整体观察是绘画的关键——浅谈基础美术教学中的认识问题

本文就整体观察的形式、内容两个方面进行了分析、归纳。论述了认识在绘画中的重要作用。     

Sound-velocity measurements for HFC-134a and HFC-152a with a spherical resonator

A spherical acoustic resonator was developed for measuring sound velocities in the gaseous phase and ideal-gas specific heats for new refrigerants. The radius of the spherical resonator, being about 5 cm, was determined by measuring sound velocities in gaseous argon at temperatures from 273 to 348 K and pressures up to 240 kPa. The measurements of 23 sound velocities in gaseous HFC-134a (1,1,1,2-tetrafluoroethane) at temperatures of 273 and 298 K and pressures from 10 to 250 kPa agree well with the measurements of Goodwin and Moldover. In addition, 92 sound velocities in gaseous HFC-152a (1,1-difluoroethane) with an accuracy of ±0.01% were measured at temperatures from 273 to 348 K and pressures up to 250 kPa. The ideal-gas specific heats as well as the second acoustic virial coefficients have been obtained for both these important alternative refrigerants. The second virial coefficients for HFC-152a derived from the present sound velocity measurements agree extremely well with the reported second virial coefficient values obtained with a Burnett apparatus.Paper dedicated to Professor Joseph Kestin.     

石匣小流域坡地水土流失监测系统的建立及应用

以石匣小流域为坡地水土流失监测试点,以遥感及地理信息系统技术为手段,以坡地径流小区定位观测为依据,建立石匣小流域坡地水土流失监测系统,定位、定性、定量监测各种坡地类型的水土流失量、污染物流失量,为水土流失监测预报提供数据,为全市山区水土流失监测预报工作提供经验及方法,为制定水土流失防治方针政策及水土流失生态环境建设提供依据.     

桥梁病害桩基的加固处理

通过对铁路桥梁钻孔灌注桩病害事故的分析 ,探讨在保证列车安全运营条件下的临时加固措施 ,并提出了对此问题的一些看法     

Colour measurement of fish minces using hunter L,a, b values

Hunter L, a and b values are used to order fish mince colour according to species or processing parameters. Mince colour difference (ΔE) or statistical examination of L, a and b values are used to establish a 3-dimensional plot to illustrate colour differences between samples.     

The intervalley X6→Γ6, L6 scattering time in GaAs measured by ultrafast pump-probe infrared absorption spectroscopy

A direct measurement of the dynamics of electrons in the X₆ valley for a GaAs crystal by time-resolved absorption spectroscopy is reported for the first time. IR picosecond probe pulses were used to monitor the growth and decay of the population in the X₆ valley subsequent to excitation by a 527 nm pump pulse. The intervalley X₆→Γ₆, L₆ scattering time t_x of 0.70 ± 0.50 ps is determined and the crossection for the X₆→X₇ transition is estimated to be 1.8 × 10⁻¹⁶ cm².     

The distribution of anthocyanins in grape skin extracts of port wine cultivars as determined by high performance liquid chromatography

The distribution of anthocyanins in methanolic skin extracts of 16 grape cultivars used for port wine production and grown at five sites in the Douro Valley in Northern Portugal has been assessed by high performance liquid chromatography. Results are confined to the seven most readily separated and identified anthocyanins and are expressed as percentages of their total (88–99% of the total integrated area). Anthocyanins based on malvidin (Mv) predominated. Of these, Mv 3-glucoside was the major pigment (33–60%), being exceeded by Mv 3-p-coumarylglucoside (2–51%) in only two cultivars; Mv 3-acetylglucoside (1–15%) was consistently the lowest. Peonidin 3-glucoside (1–27%) was prominent in four cultivars, but delphinidin 3-glucoside (1–11%), petunidin 3-glucoside (2–11%) and cyanidin 3-glucoside (trace-6%) were of low proportions throughout. The ratio Mv 3-acetylglucoside/total Mv glucosides appeared characteristic of cultivar, independent of site, and a useful aid to identification of grape cultivars. The coloured pulp of some cultivars contained peonidin 3-glucoside as a major component, present in greater proportions than in the skin; the percentage of Mv 3-p-coumarylglucoside was lower in pulp than in skin. The identities of six of the seven anthocyanins were confirmed by fast atom bombardment mass spectrometry and the structures of the Mv derivatives were determined by nuclear magnetic resonance. The formation of formyl and acetyl anthocyanin artefacts is described.     

制备低硫可膨胀石墨的研究

研究了以过二硫酸铵作氧化剂低硫可膨胀石墨的制备，找到了在较低温度下，制备低硫可膨胀石墨的最佳条件。即过二硫酸铵和石墨的重量比为１５％；反应温度为５５℃；反应时间为４０ｍｉｎ；硫酸浓度为９８％；硫酸与石墨的重量比为４∶１，草酸和硝酸（浓度为６５％）的重量比为７．５％时，所制得的可膨胀石墨含硫量为０．６５％，膨胀容积为２００ｍＬ／ｇ可膨胀石墨。并且，其终端产品柔性石墨具有优良的力学性能和抗氧化性能。     

一种微机控制的多测头凸轮轴测量系统

本文介绍一种由机械装置，高精度圆光栅编码器，光栅位移传感器，微型计算机，接口控制电路等组成的多测头凸轮轴测量系统，该系统安装调整方便，定位准确，测量精度高，操作简单，工作可靠，能快速实现对凸轮轴的自动测量。