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991.
1INTRODUCTIONα Aminophosphonicacids,bioisosteresofnaturalaminoacids,haveatractedmuchatentionbecausetheyshowwidebiologicalacti...  相似文献   
992.
This article presents a review of the recent literature describing the use of plant callus for the production of biochemicals, as well as specific examples of work done in our laboratory to analyze the production of ribosome inactivating proteins fromTrichosanthes kirilowii callus. The article discusses research advances in the development, characterization, and improvement of plant callus cell lines, including new cell lines and potentially useful products, influence of media composition, and environmental conditions on growth and product distribution, cell line selection strategies, and long-term stability.  相似文献   
993.
《Analytical letters》2012,45(6):1061-1070
Abstract

A simple digestion procedure for the determination of Cd, Cu, Mo and V in plant leaves by graphite furnace atomic absorption spectrometry and mass inductively coupled plasma was developed. Approximately to 100 mg of the previously dried plant material (200 mg of fresh material) were weighed into a 50mL plastic conical ended vial and 2mL of subboiled 65% HNO3 was added. The vial was then tightly closed and digestion performed at 80°C in an oven overnight; thereafter, 2mL of 30% H2O2 were added and a light yellow solution was obtained. The volume was made up to 50mL in the vial itself and the solution was ready for analysis. Although the time required for the digestion is long, large batches are possible, and make the procedure useful for high sample throughput. As only one vessel is used for the whole procedure, contamination risks are minimized. The reagents employed are possible to be obtained with high purity, permitting low blank values and detection limits. The accuracy of the procedure was tested by the analysis of certified reference materials and good concordance was observed between experimental and certified values.  相似文献   
994.
This paper describes the process of determining the presence of volatile organic compounds in air emissions from industrial wastewater treatment plants (WWTP). The analytical method, based on thermal desorption-gas chromatography-mass spectrometry, was developed to simultaneously determine of 99 volatile organic compounds (VOCs) in air samples. This method is rapid, environmentally-friendly (since no organic solvents are used to extract the analytes) and compatible with a large range of thermally stable polar and apolar compounds. The target VOCs were selected on the basis of their occurrence in real samples and their adverse effects on the environment and human health. To cover the wide range of target compounds, multisorbent tubes filled with Tenax TA and Carbograph 1TD were used. Method validation showed good repeatabilities, low detection limits, a high linear range and good recoveries. At a fixed sample volume of 600?mL no significant losses for any of the target compounds were found in the samples. Stability during storage indicated that samples must be keep refrigerated at 4°C and analysed within three days of collection. Real samples were taken from air emissions of an industrial wastewater treatment plant located in the Southern Industrial Area of Tarragona (Spain) with the aim of studying its contribution as a source of atmospheric VOCs. This WWTP collects wastewater from several chemical factories which produce isocyanates, polyurethanes, chlorinated organics and functional chemicals among other products. Samples from the collecting tank after the primary sedimentation showed higher VOC concentrations than samples from the secondary treatment tank. The most abundant VOCs found in these emissions are included in the USEPA List of Hazardous Air Pollutants. The highest values correspond to acrylonitrile (up to 1843?µg?m?3) and styrene (up to 573.70?µg?m?3). The levels of chloroform, 1,4-dioxane, ethylbenzene, 1,2,3-trimethylbenzene and 1,4-diethylbenzene were also high.  相似文献   
995.
The adverse health effects of the Residual Oil Fly Ash (ROFA) emitted by a Hungarian power plant on inhabitants living in the villages surrounding the city where the power plant is situated and in the city itself were investigated. For the investigations, data obtained from the National Public Health and Medical Officer Services, the National Cancer Registry of Hungary, the Public Administration Office of Pest and Fejér Counties were used. The frequency of lower respiratory system diseases and malignant neoplasms amongst the inhabitants of the settlements 0–13 km far from the power station compared with that of the control settlement for different age-groups were calculated. The prevalence and incidence rates, calculated for the inhabitants of the city where the power plant is situated were always comparable to those of the control settlement, because the heavy metal containing ROFA particles emitted from the 202-m-high stack are deposited outside the town. The prevalence rates of adult patients treated for malignant neoplasms and chronic lower respiratory system diseases were about two times and up to eight times higher than in the control settlement, respectively, for three villages situated 8–12 km far from the source in the predominant direction of wind blow as of 1st of January 2000 and 1st of January 2002. In these villages, the incidence rates for newly recognised malignant neoplasms of lip, oral cavity and pharynx were four times higher than those in the control settlement between 1st of January 2000 and 1st of January 2002. It may be supposed that the emitted fly ash is responsible for the more frequent occurrence of the examined diseases in the investigated settlements. Data presented are suggestive of an increased risk, which will further be investigated by the usual methods of the epidemiology.  相似文献   
996.
Agarwood is a highly valuable fragrant wood of Aquilaria spp. (Thymelaeaceae) which has been widely utilized in traditional medicine, religious rites, and cultural activities. This study summarizes a review on the identification of Aquilaria cultivars, volatile and non-volatile phytochemicals, pharmacological uses, and agarwood grading system to determine its quality, and different agarwood induction methods. Due to the highly demanding and depleted natural resources, the research on agarwood is still insufficient, and it has broad research and development prospects in many industries. However, due to the significant scientific nature of agarwood application, developing high-quality products and drugs from agarwood have become highly important, while no one has discussed in detail the phytochemicals uses and provided a summary until now. The main phytochemicals of agarwood include terpenoids, dominated by sesquiterpenes. For centuries, terpenoids have been used in traditional Chinese medicine and have been shown to possess various pharmacological properties, including bacteriostatic, antibacterial, sedation, analgesia, anti-inflammation, anti-asthmatic, hypoglycemic, antidepressant, and many others. Alongside biological activity screening, phytochemical advances and pharmacological research have also made certain progress. Therefore, this review discusses the research progress of agarwood in recent years and provides a reference basis for further study of Aquilaria plants and agarwood.  相似文献   
997.
曹蕾  汪焱钢  宋新建  刘国华 《有机化学》2005,25(8):1007-1010
以5-氨基-2-巯基的席夫碱与亚磷酸二乙酯反应, 合成了15个新的α-(1,3,4-噻二唑-5-基)氨基烃基膦酸酯, 初步的生物活性测试表明部分目标化合物具有较好的植物生长调节活性, 其中2,4-二氯苯甲醛、呋喃甲醛和吲哚甲醛的席夫碱生成的α-氨基烃基膦酸酯具有较好的生长素活性.  相似文献   
998.
Dietary plant polyphenols are natural bioactive compounds that are increasingly attracting the attention of food scientists and nutritionists because of their nutraceutical properties. In fact, many studies have shown that polyphenol-rich diets have protective effects against most chronic diseases. However, these health benefits are strongly related to both polyphenol content and bioavailability, which in turn depend on their origin, food matrix, processing, digestion, and cellular metabolism. Although most fruits and vegetables are valuable sources of polyphenols, they are not usually consumed raw. Instead, they go through some processing steps, either industrially or domestically (e.g., cooling, heating, drying, fermentation, etc.), that affect their content, bioaccessibility, and bioavailability. This review summarizes the status of knowledge on the possible (positive or negative) effects of commonly used food-processing techniques on phenolic compound content and bioavailability in fruits and vegetables. These effects depend on the plant type and applied processing parameters (type, duration, media, and intensity). This review attempts to shed light on the importance of more comprehensive dietary guidelines that consider the recommendations of processing parameters to take full advantage of phenolic compounds toward healthier foods.  相似文献   
999.
建立了ICP- MS混合模式测定蔬菜、水果、大米等植物性农产品中痕量元素的检测方法.样品经HNO3 + H2O2消解,以74Ge,115In、209Bi作为内标溶液消除基体干扰,动能歧视型碰撞/反应池技术消除质谱干扰的方式测定植物性农产品中As,Hg,Pb,Cd,Cr,Se,Cu,Ni,Zn 9种痕量元素.结果表明:该...  相似文献   
1000.
合成了一系列的1-芳基-1,4-二氢-3-芳酰肼基甲酰基-各甲基斗哒嗪酮类化合 物,并用离体黄瓜子叶生根法测试其生物活性,生测结果表明,所有的化合物均显 示出一定的生物活性,并且芳环上的取代基对活性有重要影响.采用化合物的物理 化学参数及化合物促进黄瓜子叶生根的活性,进行了结构与活性定量关系研究,建 立了较好的结构与活性的相关式,化合物的亲脂性和取代基的电性对化合物的生物 活性具有重要的影响.研究结果对3-芳酰肼基甲酰基斗哒嗪酮类化合物的改性或新 类似物的合成具有指导意义.  相似文献   
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