皮革后整理加工废水处理

针对皮革后整理加工废水有机浓度高、可生化性的差特点,经小试后确定采用混凝沉淀-水解酸化-生物接触氧化-流离生化法处理工艺。实践表明,对于难生化处理的有机废水,该工艺设计合理,运行稳定,启动容易,运行费用低,抗冲击的负荷能力强,废水经处理后能达到《污水综合处理排放标准》GB8978-1996一级排放标准。     

基于矢量控制的全电动注塑机控制系统设计

根据全电动注塑机的工艺结构及对控制系统的要求,通过分析全电动注塑机的结构,在把矢量控制应用到永磁同步电机控制的基础上,提出了一种全电动注塑机控制系统的设计方案。经过分析和研究,表明该方案能够进一步提高全电动注塑机的精确控制能力,其稳定性好、可靠性高,能够较好地满足对全电动注塑机控制精度和稳定性的要求。     

过渡金属催化合成芳基硫化物

芳基硫化物具有很好的生物活性,在医药行业和有机合成中具有广泛的应用.不同过渡金属催化合成芳基硫化物成为当前研究的一个热点.本文简单综述了不同过渡金属催化硫醇的芳基化反应合成芳基硫化物.     

水性紫外光固化合成革用聚氨酯丙烯酸酯树脂的合成及性能研究

采用聚丁二醇(PBG)、2,4-甲苯二异氰酸酯、二羟甲基丙酸(DMPA)和丙烯酸羟乙酯合成了紫外光固化水性聚氨酯丙烯酸酯树脂,利用FT-IR对树脂进行了表征,探讨了树脂亲水基团含量和中和度对乳液性能的影响,分析表征了固化膜的基本性能。结果表明:乳液的粒径随着—COOH含量的提高而下降,乳液的分散性、稳定性及黏度随—COOH含量增加而增大;乳液黏度在中和度为90%时达到最高6.222 mPa.s,粒径达到最小59.8 nm。固化膜的吸水率随—COOH含量的增加而上升,固化膜对PVC板具有很好的附着力,其铅笔硬度随着DMPA/PBG比例的增加而上升。     

热塑性交联聚乙烯（TPEXa）管材的制备及性能研究

选取耐热聚乙烯（PERT）进行微交联改性制备出一种热塑性交联聚乙烯（TPEXa）管材,使其在保留PERT管热塑性的基础上提高耐热性和抗蠕变性,研究了交联剂含量对TPEXa材料熔体质量流动速率和交联度的影响,并对TPEXa管材的静液压性能、热熔回收性能及回收料的力学性能进行了测试。结果表明,当交联剂的含量为0.08 %时,TPEXa材料的熔体质量流动速率为5.6 g/10 min（190 ℃,21.6 kg）,交联度为2.3 %,负荷变形温度可以达到78 ℃（Tf0.45）,耐温性能较好。制备的管材可以通过95 ℃下22 h、165 h和1 000 h静液压测试,测试所用环应力超过PERT II管接近PEX管材环应力的规定,具有较好的耐温性能和抗蠕变性能,并且可以进行热熔回收,回收料具有较好的力学性能。     

A sustainable printed circuit board derived hierarchically porous carbon/polyaniline composites for supercapacitors

The hierarchically porous carbon/polyaniline electrodes derived from the nonmetallic part of waste printed circuit board have been synthesized by a convenient carbonization and activation method. A detailed analysis of the morphology, structure, and electrochemical performances of as-prepared composites is presented. As expected, the balanced specific surface area and porous structure manifest their remarkable electrochemical performances. Apparently, the multiple synergistic effects are crucial to simultaneously achieving high capacity and significantly increased stability. As a result, the electrodes display exceptional rate capability, superior cyclic stability, and high specific capacitance (520.0 F/g at 1 A/g). Furthermore, the asymmetrical device possesses an improved energy density of 9.3 Wh/kg with a power density of 62.4 W/kg in H₂SO₄ electrolyte. Moreover, a potential mechanism contributing to the superior performance of hierarchically porous carbon/polyaniline composites has been studied in detail. Noteworthy, this study provides a feasible strategy for recycling waste printed circuit boards. Importantly, this approach will provide a path toward the rational synthesis and design of electrode materials for supercapacitors that take both high-performance and cost-effective into account.     

Influence of charge compensation on the photoluminescence and temperature sensing of zinc titanate composites

Eu³⁺ activated zinc titanate red-emitting phosphors have been synthesized by a solid state reaction, and Li⁺ is added as the charge compensator to tune the optical performances of the phosphors. The structure of samples synthesized at different temperature reveals temperature dependence. The crystallization of particles is improved with increasing calcination temperature. The surface morphology and element distribution of the samples are observed by scanning electron microscope (SEM) and energy dispersive X-ray spectrometer (EDS). Various elements are evenly distributed in the matrix materials. The luminescence intensity of Eu³⁺ is effectively improved by co-doping Li⁺, and the luminescence intensity of the phosphor with Li⁺ content of 5 mol% and 7 mol% is twice than that of the phosphor without Li ⁺ when the annealing temperature is 600 °C. While the influence of Li ⁺ on the photoluminescence performance becomes weaker with the annealing temperature increasing. The highest relative sensitivity of 0.65%/K is obtained in the sample annealed at 1000 °C, which is not affected by the Li⁺ dopants.     

Preparation of calcium sulfate dihydrate and calcium sulfate hemihydrate with controllable crystal morphology by using ethanol additive

Calcium sulfate hemihydrate (CSH) with controlled crystal morphology has attracted broad interests due to its superior physical and chemical properties, as well as excellent biological performance. In this study, calcium sulfate dehydrate (CSD) was firstly synthesized via the reaction of H₂SO₄ and Ca(OH)₂ using ethanol as morphology modifier. The prepared CSD was then converted to CSH through a hydrothermal method. It was found that the precipitation time of CSD powders was dramatically shortened and the morphology of CSD crystals was changed from thick tabular to short-rod with the increment in ethanol addition. The finally-obtained CSH crystals were found to have hexagonal prisms shape with smaller aspect ratios. The CSH powder with the desired crystal morphology would provide improved setting behavior and biological performance of the CSH bone cement.     

Cold sintering assisted CaF2 microwave dielectric ceramics for C-band antenna applications

A cold sintering process is adopted to pre-densify CaF₂ ceramics from 85.7% at 300 MPa to 91.7% at 750 MPa. Subsequent post-annealings at 1000–1150 °C lead to further improvements in densification, where great enhancements of grain size and crystallinity are also observed from the scanning and transmission electron micrographs. Significant advances in Qf values are achieved in the post-annealed CaF₂ ceramics. The optimum Qf value (80,522 GHz) is achieved after cold sintering at 750 MPa and post-annealing at 1000 °C, which is three times higher than the conventional sintered one at 1000 °C (26,448 GHz). Moreover, the obtained low-ε_r (5.9–6.5) of CaF₂ ceramics suggests broad application prospects in the high-band microwave communications. A microstrip patch antenna is fabricated using the CaF₂ ceramics as the substrate, which operates at 7.89 GHz in the C-band, with an S₁₁ of ?13.4 dB, simulated high gain and efficiency of 6.41 dBi and ?0.56 dB, respectively.