岩土工程弹塑性物性辨识问题数值求解格式

本文提出了求解复杂结构弹塑性物性辨识问题的正则化最小二乘迭代反演算法。给出了差分近似导数的灵敏度计算格式。为克服不适定性带来的困难，并保证解的稳定性和合理性，提出了相应的数值处理方法。     

二维波阻抗反演在东海南部某工区的应用实例

由于白垩系和侏罗系年代老,埋藏深,储层孔渗条件差,导致地震剖面上反射界面较弱,分辨率低;加上二维工区面积大,井资料少等因素,使得该地区的储层预测工作很难开展。主要针对东海南部某二维工区中生代地层进行了地震波阻抗反演,对该工区可能存在的储层空间展布进行了预测,结果显示白垩系的顶部发育一套玄武岩层,底部发育一套含砾砂岩地层,主要集中在工区东南部构造上;白垩系中段以砂泥岩薄互层为主;上侏罗统储层物性较好,具有一定厚度和空间分布;中、下侏罗统存在较薄的致密砂层。     

澜沧江小橄榄坝滩整治试验研究

作者在分析小橄榄坝滩河床演变特点和碍航成因的基础上，针对小橄榄坝滩宽浅、分汉，且为急弯的河段特点，综合考虑其河床演变、碍航成因及航道整治目的等因素，制定了控制中枯水河势，稳定规划航槽及流路，兼顾河岸稳定和远期发展的整治原则。比较了在主导河岸采用丁坝群和长顺坝整治的效果与差别，认为主导河岸采用长顺坝可有效避免丁坝所带来的挑流、局部冲刷及由此产生的航槽冲刷不稳定、局部流态紊乱及比降分布不均等问题，可获得较好的整治效果。     

生物质无氧气化制氢系统的热力学计算

介绍了一种基于CO_2接受体气化法的生物质无氧气化制氢系统。采用热力学平衡模型,研究了以玉米秸这一典型生物质为原料时系统压力、温度、[H_2O]/[C]比、[Ca]/[C]比对制氢过程的影响规律。获得典型工况下,系统制氢效率对这几个参数的相对线性敏感性系数。结果表明,H_2浓度在一定范围内随压力升高而明显增大,同时H_2产量会有少量降低,过高的温度会明显降低H_2产量及浓度。综合考虑,合适的气化压力在1.3～2.5MPa之间,不同压力具有不同适合制氢的最高温度。[H_2O]/[C]比的提高可以促进H_2生成,但大于1.5之后,H_2浓度明显下降,合适的[H_2O]/[C]比在1.5～2.0之间。[Ca]/[C]比的增加有利于H_2产量及浓度的提高。线性敏感性系数的计算表明,计算工况下[H_2O]/[C]比对制氢效率的影响非常大,压力和温度的影响也比较显著,[Ca]/[C]比的影响为零。     

Optimization and performance prediction of a new near-zero emission coal utilization system with combined gasification and combustion

In accordance with the new near-zero emission coal utilization system with combined gasification and combustion, which is based on the CO₂ acceptor gasification process, the product gas composition of the gasifier and the combustor was calculated by means of thermodynamic equilibrium calculation software FactSage 5.2. Based on these calculations, the whole system efficiency calculation method that complies with the mass and energy conservation principle was established. To enhance the system efficiency, the system pressure and the gasifier carbon conversion ratio were optimized. The results indicate that the system efficiency increases with increasing pressure and gasifier carbon conversion ratio. After taking into consideration the influence of the pressure and carbon conversion ratio on the performance of the system, the gasifier and the combustor were synthetically studied. The optimum system pressure and carbon conversion ratio were obtained as 2.5 MPa and 0.7, respectively. The system efficiency could reach around 62.1% when operated in these two optimum parameters. If the advanced ion transport membrane (ITM) air separation technology is used, there would be an increase of another 1.3%. Translated from Proceedings of the CSEE, 2006, 26(9): 7–13 [译自: 中国电机工程学报]     

二(噁)英光降解研究进展

主要综述并总结了二噁英的光降解技术,包括二噁英标准物在各种基质中(包括有机溶剂、土壤、植被表面)的光解以及光催化降解;试验中产生的二噁英的光降解;实际存在介质中(如垃圾焚烧厂飞灰)二噁英的光解。最后提出了二噁英光降解今后的研究方向。     

味精粗料作为聚谷氨酸合成前体的培养条件优化

为降低聚谷氨酸生产成本,采用本实验室筛选得到的枯草芽孢杆菌,编号为CGMCC No.1250。考察了不同的谷氨酸钠替代品,味精粗料最佳,并考察了味精粗料的含量、碳源和氮源及其浓度、NaCl浓度、装液量以及温度等对-γPGA产量的影响。实验结果表明,对于该菌株,最适碳源和氮源分别是蔗糖和蛋白胨;在含有70 g/L蔗糖5、0 g/L蛋白胨、30 g/L NaCl,pH7.0,含味精粗料体积分数为26.6%(含谷氨酸120 g/L)的发酵液中,37℃,220 r/min培养24 h,-γPGA的产量达到41.7g/L。     

织物配色模纹的计算机辅助设计

通过建立配色模纹的数学模型，经VB6．0程序语言编程，推出由基础组织及色经色纬循环的配色模纹图，并同时可以实现其反推过程。     

环洞庭湖上游抽水蓄能调水刍议

洞庭湖区誉称鱼米之乡,上有湘、资、沅、澧四水汇入,现今各大河流均建有控制水库,但因受库容、淹没等条件限制,对于特殊的洪水、干旱,各水库单独调蓄,有时还有所不足。文章设想借用抽水蓄能联通上库,相接二个流域水库,相互补充调剂,以发挥原水库更大的效能。     

Quantitative approach to collaborative learning: performance prediction,individual assessment,and group composition

The benefits of collaborative learning, although widely reported, lack the quantitative rigor and detailed insight into the dynamics of interactions within the group, while individual contributions and their impacts on group members and their collaborative work remain hidden behind joint group assessment. To bridge this gap we intend to address three important aspects of collaborative learning focused on quantitative evaluation and prediction of group performance. First, we use machine learning techniques to predict group performance based on the data of member interactions and thereby identify whether, and to what extent, the group’s performance is driven by specific patterns of learning and interaction. Specifically, we explore the application of Extreme Learning Machine and Classification and Regression Trees to assess the predictability of group academic performance from live interaction data. Second, we propose a comparative model to unscramble individual student performances within the group. These performances are then used further in a generative mixture model of group grading as an explicit combination of isolated individual student grade expectations and compared against the actual group performances to define what we coined as collaboration synergy - directly measuring the improvements of collaborative learning. Finally the impact of group composition of gender and skills on learning performance and collaboration synergy is evaluated. The analysis indicates a high level of predictability of group performance based solely on the style and mechanics of collaboration and quantitatively supports the claim that heterogeneous groups with the diversity of skills and genders benefit more from collaborative learning than homogeneous groups.