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排序方式: 共有107条查询结果,搜索用时 593 毫秒
41.
Xiaoqing Jiang Bingqian Zhang Guangyue Yang Zhongmin Zhou Xin Guo Fengshan Zhang Shitao Yu Shiwei Liu Shuping Pang 《Angewandte Chemie (International ed. in English)》2023,62(22):e202302462
Carbonyl functional materials as additives are extensively applied to reduce the defects density of the perovskite film. However, there is still a lack of comprehensive understanding for the effect of carbonyl additives to improve device performance. In this work, we systematically study the effect of carbonyl additive molecules on the passivation of defects in perovskite films. After a comprehensive investigation, the results confirm the importance of molecular dipole in amplifying the passivation effect of additive molecules. The additive with strong molecular dipole possesses the advantages of enhancing the efficiency and stability of perovskite solar cells (PSCs). After optimization, the companion efficiency of PSCs is 23.20 %, and it can maintain long-term stability under harsh conditions. Additionally, a large-area solar cell module-modified DLBA was 20.18 % (14 cm2). This work provides an important reference for the selection and designing of efficient carbonyl additives. 相似文献
42.
Curcumin polymorphs were found to precipitate concomitantly during liquid antisolvent precipitation. While, commercially available curcumin exists in a monoclinic form, the curcumin particles when precipitated in presence of additives and ultrasound were either found to be the mixtures of orthorhombic (Form 3) and monoclinic form (Form 1) or were found to be in orthorhombic form (Form 3) or monoclinic form (Form 1). The experimentally observed particle morphologies did not match clearly with the predicted BFDH morphologies of curcumin and the experimentally observed morphologies were more elongated as compared to the predicted BFDH morphologies. At lower ultrasonic irradiation times, the monoclinic form (Form 1) was found to dominate the mixture of particles. However, an increase in ultrasonic irradiation time was found to increase the percentage of orthorhombic form (Form 3) in the particles indicating that the increase in ultrasonic energy facilitates formation of orthorhombic form over the monoclinic form, irrespective of the additive used. These results therefore suggest that the ultrasonic energy can be effectively used to manipulate the polymorphic outcome of the precipitation. 相似文献
43.
M. Suman G. Silva D. Catellani U. Bersellini V. Caffarra M. Careri 《Journal of chromatography. A》2009,1216(18):3758-3766
A new, reliable liquid chromatography/atmospheric-pressure chemical ionisation mass spectrometry (LC–APCI-MS) method was developed for the quantitative determination of food emulsifiers composed of mono- and diacylglycerols of fatty acids (E471 series) in complex food matrices. These additives are extremely interesting for the food industry because of their useful properties. Indeed, they improve the manufacture of products by acting as foams and creams stabilisers, crumb-softeners, or antistaling agents. The proposed method also allows us to qualitatively characterise new food emulsifiers composed of other acid esters of mono- and diacylglycerols (E472 series). The validation of the method was performed on blank minicake spiked samples for detection limits (reaching ppm levels), linearity, recovery, precision, and accuracy. The method was then successfully applied to commercial additives containing mixtures of emulsifiers, as well as to food products such as margarines and minicakes. 相似文献
44.
ICP-AES测定饮用水中5种重金属元素 总被引:5,自引:0,他引:5
应用电感耦合等离子体-原子发射光谱法(ICP-AES)直接测定饮用水中砷、镉、铬、汞和铅5种痕量重金属元素。为了降低光谱分析检出限,在水样品中加入一定体积的有机添加剂,以提高光谱的信背比。实验结果发现,当加入6%的正丙醇以后,光谱信背比增加幅度是最大的,元素砷、镉、铬、汞和铅的光谱信背比比无添加剂时分别提高了177.4%、45.2%、38.9%、354.7%和83.8%。定量分析结果表明,各元素的相对标准偏差(RSD)在4.5%—8.0%之间,回收率为96.7%—107.1%。 相似文献
45.
46.
G. N. K. Ramesh Bapu G. Devaraj J. Ayyapparaj 《Journal of Solid State Electrochemistry》1998,3(1):48-51
An alkaline non-cyanide zinc plating solution consisting of 10 g/l zinc oxide, 90 g/l sodium hydroxide and 1.5 g/l gelatine
was prepared . Using this solution, a smooth, uniform and fine-grained semi-bright deposit was obtained on mild steel sheets
over a wide range of current density and pH at 303 K. The plating bath had about 63% current efficiency and 25% throwing power
at 303 K and at pH 10. Caffeine and vanillin additions to this bath gave bright zinc deposits.
Received: 30 January 1998 / Accepted: 15 May 1998 相似文献
47.
48.
A novel system for sample introduction into a Gas Chromatograph (GC) using an automated in-column pyrolysis device has been
developed. The in-column pyrolysis device is suitable for use with any GC or GC-MS system. Solid samples are dissolved or
emulsions can be diluted and injected into the system. Because the system is designed for introducing liquid samples, a better
control of the injected sample amounts is achieved. This leads to high reproducibility of the peak areas, offering new opportunities
for quantitation of polymers or other high molecular weight materials. In addition, a better statistical representation of
the material to be analyzed is given if the samples are dissolved in a solvent. The system can be operated both in a normal
GC injection mode, and in the pyrolysis mode. As a conventional GC injector working in on-column or Programmed Temperature
Vaporization (PTV) injection mode, (without the pyrolysis function), information on the volatile fraction of a sample can
be obtained. Once the volatile materials in the sample have been separated, a second analysis on the non-volatile matrix can
be performed by initiating the pyrolysis sequence, yielding information on the non-volatile fraction of the sample. Both features,
on column or PTV injection mode and in-column pyrolysis can be used separately or in combination. This new technology is expected
to be useful for the determination of additives, monomers, solvents and other volatile components in a non volatile matrix,
such as polymers, as well as in the characterization of the non-volatile matrix itself, in a single run.
Revised: 20 June and 21 July 2005 相似文献
49.
50.
Yulu Yang Huaping Wang Chunlei Zhu Prof. Jianmin Ma 《Angewandte Chemie (International ed. in English)》2023,62(22):e202300057
Lithium metal batteries (LMBs) comprising Li metal anode and high-voltage nickel-rich cathode could potentially realize high capacity and power density. However, suitable electrolytes to tolerate the oxidation on the cathode at high cut-off voltage are urgently needed. Herein, we present an armor-like inorganic-rich cathode electrolyte interphase (CEI) strategy for exploring oxidation-resistant electrolytes for sustaining 4.8 V Li||LiNi0.6Co0.2Mn0.2O2 (NCM622) batteries with pentafluorophenylboronic acid (PFPBA) as the additive. In such CEI, the armored lithium borate surrounded by CEI up-layer represses the dissolution of inner CEI moieties and also improves the Li+ conductivity of CEI while abundant LiF is distributed over whole CEI to enhance the mechanical stability and Li+ conductivity compared with polymer moieties. With such robust Li+ conductive CEI, the Li||NCM622 battery delivered excellent stability at 4.6 V cut-off voltage with 91.2 % capacity retention after 400 cycles. The excellent cycling performance was also obtained even at 4.8 V cut-off voltage. 相似文献