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221.
Mandal U Gowda V Ghosh A Bose A Bhaumik U Chatterjee B Pal TK 《Chemical & pharmaceutical bulletin》2008,56(2):150-155
The aim of the present study was to apply the simultaneous optimization method incorporating Artificial Neural Network (ANN) using Multi-layer Perceptron (MLP) model to the development of a metformin HCl 500 mg sustained release matrix tablets with an optimized in vitro release profile. The amounts of HPMC K15M and PVP K30 at three levels (-1, 0, +1) for each were selected as casual factors. In vitro dissolution time profiles at four different sampling times (1 h, 2 h, 4 h and 8 h) were chosen as output variables. 13 kinds of metformin matrix tablets were prepared according to a 2(3) factorial design (central composite) with five extra center points, and their dissolution tests were performed. Commercially available STATISTICA Neural Network software (Stat Soft, Inc., Tulsa, OK, U.S.A.) was used throughout the study. The training process of MLP was completed until a satisfactory value of root square mean (RSM) for the test data was obtained using feed forward back propagation method. The root mean square value for the trained network was 0.000097, which indicated that the optimal MLP model was reached. The optimal tablet formulation based on some predetermined release criteria predicted by MLP was 336 mg of HPMC K15M and 130 mg of PVP K30. Calculated difference (f(1) 2.19) and similarity (f(2) 89.79) factors indicated that there was no difference between predicted and experimentally observed drug release profiles for the optimal formulation. This work illustrates the potential for an artificial neural network with MLP, to assist in development of sustained release dosage forms. 相似文献
222.
Uttam Mandal Amlan Kanti Sarkar Kadagi Veeran Gowda Sangita Agarwal Anirbandeep Bose Uttam Bhaumik Debotri Ghosh Tapan Kumar Pal 《Chromatographia》2008,67(3-4):237-243
A bioanalytical method has been developed and validated for determination of pregabalin in human plasma. The analytical method
consists in the precipitation of plasma sample with trichloro acetic acid (20% v/v solution in water), followed by the determination of pregabalin by an LC-MS-MS method using gabapentin as internal standard.
Separation was achieved on a Gemini C18 50 mm × 2.0 mm (3 μm) column with an isocratic mobile phase consisting of methanol–water (98:2, v/v) with 0.5% v/v formic acid. Protonated ions formed by a turbo ionspray in positive mode were used to detect analyte and internal standard.
The MS-MS detection was by monitoring the fragmentation of 160.2→55.1 (m/z) for pregabalin and 172.2→67.1 (m/z) for gabapentin on a triple quadrupole mass spectrometer. The assay was calibrated over the range 0.1–15.0 μg mL−1 with correlation coefficient of 0.9998. Validation data showed intra-batch (n = 6) CV% ≤ 6.89 and RE (%) between −4.17 and +3.08 and inter-batch (n = 18) CV% < 9.09 and RE (%) between −3.0 and +10.00. Mean extraction recovery were 80.45–89.12% for three QC samples and 87.56%
for IS. Plasma samples were stable for three freeze–thaw cycles, or 24 h ambient storage, or 1 and 3 months storage at −20 °C.
Processed sample (ready for injection) were stable up to 72 h at autosampler (4 °C). This method has been used for analyzing
plasma samples from a bioequivalence study with 18 volunteers. 相似文献
223.
Jhillu S. Yadav Basi V. Subba Reddy Sandip Sengupta Manoj K. Gupta Gakul Baishya Sukkala J. Harshavardhana Uttam Dash 《Monatshefte für Chemie / Chemical Monthly》2008,44(5):1363-1367
We developed an efficient protocol for the synthesis of thiiranes from oxiranes using a catalytic amount of molecular iodine.
The notable features of this procedure are mild reaction conditions, high conversions, short reaction times, economic viability
of the reagents, compatibility with various functionalities, and simple experimental/product isolation procedures which make
it a useful and attractive process for the synthesis of a range of thiiranes. 相似文献
224.
Uttam Kumar Das Dr. Parthasarathi Dastidar 《Chemistry (Weinheim an der Bergstrasse, Germany)》2012,18(41):13079-13090
A series of bis‐amides derived from L ‐(+)‐tartaric acid was synthesized as potential low‐molecular‐weight gelators. Out of 14 bis‐amides synthesized, 13 displayed organo‐, hydro‐, and ambidextrous gelation behavior. The gels were characterized by methods including circular dichroism, differential scanning calorimetry, optical and electron microscopy, and rheology. One of the gels derived from di‐3‐pyridyltartaramide ( D‐3‐PyTA ) displayed intriguing nanotubular morphology of the gel network, which was exploited as a template to generate highly aligned 1D silica fibers. The gelator D‐3‐PyTA was also exploited to generate metallogels by treatment with various CuII/ZnII salts under suitable conditions. A structure–property correlation on the basis of single‐crystal and powder X‐ray diffraction data was attempted to gain insight into the structures of the gel networks in both organo‐ and metallogels. Such study led to the determination of the gel‐network structure of the CuII coordination‐polymer‐based metallogel, which displayed a 2D sheet architecture made of a chloride‐bridged double helix that resembled a 5‐c net SnS topology. 相似文献
225.
Alok Srivastava K. K. Swain Nicy Ajith D. N. Wagh R. Acharya A. V. R. Reddy Uttam Mete 《Journal of Radioanalytical and Nuclear Chemistry》2012,294(3):425-428
Kidney stones obtained from six patients belonging to the stone belt region of India (Punjab) were analyzed for inorganic constituents using instrumental neutron activation analysis (INAA) and energy dispersive X-ray fluorescence (EDXRF) techniques. For INAA, samples were irradiated along with IAEA RM Soil 7 as reference standard in CIRUS reactor, BARC, Mumbai. Gamma activity of irradiated samples was measured using a 45% relative efficiency HPGe detector coupled to 8?k channel analyzer. EDXRF method was used for determination of concentration of Ca. The concentrations of ten elements namely Ca, Na, K, Mn, Co, Cr, Zn, Br, Sm and Cl, are reported and discussed. 相似文献
226.
227.
Organocatalytic enantioselective synthesis of β-blockers: (S)-propranolol and (S)-naftopidil 总被引:1,自引:0,他引:1
Sharad P. Panchgalle Rohitkumar G. Gore Subhash P. Chavan Uttam R. Kalkote 《Tetrahedron: Asymmetry》2009,20(15):1767-1770
An efficient enantioselective synthesis of β-adrenergic blockers (S)-propranolol and (S)-naftopidil with >98% ee using an l-proline-catalyzed α-aminoxylation of an aldehyde as a key step is described. 相似文献