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91.
Zeid Abdullah Alothman Nausheen Bukhari Sajjad Haider Saikh Mohammad Wabaidur Abdulrahman A. Alwarthan 《Arabian Journal of Chemistry》2010,3(4):251-255
A novel sensitive fluorimetric method was investigated for the assay of fexofenadine hydrochloride (FEX) using silver nanoparticles (NPs) as a fluorescence probe. The NPs, which were prepared by chemical reduction of silver nitrate with sodium borohydride (reducing agent) in aqueous solution (without organic stabilizers) were water soluble, stable and had narrow emission band. The addition of drug to NPs solution caused considerable quenching of the emission band of silver NPs, which was likely due to the complexation of the drug to silver NPs. Under the optimum conditions, the quenched fluorescence (FL) intensity was linear with the concentration of FEX in the range of 1 × 10?7 to 2.5 × 10?5 mol L?1 (0.9985) with a detection limit of 1.2 × 10?8 mol L?1. The quenching mechanism of the studied drug on the emission band of silver NPs was explained by Stern–Volmer law. The developed method was applied to FEX determination in a pharmaceutical formulation (allegra tablets) and biological fluids (human serum and urine). 相似文献
92.
研究了盐酸克伦特罗(CLB)在乙炔黑电极上的电化学行为,发现阴离子表面活性剂十二烷基苯磺酸钠(SDBS)能显著提高CLB的氧化峰电流并降低其氧化过电位。优化了实验参数,建立了一种直接测定CLB的新电分析方法,其线性范围为1.0×10-7~7.5×10-5mol/L,开路富集1 min后的检出限为2.5×10-8mol/L。平行10次测定1.0×10-5mol/L盐酸克伦特的RSD为3.1%。方法用于猪尿中盐酸克伦特罗含量的测定。 相似文献
93.
多壁碳纳米管修饰电极检测盐酸氯丙嗪的研究 总被引:1,自引:0,他引:1
制备了多壁碳纳米管修饰玻碳电极,采用循环伏安法(CV)研究了盐酸氯丙嗪在修饰电极上的电化学特性,发展了一种新的检测盐酸氯丙嗪的电化学分析方法。在最佳实验条件下,用循环伏安法检测盐酸氯丙嗪,其响应电流与盐酸氯丙嗪的浓度在8.0×10-5~1.0×10-3mol/L范围内有很好的线性关系,线性方程为Ip(A)=0.0106c(mol/L)-8×10-8(R2=0.999,n=6),检出限为6.2×10-6mol/L(S/N=3)。方法可用于盐酸氯丙嗪片的测定。 相似文献
94.
The interaction between promethazine hydrochloride (PMT) and bovine serum albumin (BSA) in vitro was investigated by means of fluorescence spectroscopy and absorption spectroscopy. The fluorescence of BSA was quenched remarkably by PMT and the quenching mechanism was considered as static quenching by forming a complex. The association constants Ka and the number of binding sites n were calculated at different temperatures. The BSA-PMT binding distance was determined to be less than 8 nm, suggesting that energy transfer from BSA to PMT may occur. The thermodynamic parameters of the interaction between PMT and BSA were measured according to the van’t Hoff equation. The enthalpy change (ΔH) and entropy change (ΔS) were calculated to be −23.62 kJ mol−1 and −0.10 J mol−1 K−1, respectively, which indicated that the interaction of PMT with BSA was driven mainly by van der Waals forces and hydrogen bonds. The binding process was a spontaneous process in which Gibbs free energy change (ΔG) was negative. In addition, the results of synchronous fluorescence spectra and three-dimensional fluorescence spectra showed that binding of PMT with BSA can induce conformational changes in BSA. 相似文献
95.
Gareth J. Rowlands Author Vitae 《Tetrahedron》2010,66(9):1593-501
96.
Islam Ullah Khan Tehseen Aman Muhammad Asif Iqbal Asrar Ahmad Kazi 《Mikrochimica acta》2000,134(1-2):27-31
Fluoxetine hydrochloride reacts with benzoyl peroxide and potassium iodide, after heating for 1 min at 30 °C, to give a blue
colour having maximum absorbance at 570 nm. The reaction is selective for fluoxetine with 0.01 mg/mL as visual limit of quantitation
and provides a basis for a new spectrophotometric determination. The colour reaction obeys Beer’s law from 0.1 mg/10 mL to
2.0 mg/10 mL of fluoxetine and the relative standard deviation is 0.68%. The qualitative assessment of tolerable amounts of
other drugs is also studied.
Received September 21, 1998. Revision September 10, 1999. 相似文献
97.
Stacy P. Ali 《Journal of carbohydrate chemistry》2013,32(4):185-196
The order of reactivity of OH and NH groups of glucosamine hydrochloride (GlcNH2.HCl) and N-acetyl glucosamine (GlcNAc) toward benzylation with NaH/BnBr in DMF was investigated. For GlcNH2.HCl, benzyl groups were introduced in the order of N-Bn > N-Bn2 > 1-O-Bn > 6-O-Bn > 4-O-Bn > 3-O-Bn; for GlcNAc, benzyl groups were introduced in the order of 1-O-Bn > 6-O-Bn > 4-O-Bn > 3-O-Bn > N-Bn. A range of partially benzylated 2-N,N′-dibenzyl glucopyranosides and GlcNAc derivatives were obtained in a single step. 相似文献
98.
99.
In this work, different mass percent ratios of CoFe2O4 coupled g-C3N4 (w%-CoFe2O4/g-C3N4, CFO/CN) nanocomposites were integrated through a hydrothermal process for the sonocatalytic eradication of tetracycline hydrochloride (TCH) from aqueous media. The prepared sonocatalysts were subjected to various techniques to investigate their morphology, crystallinity, ultrasound wave capturing activity and charge conductivity. From the investigated activity of the composite materials, it has been registered that the best sonocatalytic degradation efficiency of 26.71 % in 10 min was delivered when the amount of CoFe2O4 was 25% in the nanocomposite. The delivered efficiency was higher than that of bare CoFe2O4 and g-C3N4. This enriched sonocatalytic efficiency was credited to the accelerated charge transfer and separation of e−-h+ pair through the S-scheme heterojunctional interface. The trapping experiments confirmed that all the three species i.e. •OH, h+ and •O2− were involved in the eradication of antibiotics. A strong interaction was shown up between CoFe2O4 and g-C3N4 in the FTIR study to support charge transfer as confirmed from the photoluminescence and photocurrent analysis of the samples. This work will provide an easy approach for fabricating highly efficient low-cost magnetic sonocatalysts for the eradication of hazardous materials present in our environment. 相似文献
100.
Inversion twinning in a second polymorph of the hydrochloride salt of the recreational drug ethylone
T. Stanley Cameron J. Stuart Grossert Chad R. Maheux Idralyn Q. Alarcon Catherine R. Copeland Anthony Linden 《Acta Crystallographica. Section C, Structural Chemistry》2015,71(4):266-270
A second polymorph of the hydrochloride salt of the recreational drug ethylone, C12H16NO3+·Cl−, is reported [systematic name: (±)‐2‐ethylammonio‐1‐(3,4‐methylenedioxyphenyl)propane‐1‐one chloride]. This polymorph, denoted form (A), appears in crystallizations performed above 308 K. The originally reported form (B) [Wood et al. (2015). Acta Cryst. C 71 , 32–38] crystallizes preferentially at room temperature. The conformations of the cations in the two forms differ by a 180° rotation about the C—C bond linking the side chain to the aromatic ring. Hydrogen bonding links the cations and anions in both forms into similar extended chains in which any one chain contains only a single enantiomer of the chiral cation, but the packing of the ions is different. In form (A), the aromatic rings of adjacent chains interleave, but pack equally well if neighbouring chains contain the same or opposite enantiomorph of the cation. The consequence of this is then near perfect inversion twinning in the structure. In form (B), neighbouring chains are always inverted, leading to a centrosymmetric space group. The question as to why the polymorphs crystallize at slightly different temperatures has been examined by density functional theory (DFT) and lattice energy calculations and a consideration of packing compactness. The free energy (ΔG) of the crystal lattice for polymorph (A) lies some 52 kJ mol−1 above that of polymorph (B). 相似文献