岩土介质动静力学参数与介质物理组构参数之间的关系

岩土体是地质历史的产物,有着特定的物质组分和结构构造,从而表现出复杂的工程力学性质。为研究岩土介质动、静力学参数与岩土介质物理组构参数三者的关系,文章结合工程岩土体勘察评价,对岩土介质进行了一系列物理力学测试和波动测试,取得了一定量的测试数据。分析中特别关注了岩土介质的弹性波速与介质密度之间的关系。研究发现,岩样和土样波速与密度测试值在波速-密度参数空间中展现出了几种相对性:整体有序与局部混沌的相对性、分布域位置和结构的确定与域内参数随机分布的相对性、在某一分布域内整体样本无序与各类子样本有序的相对性。把握这几种相对性对于岩土介质的理论研究和工程应用都十分有意义。     

一株兼性嗜冷产甲烷杆菌的分离与系统发育学分析

从云南哀牢山泥土中分离出一株生长温度范围为7～40℃的兼性嗜冷产甲烷杆菌8-1.该菌株革兰氏染色阳性,直径0.2～0.3μm,长2～5μm,具有弯曲和微弯杆状两种形态,不运动,单生﹑成对﹑多数成聚集状态存在.能够利用H2/CO2和甲酸盐生长,不利用甲醇﹑三甲胺﹑乙酸和二元醇类.最适生长条件:温度为35℃,pH值为7.5～8.5,盐浓度为0 mol/L NaCI.最低生长的温度可达到7℃.菌株8-1与标准株Methanobacterium subterraneum strain A8p(=DSM 11074T)的16S rRNA基因序列相似性为99%.     

基于数据挖掘技术的超市顾客群研究

利用SPSS Clementine 10.1数据挖掘工具,遵循CRISP-DM模型的商业目标、数据理解、建立模型的流程对超市顾客进行分析研究。提出衡量超市客户忠诚度的忠诚度系数指标,建立忠诚度—盈利性顾客细分模型,运用k-means算法对超市顾客进行聚类分析,帮助超市企业准确识别不同类型的顾客群,尤其是忠诚的高盈利顾客。再利用所建立的序列分析模型分析顾客类别变化路径,预测顾客价值变化趋势,及早发现潜在价值顾客,使其尽早成为企业忠诚的高价值顾客,实现超市企业利润的有效提升,最终在日益激烈的商业竞争中立于不败之地。     

农田溪流人工深潭地貌格局暂态存储特征分析

2015年11月~2016年2月,以NaCl为示踪剂,在巢湖流域某一农田源头溪流开展了5次野外示踪试验,并据此计算溪流的物理特征参数和暂态存储指标;通过对深潭渠段与平直渠段相关指标的比较,解析人工深潭地貌格局的暂态存储特征.结果表明:1人工深潭地貌格局渠段A_s/A基本都较平直渠段更高,但其交换系数α却较平直渠段低一个数量级;2人工深潭地貌格局的暂态存储对于溶质滞留的影响较平直渠段大,但其流动水体的溶质滞留能力则较平直渠段弱;3尽管深潭地貌格局拥有相对较大的A_s/A比值,但对溶质运移转化的综合影响却低于平直渠段;4人工深潭的暂态存储指标F200med可以解释18.86%~26.05%的溶质行进时间,平直渠段可以解释5.28%~33.87%,且大部分情况下平直渠段都较深潭渠段更高;5深潭地貌格局与平直渠段在φ_w、φ_A和T_s方面差异明显,而在其他指标方面则区别不显著.     

Amnion rupture sequence in a first trimester missed abortion

We report the diagnosis of amnion rupture sequence made by sonography and fetoscopy during the first trimester of gestation in a case of missed abortion. The investigation revealed a demised fetus with the characteristics of 9 weeks of development. The early fetus had an amnion adhesion at the tip of the nose and strands of amnion wrapped around the terminal phalanges of both feet. No defects in addition to the face and limb involvement were identified. The karyotype was normal: 46,XX. In the reported case, fetoscopy allowed confirmation of the sonographic diagnosis of an amnion rupture sequence in the first trimester of gestation and consequently helped to clarify the cause of abortion in this case of early fetal demise. Copyright © 2001 John Wiley & Sons, Ltd.     

空空导弹环境试验顺序研究

综合考虑了环境试验的目的、特性和试验间的相互影响,提出了确定环境试验顺序所遵循的一般原则和几种常见试验项目顺序的安排建议,研究了空空导弹研制和生产的不同阶段的环境试验顺序。     

Continuous desulfurization and bacterial community structure of an integrated bioreactor developed to treat SO2 from a gas stream

Sulfide dioxide(SO2) is often released during the combustion processes of fossil fuels. An integrated bioreactor with two sections, namely, a suspended zone(SZ) and immobilized zone(IZ), was applied to treat SO2 for 6 months. Sampling ports were set in both sections to investigate the performance and microbial characteristics of the integrated bioreactor. SO2 was effectively removed by the synergistic effect of the SZ and IZ, and more than 85%removal efficiency was achieved at steady state. The average elimination capacity of SO2 in the bioreactor was 2.80 g/(m3·hr) for the SZ and 1.50 g/(m3· hr) for the IZ. Most SO2 was eliminated in the SZ. The liquid level of the SZ and the water content ratio of the packing material in the IZ affected SO2 removal efficiency. The SZ served a key function not only in SO2 elimination, but also in moisture maintenance for the IZ. The desired water content in IZ could be feasibly maintained without any additional pre-humidification facilities. Clone libraries of 16 S r DNA directly amplified from the DNA of each sample were constructed and sequenced to analyze the community composition and diversity in the individual zones.The desulfurization bacteria dominated both zones. Paenibacillus sp. was present in both zones, whereas Ralstonia sp. existed only in the SZ. The transfer of SO2 to the SZ involved dissolution in the nutrient solution and biodegradation by the sulfur-oxidizing bacteria.This work presents a potential biological treatment method for waste gases containing hydrophilic compounds.     

A Petrographic Investigation of two Sequential Extraction Techniques Applied to Anaerobic Canal Bed Mud

The application of sequential extraction procedures to determine metal speciation in sediments is fraught with uncertainty regarding what is actually dissolving or re-precipitating at each stage. In order to choose an appropriate scheme for the investigation of contaminated anaerobic mud two different sequential extraction procedures (Kersten and Förstner, 1986; Quevauviller, 1998) were investigated using a Cryogenic SEM (CryoSEM) technique coupled with energy dispersive X-ray analysis (EDXA). This enabled assessment of the degree of reagent selectivity and any re-precipitation associated with the respective methods. Analysis of the non-leached sediment revealed the most abundant authigenic minerals in order of decreasing abundance to be Fe²⁺-phosphate vivianite (Fe₃(PO₄)₂·8H₂O), mixed Fe, Zn, Cu sulphides, pyrite and calcite. After each stage of the sequential extraction the sediment residue was examined using CryoSEM. After extraction of the exchangeable fraction no obvious evidence of mineral dissolution was observed. Calcite was not completely dissolved during the carbonate extraction stage of either procedure. Vivianite began to dissolve in the carbonate extraction stage of both procedures and was completely dissolved by oxide extraction stage of both procedures. The sediment leached by acidified ammonium oxalate, contained abundant Fe oxalate crystals, suggesting that a large proportion of the Fe released from the vivianite has been re-precipitated. The Fe oxalate was then dissolved with the subsequent sulphide fraction. The technique used to extract the sulphide and organic fraction is the same in both schemes and no sulphide or metal rich organic matter was found in either residue.