With the light on/off,the nanojunctions showed current high/low as nanometer scaled photo switch. 相似文献