Suppression of volcanism during rapid extension in the basin and range province, united states

Continental extension and volcanism are generally thought to be complementary. Stratigraphic and structural data from some highly extended parts of the Basin and Range province reveal instead that rapid extension appears to have suppressed volcanism. This relation may reflect enhanced crystallization of midcrustal magmas during extension resulting from exsolution of magmatic volatiles, increased interaction of magmas with meteoric water, and dispersal of magma into smaller bodies. Some rift environments may thus be characterized by voluminous synextensional plutonism with little or no concomitant volcanism.     

周小舟教授治疗肝癌经验

周小舟教授认为肝癌的病因是内因正气亏虚和外因外染疫毒相互作用所致,其主要病机是气虚血瘀,针对主要病机设立芪术抗癌方辨证加减治疗,临床疗效显著;周教授通过实验及临床研究亦初步阐明了芪术抗癌方的作用机制,值得临床借鉴。     

热处理对水牛乳稳定特性的影响

为比较不同热处理条件对水牛乳稳定性的影响,实验采用不同条件热处理后的pH缓冲容量、总溶解固体（total dissolved solids,TDS）、蛋白沉淀量及表观黏度等指标研究杂交高代水牛乳样品。结果表明：与未经处理的水牛乳样品相比,水牛乳经不同条件热处理后,其pH缓冲容量、TDS、蛋白沉淀量及表观黏度皆发生显著变化。其中水牛乳分别在经121℃/15 min和95℃/5 min处理后,其pH缓冲容量、TDS、蛋白沉淀量及表观黏度分别达到最大值和最小值。因此,认为在本实验研究范围内,水牛乳经121℃/15 min及95℃/5 min处理后,对其稳定性影响最大。     

Chromatographic methods for determination of macrolide antibiotic residues in tissues and milk of food-producing animals

Tylosin, an antibiotic developed specifically for agricultural use, and erythromycin are the main macrolide antibiotics used in animal production. Two-dimensional thin layer chromatography has been used for detection of tylosin in poultry meat, eggs, and milk and for erythromycin in poultry meat. Detection limits reported are, for tylosin, 0.1 ppm in poultry meat, 0.05 ppm in egg, and 0.01 ppm in milk, and for erythromycin, 0.25 ppm in poultry meat. Liquid chromatography (LC) has also been used for determination of tylosin in milk, blood, and tissues of animals. Samples (milk, blood serum, or tissue homogenates in water or pH 2.2 buffer) were deproteinized with acetonitrile, tylosin was partitioned into methylene chloride, and the extracts were concentrated and dissolved in acetonitrile. Chromatography was done on a reverse phase end-capped C18 column using 0.002-0.005 M ammonium dihydrogen phosphate-acetonitrile-methanol (10 + 60 + 30-5 + 80 + 15). Solvent composition was varied with the type of sample analyzed. The method will detect 0.1 ppm tylosin in tissues and less in milk and blood serum. The LC method was more sensitive than microbiological assays for detection of tylosin in tissues of treated swine; recoveries of tylosin by the LC method were frequently several-fold higher.     

The Current State of Solar Modeling

Data from the Global Oscillation Network Group (GONG) project and other helioseismic experiments provide a test for models of stellar interiors and for the thermodynamic and radiative properties, on which the models depend, of matter under the extreme conditions found in the sun. Current models are in agreement with the helioseismic inferences, which suggests, for example, that the disagreement between the predicted and observed fluxes of neutrinos from the sun is not caused by errors in the models. However, the GONG data reveal subtle errors in the models, such as an excess in sound speed just beneath the convection zone. These discrepancies indicate effects that have so far not been correctly accounted for; for example, it is plausible that the sound-speed differences reflect weak mixing in stellar interiors, of potential importance to the overall evolution of stars and ultimately to estimates of the age of the galaxy based on stellar evolution calculations.     

刈牧后休闲期对草地牧草生产的影响

通过不同间隔时期对多年生黑麦草、白三叶混播草地牧草产量的监测与分析,得出随着休闲期的增加,青绿物质和死亡物质均呈现上升趋势,在较低和较高草地牧草现存量下都会降低牧草生长率。     

贵州足球场草坪建植及化管理模型研究

在一定的生境和管理条件下,以修剪高度、修剪次数和施N、P、K量为因素,利用二次正交回归设计,用模糊综合评分法评定草坪质量,最佳3因子水平为:修剪高度5～7.4cm,修剪次数4～6次/月,施N量为2.5～3.7g/(m2·年),施P、K量各为L25～1.85g/(m2·年),建立了草坪质量与养护3因子间的显著相关回归模型.