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101.
采用电感耦合等离子体发射光谱法(ICP-AES)测定地表水和地下水中的全S、P、B来近似代替水中的SO42-、PO43-、H3BO3。结果表明,ICP-AES可同时测定地表水和地下水的SO42-、PO43-、H3BO3,方法检出限分别为0.0265mg/L、0.0320mg/L、0.0192mg/L。方法的精密度(RSD,n=6)为0.53﹪~6.09﹪,加标回收率为91.9﹪~102.2﹪,经与单个项目分别测定的方法比对实验,测定值无明显系统偏差。方法快速、准确,经国家标准物质验证,结果与标准值相符。 相似文献
102.
Oxidative degradation of dinitrotoluenes (DNTs) in wastewater was performed using persulfate anions combined with ultrasonic irradiation, wherein a synergistic effect is observed. The batch-wise experiments were carried out to elucidate the influence of various operating parameters on sono-activated persulfate oxidation, including ultrasonic power intensity, persulfate anion concentration, reaction temperature and acidity of wastewater. It is noteworthy that the nitrotoluene contaminants could be almost completely eliminated by virtue of sono-activated persulfate oxidation, wherein sulfate radicals serve as principal oxidants, of which amounts are significantly enhanced via addition of sodium sulfate. Based on the results given by gas chromatograph-mass spectrometer (GC-MS), it is postulated that the methyl group of DNTs preliminarily underwent oxidation pathway into dinitrobenzoic acid, followed by decarboxylation to form 1,3-dinitrobenzene (DNB). In sum, the sono-activated persulfate oxidation is a promising method for treatment of nitrotoluenes in wastewater. 相似文献
103.
Degradation of the antibiotics amoxicillin in aqueous solution using sulphate radicals under ultrasound irradiation was investigated. The preliminary studies of optimal degradation methodology were conducted with only oxone (2KHSO5·KHSO4·K2SO4), cobalt activated oxone (oxone/Co2+), oxone + ultrasonication (oxone/US) and cobalt activated oxone + ultrasonication (oxone/Co2+/US). The chemical oxygen demand (COD) removal efficiency were in the order of oxone < oxone/Co2+ < oxone/US < oxone/Co2+/US for the amoxicillin solution. The variables considered for the effect of degradation were the temperature, the power of ultrasound, the concentration of oxone, as well as catalyst and the initial amoxicillin concentration. More than 98% of COD removal was achieved within 60 min under optimum operational conditions. Comparative analysis revealed that the sulfate radicals had the high oxidation potential and the use of ultrasound irradiation reduced the energy barrier of the reaction and increased the COD removal efficiency of organic pollutants. The degradation of amoxicillin follows the first-order kinetics. 相似文献
104.
The first total synthesis of lamellarin α 20-sulfate (1), a selective inhibitor of HIV-1 integrase, has been completed. The lamellarin α core in which 13-OH and 20-OH were differentially protected by isopropyl and benzyl groups, respectively, was constructed by using Hinsberg-type pyrrole synthesis and Suzuki-Miyaura coupling as the key reactions. The 20-sulfate was prepared by a sequence including debenzylation of 20-OBn, 2,2,2-trichloroethylsulfation of the resulting 20-OH, deprotection of 13-Oi-Pr, and final reductive cleavage of the 2,2,2-trichloroethyl ester. 相似文献
105.
Sulfate strongly adsorbs on metal oxides and soils with variable charges. However, its surface precipitation has not been clearly evaluated and its adsorption mechanism has been in dispute. In the present study, an allophanic andisol, a typical volcanic ash soil having both negative and positive variable charges, was used to identify the adsorption mechanism of sulfate. Sulfate adsorption isotherms were obtained by a batch method at pH values of 4, 5, 6, and 7 in a wide range of concentrations in an Na-H-SO(4)-OH system. Theoretical isotherms were applied to the measured values for the evaluation. The surface precipitation was detected by the measured adsorption isotherms, and the BET isotherm confirmed the presence of multilayer adsorption. Stronger and weaker adsorption sites were suggested by using the Langmuir isotherm for the monolayer adsorption. The adsorption energies obtained from the Langmuir equation and recent spectroscopic analysis suggested that the stronger adsorption corresponded to an inner-sphere surface complex and that the weaker adsorption corresponded to outer-sphere surface complexation. The BET and Langmuir equations showed three types of adsorption mechanisms for the sulfate adsorption on the soil. 相似文献
106.
研究建立了离子对 -反相高效液相色谱法 ( IP- HPLC)同时测定解磷注射液中氯磷定、硫酸阿托品、盐酸苯那辛含量的分析方法及其有关物质和降解产物检查法。采用 ZORBAXSB C18色谱柱 ,流动相 :甲醇 -乙腈 - 1mol· L-1磷酸 (用三乙胺调 p H=3.0 ) - 0 .2 mol· L-1磷酸二氢钠 (用磷酸调 p H=3.0 ) - 0 .9%十二烷基硫酸钠水溶液 ( 2 0 0∶ 4 0 0∶ 10∶ 90∶ 30 0 ) ,在流速 1.0 m L· min-1下 ,检测波长 2 2 0 nm处 ,测定氯磷定、硫酸阿托品、盐酸苯那辛 ,其回收率分别为 10 0 .36% ( RSD 0 .90 % )、99.4 4 % ( RSD 1.0 9% )、99.82 %( RSD 1.2 3% )。该方法简便、快速 ,适用于制剂中各组分含量的同时测定 相似文献
107.
108.
采用火焰原子吸收光谱法间接测定饮用水中硫酸盐的含量。利用硫酸根可与钡离子定量结合产生沉淀,采用火焰原子吸收光谱法测定滤液中剩余钡离子浓度,根据钡离子消耗量间接测定硫酸盐含量。钡离子的质量浓度在200 mg·L-1以内与其吸光度呈线性关系,方法的检出限(3s)为1.6mg·L-1。方法用于标准水样的分析,测定值的相对标准偏差(n=6)在0.72%~3.9%之间,测定结果与国家标准方法测定值相符。 相似文献
109.
Syriacin, a novel unusual sulfated ceramide glycoside with branched very-long-chain fatty acid, i.e., (all Z)-34S-methylhexatriaconta-5,9,12,15,18,21-hexaenoic acid, has been isolated from the freshwater sponge Ephydatia syriaca. Its structure was identified by means of extensive spectroscopic analysis (IR, UV, 2D NMR, MS, CD) and chemical degradation. Syriacin showed antifeeding activity against goldfish at natural concentration (∼10 μg/ml). 相似文献
110.
硫酸钡分光光度比浊法间接测定有机催化剂2-乙基蒽醌中的硫 总被引:1,自引:0,他引:1
本文研究了用浓硝酸将2-乙基蒽醌中的硫定量转化成硫酸根,然后用硫酸钡分光光度比浊法间接测定其硫含量的方法。建立的方法简单、快速、实用。试样分析结果表明准确度及精密度均符合要求。 相似文献