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981.
982.
Infrared spectra for methyl borate, B(OCH3)3 were recorded in the gas phase and solutions. Raman spectra were recorded for the same compound in liquid and solid states. The data were interpreted on the basis of a C3h molecular model. A normal coordinate analysis for the complete model is included. The developed force constants were used to calculate the mean amplitudes of vibration which were compared with recent results from electron diffraction. 相似文献
983.
984.
Recently, plant-derived proteins have increased in interest and use owing to a combination of interesting properties and industry-wide trends to replace animal-derived proteins. Electrohydrodynamic processing can be used to develop microstructures and nanostructures of plant proteins in a facile manner and, thus, increase their opportunities in the food, pharmaceutical, and biomedical industries. One of the most currently studied and promising plant proteins is zein. This review covers the most studied strategies to produce electrospun and electrosprayed zein-based structures. The most relevant properties, such as size, morphology, and surface area, are discussed as per the potential areas of interest, for instance, in the food, biomedical, and pharmaceutical industries. In addition, applications of other electrospun/electrosprayed plant-derived proteins are also presented, confirming the increasing interest of different industries in alternative proteins which can help promote sustainability. 相似文献
985.
Regulations relating to mycotoxins in food 总被引:1,自引:0,他引:1
Regulations relating to mycotoxins have been established in many countries to protect the consumer from the harmful effects
of these compounds. Different factors play a role in the decision-making process of setting limits for mycotoxins. These include
scientific factors, for example the availability of toxicological data and occurrence data, detailed knowledge about possibilities
for sampling and analysis, and socio-economic issues. By the end of 2003, approximately 100 countries (covering approximately
85% of the world’s inhabitants) had specific regulations or detailed guidelines for mycotoxins in food. The regulations were
related to aflatoxins (B1, B2, G1 and G2), aflatoxin M1, trichothecenes (deoxynivalenol, diacetoxyscirpenol, T-2 toxin and HT-2 toxin), fumonisins (B1, B2, and B3), agaric acid, ergot alkaloids, ochratoxin A, patulin, phomopsins, sterigmatocystin, and zearalenone. In Europe, and in particular
in the EU, regulatory and scientific interest in mycotoxins has undergone a development in the last decade from autonomous
national activity towards more EU-driven activity with a structural and network character. Harmonized EU limits now exist
for 40 mycotoxin–food combinations. It is expected this number will grow in 2007 to approximately 50. The direct or indirect
influence of European organizations and programs on the EU mycotoxin regulatory developments is significant. They include
the European Food Safety Authority, the Scientific Cooperation on Questions relating to Food, the Rapid Alert System for Food
and Feed, the creation of an EU Community Reference Laboratory for Mycotoxins and a mandate of the EC to the European Standardization
Committee in methods for analysis for mycotoxins in food. Large pan-European research and networking projects as “BioCop”
and “MoniQA” are also important. 相似文献
986.
Basu AK Chattopadhyay P Roychoudhuri U Chakraborty R 《Bioelectrochemistry (Amsterdam, Netherlands)》2007,70(2):375-379
The development of a cholesterol biosensor by co-immobilization of cholesterol esterase (ChEt) and cholesterol oxidase (ChOX) on oxygen electrode is described. The electrode consists of gold cathode and Ag/AgCl anode. The enzymes were immobilized by cross-linking with glutaraldehyde and Bovine Serum Albumin (BSA). The immobilized enzymatic membrane was attached to the tip of the electrode by a push cap system. The optimum pH and temperature of the sensor was determined, these are 6 and 25 degrees C respectively. The developed sensor was calibrated from 1-75 mg/dl of cholesterol palmiate and found linear in the range of 2-50 mg/dL. The calibration curve was drawn with V(i) (ppm/min)(initial velocity) vs different concentrations of cholesterol palmiate (mg/dL). The application of the sensor to determine the total cholesterol in different real food samples such as egg, meat was investigated. The immobilized enzymatic layer can be reused over 30 times and the stability of the enzymatic layer was studied up to 9 weeks. 相似文献
987.
A simple, rapid and sensitive on-line method for the simultaneous determination of benzoic and sorbic acids in food was developed
by coupling in-tube solid-phase microextraction (SPME) to high-performance liquid chromatography (HPLC) with UV detection.
The diethylamine-modified poly(glycidyl methacrylate-co-ethylene dimethacrylate) monolithic capillary selected as the extraction
medium exhibited a high extraction capability towards benzoic and sorbic acids. To obtain optimum extraction performance,
several in-tube SPME parameters were investigated, including pH value, inorganic salt, and the organic solvent content of
the sample matrix. After simple dilution with 0.02 mol/L phosphate solution (pH 4.0), carbonated drink, juice drink, sauce
and jam samples could be directly injected for extraction. For succade samples, a small amount of acetonitrile was required
to extract analytes prior to dilution and subsequent extraction. The linearity of the method was investigated over a concentration
range of 5–20000 ng/mL for both analytes, and the correlation coefficients (R
2 values) were higher than 0.999. The detection limits for benzoic and sorbic acids were 1.2 and 0.9 ng/mL, respectively. The
method reproducibility was tested by evaluating the intra- and interday precisions; relative standard deviations of less than
4.4 and 9.9%, respectively, were obtained. Recoveries of compounds from spiked food samples ranged from 84.4 to 106%. The
developed method was shown to be suitable for the routine monitoring of benzoic and sorbic acids in various types of food
samples. 相似文献
988.
This review summarizes scientific research activity on biosensors, especially screen-printed, electrode-based biosensors.
The basic configurations of biosensors based on screen-printing technology are discussed and different procedures for immobilization
of the biorecognition component are reviewed. Theoretical aspects are exemplified by practical environmental and food-analysis
applications of screen-printed, electrode-based biosensors. 相似文献
989.
The present review deals with novel developments in immunosensors destined for final application in food analysis. In this perspective particular emphasis will be given to the most important approaches which recently have been used for immunosensor construction and assembling. For this reason, electrochemical, surface plasmon resonance (SPR) and quartz crystal microbalance (QCM) techniques will be explored in detail and recent and practical examples on food matrices will be reviewed. Objective of this survey is to give a general overview of the possible application of immunosensors to the food analysis field. 相似文献
990.
Today it is common to find samples with various additives from several families. This is the case of sweeteners, preservatives and antioxidants. We have selected a set of additives broadly used in foods and cosmetics with an ample variety of polarities, namely: aspartame (AS), acesulfame (AK)/saccharin (SA), metylparaben (MP), ethylparaben (EP), propylparaben (PP), butylparaben (BP), propylgallate (PG) and butylhydroxyanysole (BA). The monolithic column used as separative system is a 5 mm commercial precolumn of silica C18 coupled to a flow injection manifold working with a peristaltic pump. The mixture was separated in only 400 s with resolution factors greater than 1.1 in all cases. To achieve the separation in the FIA system we used two carriers: first, a mixture of ACN/water buffered with 10 mM pH 6.0 phosphate buffer and second, a methanol:water mixture to improve the carrier strength and speed up the more apolar analytes at 3.5 mL min−1. Detection is accomplished by means of a diode array spectrometer at the respective wavelength of each compound. The comparison of the analytical parameters obtained for this procedure with a standard HPLC method validates our new method, obtaining a method that is quick, with high repeatability and reproducibility and with good resolution between analytes. We have successfully applied the method to real food and cosmetics samples. 相似文献