垃圾渗滤液膜滤浓缩液处理技术研究与应用进展

截至目前,作为垃圾渗滤液深度处理工艺之一的膜分离工艺,可保证垃圾渗滤液处理后达标排放,但同时将产生大量的膜滤浓缩液。浓缩液含有大量难降解有机污染物,若不能进行妥善处理处置,将会造成严重的二次污染。根据相关研究及工程应用案例,从工艺原理、应用效果、处理成本及技术发展角度,对渗滤液膜滤浓缩液处理工艺进行分类探讨,评述回灌法、物理处理法(浸没燃烧蒸发法和机械式蒸汽再压缩处理法)、化学处理法(焚烧、高级氧化和超临界水氧化法)、物化处理法(絮凝沉淀、吸附、膜分离和固化稳定化处理)等单元工艺和无膜/有膜等组合工艺的技术特点、现存问题及应用范围,最后总结不同条件下产生膜滤浓缩液的处理工艺路线,有针对性地提出渗滤液膜滤浓缩液处理的发展方向,期望可为垃圾渗滤液膜滤浓缩液处理工艺的深入研究与广泛应用提供技术参考。     

包含需求侧管理的输配电系统优化运行──模型及应用研究

研究了包含蓄热（冷）技术装置、负荷（商业集中式空调负荷等）直接控制（音频、无线电等）技术以及分时（峰谷）电价结构等需求侧管理措施的输配电系统优化运行（调度）的多目标规划模型，并应用模型及软件（整体资源计划软件，ＩＲＰ－ＣＳ，ＣＯＲＥ版权）进行了实例分析，给出了结果。     

Pore-forming agent induced microstructure evolution of freeze casted hydroxyapatite

There were interconnected small lamellar pores, big spherical pores and ceramic walls in the hydroxyapatite (HAP) ceramics fabricated by a freeze casting/pore-former method. As keeping the content of polymethyl methacrylate (PMMA) constant and decreasing the size of PMMA, the size of spherical pores and length of ceramic wall both decreased, and the compressive strength increased. As keeping the size of PMMA and decreasing the content of PMMA, the open porosity decreased and compressive strength increased. The shapes of pores caused by ice crystals were reticular, lamellar and treelike, in turn. The HAP ceramics with the spherical pores of 150-250 μm, open porosity of 62.13% and compressive strength of 7.01 MPa are prospective to have biomedical application.     

DC-field-induced synthesis of ZnO nanowhiskers in water-in-oil microemulsions

ZnO nanowhiskers were successfully fabricated using DC-field induced water-in-oil microemulsions method. Phase structure, morphology and microstructure of the product were investigated by X-ray diffraction and transmission electron microscopy. Parameters in preparation process such as electric field intensity and surfactant were discussed and the product formation mechanism was studied. XRD and TEM results showed that the obtained ZnO particle was hexagonal wurtzite-type with 1-3 nm in diameter and 20-70 nm in length, and morphology of the particles was shown to be correlated not only with the electric field intensity but also with the surfactant. There was a threshold when the electric field intensity was 80 V/mm. The morphology of the particles was basically spherical before the threshold, while L/D increased with the raise of electric field intensity. ZnO nanowhiskers were obtained under mixed surfactants but spherical particles were got with a single surfactant.     

First Principles Study on the Electronic Properties of Zn(64)Sb(64-)Te Solid Solution (x = 0, 2, 3, 4)

The electronic properties of Te doped-ZnSb systems are investigated by first-principles calculations. We focus on the Zn(64)Sb(64-) (x)Te(x) systems (x = 0, 2, 3, 4), which respond to the 0, 1.56at%, 2.34at% and 3.12at% of Te doping concentration. We confirm that the amount of Te doping will change the conductivity type of ZnSb. In the cases of x = 2 and 3, we find that the Te element in ZnSb introduces some bands originating from Te s and p orbits and a donor energy level in the bottom of the conduction band, which induce the n-type conductivity of ZnSb. From these findings for the electronic structure and the conductivity mechanism, we predict that Te doping amounts such as 1.56at% and 2.34at% can be considered as suitable candidates for use as donor dopant.     

Two-step continuous synthesis of tetraethylthiuram disulfide in microstructured reactors

We present two-step continuous synthesis of tetraethyl thiuram disulfide using microstructured reactors, starting with the formation of N, N-diethyldithiocarbamic acid from carbon disulfide and diethylamine in the first mi- crostructured reactor, and the oxidation of N, N-diethyldithiocarbamic acid by hydrogen peroxide in the second one. We studied the effects of reaction temperature, LHSV and total flow rate on the yield of the product. In the first microstructured reactor assembled with an HPIMM micromixer and a stainless steel capillary as the delay loop, the yield of N, N-diethyldithiocarbamic acid reached 96.3% in the 40 wt% diethylamine ethanol solution under reaction conditions of the CS₂/(C₂H₅)₂NH molar ratio of 1.1: 1, total flow rate of 4 mL/min, LHSV of 42.4 h⁻¹, and reaction temperature of 25 °C. Consequently, the obtained N, N-diethyldithiocarbamic acid solution was reacted with H₂O₂ solution in another microstructured reactor assembled with SIMM-V2 and a PTFE capillary as the delay loop, the yield of the high purity tetraethylthiuram disulfide reached 89.3% under the optimized reaction conditions.     

A facile technique to prepare cross-linked enzyme aggregates using <Emphasis Type=Italic>p</Emphasis>-benzoquinone as cross-linking agent

To obtain robust and thermo-stable enzyme aggregates, p-benzoquinone was used as cross-linker and bovine serum albumin (BSA) as crowding macromolecules to prepare cross-linked enzyme aggregates (CLEAs) of lipase. Effects of cross-linking time and cross-linker content on the activity, thermal stability and characteristics of enzyme aggregates were examined carefully. It was observed that when the content of p-benzoquinone was 5 mM and amount of BSA was 125% of that of lipase (w/w), the specific activity of cross-linked co-aggregates of lipase and BSA was 79.8 U mg⁻¹, 2.44-fold of that of cross-linked enzyme aggregates of lipase without BSA. Moreover, after heat treatment for 96 h at 50 °C, the CLEAs prepared with this facile routine kept 75.18% of their initial activity, 5.01-fold more than that of the just CLEAs using glutaraldehyde. Furthermore, BSA macromolecules in lipase CLEAs enhanced the catalytic efficiency of free and just lipase CLEAs without BSA by 1.45 and 2.83 times, respectively. The proposed crosslinking technique would rank among the potential strategies for efficiently preparing robust and thermo-stable enzyme aggregates.     

链转移剂对辐射合成聚合物聚醚多元醇的影响

采用辐射合成方法制备了聚合物聚醚多元醇(POP),研究了链转移剂异丙醇对辐射合成POP中体系粘度、固含量和热性能的影响.实验结果表明,当链转移剂质量分数大于0.6％时,随着链转移剂用量的增加,固含量迅速增大,粘度增长缓慢;热失重分析表明,链转移剂用量对POP微粒的热稳定性具有一定影响,在链转移剂质量分数为0.8％时热稳...     

The role of surface charge density in cationic liposome-promoted dendritic cell maturation and vaccine-induced immune responses

Cationic liposomes have emerged as a novel adjuvant and antigen delivery system to enhance vaccine efficacy. However, the role of surface charge density in cationic liposome-regulated immune responses has not yet been elucidated. In the present study, we prepared a series of DOTAP/DOPC cationic liposomes with different surface densities by incorporating varying amounts of DOPC (a neutral lipid) into DOTAP (a cationic lipid). The results showed that DOTAP/DOPC cationic liposome-regulated immune responses relied on the surface charge density, and might occur through ROS signaling. The liposomes with a relatively high charge density, such as DOTAP/DOPC 5:0 and 4:1 liposomes, potently enhanced dendritic cell maturation, ROS generaion, antigen uptake, as well as the production of OVA-specific IgG2a and IFN-γ. In contrast, low-charge liposomes, such as DOTAP/DOPC 1:4 liposome, failed to promote immune responses even at high concentrations, confirming that the immunoregulatory effect of cationic liposomes is mostly attributable to their surface charge density. Moreover, the DOTAP/DOPC 1:4 liposome suppressed anti-OVA antibody responses in vivo. Overall, maintaining an appropriate surface charge is crucial for optimizing the adjuvant effect of cationic liposomes and enhancing the efficacy of liposome-based vaccines.     

Nonvolatile resistive switching in single crystalline ZnO nanowires

We demonstrate nonvolatile resistive switching in single crystalline ZnO nanowires with high ON/OFF ratios and low threshold voltages. Unlike the mechanism of continuous metal filament formation along grain boundaries in polycrystalline films, the resistive switching in single crystalline ZnO nanowires is speculated to be induced by the formation of a metal island chain on the nanowire surface. Resistive memories based on bottom-up semiconductor nanowires hold potential for next generation ultra-dense nonvolatile memories.