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1.
以合成的g-C3N4纳米片和Ag/TiO2空心微球为原料,采用机械搅拌的方法构筑了g-C3N4/Ag/TiO2三元复合光催化剂。采用X射线衍射(XRD)、傅里叶变换红外光谱(FT-IR)、扫描电镜(SEM)、X射线光电子能谱(XPS)、紫外-可见光漫反射(UV-Vis DRS)和光致发光光谱(PL)对g-C3N4/Ag/TiO2进行了表征。研究表明,g-C3N4/Ag/TiO2是由Ag/TiO2微球和g-C3N4纳米片复合而成的。与TiO2相比,其可见光响应范围延长,光生载流子的分离速率加快。在室温下,用降解罗丹明B的反应考察了g-C3N4/Ag/TiO2的可见光催化活性。研究表明,光照180 min时,g-C3N4(0.5%)/Ag/TiO2显示了最高的光催化活性(91.9%),分别是TiO2和Ag/TiO2的7.5和1.8倍。光催化活性的提高与合理的异质结构建和Ag的导电性能有关。  相似文献   
2.
张岩  董刚  杨银堂  王宁  王凤娟  刘晓贤 《物理学报》2013,62(1):16601-016601
基于互连线的分布式功耗模型,考虑自热效应的同时采用非均匀互连线结构,提出了一种基于延时、带宽、面积、最小线宽和最小线间距约束的互连动态功耗优化模型.分别在90和65 nm互补金属氧化物半导体工艺节点下验证了功耗优化模型的有效性,在工艺约束下同时不牺牲延时、带宽和面积所提模型能够降低高达35%互连线功耗.该模型适用于片上网络构架中大型互连路由结构和时钟网络优化设计.  相似文献   
3.
The coexistence of multiferroic orders has attracted increasing attention for its potential applications in multiple-state memory, switches, and computing, but it is still challenging to design single-phase crystalline materials hosting multiferroic orders at above room temperature. By utilizing versatile ABX3-type perovskites as a structural model, we judiciously introduced a polar organic cation with easily changeable conformations into a tetrafluoroborate-based perovskite system, and successfully obtained an unprecedented molecular perovskite, (homopiperazine-1,4-diium)[K(BF4)3], hosting both ferroelectricity and ferroelasticity at above room temperature. By using the combined techniques of variable-temperature single-crystal X-ray structural analyses, differential scanning calorimetry, and dielectric, second harmonic generation, and piezoresponse force microscopy measurements, we demonstrated the domain structures for ferroelectric and ferroelastic orders, and furthermore disclosed how the delicate interplay between stepwise changed dynamics of organic cations and cooperative deformation of the inorganic framework induces ferroelectric and ferroelastic phase transitions at 311 K and 455 K, respectively. This instance, together with the underlying mechanism of ferroic transitions, provides important clues for designing advanced multiferroic materials based on organic–inorganic hybrid crystals.

An unprecedented tetrafluoroborate-based perovskite reveals the coexistence of ferroelastic and ferroelectric transitions arising from delicate interplay between stepwise frozen organic cations and cooperative deformation of the framework.  相似文献   
4.
刘小贤  童培庆 《中国物理 B》2008,17(11):3930-3935
A second-order dynamic phase transition in a non-equilibrium Eggers urn model for the separation of sand is studied. The order parameter, the susceptibility and the stationary probability distribution have been calculated. By applying the Lee-Yang zeros method of equilibrium phase transitions, we study the distributions of the effective partition function zeros and obtain the same result for the model. Thus, the Lee-Yang theory can be applied to a more general non-equilibrium system.  相似文献   
5.
FT-Raman and/or FT-IR spectra of 3-amino-2-cyclohexen-1-one (ACyO) in solid state and/or in solvents of water and acetonitrile were obtained. Density functional theory calculations were done to help elucidate the vibrational band assignments. The A-band resonance Raman spectra of ACyO were acquired in water and acetonitrile solvents to examine the excited state structural dynamics and the state-mixing or curve-crossing tuned by solvents. A preliminary resonance Raman intensity analysis using the time-dependent wave-packet theory and simple model was done for ACyO in acetonitrile solvent. Resonance Raman spectroscopic probing of the excited state curve-crossing or state-mixing was proposed.  相似文献   
6.
羟丙基壳聚糖纳米微球的制备及其缓释效果   总被引:1,自引:0,他引:1  
谢宇  尚晓娴  颜流水 《应用化学》2009,26(2):193-197
壳聚糖;羟丙基;纳米微球;牛血清蛋白;缓释  相似文献   
7.
纳米晶氧化镍的制备及表征   总被引:5,自引:0,他引:5  
Nano-NiO powder was prepared by thermal decomposition of the precursor of NiC2O4·2H2O obtained via Ni(NO3)2·6H2O and H2C2O4·2H2O reacting in ethanol solvent. IR and TGA-DTA indicate physisorption and chem- isorption ethanol co-exist in the precursor. XRD suggests the obtained cubic NiO is stable below 700 ℃. TEM shows the as-calcined NiO at 400 ℃ for 2 hours was of narrow distribution, weak agglomeration and small particle size (average 8 nm). The reason for weak agglomeration was explained.  相似文献   
8.
8-氯-4-(2-氯-4-氟苯氧基)喹啉(CCFQ)是DowElanco公司开发的新颖杀菌剂,它具有独特的杀菌机理—抑制与嘧啶生物合成有关的二氢乳清酸酯脱氢酶[1],能防治对现有杀菌剂产生抗性的病原菌,与现有杀菌剂无交互抗性,并且可与多种杀菌剂复配增效.文献[2]合成条件苛刻,原料损失很大,且需色谱分离提纯,收率较低.为解决以上问题,本文以固载氟化钾为催化剂,对4,8-二氯喹啉和2-氯-4-氟苯酚的缩合反应进行研究,发现催化缩合法条件温和,分离方法简单,收率可达75%.ClNCl FOHClKF/Al2O3ClNOClF主要仪器为NICOLET60SXR-FTIR红外光谱仪,KBr压…  相似文献   
9.
The bilinear form of the (2+1)-dimensional non-isospectral AKNS system is derived. Its N-soliton solutions are obtained by using the Hirota method. As a reduction, a (2+1)-dimensional non-isospectral Schrodinger equation and its N-soliton solutions are constructed.  相似文献   
10.
利用Anton Paar DMA4500振动管密度计测量了293.15 K时二元体系甲苯-N,N-二甲基甲酰胺(C6H5CH3-DMF)在C6H5CH3(摩尔分数0~1)中的溶液密度, 利用最小二乘法关联了溶液密度与组成的函数关系, 关联精度为±0.005 kg/m3. 通过密度数据分别计算了二元体系中C6H5CH3和DMF的表观摩尔体积, 并利用非线性最小二乘拟合法, 分别拟合得到了优化的C6H5CH3和DMF的表观摩尔体积和摩尔分数的函数关系, 以及C6H5CH3和DMF的表观摩尔体积和质量分数的函数关系. 通过对函数关系的极限运算得到了C6H5CH3和DMF的极限偏摩尔体积、标准偏摩尔体积和摩尔体积. 还计算了不同组分下体系的超额摩尔体积, 数据可用四参数Redlich-Kister方程关联拟合得到方程系数. 计算关联了C6H5CH3和DMF的超额偏摩尔体积与摩尔分数的关系. 由三参数多项式极限法得到组分的极限超额偏摩尔体积值与Redlich-Kister系数法得到的值在误差范围内一致.  相似文献   
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