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991.
Benzimidazole-based chromogenic chemosensor for the recognition of oxalic acid via counter ion displacement assay in semi-aqueous medium 总被引:1,自引:0,他引:1
An azo dye-coupled benzimidazole-based receptor 1 was synthesized and investigated as a receptor for metal ions in semi-aqueous medium. The receptor recognizes Cu2+ with high selectivity over other metal ions. The resultant complex 1·Cu2+ was found to selectively bind oxalic acid via counter ion displacement. 相似文献
992.
Quantitative analysis of biotin in biological fluids, foods, and pharmaceutical is important for diagnosis and treatment of biotin‐related diseases and health maintenance. In this work, a novel G‐quadruplex/hemin DNAzyme‐based microchip electrophoresis chemiluminescence (CL) assay method was established for rapid and highly sensitive detection of biotin. This method is based on the specific binding between biotin and streptavidin, the catalytic CL characteristics of G‐quadruplex/hemin DNAzyme to the oxidation–reduction reaction of hydrogen peroxide with luminol, and the on‐line separation function of microchip electrophoresis. Under the optimal experimental conditions, on‐chip biotin analysis was achieved within 1 min. The CL intensity is linearly proportional to the concentration of biotin in the range of 13–630 nM with a detection limit of 6.4 nM. The proposed method has been applied for the detection of biotin in flour, biotin contents in three flour samples are found in the range of 199–223 ng/g with a mean value of 214 ng/g. The recoveries were in the range of 94–103%. With excellent sensitivity and good selectivity, the proposed method could be applied in a wide range of biological fluids, foods, and pharmaceutical analysis. 相似文献
993.
This study was undertaken to develop thin layers of silica gel G impregnated with transition metal ions for separation, identification and estimation of purines. The influence of transition metal ions and eluting solvents on chromatographic behaviour (hRf) has been studied. The method was applied for qualitative analysis of purines in the mixtures and quantitative analysis of purine bases in the mixture as well as in pharmaceutical formulations. The results were compared statistically with those obtained by official methods. The method is simple, reproducible, and accurate within 1.3 ± 0.6%. 相似文献
994.
995.
Liangpin Xiao Xianming Liu Runtao Zhong Kaiqing Zhang Xiaodi Zhang Xiaomian Zhou Bingcheng Lin Yuguang Du 《Electrophoresis》2013,34(20-21):3003-3007
Three‐dimensional (3D) paper‐based microfluidics, which is featured with high performance and speedy determination, promise to carry out multistep sample pretreatment and orderly chemical reaction, which have been used for medical diagnosis, cell culture, environment determination, and so on with broad market prospect. However, there are some drawbacks in the existing fabrication methods for 3D paper‐based microfluidics, such as, cumbersome and time‐consuming device assembly; expensive and difficult process for manufacture; contamination caused by organic reagents from their fabrication process. Here, we present a simple printing–bookbinding method for mass fabricating 3D paper‐based microfluidics. This approach involves two main steps: (i) wax‐printing, (ii) bookbinding. We tested the delivery capability, diffusion rate, homogeneity and demonstrated the applicability of the device to chemical analysis by nitrite colorimetric assays. The described method is rapid (<30 s), cheap, easy to manipulate, and compatible with the flat stitching method that is common in a print house, making itself an ideal scheme for large‐scale production of 3D paper‐based microfluidics. 相似文献
996.
Kaliyaperumal Viswanathan Shi‐Tin Haung Chia‐Yu Chang Ching‐Ju Chan Y. C. Lee 《中国化学会会志》2013,60(8):1075-1081
A magnetic separator attached in a zig zag flow channel assembly has been fabricated to detect myoglobin on the micro particles. An anti‐myoglobin conjugated magnetic hybrid and myoglobin conjugated silica micro particles were prepared and used for myoglobin detection on channel. For the detections, the competitive assay principle was followed based on affinity interaction of anti‐myoglobin‐myoglobin. The caliberation curve was plotted based on the deposit percentage of myoglobin conjugated silica micro particles. The calibration curve of the myoglobin showed the linear range between 1 × 10?8 ‐ 5 × 10?11 (M) (R2 = 0.9944). The minimum detectable concentration was 300 pg/mL. Hence all that concludes that, the application of zig zag flow channel with magnetic separator has offered new, simple and rapid approach for detecting myoglobin in whole blood samples with in 30 min. 相似文献
997.
998.
复合式蝎形引物实时定量检测端粒酶延伸产物 总被引:1,自引:0,他引:1
针对端粒酶延伸产物中靶基因序列的特殊性,开发了一种可产生荧光的复合式蝎形引物,该引物的5'端带有可特异性检测靶基因的探针序列,PCR阻断剂将其与引物序列连接.当复合式蝎形引物延伸,探针序列与同一分子内的靶基因杂交,荧光信号产生.运用该技术,建立了定量检测端粒酶延伸产物的实时荧光PCR方法.该法可在快速PCR循环条件下,对0.15~1.50×103 amol/μL范围内的样品进行定量检测,线性相关系数R2=0.9992.该法操作简便,无需PCR后额外的检测步骤. 相似文献
999.
Gertrud E. Morlock Julia Heil Valrie Bardot Loïc Lenoir Csar Cotte Michel Dubourdeaux 《Molecules (Basel, Switzerland)》2021,26(5)
An effect-directed profiling method was developed to investigate 17 different fortified plant extracts for potential benefits. Six planar effect-directed assays were piezoelectrically sprayed on the samples separated side-by-side by high-performance thin-layer chromatography. Multipotent compounds with antibacterial, α-glucosidase, β-glucosidase, AChE, tyrosinase and/or β-glucuronidase-inhibiting effects were detected in most fortified plant extracts. A comparatively high level of antimicrobial activity was observed for Eleutherococcus, hops, grape pomace, passiflora, rosemary and Eschscholzia. Except in red vine, black radish and horse tail, strong enzyme inhibiting compounds were also detected. Most plants with anti-α-glucosidase activity also inhibited β-glucosidase. Green tea, lemon balm and rosemary were identified as multipotent plants. Their multipotent compound zones were characterized by high-resolution mass spectrometry to be catechins, rosmarinic acid, chlorogenic acid and gallic acid. The results pointed to antibacterial and enzymatic effects that were not yet known for plants such as Eleutherococcus and for compounds such as cynaratriol and caffeine. The nontarget effect-directed profiling with multi-imaging is of high benefit for routine inspections, as it provides comprehensive information on the quality and safety of the plant extracts with respect to the global production chain. In this study, it not only confirmed what was expected, but also identified multipotent plants and compounds, and revealed new bioactivity effects. 相似文献
1000.
Immunosensors and biochemical array detection systems based on electrochemical transducers have many advantages such as low detection limit, fast response, simple design and ease of miniaturization. However, further development of such sensors will depend on the availability of suitable substrates that can be converted by a labeling enzyme to an electrochemically active product. Here, we report the synthesis of 4-amino-1-naphthylphosphate and it’s application as a new substrate for alkaline phosphatase. The electrochemical and enzymatic properties of this compound were investigated and compared with the properties of other aromatic 1,4-dihydroxy and 1,4-hydroxy-amine derivatives. The product of the enzyme reaction was 4-aminonaphthol, which was rapidly converted in the presences of air to 1,4-iminonaphthoquinone. This compound could then be detected in an amperometric flow injection assay (AFIA) with −200 mV versus Ag/AgCl potential application. The analytical range for mouse IgG, in an alkaline phosphatase amplified sandwich immuoassay with amperometric detection, was 0.01-100 μg ml−1. 相似文献