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71.
《Analytical letters》2012,45(18):2870-2878
Dicyclanil is a toxic, pyrimidine-derived insect growth regulator used in veterinary medicine for the prevention of myiasis. A competitive indirect enzyme-linked immunosorbent assay was developed firstly for the determination of dicyclanil in animal tissue. The antigen was prepared using the glutaraldehyde method and polyclonal antibodies were obtained by immunizing rabbits with a dicyclanil-bovine serum albumin conjugate. The antibody obtained was specific for dicyclanil with an IC50 of 9 ng/mL. Recoveries from sheep tissue and liquid milk were in the range of 52.5–72.4%, with coefficients of variation between 4.7% and 11.9%. The results were further confirmed by high performance liquid chromatography–tandem mass spectrometry. 相似文献
72.
Yixuan Xie Chao Peng Yunyi Gao Xiaohong Liu Tianbo Liu Abraham Joy 《Journal of polymer science. Part A, Polymer chemistry》2017,55(23):3908-3917
Glycopolymers have been widely used to understand the interactions between carbohydrates and lectins, which facilitate the diagnosis and detection of disease and pathogens as well as the development of vaccines. While studies have been focused on the correlation of glycopolymer structure and their binding to lectins, graft‐type glycopolyesters are uncommon. Herein, we report the design and synthesis of mannose‐based graft polyesters by “grafting‐from” method and investigate their interactions with Concanavalin A (Con A). As confirmed by 1H NMR spectroscopy and sulfuric acid‐UV method, graft polyesters with different lengths of mannose graft were successfully synthesized. Our results from turbidimetry binding assay showed that graft polyesters with longer mannose graft exhibit higher initial binding rate (ki). Isothermal titration calorimetry measurements of these graft polyesters with Con A showed that polymers exhibit higher binding affinity (ka) with the number of side chain mannose. This study provides understanding of the interaction between Con A and mannose‐based graft polyesters, which can be employed for the development of glycopolymeric therapeutics. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 3908–3917 相似文献
73.
Shuibing Yang Chengmei Liu Weilin Liu Guihong Tong Huijuan Zheng 《Journal of Dispersion Science and Technology》2013,34(11):1608-1614
Vitamin C nanoliposomes were prepared by combining a conventional method (film evaporation) with dynamic high pressure microfluidization. Their physicochemical characterizations (antioxidant activity, particle size, entrapment efficiency, morphology, in vitro drug release, and storage stability) and skin permeation behavior were investigated. The results showed that vitamin C nanoliposomes, having equivalent DPPH (2, 2-diphenyl-1-picrylhydrazyl) free radical scavenging capacity of pure vitamin C solution without loss of their biological activity, exhibited better storage stability at 37°C for 24 hours and at 4°C for 60 days, a more excellent sustained drug release as well as higher skin penetration rate than vitamin C liposomes. 相似文献
74.
《Analytical letters》2012,45(13):2485-2496
Abstract Blood samples were assayed for PSA values immediately after sampled or by standing for an assigned period. Variation of the free‐ (f), total‐ (t) values, and the free to total (f/t) ratios were determined. Mathematical models were used to interpret the phenomena of deviation. Smaller values of PSA values changed randomly with time and temperature of standings, resulting in varying f/t ratios, while larger initial PSA values were relatively unaffected to any significant extent. Model interpreted that the changes of PSA values might be caused by higher temperature and time of standings, and conformational participation was also possible. 相似文献
75.
Michelle Co Camilla Zettersten Leif Nyholm Per J.R. Sjöberg Charlotta Turner 《Analytica chimica acta》2012
Experiments with birch bark samples have been carried to enable a distinction between extraction and degradation effects during pressurised hot water extraction. Two samples, E80 and E180, contained birch bark extracts obtained after extraction at 80 and 180 °C for up to 45 min, respectively. Two other samples, P80 and P180, were only extracted for 5 min at the two temperatures and were thereafter filtered and hydrothermally treated at 80 and 180 °C, respectively. During the latter treatment, samples were collected at different times to assess the stability of the extracted compounds. An offline DPPH (2,2-diphenyl-1-picrylhydrazyl) assay, as well as a high performance liquid chromatographic separation coupled to an electrochemical detector, were used to determine the antioxidant capacity of the processed samples. The results obtained with the different techniques were compared to assess the yield of the extraction and degradation processes. In addition, an online hyphenated system comprising high performance liquid chromatography coupled to diode-array; electrochemical; and tandem mass spectrometric detection (HPLC-DAD-ECD-MS/MS) was used to study the compositions of the extracts in more detail. The results for the samples processed at 80 °C showed that the extraction reached a steady-state already after 5 min, and that the extracted compounds were stable throughout the entire extraction process. Processing at 180 °C, on the other hand, gave rise to partly degraded extracts with a multitude of peaks in both the diode array and electrochemical detectors, and a higher antioxidant capacity compared to for the extracts obtained at 80 °C. It is concluded that HPLC-DAD-ECD is a more appropriate technique for the determination of antioxidants than the DPPH assay. The mass spectrometric results indicate that one of the extracted antioxidants, catechin, was isomerised to its diastereoisomers; (+)-catechin, (−)-catechin, (+)-epicatechin, and (−)-epicatechin. 相似文献
76.
《Macromolecular bioscience》2018,18(3)
Despite great progress, it is still of high interest to explore new homogeneous assays for simple, visual, and selective protein detection. Herein, one new colorimetric sensor has been developed for visual detection of protein by using polymeric micelles as a sensing scaffold and the molecular recognition between protein and the ligand on the surface of the polymeric micelles as the driving force to trigger the readout of the detection signal. The polymeric micelles formed via the self‐assembly of the amphiphilic block polymer biotin‐labeled poly(ethylene glycol)‐block‐poly(3‐acryl aminophenylboronic acid) are endowed with colorful feature by incorporation of alizarin red S (ARS) into the hydrophobic core. Based on the response to streptavidin recognition, these micelles are further disintegrated through the competitive binding of α‐cyclodextrin with boronic acid for disassociation of ARS, which achieves orange–yellow to pink–purple transition in 2 h. This work will open the way to develop one new mix‐and‐measure, visual, and homogeneous assay. 相似文献
77.
Quantitation of memantine hydrochloride bulk drug and its tablet formulation using proton nuclear magnetic resonance spectrometry 下载免费PDF全文
Archana Sahu Mallikarjun Narayanam Moolchand Kurmi Mayurbhai Kathadbhai Ladumor Saranjit Singh 《Magnetic resonance in chemistry : MRC》2016,54(8):632-636
The use of quantitative nuclear magnetic resonance spectrometry for the determination of non‐UV active memantine hydrochloride with relative simplicity and precision has been demonstrated in this study. The method was developed on a 500 MHz NMR instrument and was applied to determination of the drug in a tablet formulation. The analysis was performed by taking caffeine as an internal standard and D2O as the NMR solvent. The signal of methyl protons of memantine hydrochloride appeared at 0.75 ppm (singlet) relative to the signal of caffeine (internal standard) at 3.13 ppm (singlet). The method was found to be linear (r2 = 0.9989) in the drug concentration range of 0.025 to 0.80 mg/ml. The maximum relative standard deviation for accuracy and precision was <2. The limits of detection and quantification were 0.04 and 0.11 mg/ml, respectively. The robustness of the method was revealed by changing nine different parameters. The deviation for each parameter was also within the acceptable limits. The study highlighted possibility of direct determination of memantine hydrochloride in pure form and in its marketed tablet formulation by the use of quantitative NMR, without the need of derivatization, as is the requirement in HPLC studies. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
78.
《Analytical letters》2012,45(2):239-252
Abstract Two mixtures (caffeine mixture (I) and codeine mixture (II)) of 3-components, containing acetaminophen and salicylamide as majors, have been assayed using different computer-assisted spectrophotometric methods. These methods are the Unique Absorbance Method (UAM), the Unique Orthogonal Function Method (UOFM), and Unique Fourier Function Method (UFFM), and also their correspondences under the least squares approach. The parameters have been optimized for the accurate determination of the minor component caffeine in mixture (I). In mixture (II), however. codeine has been extracted - in two steps-prior to the correction of interferences from the major components acetaminophen and salicylamide. 相似文献
79.
Neila A. Caplan G. M. Blackburn 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-4)
Abstract Novel, aromatic bisphosphonates have been synthesised as non-systematic analogues of 1,3-bisphosphoglyceric acid (1,3-BPG). These incorporate non-scissile α-halo and α-methylene phosphonates and have submicromolar K i values for 3 -PGK. 相似文献
80.