水系区域化工项目突发性水污染的原因与对策

基于国内外对突发性水污染问题的相关研究,对我国水系区域化工项目突发性水污染事故的特点和原因进行了分析,详细论述了区域化工项目安全与环境准入的不足,进而提出了完善水系区域化工项目安全环境准入的几点建议.     

基于土地权属的地块细分研究——以太原市绒织印染厂控规修改为例

土地权属是编制控规的重要依据,在传统的控规地块细分过程中,土地权属仅作为一项技术依据,其法律效力没有得到应有的重视。以太原市绒织印染厂控规修改为例,基于土地权属对控规编制中的地块细分问题进行了探讨,提出了公平、协商、模拟3条原则。     

Skin collagen fiber-based radar absorbing materials

By using skin collagen fiber (CF) as raw material,Schiff base structure containing CF (Sa-CF) was synthesized through CF-salicylaldehyde reaction.Then a novel radar absorbing material (Fe-Sa-CF) was prepared by chelating reaction between Sa-CF and Fe 3+.The coaxial transmission and reflection method was used to analyze the complex permittivity and complex magnetic permeability of these CF-based materials,and the radar cross section (RCS) method was used to investigate their radar absorbing properties in the frequency range of 1.0-18.0 GHz.Experimental results indicated that the conductivity of CF increased from initial 1.08×10-11 to 2.86×10-6 S/cm after being transferred into Fe-Sa-CF,and its dielectric loss tangent (tanδ) in the frequency range of 1.0-17.0 GHz also increased.These facts suggest that the Fe-Sa-CF is electric-loss type radar absorbing material.In the frequency range of 3.0-18.0 GHz,Sa-CF (1.0 mm in thickness) exhibited somewhat radar absorbing property with maximum radar reflection loss (RL) of-4.73 dB.As for Fe-Sa-CF,the absorbing bandwidth was broadened,and the absorbing intensity significantly increased in the frequency range of 1.0-18.0 GHz where a maximum radar RL of-9.23 dB was observed.In addition,the radar absorbing intensity of Fe-Sa-CF can be further improved by increasing membrane thickness.When the thickness reached to 2.0 mm,the RL values of Fe-Sa-CF were-15.0-18.0 dB in the frequency range of 7.0-18.0 GHz.Consequently,a kind of novel radar absorbing material can be prepared by chemical modification of collagen fiber,which is characterized by thin thickness,low density,broad absorption bandwidth and high absorption intensity.     

Improved acetone sensing properties of flat sensors based on Co-SnO2 composite nanofibers

Co-SnO2 composite nanofibers were synthesized by an electrospinning method and characterized by X-ray diffraction, field emission scanning electron microscopy, and transmission electron microscopy. Gas sensors were fabricated by spinning these nanofibers onto flat ceramic substrates, which had signal electrodes and heaters on their top and bottom surfaces, respectively. Compared with sensors loaded with pure SnO2 nanofibers, the Co-SnO2 nanofiber sensors exhibited improved acetone sensing properties with high selectivity and rapid response and recovery times. The response was 33 when the sensors were exposed to 100 μL/L acetone at 330°C, and the corresponding response with 100 μL/L of ethanol was only 6. The response and recovery times to acetone were about 5 and 8 s, respectively. These results indicate Co-SnO2 composite nanofibers are good candidates for fabrication of high performance acetone sensors for practical application.     

Evolution of the East Asian monsoon and its response to uplift of the Tibetan Plateau since 1.8 Ma recorded by major elements in sediments of the South China Sea

Evolution of the East Asian monsoon and its response to uplift of the Tibetan Plateau has been investigated in the study of global change. Core sediment samples drilled in the South China Sea during ODP Leg184 are the best materials for studying long-term variability of the East Asian monsoon. R-mode factor analysis of major elements in the fine grain-sized carbonate-free sediments (<4 μm) of the upper 185 mcd splice of ODP Site 1146 drilled during Leg184 in the South China Sea shows that Ti, TFe2O3, MgO, K2O, P, CaO, and Al2O3 are representative of a terrestrial factor. The variation in the terrestrial factor score is subject to chemical erosion in the source region and thus indicates the evolution of the East Asian summer monsoon. The terrestrial factor score has three stepwise decreases at ~1.3 Ma, ~0.9 Ma, and ~0.6 Ma, indicating the phased weakening of the East Asian summer monsoon is related to wholly stepwise, quick uplifts of the Tibetan Plateau since 1.8 Ma. The periodic fluctuation of the terrestrial factor score since ~0.6 Ma indicates that the glacial-interglacial cycles have been the main force driving the evolution of the East Asian monsoon. As in the case of Chinese loess, the long-term evolution of the East Asian monsoon recorded in sediments of the South China Sea reflects a coupled effect of the glacial-interglacial cycle and uplift of the Tibetan Plateau.     

壳聚糖/ZnO复合材料制备及表征

通过在壳聚糖(CS)溶液中掺入乙酸锌制备了Zn2+/CS复合膜,采用化学溶液沉积法,在Zn2+/CS复合膜上生长氧化锌(ZnO),并通过改变生长液的组成成分寻找其最简单、优化的试验方案.通过UV-Vis、XRD和SEM表征,对样品进行分析研究.结果表明,在Zn(NO)3.6H2 O和NaOH组成的化学溶液环境中,Zn2+/CS复合膜中的ZnO最易生长,在Zn2+/CS复合膜的表面首先形成了一层ZnO粒子膜,然后ZnO粒子长大成六角纤锌结构、没有明显的择优取向的ZnO棒.光学性能测试显示ZnO/壳聚糖复合材料具有良好的光致发光性能.电阻率的测定表明ZnO/壳聚糖复合材料是一种防静电材料.     

絮凝过滤在石化废水深度处理中的应用研究

通过小试实验,比较分析无机、有机及复合絮凝剂对某石化企业污水处理厂出水的絮凝效果,通过处理效果和成本分析,筛选得到了聚合氯化铝-聚二甲基二烯丙基氯化铵复合絮凝剂(PAC-PDMDAAC).该絮凝剂在投加量为50 mg.L-1时,浊度最大去除率为72.4%;在实验投加量范围内,CODC r去除率均在40%以上;投加量为40 mg.L-1时,最大去除率达59.3%.在小试的基础上,将该絮凝剂应用于中试实验,分析监测不同构筑物对CODC r的去除效果等参数,确定了合理的投药量、排泥量、反冲洗时间、沉淀时间、处理水量等指标.     

对A=11同质异位素核的奇异性质研究

在单粒子势模型的框架下,通过在核中心势中引入l2修正项(l表示核子的轨道角动量),计算了A=11同质异位素核的均方根半径值、能级值和密度分布.理论计算得到的半径值和能级结构与实验结果一致.特别是,理论计算能够同时实现镜像核11Be和11N中251/2-1p1/2能级间的反转,从而解释了11Be和11N的反常的自旋宇称值...     

亚微米Fe包Co空心微球的制备

研究了一种制备Fe包Co空心微球的新方法.以纳米铁粒子为模板,水合肼为还原剂,通过化学镀制备出具有核-壳结构的Co包Fe纳米粒子,用HCl溶去Fe核制备出空心Co微球,以空心Co微球为模板,NaBH4为还原剂,通过化学镀Fe制备了亚微米Fe包Co的空心微球.研究发现,在化学镀Fe过程中,Fe包Co空心微球之间极易形成硬黏结,通过降低反应物浓度和反应温度,增大反应液pH值抑制镀液中Fe粒子的独立形核,则可明显防止Fe包Co空心微球之间硬黏结的发生.     

铝合金表面构建超疏水性的化学改性机理

系统研究了刻蚀一化学改性两步法中的蒸镀改性工艺对铝合金表面形貌和润湿性的影响,提出了刻蚀与化学改性同时进行的一步浸泡法制备超疏水铝合金.结果表明,两步法蒸镀改性工艺中,硬脂酸端部的极性亲水羧基与铝合金表面羟基以共价键结合,从而在铝合金表面形成一层硬脂酸膜,使铝合金实现低表面能化,水滴在其表面处于Cassie状态,接触角...