基坑开挖与临近桩基相互作用分析

基坑开挖时临近建筑物的桩基础将受到开挖引起土体位移的作用, 导致桩身产生附加应力、弯矩和侧向位移。文中采用三维弹塑性有限元法, 模拟无支撑基坑开挖与临近桩基的相互作用。对比分析了临近桩基对基坑开挖所引起土体变形场的影响, 并讨论了基坑的空间效应、开挖深度、支护墙刚度、桩基和基坑距离、桩基刚度和桩头约束条件等因素对临近桩基附加侧向位移和弯矩的影响, 得出了一些有意义的结论, 可为分析基坑开挖对临近桩基影响时提供一定的理论指导。     

水平受荷桩的耦合算法

目前,计算水平受荷桩基时较为流行的是p-y 曲线法和Poulos 弹性理论法。本文在p-y 曲线法和Poulos 弹性理论法的基础上,提出一种能够考虑两者优点的耦合算法。根据p-y 曲线法分析得出相对于不同土体应力状态的弹性模量,利用分析得出的弹性模量,采用Poulos 弹性理论法考虑桩土之间的相互作用。实例分析表明,提出的耦合算法能够较为有效地分析水平受荷桩基。     

软土地基上工业厂房堆场的地基处理优化分析

软土地基中工业厂房的柱下桩基在长期堆载作用下易产生较大的侧向位移和位移累积，从而引起厂房出现危险甚至坍塌。本文采用有限元法，通过对不同的地基处理方案进行对比分析研究，结合某工业厂房堆场的地基处理优化设计，讨论分析了软土地基中工业厂房堆场的地基处理措施与方法。     

买卖合同争议案例

周律师:您好!000吨至南美南方某进出口公司(卖方)出售一级大米10,船时货物经公某国贸易公司(买方),合同按FOB术语成交,装及时向证机构检验,符合合同规定的品质条件,卖方在装船后买方发出装船通知。但是,在运输途中由于遭遇恶劣气候海浪目响泡,品质受到影。当货物到达的过大,致使大米被海水漫求售,因而买方要卖方赔偿差港后,只能按三级大米的价格出价损失。问题:负1、卖方是否应对该项损失责,为什么?方易术语成交,卖是否应对该项2、如以CFR或者CIF贸损失负责,为什么?主3、买方的损失可以向谁张索赔?     

连续有机负荷冲击对SBR系统的影响

通过检测SBR系统中COD浓度和污泥特性的变化,研究了连续多个周期的有机负荷冲击对SBR系统运行的影响.结果表明,在正常进水的周期有机负荷为0.02 kgCOD/(kgMLVSS·h)的条件下,当周期有机冲击负荷为0.20 kgCOD/(kgMLVSS·h)时,后一冲击周期的出水COD值均比前一冲击周期的要高,并表现出两种不同层次的增长,为此首次提出了"贮存-利用(增殖)"模型进行解释;当周期有机冲击负荷为0.10 kgCOD/(kgMLVSS·h)时,SBR系统能够耐受连续多个周期的高有机负荷冲击;当周期有机冲击负荷为0.23 kgCOD/(kgMLVSS·h)时,在不排泥的情况下,活性污泥的快速增长可使SBR系统快速适应进水COD浓度的增加.     

广播电视卫星地球站抗干扰监控技术浅探

在干扰表现形式、干扰判断指标及干扰过程的分析进行分析的基础上,采用专用解码器技术与闭环控制技术设计方案,通过下行信道参数与上行信道参数判断技术,能够真正提高卫星广播电视地球站干扰判断的准确性与处理的及时性,进而实现自动化运行管理.     

Phenotypic and genetic characterization of a novel strain of Acidithiobacillus ferrooxidans （AF2）

A comparative study on the phenotypic and genetic characteristics among Acidithiobacillus ferrooxidans (AF2), a typic strain ATCC23270 and a previously isolated strain AF3 was performed. AF2 can use ferrous ion (Fe²⁺) or elemental sulfur (S⁰) as sole energy source, but oxidizes S⁰ more effectively than Fe²⁺, which is different from ATCC23270 and AF3. The G+C content of AF2 is 51.8% (molar fraction), however, ATCC23270 and AF3 strains have G+C content of 63.7% and 64.8% (molar fraction), respectively. The DNA-DNA hybridization results show that AF2 has 41.53% and 52.38% genome similarity to ATCC 23270 and AF3, respectively, but AF3 has a high genome similarity of 89.86% to ATCC 23270 strain. Rusticyanin (rus) and subunit III of aa₃-type cytochrome oxidase (coxC) genes are not detected in AF2, but Fe²⁺ oxidase (iro) gene can be detected. To understand the genomic organization of iro gene, a cosmid library of AF2 genome was constructed and iro gene-containing clone was screened. The sequencing result shows that although the nucleotide sequence of iro gene in AF2 is completely identical to that of ATCC 23270 strain, its genomic organization is different from that of ATCC 23270. In AF2, iro is located at downstream of purA gene, while it is located at downstream of petC-2 gene in ATCC 23270 strain. These results indicate that AF2 is a novel strain of A. ferrooxidans, and that phenotypic differences among the strains of A. ferrooxidans are closely correlated with their genetic polymorphisms.     

Aerobic biodegradation of di-n-butyl phthalate by Xiangjiang River sediment and microflora analysis

Di-n-butyl phthalate (DBP), one of phthalate acid esters (PAEs), was investigated to determine its biodegradation rate using Xiangjiang River sediment and find potential DBP degraders in the enrichment culture of the sediment. The sediment sample was incubated with an initial concentration of DBP of 100 mg/L for 5 d. The biodegradation rate of DBP was detected using HPLC and the degraded products were analyzed by GC/MS. Subsequently, the microbial diversity of the enrichment culture was analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). The results reveal that almost 100% of DBP is degraded after merely 3 d, generating two main degraded products: mono-butyl phthalate (MBP) and 9-octadecenoic acid. After a six-month enrichment period under the pressure of DBP, the dominant family in the final enrichment culture is clustered with the Comamonas sp., the remaining are affiliated with Sphingomonas sp., Hydrogenophaga sp., Rhizobium sp., and Acidovorax sp. The results show the potential of these bacteria to be used in the bioremediation of DBP in the environment.     

OCT—M加氢技术的工业应用

介绍了九江分公司原600kt／a柴油加氢装置应用OCT—M技术对装置进行改造的情况。通过对催化稳定汽油轻重切割、应用FGH-21／FGH-31催化剂、增设加氩汽油部分内循环流程及临氢系统注氨等设施，把装置改造为400kt／a的OCT—M催化汽油选择性加氢脱硫装置。运行结果表明：硫质量分数为1100ug／g；烯烃体积分数为43．3％；研究法辛烷值93．0的催化汽油经过加氢后，产品汽油硫质量分数达到240ug／g、烯烃36．8％、研究法辛烷值91．4。     

安钢2号高炉大修开炉快速达产实践

安钢2号高炉大修期间采用多项新技术和新设备,确定合理开炉工艺参数,科学管理、周密准备,顺利开炉成功。开炉后,快速达产,取得了较好的技术经济指标。