Simulation on the Characteristics of Flow Pattern in Sprial uP-flow Reactor

In order to analyze the reason why the Spiral Up-flow Reactor system has excellent removal effect of COD, N and P, the authors use PHOENICS, a computational fluid dynamics program, to investigate the hydraulic characteristics and flow model of the anaerobic part of Spiral uP-flow reactor. The result shows that the fluid in the reactor unit flowed upward by the spiral way, and that flow pattern was combined by plug flow and complete-mix flow, and that the percentage of plug flow was about sixty-five percent. Spiral Up-flow Reactor units the Characteristics of PFR and CSTR, which makes it work well.     

明甪直天王殿松木斗拱振动台试验研究

以甪直保圣寺天王殿斗拱为参考对象,进行无缩尺松木斗拱模型的地震台试验研究。通过对斗拱的加速度与动力放大系数变化趋势、斗拱在振动过程中位移响应变化特征、斗拱变形最大时刻和各构件变形最大时刻的滑移位移和回转位移数值对比分析,得出以下结论：地震加速度用于衡量地震烈度,并不能直接反映斗拱试件的最大变形;振动频率的变化对斗拱回转变形的变化起重要作用,振幅是决定各构件水平滑移的主要因素;各构件变形最大值与斗拱整体变形最大值具有很强相关性,其中栌斗和华拱的回转变形对斗拱的整体变形而言,处于支配地位;斗拱的华拱连下昂部分主要起装饰作用,其榫卯连接节点位置在振动过程中较为薄弱,在对实际文物维护修缮过程中应引起重视并采取相关加固措施。     

烷基-二醇基硅胶填料的合成及对莠去净类除草剂的在线分离

三步合成了烷基-二醇基硅胶(ADS)色谱材料，首先用γ-缩水甘油醚氧丙基三甲氧基硅烷把功能基团键合到硅胶基体上，再把该环氧化硅胶与硬脂酸反应以制备酯型十八烷基反相填料，最后在20MPa压力下装成色谱预柱(35×4.6mm I.D)。用该预柱通过六通阀后接ODS分析柱(250×4.6mm I.D)，构成中心切割二维HPLC。该系统能对具有一定疏水性的化合物进行在线富集，实现环境及生物复杂样品直接进样分离分析。使用该系统对尿中的莠去净和西玛津残留进行了分离分析，以含有0.1%乙酸的酸性水缓冲液对加标尿液中莠去净类化合物保留在预柱上，干扰分析的大分子被排阻而无保留通过，其它干扰分子保留小而通过，再切换六通阀，以乙腈和0.1%乙酸水溶液进行梯度洗脱，进而在下一级ODS分析柱上进行分离（紫外检测225nm），两种除草剂的分离分析取得了良好的定性定量结果     

Measurements to Protect Owners'' Benefits under the Non-price Bottom Bidding

Investment on construction projects has become an important factor in improving the development of economy in China.The non-price bottom bidding is a representation that the investment on projects is becoming standardized.During the years of trying out the non-price bottom bidding,the colluding in bidding or bidding below the cost has happened several times,which have damaged the benefits of owners.To solve theses problems,this paper firstly studies the reason of these problems-the failure in the normal relationship between principal and agent.Then,some measures have been presented as follows: building systematic and scientific system of qualification prejudication,judging behaviors of colluding in bidding and bidding below the cost with reason and providing a surety mechanism of the project.The authors hope that these measures are beneficial to non-price bottom bidding.     

Distributed Power Flow Method Based on Ward Equivalent

With interconnecting and developing of power system, the problem of power flow computation on dispersed data resource need to be solved. A new distributed computation method of power flow based on Ward equivalent is presented. According to master-slaver splitting principle, multi-area interconnected power system is divided into master-slaver areas. Boundary buses in different areas are defined as different bus-types. Neighborhood areas are equivalent by Ward equivalent principle, and the equivalent injection power and equivalent impedance are worked out. Power flows from master area to slaver areas are solved by Newton method, and the equivalent injection power and equivalent impedance on the boundary are modified by their solutions. The process above repeats until to convergence. The proposed distributed power flow method takes full advantage of the information of power, voltage, network configuration in neighborhood areas, so it is better on convergence and quality of solution. The proposed algorithm is testified by IEEE 14-bus system and a practical 181-bus system.     

NETWORK FEOW APPROACH TO RELIABILITY EVALUATION IN IARGE SCALE NETWORKS BY MIXING INCREASING ELOW WITH DECREASING FLOW

Based on the maximum flow principle about networks, a network flow approach to reliability evaluation in large scale netwerks ty mixing inereasing flow with decreasing flow is proposed in this paper.This approach gets the initial flow of each branch in a r.etwork associated with a state of the retwork by decreasing flows of some branches correlative to another state of the network.As a result, the number of flow compute required can be reduced enormously.The numerical example shows that the approach is powerful. The comparison of this approach with the minimal cutset one is also given in this paper.     

Analysis on Limitation of Present Urban Planning in China

In urban design, only by continuous and dynamic research work from design to finally putting it into practice, can we made good control on city appearance. This article analyzes nowadays defects in our urban design from two aspects as the result establishment and validated control, and tries to conceive a feasibility plan to solve the problem.     

Current Status of DIMOX in Synthesizing Al/Al2O3 by Aluminum Alloy

The processes, microstructures, properties and mechanisms of DIMOX in synthesizing Al/Al 2O 3 by Al-Mg-Si alloy are reviewed and their problems are considered mainly as following:non_homogeneous oxidation growth of Al/Al 2O 3 at the surface of melts and the porosity of Al/Al 2O 3 limites structural application of Al/Al 2O 3 composite. The mechanisms and models of microchannel,magnesium action,silicon action,and induction are outlined. Several problems which need to be noticed are pointed out,which are diffusion and transfer of oxygen in aluminium melts;the role of MgO and MgAl 2O 4 at outer layer;the reaction feature of solid_gas in the oxidation microstructures of Al_Mg_Si alloy;SiO 2 induction mechanism of silicon and its correlation with the mechanism of magnesium action in Al_Mg_Si alloy.     

Artificial Neural Networks Models for Flow Stress during High Temperature Plastic Deformation of Al-Li Alloy

Using gained experimental data to develop the models of stable flow stresses at high temperature plastic deformation by statistical methods for alloy materials, precision of the models is poor and at the same time the processes of modeling are complicated with great workload. On the basis of the data obtained on Gleeble-1500 Thermal Simulator,the predicting models for the relation between stable flow stress during high temperature plastic deformation and deformation strain, strain rate and temperature for 1420 Al-Li alloy have been developed with BP Artificial Neural Network method. The results show that the model on basis of BPNN is practical and it reflects the real feature of the deforming process. It states that the difference between the real value and the output of the model is in order of 5 percent.