脉冲式流量波动对厌氧氨氧化UASB反应器的影响

通过试验模拟不同幅度、不同频率的脉冲式进水流量波动,研究脉冲式流量波动对已稳定运行的厌氧氨氧化UASB反应器性能的冲击影响.结果表明,在脉冲波动幅度小于60mL/min（上升流速1.33cm/min）范围内,厌氧氨氧化UASB反应器表现出良好的适应性和承受力,甚至对于高频率的波动冲击,出水也可达到一级A标准,NH₄⁺-N和NO₂^--N去除率都基本维持在80%以上,总氮去除率维持在70%以上.而当脉冲的波动幅度为100mL/min（上升流速2.22cm/min）时,则UASB反应器的出水水质波动性大,随着波动频率的增大,反应器的适应时间增长,一直到波动频率为1.5h时,反应器出水NH₄⁺-N和NO₂^--N浓度难以稳定在5mg/L以下.随着波动幅度由40mL/min增大到60,100mL/min,反应器内污泥中厌氧氨氧化菌的丰度值和厌氧氨氧化菌占全细菌的百分含量均呈现先增多后减少的趋势,在波动幅度为60mL/min时均为最大,可能是由于此时污泥和基质的混合与接触更为高效,氮去除效率高,更有利于厌氧氨氧化菌的生长.     

电视、中波发射塔对电磁辐射环境的影响

通过对包头市城区历年的电磁环境监测,以及电视和中波发射塔周围电磁辐射情况,了解其环境质量状况和主要污染源。历年环境监测综合场强为0.30~0.47 V/m,年平均值为0.41 V/m。而广播和电视发射塔因距离而异,它们综合场强均值分别为1.26~3.43 V/m、1.44~5.34 V/m。虽然这些监测值都在标准限值之内,但可以看出广播和电视发射塔对电磁辐射综合场强的影响极大。     

电磁屏蔽织物孔洞区域金属纤维排列特征分析

本文介绍了电磁屏蔽织物孔洞区域金属纤维排列对屏蔽效能的影响,通过提取孔洞区域金属纤维,并与正常织物中金属纤维的排列进行对比,给出了定量表述金属纤维特征的参数,如密度、取向度和整齐度等,描述了孔洞区域金属纤维的排列特征。根据定量表述参数,结合织物样品屏蔽效能测试结果,对比金属纤维参数不同的织物样品屏蔽效能测试结果,得出孔洞区域金属纤维的密度、取向度和整齐度不同,有孔洞织物屏蔽效能也不同的结论。     

电磁屏蔽针织服装屏蔽作用的影响因素及机理

本文简述了电磁辐射的危害,论述了电磁屏蔽服装的一般原理。结合前人的研究,针对针织服装特点详细分析了织物厚度、线圈长度、针织组织、服装结构设计等对屏蔽作用的影响规律及机理。最后,提出织物组织结构参数与屏蔽纤维含量、屏蔽纤维之间孔隙的关系,屏蔽纤维含量与屏蔽纤维之间孔隙的合理配置是针织物电磁屏蔽效能研究的关键。同时,进行电磁屏蔽针织服装研究时可以结合人体模型并增加服装结构研究的切入点。     

雷管自动装配线上袋式除尘器的设计和研究

以军民两用雷管主要填充物黑索金为研究对象,详细论述了小型低压脉冲袋式除尘器在雷管自动装配线上的应用,及该结构中几个关键点的设计。     

大学生受电脑电磁辐射的研究

为了研究大学生受电脑电磁辐射的实际状况,采用EMR300电磁辐射分析仪,对电脑电磁辐射在100kHz～3GHz的电场强度值(V/m),进行了实验室研究性监测和宿舍、机房内的现场监测.监测的结果表明:宿舍中心处电磁辐射环境强度(100kHz～3GHz频率范围内的综合电场强度)低于0.5V/m;距离显示器屏幕前方0.4m以上操作电脑,则眼睛处辐射强度在安全值内.而目前,机房内台式电脑按行紧密摆放,前排电脑操作者后脑正对后一排电脑显示器突出的后部处,在后脑处辐射强度可超过10V/m;此外,学生宿舍空间拥挤,鼠标、键盘通常与显示器近距离摆放在一起,造成显示器辐射与键盘、鼠标自身辐射叠加,导致在键盘和鼠标处手掌受到的辐射强度大,不容忽视.     

Influence of phytoplankton on complexing capacity of seawater†

Differential Pulse Anodic Stripping Voltammetry (DPASV) was employed to measure Apparent Copper Complexing Capacity (L_t) and Stability Constants (K_s) of related cupric complexes of cell exudates of the phytoplanktonic alga Dunaliella salina. Three natural seawater samples collected 0.1, 2, 5 miles off the Tyrrhenian coast were used as culture medium. The measurements were carried out 1h and 7 days after the inoculum. Furthermore, on one culture the medium was passed through C₁₈‐SEP‐PAK cartridges in order to separate the cell exudates. The results show that Dunaliella salina influences the value of L_t but does not affect the value of K_s . The C₁₈SEP‐PAK retain only 50% of the ligands produced by the cells and capable of complexing copper.     

Polarographic investigations on the complexation of cadmium and zinc by thiol peptides

Complex formation of Cd²⁺ and Zn²⁺ with thiol derivatives has been investigated by differential pulse polarography. The binding of Cd²⁺ and Zn²⁺ with cysteine (CySH), glutathione (GSH) and the model peptide N‐acetyl‐cysteine‐methylamide (ASH) reveals different stoichiometry. Thus, Cd²⁺ forms 1:1 and 1:2 complexes with CySH while 1:2 and 1:4 complexes have been observed with GSH and ASH, respectively. Overall formation constants of Cd²⁺ with CySH (Iogβ ₂ 15.3) and with GSH (Iogβ5₂ 14.4) have been estimated using competitive complexation with nitrilotriacetic acid (NTA). Investigation of competition between Zn²⁺ and Cd²⁺ for the thiol complexation has underlined the role played by the amino group in CySH for the stabilization of Zn complexes in contrary to Cd complexes.     

Quantification of metallothionein in whole body gammarus locusta (crustacea: amphipoda) using differential pulse polarography

A polarographic method was optimised for the quantitative determination of metallothionein (MT) in whole body Gammarus locusta (Crustacea: Amphipoda). The identity of the MT-like proteins was examined using electrophoretic analysis (SDS-PAGE) and induction studies (water-borne exposures to copper). The MT-method was then used to examine changes in MT levels over the lifetime (juveniles, sub-adults and adults) of a laboratory population of G. locusta; copper (Cu) and zinc (Zn) body burden were also measured by flame atomic absorption spectrometry. MT was quantified by heat-denaturation of 30?000?g supernatants (to remove the bulk of non-MT proteins) followed by differential pulse polarography (DPP) to measure sulphydryl-group containing proteins. DPP proved to be a sensitive and reliable method to quantify heat-stable total sulphydryl-proteins. The majority of the latter was indicated to be MT from SDS-PAGE and induction studies. SDS-PAGE revealed a putative MT of 23?±?0.6?kDa app. mol. wt., consistent with the average size of dimeric MTs (10–20?kDa) found in several aquatic invertebrate species. Copper-exposure revealed parallel increases in the amounts of 23?kDa protein and total sulphydryl-proteins. Levels of whole body MT (rabbit pure MT as standard) range between 1.3 and 2.3?mg?g^?1 dry wt. over the lifetime of G. locusta. Sex-related changes in MT status were observed, the levels in females being 1.6 times higher than in males (p<0.05). Copper and Zn body content changed over the lifetime of G. locusta, the levels in juveniles (p>0.05) and sub-adults (p<0.05) being higher than in adults. It is concluded that the inclusion of MT in ecotoxicological studies with amphipod crustaceans require some caution with respect to the stages of moulting and/or sexual maturation of organisms, but this should not provide any major impediment in its use in metal pollution monitoring.     

不同类型除尘器改造为脉冲除尘器技术

介绍了除尘器改造的原则、技术和方法,并结合多个除尘器改造的工程实例,分享了不同类型除尘器改造为脉冲除尘器成功经验。经过改造的除尘器能够满足集气吸尘罩处风量的要求,减少了除尘器出口排放浓度,降低了除尘器的运行阻力。