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171.
《Analytical letters》2012,45(14):2883-2899
ABSTRACT|The catalytic activity of various mimetic enzymes instead of the peroxidase have been investigated by 4-aminoantipyrine (4-AAP) and 2, 3, 4-trichlorophenol (TCP) to form a dye utilizing hydrogen peroxide as hydrogen acceptor. The different Chlorophenolic derivatives, which act as a substrate in β-CD-hemin-H2O2-4-AAP catalytic reaction, have been systematically studied.|Meanwhile, the relationship of structure-effect for the β-CD-hemin as catalyst, and chlorphenols as substrate has been respectively discussed. The mechanism of catalytic reaction has been investigated. The results showed that β-CD-hemin was the best mimetic enzyme for peroxidase among those tested and TCP was a good substrate for the determination of hydrogen peroxide with β-CD-hemin. The method for the determination of hydrogen peroxide was proposed using 4-AAP-TCP system with β-CD-hemin as catalyst. A linear calibration graph was obtained over the H2O2 concentration of 4.8×10-?8-7.7×10-?5M, and the relative standard deviation at a H2O2 concentration of 2.8×10-?5M was 2.5%. The apparent molar absorptivity of the chromogenic reaction for H2O2 was 1.54× 104 L.mol-?1.cm?1. Satisfactory results were obtained in the determination of H2O2 in synthetic samples by this method. Also, the method was coupled with the glucose oxidation reaction to determination glucose in human serum. 相似文献
172.
《Analytical letters》2012,45(8):1622-1631
Abstract Catalyzed determination of glucose with mimic glucose oxidase is constructed by the reaction of β‐cyclodextrin, maleic anhydride, and chloroacetic acid with iron trichloride in hydrogen peroxide. The method is simple and convenient, and sensitivity and repeatability are ideal. Beer's law is obeyed in a concentration range of 30–197 µg · ml?1 glucose with an excellent correlation coefficient (r=0.9994), while the detection limit is 4.10 µg · ml?1, the RSD is 0.98% (n=8). The recovery of sample is 95.8–103.1%. 相似文献
173.
《Analytical letters》2012,45(4):505-514
Abstract An amperometric procedure for the measurement of magnesium(II) has been developed using the enzyme hexokinase in solution and glucose oxidase immobilized onto a preactivated polymeric support. The reaction of hexokinase was monitored following the decrease in current due to the glucose consumption by the enzyme in the presence of the ATP-Mg2+ complex. The reaction rate was dependent on the concentration of magnesium(II) in solution. Concentrations of hexokinase and ATP were optimised. Measuring the current change in the 1-3 min interval after the start of the reaction magnesium(II) can be determined in the 4 × 10?5 to 10?3 M range. Other divalent cations tested showed no interference. The magnesium(II) content of 5 pharmaceutical products was measured with the amperometric and compared to a spectrophotometric procedure. The results correlated well. 相似文献
174.
《Analytical letters》2012,45(12):1417-1427
Abstract A method is described of fast spectrometric determination of glucose oxidase activity based on enzymatic reduction of benzoquinone to hydroquinone and on the measurement of the rate of increase of hydroquinene absorbance at 290 nm. The enzymatic activity is deduced from the initial rate. The method is rapid and sensitive. 相似文献
175.
《Analytical letters》2012,45(3):431-440
Abstract Continuous glucose monitoring (CGM) is expected to become an ideal way to monitor glycemic levels in diabetic patients. On the other hand, biofuel cells can be used as an alternative energy source in future implantable devices, such as implantable glucose sensors in the artificial pancreas. Glucose dehydrogenase from Acinetobacter calcoaceticus, which harbors pyrroloquinoline quinone as the prosthetic group (PQQGDH), is one of the enzymes most attractive as a glucose sensor constituent and as the anode enzyme in biofuel cells, due to its high catalytic activity and insensitivity to oxygen. However, the application of PQQGDH for these purposes is inherently limited because an electron mediator is required for the electron transfer to the electrode. We have recently reported on the development of an engineered enzyme, quinohemoprotein glucose dehydrogenase (QH‐GDH), in which the cytochrome c domain of the quinohemoprotein ethanol dehydrogenase (QH‐EDH) was fused with PQQGDH, to enable electron transfer to the electrode in the absence of an artificial mediator. In this study, we constructed a direct electron‐transfer‐type CGM system employing QH‐GDH. This CGM system showed sufficient current response and high operational stability. Furthermore, we successfully constructed a compartmentless biofuel cell employing QH‐GDH. 相似文献
176.
HEC/SiO2凝胶复合物包埋固定化葡萄糖氧化酶的研究 总被引:8,自引:0,他引:8
溶胶-凝胶技术;HEC/SiO2凝胶复合物包埋固定化葡萄糖氧化酶的研究 相似文献
177.
178.
用15 nm的纳米金标记羊抗人铜蓝蛋白抗体(GCP)可获得铜蓝蛋白(CP)纳米金探针(AuGCP). 在pH 7.8柠檬酸-磷酸氢二钠缓冲溶液中, CP与AuGCP发生特异性结合生成胶体金免疫复合物. 离心分离后, 离心液中的AuGCP可作为酒石酸铜(C4H4O6Cu)-葡萄糖反应体系的催化剂, 生成的Cu2O微粒在620 nm处有一共振散射峰. 在选定条件下, 620 nm处共振散射信号降低值△I620 nm与铜蓝蛋白浓度cCP在0.18~45 ng/mL范围内存在良好线性关系, 回归方程为 ΔI620 nm=2.27cCP+5.05, 相关系数为0.9940, 检出限为0.14 ng/mL. 该法用于人血清中铜蓝蛋白的检测, 结果满意. 相似文献
179.
180.
Florin Turcu Gerhard Hartwich Dominik Schfer Wolfgang Schuhmann 《Macromolecular rapid communications》2005,26(4):325-330
Summary: The integration of gradients of enzyme activity in microstructured biosensor arrays enables intrinsic on‐line quality control of biosensor performance. Multiple sensor elements with different compositions and hence varying responses for the same analyte are evaluated as a basis for improving data reliability. The formation of glucose oxidase/polymer microstructures using a piezo microdispenser and their examination by scanning electrochemical microscopy (SECM) are used to demonstrate the feasibility of this approach.