土壤环境中具有Keggin结构的Al13草酸盐胶体合成及其表征

采用XRD,FTIR和MAS27 Al NMR方法表征从Al13溶液中合成的草酸盐胶体.结果表明:胶体具有明显的XRD衍射峰,有别于常见的Al系及其草酸盐沉淀;位于810cm-1处络合物中Al-O伸缩振动证明胶体是由Al13和草酸根直接络合形成;红外光谱中位于725cm-1处的(Al-O)Td键和固体核磁共振波谱中位于约61ppm处的Al(O)4特征峰共同证明胶体具有特殊的Keggin结构,高pH(=7.8)环境下Al13草酸盐胶体仍能保持Keggin结构;经过化学分析,该草酸盐胶体化学式为AlO4Al12(OH)24(H2O)12(C2O4)7/2.     

深海环境对激光选区熔融Ti6Al4V应力腐蚀断裂行为的影响

目的 比较增材制造技术制备的Ti6Al4V相比于传统锻造材料在深海环境下耐应力腐蚀性能的差异.方法 利用慢应变速率拉伸、扫描电镜观察、XPS分析,对比了锻造的Ti6Al4V合金(WT-Ti6Al4V)和激光选区熔融技术制备的Ti6Al4V合金(SLM-Ti6Al4V)在海洋环境中不同静水压力(0、4、8 MPa)、温度...     

Total release fogger exposures reported to Texas poison centers, 2000–2009

Total release foggers or “bug bombs” are products designed to fill an area such as a home or workplace with insecticide. Because of their method of action, unintentional exposures may occur. Cases for this retrospective study were all fogger exposures reported to Texas poison centers during 2000–2009. The distribution of cases was identified for various demographic and clinical factors. There were 2855 fogger exposures. Among the patients 56.0% were females and 69.5% were 20 years or older. Considering the exposure circumstances 95.6% were unintentional and 62.2% occurred through inhalation. The management site was 75.2% on site. The medical outcomes were no effect (11.8%), minor effect (25.1%), moderate effect (7.4%), major effect (0.1%), not followed (no effects expected) (3.5%), not followed (minimal effects expected) (39.3%), not followed (potentially toxic) (4.9%), and effects probably unrelated to exposure (7.7%). The most frequently reported clinical effects were cough (25.4%), vomiting (13.3%), nausea (9.2%), dyspnea (8.7%), throat irritation (7.9%), and headache (5.6%). The public needs to be educated about the potential hazard of exposures to foggers. However, most fogger exposures reported to poison centers are not likely to be seriously toxic and can be managed at home.     

NO和H2O2对大豆幼苗铝毒害的缓解效应及其相互作用

NO和H₂O₂作为信号分子参与植物对非生物胁迫的响应,为了确定NO和H₂O₂介导的大豆耐铝作用以及二者的交互作用,以浙春3号大豆为材料,分析了铝毒胁迫下根尖内源及外源NO和H₂O₂对大豆铝毒的缓解效应,并研究了NO和H₂O₂代谢相关酶的活性变化, 其中外源NO由SNP(亚硝基铁氰化钠,Na₂[Fe(CN)₅NO]·2H₂O)提供. 结果显示:Al处理显著抑制大豆根生长,促使Al在根尖积累并显著提高大豆根尖内源w(NO)和w(H₂O₂). 在H₂O₂₊Al、SNP+Al和H₂O₂₊SNP+Al处理下,大豆根相对伸长率比单独Al处理下分别升高了64.6%、63.5%和69.5%,根尖w(Al)则分别减少了34.6%、36.8%和32.9%,表明NO和H₂O₂对铝毒害均具有缓解作用.外源NO能够促使根尖内源H₂O₂显著积累,降低POD(过氧化物酶)活性,而外源H₂O₂对内源根尖w(NO)无影响.NO和H₂O₂在缓解铝毒的信号途径中存在信号互作,NO处于H₂O₂的上游,其通过POD活性调节内源w(H₂O₂).      

彩色夹心板在噪声治理中的应用

在噪声治理中,采用彩色夹心板作隔声构件,在武汉总厂涂装分厂制冷站应用成功,用响度指数这个绝对数表示,治理前后噪声总响度降低79.65%,隔声效果非常好,达到了预期的目的.     

还原剂对Ag/Al2O3催化剂上NO还原的影响

在富氧条件下,研究了CH4、C3H8、C 3H6、C8H18、CH 3OH、C2H5OH,以及C3H6与CH3OH、C3H6与C2H5OH组合作还原剂时,在Ag/Al2O3催化剂上NO的还原活性.结果表明,不同碳氢化合物还原NO的活性温度存在较大的差异.SO2的存在会导致CH3OH还原NO的活性提高,而其他碳氢化合物还原NO的活性降低.随着还原剂浓度提高,NOx转化率增大,不过,过高的还原剂浓度对NO还原不利.组合使用CH3OH与C3H6或C2H5OH与C3H6作为还原剂,能显著拓宽活性温度范围.     

聚合氯化铝Al13模型化合物的量子化学计算

采用MNDO方法对聚合氯化铝(PAC)中的Al13模型化合物进行了量子化学计算.结果表明:作为电子给体化学反应的活性点主要是羟基氧原子或羟基桥键氧原子,作为电子受体化学反应的活性点主要是六配位的Al.羟铝比(OH/Al)大的模型物, 铝氧四面体中Al所带正电荷明显减少,表明OH/Al比大时将有更多的电子流向Al(Ⅲ).与此同时,羟桥Al-O的键级会逐渐减小,有利于PAC的水解.水解过程实际上是通过OH-的HOMO和被水解形态组分的LUMO相互作用使Al-O(H2O)键断裂形成Al-O(OH)键的过程.     

Al(Ⅲ) speciation distribution and transformation in high concentration PACl solutions

Effects of Al(Ⅲ) concentration and pH on the speciation of Al(Ⅲ) in polyaluminum chloride (PACl) solutions especially on the Al13 fraction were investigated. A series of PACl samples were prepared over the range of Al(Ⅲ) concentration from 0.01 to 2.0 mol/L with the B (OH/Al ratio) value from 1.0 to 2.5 by forced hydrolysis of AlCl3. The samples were characterized by ferron assay,pH and 27Al NMR. It was shown that the Al(Ⅲ) concentration had a dramatic effect on the hydrolysis processes and the species distribution of PACl was in relate to the decrease of pH. The fraction of Al species, Alb (or Al13) decreased and Alc increased with increase of total Al(Ⅲ) concentration. Under the condition of Al(Ⅲ) 2.0 mol/L, B = 2.5, the pH value was 2.73 and no Al13 could be detected. During diluting and aging, the species distribution evolved. The Al13 could then be detected again and the amounts increased with time. If the diluted samples were concentrated by freeze dry at -35℃ or heating at 80℃, the pH value and Al13 content would decrease with the increased concentration. It demonstrated that the key factor for formation of Al13 in concentrated PACl was pH value.     

Effects of chitosan on growth of an aquatic plant (Hydrilla verticillata) in polluted waters with different chemical oxygen demands

Effects of chitosan on a submersed plant, Hydrilla verticillata, were investigated. Results indicated that H. venicillata could prevent ultrastructure phytotoxicities and oxidativereaction from polluted water with high chemical oxygen demand (COD). Superoxide dismutase (SOD) activity and malondialdehyde (MDA) contents in H. verticillata treated with 0.1% chitosan in wastewater increased with high COD (980 mg/L) and decreased with low COD (63 mg/L), respectively. Ultrastructural analysis showed that the stroma and grana of chloroplast basically remained normal. However, plant cells from the control experiment (untreated with chitosan) were vacuolated and the cell interval increased. The relict of protoplast moved to the center, with cells tending to disjoint. Our findings indicate that wastewater with high COD concentration can cause a substantial damage to submersed plant, nevertheless, chitosan probably could alleviate the membrane lipid peroxidization and ultrastructure phytotoxicities, and protect plant cells from stress of high COD concentration polluted water.     

危险品运输车辆监控预警系统设计与开发

遵循危化品运输车辆有关标准和规范,集成计算机、控制、通讯、空间定位和安全管理等技术,提出车辆监控预警系统建设的总体结构和功能框架,阐述了系统的7个特点。设计和开发了车载终端硬件组成、自动监测、报警、安全保护、数据及音视频信息交互等功能以及监控中心的组成与结构、系统性能和功能。给出了异地危化品运输车辆的监控方式,并对5种无线通讯方式进行比较。