全文获取类型
收费全文 | 110篇 |
免费 | 5篇 |
国内免费 | 15篇 |
专业分类
化学 | 98篇 |
晶体学 | 1篇 |
力学 | 2篇 |
综合类 | 1篇 |
数学 | 7篇 |
物理学 | 21篇 |
出版年
2023年 | 6篇 |
2022年 | 7篇 |
2021年 | 11篇 |
2020年 | 15篇 |
2019年 | 9篇 |
2018年 | 7篇 |
2017年 | 3篇 |
2016年 | 3篇 |
2015年 | 7篇 |
2013年 | 8篇 |
2012年 | 11篇 |
2011年 | 11篇 |
2010年 | 1篇 |
2009年 | 3篇 |
2008年 | 2篇 |
2007年 | 4篇 |
2006年 | 3篇 |
2005年 | 1篇 |
2004年 | 5篇 |
2003年 | 4篇 |
2002年 | 1篇 |
1999年 | 2篇 |
1998年 | 2篇 |
1996年 | 1篇 |
1995年 | 1篇 |
1994年 | 1篇 |
1992年 | 1篇 |
排序方式: 共有130条查询结果,搜索用时 43 毫秒
121.
压电现象在新能源开发、 传感、 医药材料设计及可穿戴电子设备中具有广泛的潜在应用, 并受到普遍重视. 在压电材料中, 聚偏氟乙烯(PVDF)及其共聚物因具有良好的柔韧性、 易加工性、 稳定性和生物相容性等优点而备受关注. 本文综合评述了近年来在制备工艺和材料复合两个维度提高PVDF基压电材料输出性能的研究进展. 在研究PVDF压电性原理的基础上, 阐释了流延法、 静电纺丝法、 拉丝法及纳米限域策略等工艺和添加小分子、 高分子、 石墨类粒子及无机纳米粒子等复合策略提升其压电性能的机理. 这些制备工艺的提高和填料的掺杂有助于偶极子的排列和高β相的形成. 最后, 对目前存在的一些挑战进行了概述和讨论, 并对PVDF基材料的发展前景提出展望. 相似文献
122.
Monolithic columns have been prepared with a novel bonded silica stationary phase, tetradecylamine bonded silica (TDAS), and used in pressurized capillary electrochromatography (pCEC). The monolithic silica column matrix was prepared by a sol-gel process and then chemically modified with the spacer (3-glycidoxypropyl)trimethoxysilane and tetradecylamine. The introduced embedded polar amine groups dominated the charge on the surface of the monolithic stationary phase and generated an EOF from cathode to anode under acidic conditions. The tetradecyl hydrophobic chains in TDAS provide chromatographic interactions. The chromatographic characteristics of the prepared monolithic column were studied. Some aromatic compounds including alkylbenzenes, aromatic hydrocarbons, phenols, and anilines were successfully separated on the TDAS monolithic column in pCEC mode. As expected, the TDAS monolithic stationary phases exhibit typical reversed-phase electrochromatographic behavior toward neutral solutes due to the introduced tetradecyl groups. Hydrophobic as well as electrophoretic migration processes within the monoliths were observed in the separation of basic anilines. Symmetrical peaks can be obtained for anilines because the embedded polar amine groups on the surface can effectively shield the adsorption of positively charged analytes onto the stationary phase. 相似文献
123.
Molecular dynamics simulations combined with spectroscopic analysis were applied to understand the nature of recognition in
molecularly imprinted polymers (MIPs), and for optimizing the MIP formulation. The best monomers for synthesizing imprinted
materials for 17β-estradiol (BE2) were selected by evaluating the strength of the template–monomer interaction derived from molecular dynamics
simulations. A number of potential functional monomers for BE2 were screened for hydrogen-bonding strength in order to analyze
template–monomer interactions favorable for synthesizing noncovalent MIPs, with the simulations revealing that methacrylic
acid, 2-(diethylamino)ethyl methacrylate, and methacrylamide provided the highest binding affinity to BE2. These theoretical
predictions agree with previously reported results on batch rebinding studies using the corresponding functional monomers
for synthesizing a series of MIPs. Molecular analysis such as 1H NMR was used for experimentally confirming the prevalent template–monomer interactions derived from the modeling results.
Molecular dynamics simulations indicating monomer dimerization in the prepolymerization solution correlated with the nature
of the porogenic solvent, which was confirmed by NMR studies on hydrogen-bonding interactions of methacrylic acid in different
solvents. Furthermore, batch rebinding studies revealed that the specific functionalities of the monomers essential to rebinding
are retained after polymerization, which proves that the application of computational methods for modeling the prepolymerization
solution provides useful information for optimizing real MIP systems. 相似文献
124.
Corn stover silage is an attractive raw material for the production of biofuels and chemicals due to its high content of carbohydrates
and easy degradability. The effects of Fe(NO3)3 pretreatment conditions on sugar yields were investigated for corn stover silage. In addition, a combined severity factor
was used to evaluate the effect of pretreatment conditions on the concentration of total sugars and inhibitors. Optimum pretreatment
condition was obtained at 150 °C for 10 min with 0.05 M Fe(NO3)3, at which the yields of soluble xylose and glucose in liquid achieved 91.80% of initial xylose, 96.74% of initial arabinose
and 19.09% of initial glucose, respectively, meanwhile, 91.84% of initial xylose, 98.24% of initial arabinose, and 19.91%
of initial glucose were removed. In addition, a severity analysis showed that the maximum sugar concentration of 33.48 g/l
was achieved at combined severity parameter value of 0.62, while the inhibitor concentration was only 0.03 g/l. Fe(NO3)3 is an effective catalyst to enhance hemicellulose hydrolysis in corn stover silage, the yields of monomeric xylose in the
liquid fraction reached as high as 91.06% of initial xylose and 96.22% of initial arabinose, respectively. 相似文献
125.
Jiansheng Huo Yuhui Zheng Shuting Pang Qianming Wang 《Cellulose (London, England)》2013,20(2):841-848
In this paper, a novel luminescent hydrogel was successfully prepared by incorporating Tb-HSA (HSA = Human Serum Albumin) complex into cellulose host. The green luminescence intensities of Tb(III) exhibited on–off changes in terms of pH variation. At the same time, europium activated phosphor (GdVO4:Eu3+) was immobilized into the cellulose hydrogels through two approaches. The photophysical properties of luminescent gels with the temperature variation were investigated by fluorescence. The new group of soft materials will display task-specific usages in sensing fields. 相似文献
126.
近年来, 与铜氧化物高温超导体具有类似电子结构的5d 轨道 Ruddlesden-Popper 类型铱氧化物由于体系中库伦排斥和自旋轨道耦合之间的合作效应被人们广泛探究. 其中, 金属绝缘体转变的关键影响因素是该方向的核心研究问题, 该结果对推进掺杂莫特绝缘体体系的研究具有重要作用. 因为铱氧化物与铜氧化物在单能带哈伯德模型的次 近 邻 跃 迁 项 具 有 不 同 符 号, 因 此 空 穴 掺 杂 铱 氧 化 物 类 比 电 子 掺 杂 铜 氧 化 物. 我 们 将 空 穴 掺 杂Ruddlesden-Popper 类型铱氧 化 物 系 统 依 据 几 种 不 同 的 掺 杂 元 素 进 行 分 类, 分 别 介 绍 其 角 分 辨 光 电 子 能 谱(ARPES) 探测到的电子结构, 对其中金属绝缘体转变类型进行了总结, 并对该领域中的未来研究方向做出了展望. 相似文献
127.
128.
129.
以4-(2-吡啶基)-苯甲醛、邻菲罗啉、对羟基苯甲醛、香草醛、溴丁烷和三氯化铱水合物为原料,合成了两种铱配合物IrL1和IrL2,其结构经核磁共振氢谱、碳谱、质谱和傅里叶红外光谱表征。研究了两种配合物在不同溶剂中的紫外可见吸收光谱和荧光发射光谱。结果表明:配合物IrL1和IrL2在乙醇中的荧光强度高于其它溶剂,最大发射波长位于542 nm。采用MTT实验和共聚焦显微成像技术研究了配合物IrL1和IrL2在HepG2细胞中的应用效果。结果表明:两种配合物细胞毒性较低,能够着色于固定细胞的细胞质中。 相似文献
130.
Tiantian Zhang Yuxin Xiao Hailan Wang Shuting Kong Rongjuan Huang Dr. Vonika Ka-Man Au Prof. Tao Yu Prof. Wei Huang 《Angewandte Chemie (International ed. in English)》2023,62(39):e202301896
Thermally activated delayed fluorescence (TADF) materials have attracted great potential in the field of organic light-emitting diodes (OLEDs). Among thousands of TADF materials, highly twisted TADF emitters have become a hotspot in recent years. Compared with traditional TADF materials, highly twisted TADF emitters tend to show multi-channel charge-transfer characters and form rigid molecular structures. This is advantageous for TADF materials, as non-radiative decay processes can be suppressed to facilitate efficient exciton utilization. Accordingly, OLEDs with excellent device performances have also been reported. In this Review, we have summarized recent progress in highly twisted TADF materials and related devices, and give an overview of the molecular design strategies, photophysical studies, and the performances of OLED devices. In addition, the challenges and perspectives of highly twisted TADF molecules and the related OLEDs are also discussed. 相似文献