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91.
Jiang ZH Tanaka T Sakamoto T Kouno I Duan JA Zhou RH 《Chemical & pharmaceutical bulletin》2002,50(1):137-139
A new biflavanone (1) with a C-3/C-3" linkage, a new daphnane-type diterpene (2) acylated by an unsaturated fatty acid, and a new coumarin glycoside (3), along with six lignans, two phenylpropanoids, five flavonoids, two diterpenes, and three coumarins were isolated from the roots of Stellera chamaejasme L. (Thymelaeaceae). Elucidation of these secondary metabolites of S. chamaejasme L. supplied strong chemical verification of the close taxonomic relationships among the genera Stellera, Daphne, and Wikstroemia, all of which belong to the family Thymelaeaceae. 相似文献
92.
Nakahara R Fujimoto T Doi M Morita K Yamaguchi T Fujita Y 《Chemical & pharmaceutical bulletin》2008,56(7):977-981
Methods for the fluorophotometric determination of hydrogen peroxide (H(2)O(2)) and other reactive oxygen species (ROS) were proposed by using the fluorescence reaction between H(2)O(2) or other ROS and fluorescein hydrazide (FH). In the determination of H(2)O(2), the calibration curve exhibited linearity over the H(2)O(2) concentration range of 2.1-460 ng ml(-1) at an emission wavelength of 527 nm with an excitation of 460 nm and with the relative standard deviations (n=6) of 4.06%, 1.78%, and 2.21% for 3.1 ng ml(-1), 30.8 ng ml(-1), and for 308 ng ml(-1) of H(2)O(2), respectively. The detection limit for H(2)O(2) was 0.7 ng ml(-1) due to three blank determinations (rho=3). The calibration curves for ROS-related compounds were also constructed under the optimum conditions. This method was successfully applied in the assay of H(2)O(2) in human urine. In addition, we performed the characterization of FH, and interesting information was obtained with regard to the relationship between the chemical structure and fluorescence. 相似文献
93.
In an attempt to explore the mechanism for the synthesis of silsesquioxanes (POSS), the entire reaction processes from HSi(OH)3 to T8, one of the most common and stable POSS was investigated with electronic structure theory calculations, including electron correlation effects. In addition, the effect of some controlling factors, which play important roles in the reaction mechanism, is discussed. 相似文献
94.
Takako Ishiguro Yukichi Sakata Hidetoshi Arima Daisuke Iohara Makoto Anraku Kaneto Uekama Fumitoshi Hirayama 《Journal of inclusion phenomena and macrocyclic chemistry》2018,92(1-2):147-155
The release control of fragrances, benzyl acetate (BA), citral (CR), linalool (LL), citronellol (CL) and linalyl acetate (LA), was conducted using β-cyclodextrin (β-CyD), 2-hydroxypropyl-β-CyD (HP-β-CyD) and 2,6-di-O-methyl β-CyD (DM-β-CyD). The release rate of the fragrances from 30% ethanol/water solution was significantly suppressed by the complexation with these CyDs, and the suppressing effect increased in the order of β-CyD?<?HP-β-CyD?<?DM-β-CyD. The concentration-dependent change of the release rate was quantitatively analyzed to obtain the stability constant (Kc) of the fragrance-CyD complexes. These Kc values were in good agreement with those determined by the solubility method. The results suggest that the release of fragrances can be prolonged by the complexation with β-CyDs and their effects can be controlled by choosing appropriate CyD derivatives with higher Kc values and by setting proper concentrations of the host molecules. 相似文献
95.
Determination of acrolein in serum by high‐performance liquid chromatography with fluorescence detection after pre‐column fluorogenic derivatization using 1,2‐diamino‐4,5‐dimethoxybenzene
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Takahiro Imazato Mariko Kanematsu Naoya Kishikawa Kaname Ohyama Takako Hino Yukitaka Ueki Eisuke Maehata Naotaka Kuroda 《Biomedical chromatography : BMC》2015,29(9):1304-1308
Acrolein is a major unsaturated aldehyde that is generated during the lipid peroxidation process. The measurement of acrolein in biological samples should be useful to estimate the degree of lipid peroxidation and to evaluate the effect of hazardous properties of acrolein on human health. In this study, a highly sensitive and selective high‐performance liquid chromatography with fluorescence detection method was developed for the determination of acrolein in human serum. The proposed method involves the pre‐column fluorogenic derivatization of acrolein with 1,2‐diamino‐4,5‐dimethoxybenzene (DDB) as a reagent. The fluorescent derivative of acrolein could be detected clearly without any interfering reagent blank peaks because DDB does not have intrinsic fluorescence itself, and the detection limit was 10 nM (signal‐to‐noise ratio = 3). The proposed method could selectively detect acrolein in human serum with a simple protein precipitation treatment. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献
96.
Sakamoto M Moriyasu T Minowa K Kishimoto K Kadoi H Hamano T Fukaya H 《Journal of AOAC International》2012,95(4):1048-1052
A sildenafil-related compound was detected in a dietary supplement marketed as an aphrodisiac. The compound was detected during analysis of the dietary supplement using LC-UV and LC/electrospray ionization-MS. The structure of the compound was established using high resolution MS, NMR spectrometry, and X-ray crystal structure analysis. The compound was identified as 5-(5-((3,5-dimethylpiperazin-1-yl)sulfonyl)-2-ethoxyphenyl)-l-methyl-7-((1-methyl-4-nitro-1H-imidazol-5-yl)thio)-3-propyl-1H-pyrazolo[4,3-d] pyrimidine. Based on this structure, the compound was named nitroprodenafil. The dietary supplement was found to contain 90 mg nitroprodenafil/capsule. This article describes the structural characterization of a new sildenafil-related compound. The compound was detected during analysis of a dietary supplement using LC-UV and LC/electrospray ionization (ESI)-MS. The structure was established using high resolution MS (HRMS), NMR spectrometry, and X-ray crystal structure analysis. The structures of methisosildenafil, thiomethisosildenafil, and this new analog, named nitroprodenafil (21), are shown in Figure 1. In the Demizu et al. report, the compound is named mutaprodenafil instead ofnitroprodenafil. Considering the naming right, the authors of this paper think the use of mutaprodenafil is appropriate as the compound name, although nitroprodenafil is used. 相似文献
97.
Iyota H Tomimitsu T Shimada K Ikeda N Motomura K Aratono M 《Journal of colloid and interface science》2006,299(1):428-434
Adsorption and micelle formation of a surfactant in the presence of inorganic salts with different charge numbers of cations were investigated from the viewpoint of mixed adsorption and micelle formation of salt and surfactant. Surface tension of aqueous solutions of the mixtures of octyl methyl sulfoxide (OMS) with calcium chloride and lanthanum chloride was measured as a function of the total molality of the mixture and the mole fraction of OMS in the mixture at 298.15 K under atmospheric pressure. Composition of the adsorbed film and micelle was numerically evaluated from the dependence of the total molality at a given surface tension and the mixture CMC on the bulk composition to draw phase diagrams of adsorption and micelle formation. Judging from the phase diagrams together with the ones of the sodium chloride system, miscibility of inorganic salt and OMS in the adsorbed film and micelle increases with an increase in the charge number of inorganic cation, which is attributable to the attractive interaction between inorganic cation and the polar head group of OMS molecule in the adsorbed film and micelle. 相似文献
98.
Takako Nakamura 《Applied Surface Science》2010,257(4):1368-1370
Diamond powder functionalized with optically active functional groups was fabricated by the photoreaction of H-terminated diamond powder and an alkene containing an optically active amide group and found to show a chiral recognition behavior for racemic compounds. 相似文献
99.
Kei Zaitsu Izuru Miyawaki Kiyoko Bando Hiroshi Horie Noriaki Shima Munehiro Katagi Michiaki Tatsuno Takeshi Bamba Takako Sato Akira Ishii Hitoshi Tsuchihashi Koichi Suzuki Eiichiro Fukusaki 《Analytical and bioanalytical chemistry》2014,406(5):1339-1354
The metabolic profiles of urine and blood plasma in drug-addicted rat models based on morphine (MOR), methamphetamine (MA), and cocaine (COC)-induced conditioned place preference (CPP) were investigated. Rewarding effects induced by each drug were assessed by use of the CPP model. A mass spectrometry (MS)-based metabolomics approach was applied to urine and plasma of MOR, MA, and COC-addicted rats. In total, 57 metabolites in plasma and 70 metabolites in urine were identified by gas chromatography–MS. The metabolomics approach revealed that amounts of some metabolites, including tricarboxylic acid cycle intermediates, significantly changed in the urine of MOR-addicted rats. This result indicated that disruption of energy metabolism is deeply relevant to MOR addiction. In addition, 3-hydroxybutyric acid, l-tryptophan, cystine, and n-propylamine levels were significantly changed in the plasma of MOR-addicted rats. Lactose, spermidine, and stearic acid levels were significantly changed in the urine of MA-addicted rats. Threonine, cystine, and spermidine levels were significantly increased in the plasma of COC-addicted rats. In conclusion, differences in the metabolic profiles were suggestive of different biological states of MOR, MA, and COC addiction; these may be attributed to the different actions of the drugs on the brain reward circuitry and the resulting adaptation. In addition, the results showed possibility of predict the extent of MOR addiction by metabolic profiling. This is the first study to apply metabolomics to CPP models of drug addiction, and we demonstrated that metabolomics can be a multilateral approach to investigating the mechanism of drug addiction. 相似文献
100.
Misa Tabe Tsuyoshi Fujimoto Ryosuke Nakahara Takako Yamaguchi Yoshikazu Fujita 《Analytical sciences》2007,23(5):601-604
A simple and rapid spectrophotometric method for the determination of oxalate ion was established by the fading of a colored complex between N,N'-diethyl-N,N'-[[4,4'-dihydroxy-1,1'-binaphthalene]-3,3'-diyl]bisbenzamide and copper(II). Beer's law was obeyed in the concentration range of 0.1 - 2.0 microg cm(-3) for oxalate ion, with an effective molar absorptivity at 533 nm and the relative standard deviation being 8.0 x 10(3) dm(3) mol(-1) cm(-1) and 1.0% (n = 5), respectively. This proposed method has excellent reproducibility, and was applied to recovery tests of oxalate ion in tap water and human urine; the results were satisfactory. This is suggested that the method is based on the reaction of copper(II) to copper(I) with oxalate ion. 相似文献