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101.
Several nitro aromatic compounds bridged by an oxygen atom have been synthesized and their linear and nonlinear optical properties have been investigated. In one of the compounds (1), a powder SHG efficiency of 6.2 times of urea was observed while its absorption lies in the UV region. The highest molecular hyperpolarizability β, measured was 230×10−30 for a compound (8f) with increased conjugation. Thermal stability of these compounds has been checked using differential scanning calorimetry and the decomposition temperature (Td) was found to be high and lying between 266-298 °C. These molecules have potential importance as thermally stable, visible-transparent second order NLO materials. 相似文献
102.
《Tetrahedron letters》2014,55(50):6836-6838
An efficient and convenient protocol has been developed for ether bond formation in mild conditions. A mixture of primary/secondary ester and allylic/benzylic halide in tetrahydrofuran was treated with KOtBu at room temperature to give ether in high yield. This step economic method enabled direct alkylation of the acyl group masked O-nucleophiles. Application of this method in carbohydrate synthesis was feasible and chemo-selectivity can be achieved. 相似文献
103.
Jian Jin David W. C. MacMillan 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(5):1585-1589
The direct α‐arylation of cyclic and acyclic ethers with heteroarenes has been accomplished through the design of a photoredox‐mediated C H functionalization pathway. Transiently generated α‐oxyalkyl radicals, produced from a variety of widely available ethers through hydrogen atom transfer (HAT), were coupled with a range of electron‐deficient heteroarenes in a Minisci‐type mechanism. This mild, visible‐light‐driven protocol allows direct access to medicinal pharmacophores of broad utility using feedstock substrates and a commercial photocatalyst. 相似文献
104.
ChunBaoLI XiuJieJI ShuanMingZHANG MingLU ZhuXuanZHAO YiCUI YanLiXU QiChaoYANG WenQinZHANG 《中国化学快报》2003,14(5):459-460
In the Presence of NaBH4/BF3,allyl ethers underwent deallylation to the corresponding alcohols or phenols in good yield and high reaction rate. 相似文献
105.
The use of bio-based plasticizers with low toxicity and good compatibility with polyvinyl chloride (PVC) has attracted more attention in the recent years. With bio-based 2, 5-furandicarboxylic acid (FDCA) and butyl oligo-glycol ethers as raw materials, three liquid furan-based plasticizers of di(butyl glycol) furan-2,5-dicarboxylate, di(butyldiglycol) furan-2,5-dicarboxylate and di(butyltriglycol) furan-2,5-dicarboxylate were synthesized by direct esterification. The chemical structure of three plasticizers was characterized with FTIR, 1H NMR and 13C NMR. From DMA measurement, the glass transition temperature (Tg) of the plasticized PVC was decreased gradually when furan-based plasticizers were added to PVC formulation from 30 up to 50 phr. Due to lots of ether bonds in furan-based plasticizers, they expressed over two-fold lower migration in organic solvent compared with the traditional plasticizer diethylhexyl phthalate (DEHP). Through the characterization of elongation at break, hardness and thermal stability, furan-based plasticizers presented the same plasticization properties as DEHP, and had potential industrial application prospects. 相似文献
106.
Hai-Zhen Jiang Chao Yang Prof. Min Chen Xiao-Wei Liu Lu-Ming Yin Prof. Ya You Prof. Jun Lu 《Angewandte Chemie (International ed. in English)》2023,62(14):e202300238
Cyclic ether, such as 1,3-dioxolane (DOL), are promising solvent for low-temperature electrolytes because of the low freezing point. Their use in electrolytes, however, is severely limited since it easily polymerizes in the presence of lithium inorganic salts. The trace water plays a key role via providing the source (proton) for chain initiation, which has, unfortunately, been neglected in most cases. In this work, we present an electrophile, trimethylsilyl isocyanate (Si−NCO), as the water scavenger, which eliminates moisture by a nucleophilic addition reaction. Si−NCO allows DOL to maintain liquid over a wide temperature range even in high-concentration electrolyte. Electrolyte with Si−NCO additive shows promising low-temperature performance. Our finding expands the use of cyclic ether solvents in the presence of inorganic salts and highlights a large space for unexplored design of water scavenger with electrophilic feature for low-temperature electrolytes. 相似文献
107.
M(benzo‐18‐crown‐6)I4 (M = Cd, Hg) are obtained as red columnar crystals from the reactions of benzo‐18‐crown‐6 (b18c6), cadmium and mercury iodide, respectively, and iodine in molar ratios of 1:1:2 in acetonitrile. They both crystallize with the orthorhombic crystal system, P212121, a = 833.7(1), b = 1610.9(1), c = 1846.8(1) pm, V = 2480.3(1) 106·pm3, Z = 4, for M = Cd and a = 823.4(1), b = 1616.5(1), c = 1866.1(1) pm, V = 2483.8(2) 106·pm3 for M = Hg. The crystal structures consist of [M(b18c6)]I2 molecules which are connected to a slightly lengthened iodine molecule via a secondary contact, according to the formulation I2@[MI2@(b18c6)]. 相似文献
108.
流动注射化学发光分析法测定蒽醌类药物 总被引:1,自引:0,他引:1
基于蒽醌类药物在碱性条件下对高碘酸钾-鲁米诺化学发光体系的化学发光信号有强烈的抑制作用这一现象,结合流动注射技术建立了一种直接测定蒽醌类药物的流动注射化学发光分析新方法。该方法测定大黄素的线性范围为1.0×10-8—3.0×10-7g/mL,检出限为2×10-9g/mL;测定大黄酸的线性范围为7.0×10-8—3.0×10-6g/mL,检出限为2×10-8g/mL;测定大黄素甲醚的线性范围为1.0×10-9—5.0×10-8g/mL,检出限为3×10-10g/mL。该方法操作简单快速、灵敏度高,可用于样品中蒽醌类药物含量的准确测定。 相似文献
109.
110.
Photolysis of diethyl ether-oxygen charge transfer complex in the presence of Sn(Ⅱ)or Cu(Ⅱ)salts gave higher yields of the oxidation products,ethyl acetate,acetaldehyde,ethanol,ethyl formate and methanol compared with those without the salts.In addition,the photolysis of an oxygen saturated te-trahydrofuran(THF)or dibutyl ether solution gave y-butyro-lactone or butanol and butyl butyrate as major products with small amounts of undetermined compounds,respectively.Their yields were also affected by the addition of Cu(Ⅱ)or Sn(Ⅱ)salts. 相似文献