丙烯醛制备1,3-丙二醇的中型试验研究

对丙烯醛水合、加氢制1，3-丙二醇工艺进行了中试研究，主要对小试技术的可靠性进行验证。结果表明，丙烯醛经水合、加氢制1，3-丙二醇的工艺技术可行，反应器、精馏塔等设备设计合理。中试丙烯醛水合单程转化率为45％～55％，3-羟基丙醛选择性达到了93％左右，3-羟基丙醛加氢收率接近100％，产品1，3-丙二醇的醛基质量分数降至5μg／g以下。与小试结果相比较，中试的水合选择性明显提高，加氢催化剂活性寿命延长。     

加入WTO后对中国会计业的影响

中国政府已于2001年12月正式加入做为当代世界规范和经济贸易关系最具权威的国际性组织WTO.加入WTO,对中国来说既是机遇,同时又是挑战,它的影响是全面的、全方位的.而对于中国会计业的影响也是深刻的,中国经济、中国企业要走向世界,中国的会计业也必须直面世界,按国际惯例行事,因此,深刻研究和分析加入WTO后对中国会计业的冲击、挑战以制定相应的政策、方针、准则就显得非常的迫切.     

USERS' TWO-DIMENSIONAL INTEREST AND ITS STORAGE METHOD

The users' interest can be mined from the web cache and can be used widely. The interest can be specialized by the two-tuple (term, weight) in the simple interest model, in which the association relations are not mined, and then the interest cannot be associated in expressing the users' interest. Based on analyzing the WWW cache model, this letter brings forward a two-dimensional interest model and gives the interrelated methods on how to store the two-dimensional interest model effectively.     

Nonlinear protein binding and enzyme heterogeneity: effects on hepatic drug removal

The kinetics of substrate removal by the liver and the resulting nonlinear changes in unbound fraction along the flow path at varying input drug concentrations were examined by a model simulation study. Specifically, we varied the binding association constant, KA, and the Michaelis-Menten constants (Km and Vmax) to examine the steady state drug removal (expressed as hepatic extraction ratio E) and changes in drug binding for (i) unienzyme systems and (ii) simple, parallel metabolic pathways; zonal metabolic heterogeneity was also added as a variable. At low KA, E declined with increasing input drug concentration, due primarily to saturation of enzymes; only small differences in binding were present across the liver. At high KA, a parabolic profile for E with concentration was observed; changes in unbound fraction between the inlet and the outlet of the liver followed in parallel fashion. Protein binding was the rate-determining step at low input drug concentrations, whereas enzyme saturation was the rate-controlling factor at high input drug concentration. Heterogeneous enzymic distribution modulated changes in unbound fraction within the liver and at the outlet. Despite marked changes in unbound fraction occurring within the liver for different enzymic distributions, the overall transhepatic differences were relatively small. We then investigated the logarithmic average unbound concentration and the length averaged concentration as estimates of substrate concentration in liver in the presence of nonlinear drug binding. Fitting of simulated data, with and without assigned random error (10%), to the Michaelis-Menten equation was performed; fitting was repeated for simulated data obtained with presence of a specific inhibitor of the high-affinity, anteriorly distributed pathway. Results were similar for both concentration terms: accurate estimates were obtained for anterior, high affinity pathways; an overestimation of parameters was observed for the lower affinity posteriorly distributed pathways. Improved estimations were found for posteriorly distributed pathways upon inhibition with specific inhibitors; with added random error, however, the improvement was much decreased. We applied the method for fitting of several sets of metabolic data obtained from rat liver perfusion studies performed with salicylamide (SAM) (i) without and (ii) with the presence of 2,6-dichloro-4-nitrophenol (DCNP), a SAM sulfation inhibitor. The fitted results showed that SAM sulfation was a high-affinity high-capacity pathway; SAM glucuronidation was of lower affinity but comparable capacity as the sulfation pathway, whereas SAM hydroxylation was of lower affinity and lower capacity.     

Disaster-readiness of medical facilities in Aichi Prefecture

One month following the Great Hanshin Earthquake of January 17, 1995, we conducted a survey of 173 hospitals in Aichi Prefecture to pinpoint problems related to their actual disaster-readiness and the medical backup systems in place to deal with such disasters. This study revealed that staff at 50% of the surveyed hospitals could reach the hospital within an hour, but that communication is almost entirely dependent on phone lines, suggesting that cordless/portable/mobile phones, radio systems, Internet, communications satellites and the like should be studied in the days to come for possible use as effective communication alternatives in times of disaster. Whereas 92% of the surveyed hospitals had manuals dealing with fire outbreaks, other areas were less well represented. For example, only 36.9% of surveyed hospitals had manuals for earthquakes, 31.7% had manuals for power outages and 14.2% had manuals to deal with flooding and water disasters. New manuals must be developed incorporating the key points garnered from experience (especially Hanshin) and be ready for use immediately. It is the time for each hospital to seriously rethink the measures it should take to deal with disasters.     

声光效应拉曼-内斯方程矩阵级数解法及声光调制器优化设计

提出一种求解正常声光相互作用拉曼 内斯 (Raman Nath)方程的矩阵级数解法 ,该解法直观方便且具有普遍性。计算结果表明 ,对Q =4 1π ,Bragg衍射的效率只有 97 5 % ;对非对称入射 ,以往的Raman Nath近似解误差较大 ;指出提高Bragg衍射效率的有效途径在于提高声光频率比并给出计算声光器件最优长度的计算公式。     

应用于生物医学的光声光谱技术的改进和实验研究

改进的光声光谱归一化技术，避免了普通的分光法归一化光声光谱技术中分束镜以及锁相放大器动态范围的影响和限制，实现宽光谱范围内准确的光谱测量。氙灯光源功率起伏用修正项修正，误差在5％以内，实现各次实验数据的可比性。     

光纤通信在市内接入网的应用

先说明市内接入网的单位用户和住家用户两大类使用通信和电视、交互型和分配型业务的要求不相同，相应地对光纤传输的应用须作不同的考虑，文中认为；光纤从市内交换局直连办公大楼是合乎现实需要的，而对于居民住家，宜选用光纤连至路边或光纤与同轴结合和适当利用无源光网络等方案，俟将来时机成熟才实行光纤连至每一家，文末有概括总结，说明接入网不同于长途网，接入网的光纤系统可以使用常规单模光纤，工作于波长1．3μm，而光放大器和波分多路系统不是普遍需要，但光电子集成在光端机中是必要的。     

烧结工艺对液相合成（SrPb）TiO3基陶瓷热敏特性影响的研究

本文在液相合成（ＳｒＰｂ）ＴｉＯ３粉的基础上，研究了升温速率、保温时间、烧结温度及降温方式对（ＳｒＰｂ）ＴｉＯ３基陶瓷的Ｖ型ＰＴＣ热敏特性的影响。实验表明：升温速率对其热敏特性影响不大，保温时间和烧结温度的作用是一致的，具有一最佳范围。而降浊方式对材料的热敏特性影响较大。综合各因素的影响，本配方中，样品的烧结制度定为：以２００℃／ｈ的速率升温，在１２５０℃保温１ｈ，炉冷至９５０℃，保温０．５ｈ，再     

地下通风系统管理的新技术——系统特征图

本文介绍系统特征图的原理与方法 ,及其推广应用的前景