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排序方式: 共有542条查询结果,搜索用时 78 毫秒
91.
Dr. Alam Venugopal Narendra Kumar Yinghao Li Shuli Yin Chunjie Li Dr. Hairong Xue Dr. You Xu Prof. Xiaonian Li Dr. Hongjing Wang Prof. Liang Wang 《化学:亚洲杂志》2018,13(16):2093-2100
Tailoring metal oxide nanostructures with mesoporous architectures is vital to improve their electrocatalytic performance. Herein, we demonstrate the synthesis of 2D mesoporous Co3O4 (meso‐Co3O4) nanobundles with uniform shape and size by employing a hard‐template method. In this study, the incipient wetness impregnation technique has been chosen for loading metal precursor into the silica hard template (SBA‐15). The results reveal that the concentration of a saturated precursor solution plays a vital role in mesostructured ordering, as well as the size and shape of the final meso‐Co3O4 product. The optimized precursor concentration allows us to synthesize ordered meso‐Co3O4 with four to seven nanowires in each particle. The meso‐Co3O4 structure exhibits excellent electrocatalytic activity for both glucose and water oxidation reactions. 相似文献
92.
K. Venugopal Chetty A. G. Godbole R. Swarup V. N. Vaidya V. Venugopal P. R. Vasudeva Rao 《Journal of Radioanalytical and Nuclear Chemistry》2005,267(1):125-130
Summary Piroxicam was labeled effectively with 99mTc due to the presence of electron donating atoms such as sulfur, nitrogen, and oxygen in its structure. The labeling yield was found to be influenced by different factors such as the amount of piroxicam, stannous chloride dihydrate, pH of the reaction mixture, reaction time and reaction temperature. The suitable amount of stannous chloride dihydrate required to produce high labeling yield of 99mTc-piroxicam was 50 μg, above this quantity (200 μg) a colloidal solution was formed. Another factor which plays a significant role in this labeling reaction is the pH of the reaction medium. The labeling reaction was done only at alkaline pH range from 9-11, because piroxicam was not soluble at acidic or neutral pH. The labeling reaction proceeded well at room temperature and the complex was decomposed by heat. The labeled piroxicam (99mTc-piroxicam ) showed good localization in inflamed foci and good imaging must be taken at 24-hour post injection, as the ratio of both types of inflammation (sterile and septic) to the background are 10.6 and 8.7, respectively. 相似文献
93.
ZnS/CdSe core‐shell and wire‐coil nanowire heterostructures have been synthesized by chemical vapor deposition assisted with pulsed laser ablation. Measurements from high‐resolution transmission electron microscopy and selected area electron diffraction have revealed that both ZnS/CdSe core‐shell and wire‐coil nanowires are of single‐crystalline hexagonal wurtzite structures and grow along the [0001] direction. While the lattice parameters of ZnS and CdSe in the core‐shell nanowires are nearly equal to those of bulk ZnS and CdSe, change of the lattice parameters in the CdSe‐coil is attributed to the doping of Zn into CdSe, resulting in the relaxation of compressive strain at the interface between CdSe‐coil and ZnS‐wire. Composition variation across the interfacial regions in the ZnS/CdSe nanowire heterostructures ranges only 10–15 nm despite the pronounced lattice mismatch between ZnS and CdSe by ?11%. Growth mechanisms of the ZnS/CdSe nanowire heterostructures are discussed. 相似文献
94.
S. N. Bhadani Madhu Tiwari Archana Agrawal Chandra Sekhar Kavipurapu 《Mikrochimica acta》1994,117(1-2):15-22
A sensitive Spectrophotometric method for the determination of iron with tiron and a cationic surfactant, cetylpyridinium chloride, at pH 5.6 is reported. The complex is extracted into a chloroform-propan-2-ol (41) mixture and shows maximum absorbance at 520 nm. Beer's law is obeyed in the range 1–14 g/ml with an average molar absorptivity of 15800 l mol–1 cm–1. The molar ratio as determined by Job's method for Fe:tiron:CPC is 143. Interferences by various ions are examined. Zr, Ti and Mo interfere heavily. The method is applied for the determination of iron in Al-based and Cu-based alloys, using appropriate masking agents. 相似文献
95.
Determination of azadirachtin in agricultural matrixes and commercial formulations by enzyme-linked immunosorbent assay 总被引:1,自引:0,他引:1
An enzyme-linked immunosorbent assay (ELISA) was developed for azadirachtin (aza), a biopesticide from the neem tree (Azadirachta indica A. Juss). The immunogen was synthesized by epoxidation using the furan ring in the aza molecule. Rabbits were immunized with either bovine serum albumin (BSA)-azadirachtin or ovalbumin (OA)-azadirachtin conjugate. Evaluation of the antisera by antibody capture assay showed that the antibody titer of antisera raised against OA-aza was 1:30,000. An indirect competitive ELISA was developed with BSA-azadirachtin as coating antigen and aza-specific antibodies raised against OA-aza immunogen. The immunoassay showed an inhibitory concentration (IC50) value of 75 ppb, with a range of detection from 0.5 to 1,000 ppb for azadirachtin [based on regression analysis, y= 85.87 (-18.89x); r2 = -0.97]. Cross-reactivity of the antibodies with 2 aza- derivatives (22,23-dihydro-23beta-methoxy azadirachtin and 3-tigloylazadirachtol) was 33 and 29%, respectively. The indirect competitive ELISA was validated and evaluated by quantitating aza in spiked agricultural commodities and from neem formulations. Azadirachtin was spiked into 5 different agricultural commodities: tomato, brinjal, coffee, tea, and cotton seed at 500 and 1,000 ppb and recovered at 62-100%. In samples drawn from 6 lots, the aza content in neem-seed kernels ranged from 0.1 to 0.15%; in commercial neem formulations the content ranged from 200 to 2,000 ppm. The method developed may be applied to environmental monitoring of aza and quality assurance studies of aza-based commercial formulations. 相似文献
96.
S. N. Bhadani Madhu Tewari Archana Agrawal K. Chandra Sekhar 《Analytical and bioanalytical chemistry》1994,349(6):478-481
A red, water-soluble complex of nickel with PAR can be extracted into chloroform with CTAB at pH 7.0. The system obeys Beer's law upto 0.5 μg/ml with a molar absorptivity of 45 200 L·mol?1·cm?1 at 540 nm. Job's method of continuous variations revealed that the composition of the extracting species is 1:2:2 for nickel:PAR:CTAB. Based on this extraction, a highly sensitive and selective spectrophotometric method for the determination of nickel in polymetallic sea-bed nodules and in steels, after prior separation of iron and manganese, was developed. The standard deviation was 0.04–0.127 μg for 5–25 μg of nickel. 相似文献
97.
Archana Gupta 《Tetrahedron letters》2006,47(46):8043-8047
An efficient and highly diastereoselective synthesis of highly substituted tetrahydrofurans from the reaction of a vicinal t-butyldiphenylsilylmethyl-substituted cyclopropyl diester with aldehydes and ketones has been developed. The 2,5-cis-disubstitution predominates over the 2,5-trans-disubstitution by as much as 12:1. The reaction with cyclic ketones generates spiro-fused tetrahydrofurans in good yields. 相似文献
98.
Sanjay Kumar Saxena Archana Mukherjee Yogendra Kumar Ramu Ram A. S. Tapase Vivek J. Anand Ashutosh Dash 《Journal of Radioanalytical and Nuclear Chemistry》2014,302(3):1237-1243
‘Permanent seed implantation’ using 125I- seeds has emerged as an effective treatment modality for management of prostate cancer. An indigenous technology for the production of 125I brachytherapy sources (‘BARC 125I Ocu-Prosta seed’) has been developed. In this current work, we describe an overview of our experience on large scale production of 125I brachytherapy sources, their quality assessment, in vivo bio-evaluation and initial experience on their journey from bench to bed-side for the treatment of prostate cancer. 相似文献
99.
Y. Kalyana LakshmiP. Venugopal Reddy 《Physics letters. A》2011,375(13):1543-1547
With a view to understand the ground state of charge ordered sodium doped neodymium manganites, electrical and magnetic studies were carried out using different measurement protocols and is found to be ferromagnetic. The anomalous low temperature behavior was explained by hindered first-order transition with glass like arrest of kinetics. 相似文献
100.
A new air‐stable Pd(II) complex containing a sulfonamide–Schiff base ligand has been synthesized, characterized and investigated as a catalyst for the Suzuki–Miyaura reactions of aryl halides with arylboronic acids. Theoretical calculations (B3LYP) and spectroscopic evidence suggest that the sulfonamide–Schiff base coordinates to the Pd centre through sulfonamide nitrogen (? SO2NH2) rather than imine (? CH?N). The complex shows excellent cross‐coupling activity with aryl bromides in water at room temperature and aryl chlorides in isopropanol at 60°C. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献