煤气中轻质油的测定

文章用实践证明，选用活性炭作为吸附剂，用于测定煤气中的轻质油是可行的，且具有装置简单、操作方便、测定时间短、精密度好等优点。     

预防校园火灾事故，创建平安校园

运用事故隐患转化理论对校园火灾事故进行分析,从而提出应对措施,以确保平安校园的创建。     

试论校园规划的整体性与延续性——以常州市戚墅堰区实验中学规划设计为例

在中学校园规划中引入了整体性与延续性的设计理念,并指出整体性是校园建筑在空间上的一体化而延续性则是校园建筑在时间上的传承性。该文以常州市戚墅堰区实验中学的规划设计为例,进一步探讨了整体性与延续性理念在实践中的应用.     

Impacts of chelate-assisted phytoremediation on microbial community composition in the rhizosphere of a copper accumulator and non-accumulator

Chelate-assisted phytoremediation has been proposed as an effective tool for the extraction of heavy metals from soil by plants. However, side effects of the addition of chelate to soil microbial community are usually neglected. We studied the potential effects of chelate (glucose and citric acid) amendment on phytoextraction of copper and microbial community composition in soil under laboratory conditions. A copper (Cu) accumulator, Elsholtzia splendens, and a non-accumulator, Trifolium repens, were grown on a sandy loam soil containing 317 mg kg(-1) Cu. Microbial community compositions were analyzed by using polymerase chain reaction-denaturing gradient gel electrophoresis (PCR-DGGE). The results showed that the biomass of E. splendens grown with the chelate did not differ from that of the control. Addition of citric acid decreased the biomass of T. repens in comparison to that of glucose treatment. Application of glucose or citric acid significantly increased the extractable Cu concentration in planted and unplanted soils. Concentrations of Cu in the shoots of E. splendens were 2.6, 1.9 and 2.9 times of those of T. repens under no chelate, citric acid and glucose treatments, respectively. PCR-DGGE fingerprint analysis revealed that there were negative correlations between bacteria diversity and NH4NO3 extractable Cu under glucose or citric acid treatment. It was indicated the amendment of glucose to the plant T. repens increased the bacteria diversity in soil as compared to that in soils of non-chelate treatment. The above results indicated chelate addition facilitated phytoremediation of soil Cu and did not have a negative effect on microbial community.     

构建绮丽多姿的绿色空间 营造最佳人居环境——“成都生态园林城市”解读

园林在成都至今已有2300多年,即使以1911年第一座公园——少城公园作为发轫,公园也已伴随成都走过了九十多年的沧桑。从寥若晨     

NUMERICAL SIMULATION OF ULTRASONIC NON-DESTRUCTIVE TESTING FOR WELDS

A computer simulation technique for ultrasonic propagation is utilized for the simulation of ultrasonic nondestructive testing (NDT).In this paper,one goal of the simulation is to compute ultrasonic field radiated by arbitrary transducers into pieces under examination.The other simulates a testing experiment.The simulation approach is based on the model for the computation of the ultrasonic field in isotropic media radiated from actual NDT transducers.After the field is known, remaining to be modeled is the interaction between this field and the scatters (defect) and the echo structure. The model of beam-defect interaction is based on the Kirchhoff‘s diffraction approximations theory applied to elastodynamics.We assumed that the incident wave fronts on the defect are plane in the case of a focused immersed transducer and material is isotropic and homogeneous.The simulating results demonstrate that the model in ultrasonic NDT of welds is practical in further research and useful in optimizing testing configurations.     

泡沫夹层结构的模压共固化成型工艺及参数选定

在分析夹层结构的基础上,概述了常用芯材包括铝蜂窝、NOMEX蜂窝和聚甲基丙烯酰亚胺泡沫塑料的性能和特点,介绍了刚性泡沫夹层结构常用的成型工艺,详细阐述了刚性泡沫夹层结构的模压共固化成型工艺及相关参数的选定。     

玻璃微珠填充PP结构与性能研究

用一步法和二步法两种混合工艺,研究了经过表面预处理的玻璃微珠填充PP的力学性能。结果表明,经过适当表面处理的玻璃微珠可以通过熔融共混均匀分散在PP中,粒子与基体界面结合良好。填充体系随着玻璃微珠含量的增加,拉伸强度增大,冲击强度下降。流动性随着玻璃微珠含量的增加而增大,然后随之下降。     

高合金钢管穿孔顶头的失效分析

介绍了高合金钢管穿孔顶头的主要失效形式,对失效顶头断口进行了SEM和光学金相分析、X射线荧光光谱化学成分分析等测试,探讨了顶头开裂的主要原因。通过适当调整Nb、Co、W等元素的含量,提高顶头铸造质量等,使穿孔顶头的使用寿命有所提高。     

退火对Cu50Zr42Al8非晶合金电阻的影响

采用惠更斯电桥法和X射线衍射技术测试了Cu50Zr42Al8块状非晶合金在不同温度(500~600℃)保温20min和550℃保温不同时间(10~60min)条件下的电阻值与结构变化。研究发现,Cu50Zr42Al8块状非晶合金的电阻值在接近晶化温度Tx的515~520℃温度区间附近增加得较快,呈现出电阻极大现象,且随着退火温度的升高和保温时间的延长,电阻值均呈现出先增大后减小的变化趋势。