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101.
Serena Fiorito Francesco Epifano Francesca Preziuso Vito Alessandro Taddeo Claudio Santi Salvatore Genovese 《Tetrahedron letters》2017,58(4):371-374
The chromane core is widely represented in nature being part of a wide array of secondary metabolites of plant, fungal, and bacterial origin. In this paper an improved method for the chemical synthesis of differently substituted chromanes is described. Substituted 2H-1-benzopyrans have been synthesized in good to excellent yields (52–81%) by treatment of 3,3-dimethylallyl and propenylbenzene ethers of differently substituted phenols with phenylselenyl chloride. 相似文献
102.
Nadine Schmidt Esther S. Boll Linus M. V. Malmquist 《International journal of environmental analytical chemistry》2017,97(12):1151-1162
Polycyclic aromatic hydrocarbons (PAHs) are soil contaminants. Because of their high lipophilicity, PAHs are associated with the organic matter in the soil. Transformation of PAHs generates polar metabolites and the interaction with organic matter in the soil changes. The polar PAH metabolites are persistent, highly water-soluble and potentially leachable from the soil; the understanding of transformation of PAHs to polar metabolites in the responsible organisms is of great importance. Here, we present a study of transformation of the PAHs pyrene and phenanthrene, by the common earthworm Eisenia fetida. The study showed that E. fetida in hydroponic culture was able to transform PAHs to conjugated phase II metabolites. We detected phenanthrene and pyrene metabolites with single- and multiple-phase II-conjugated groups. Sulphate conjugates were excreted to experiment water, and glucuronide and glucoside conjugates and metabolites with several hydroxylations and multiple conjugations were detected in worm tissue. The results demonstrate that earthworms are able to transform PAHs to water-soluble phase II metabolites, which can be excreted to the surrounding environment. 相似文献
103.
Hyung Suk Chung Sung-Woo Kim Han Sol Lee Md. Musfiqur Rahman Md. Humayun Kabir 《International journal of environmental analytical chemistry》2017,97(2):99-111
The present study was carried out to develop an analytical method for simultaneously detecting and quantifying sulfoxaflor and its metabolites (X11721061, X11719474) in brown rice and rice straw using liquid chromatography–tandem mass spectrometry. The parent compound and its metabolites were extracted and purified using original ‘QuEChERS’ method with modification. The matrix-matched calibration curve of sulfoxaflor and its metabolites in both matrices achieved good linearity with determination coefficients (R2) ≥0.9944. The overall recoveries of sulfoxaflor at two fortification levels (rice: 0.2 and 1.0 mg/kg; rice straw: 0.4 and 2.0 mg/kg) ranged from 97.37% to 107.71% with relative standard deviations (RSDs) <5%. On the other hand, the recoveries of both metabolites (X11721061 and X11719474) at 0.1 and 0.5 mg/kg (rice) and 0.2 and 1.0 mg/kg (rice straw) were satisfactory with values ranging from 83.70 % to 112.60% with RSDs <8%. During storage at ?20°C, the analyte and its metabolites were stable for up to 87 days. The limits of quantification of 0.02 mg/kg were lower than the maximum residue limit (0.2 mg/kg) set by the Korean Ministry of Food and Drug Safety for brown rice. The method was successfully applied to paddy field treated with different programme schedules and a preharvest interval of 7 days was proposed based upon the current study. In sum, the developed method is accurate and reproducible for ensuring the reliable determination of sulfoxaflor (and its metabolites) in harvested rice grain and straw samples from the field. The residual level of parent compound does not seem to pose any hazardous effect and treated rice could be safely used for consumption. 相似文献
104.
Mehdi Bakavoli Alireza Motavalizadeh Kakhky Ali Shiri Mahdieh Ghabdian Abolghasem Davoodnia Hossein Eshghi Mola Khatami 《中国化学快报》2010,21(6):651-655
<正>DBUH-Br_3 catalyzed selective conversion of sulfides to sulfoxides in the presence of H_2O_2 as oxidizing agent is described.The reaction was performed selectively at room temperature and relatively short reaction times. 相似文献
105.
Judith Cudaj 《Tetrahedron letters》2010,51(23):3092-3094
We present a total synthesis of the fungal natural product graphislactone G, a chlorinated resorcylic lactone. The key step is a Suzuki coupling used for the construction of the central biaryl bond. Graphislactone G was prepared in 13 steps with 22% yield starting with orcinol and phloroglucinic acid, where the longest linear sequence consists of nine steps. 相似文献
106.
Fátima C.M. Portugal Moisés L. Pinto João Pires J.M.F. Nogueira 《Journal of chromatography. A》2010,1217(23):3707-3710
Polyurethane (PU) foams were applied for stir bar sorptive extraction of five triazinic metabolites (desethyl-2-hydroxyatrazine, desisopropylatrazine, desethylatrazine, 2-hydroxyatrazine and desethylterbuthylazine) in water matrices, followed by liquid desorption and high performance liquid chromatography with diode array detection (SBSE(PU)-LD/HPLC-DAD). The optimum conditions for SBSE(PU)-LD were 5 h of extraction (1000 rpm) and 5% (v/v) of methanol for the analysis of desethyl-2-hydroxyatrazine and 2-hydroxyatrazine, 15% (w/v) of sodium chloride for the remaining compounds and acetonitrile as back-extraction solvent (5 mL) under ultrasonic treatment (60 min). The methodology provided recoveries up to 26.3%, remarkable precision (RSD < 2.4%), excellent linear dynamic ranges between 5.0 and 122.1 μg/L (r2 > 0.9993) and convenient detection limits (0.4-1.3 μg/L). The proposed method was applied in the analysis of triazinic metabolites in tap, river and ground waters, with remarkable performance and negligible matrix effects. The comparison of the recoveries obtained by PU and commercial stir bars was also performed, where the yields achieved with the former were up to ten times higher proving that PU is appropriate for analysis at trace level of this type of polar compounds in water matrices. 相似文献
107.
Hong Cai David P‐. Berry Giuseppe Garcea Karen Brown William P. Steward Andreas J. Gescher 《Biomedical chromatography : BMC》2011,25(6):660-663
Anthocyanins possess cancer chemopreventive properties in preclinical models. Their clinical pharmacology is only poorly understood. In this pilot study, anthocyanins and their metabolites were analysed in the urine of two patients with colorectal liver metastases. They received a single dose of 1.88 g standardized bilberry extract (mirtoselect) via either nasogastric or nasojejunal tube intra‐operatively during liver resection. HPLC‐MS/MS and HPLC‐UV analysis showed there were more anthocyanins and metabolites in the urine of the patient who received mirtoselect via the stomach than via the jejunum. This result is consistent with information obtained in rodents which suggests the stomach is the predominant site for anthocyanin absorption. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
108.
Jianyong Zhu Mingsong Fan Bin Wu Luping Qin Chenggang Huang 《Biomedical chromatography : BMC》2012,26(12):1502-1508
Casticin (3′,5‐dihydroxy‐3, 4′,6,7‐tetramethoxyflavone) has been revealed to possess various kinds of pharmacological activities, including immunomodulatory, anti‐hyperprolactinemia, anti‐tumor and neuroprotetective activities. In order to gain an understanding of the biotransformation of casticin in vivo, a systematic method based on liquid chromatography–electrospray ionization tandem mass spectrometry (LC‐ESI‐MSn) was developed to identify the metabolites of casticin in rats after oral administration of single dose of casticin at 200 mg/kg. By comparing their changes in molecular masses (ΔM), retention times and spectral patterns with those of the parent drug, the parent compound and 25 metabolites were identified in rat plasma, urine and six selected tissues. This is the first systematic metabolism study of casticin in vivo. The results indicated that methylation, demethylation, glucuronidation and sulfation were the main biotransformation pathways of casticin in vivo. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
109.
110.
L. G. Rushing A. B. Gosnell C. L. Holder W. A. Korfmacher W. Slikker 《Journal of separation science》1986,9(8):435-440
A high resolution gas chromatographic method is described for the separation of rhesus monkey urinary metabolites of doxylamine with the use of on-column injection, a fused silica column (DB-1701), and nitrogen/phosphorus detection. An ancillary separation of doxylamine and six other antihistamines is also presented. 相似文献