内曲线径向柱塞式液压马达导轨曲面加工用凸轮靠模的设计

结合NJM -12.5型内曲线径向柱塞式液压马达的制造 ,介绍其导轨曲面的结构特点和加工用凸轮靠模的设计。     

基于门控循环单元的动态过程下两相 CO2 质量流量测量

针对碳捕集与封存条件下科里奥利质量流量计测量气液两相CO_2动态过程质量流量时误差较大的问题,本文提出了一种基于门控循环单元(GRU)的动态过程下气液两相CO_2质量流量校正方法。利用GRU适合动态过程预测的特点,使用来自CO_2气液两相流实验平台的采集数据,对GRU网络模型进行训练,并使用网格搜索法结合K折交叉验证优化模型参数。使用八组典型工况下的测试集对优化后的GRU模型在测量精度和泛化性能方面进行了评估,并与最小二乘支持向量机(LS-SVM)模型进行了对比分析。实验结果表明GRU模型优于LS-SVM模型,并且GRU模型在动态波动发生后的平稳阶段,其输出结果能够快速跟随CO_2质量流量变化,相对误差在±5%以内。     

大型集聚类业务预测方法探析

以实例论述了大型集会移动话务特点、分析了大型集会移动用户规模、阐述了大型集会用户业务模型,并给出了业务量预测流程及预测实例。     

高效聚磷菌的筛选及其应用

从深圳市布吉河底泥中筛选出一株高效聚磷菌,该菌株最适宜的生长条件为：温度为25-35℃、pH为6.5-8.0,经对菌株作生理生化性质鉴定属于假单胞菌属（Pseudomonas sp.）。聚磷效果试验表明：在低磷浓度的富集培养基中（〈10 mg/L）该菌具有较强的聚磷效果,48 h的聚磷效果为81.5%,而当磷浓度高达20 mg/L时,聚磷效果仅50%左右。该菌株应用于受污染河水处理工程的强化除磷表明,除磷系统启动运行18 d后,总磷的去除率达到80%以上;28 d后,除磷系统日趋稳定,磷去除率达到90%,出水总磷含量稳定在0.5 mg/L以下,达到《城镇污水处理厂污染物排放标准》（GB 18918—2002）一级A标准。     

Cobalt Alleviates GA-Induced Programmed Cell Death in Wheat Aleurone Layers via the Regulation of H2O2 Production and Heme Oxygenase-1 Expression

Heme oxygenase-1 (HO-1) and hydrogen peroxide (H₂O₂) are key signaling molecules that are produced in response to various environmental stimuli. Here, we demonstrate that cobalt is able to delay gibberellic acid (GA)-induced programmed cell death (PCD) in wheat aleurone layers. A similar response was observed when samples were pretreated with carbon monoxide (CO) or bilirubin (BR), two end-products of HO catalysis. We further observed that increased HO-1 expression played a role in the cobalt-induced alleviation of PCD. The application of HO-1-specific inhibitor, zinc protoporphyrin-IX (ZnPPIX), substantially prevented the increases of HO-1 activity and the alleviation of PCD triggered by cobalt. The stimulation of HO-1 expression, and alleviation of PCD might be caused by the initial H₂O₂ production induced by cobalt. qRT-PCR and enzymatic assays revealed that cobalt-induced gene expression and the corresponding activities of superoxide dismutase (SOD), catalase (CAT) and ascorbate peroxidase (APX), three enzymes that metabolize reactive oxygen species, were consistent with the H₂O₂ accumulation during GA treatment. These cobalt responses were differentially blocked by co-treatment with ZnPPIX. We therefore suggest that HO-1 functions in the cobalt-triggered alleviation of PCD in wheat aleurone layers, which is also dependent on the enhancement of the activities of antioxidant enzymes.     

Effect of Acceptor and Donor Dopants on the Dielectric and Tunable Properties of Barium Strontium Titanate

The effects of different concentrations of Mn²⁺, Mg²⁺, Al³⁺, Fe³⁺, La³⁺, and Nb⁵⁺ on the dielectric and tunable properties of Ba_0.6Sr_0.4TiO₃ ceramics were investigated. It was found that doping in small amounts with acceptor ions such as Mg²⁺, Fe³⁺, and Al³⁺ could meliorate the dielectric properties clearly. Decrease of dielectric loss was attributed to the formation of compensating defects originating from acceptor substitution. It was concluded that the tunability was linked to both the dielectric constant and the grain size. A higher figure of merit was obtained by doping the ceramics with smaller ions of Al and Fe, compared to Ti.     

Effects of particle size of zero-valent iron (ZVI) on peroxydisulfate-ZVI enhanced sludge dewaterability

The advanced oxidization process has proven to be an effective conditioning technique for the improvement of sludge dewaterability. Zero-valent iron (ZVI) is often used as the catalyst of the oxidization process. This study applied ZVI with different particle sizes to the ZVI- peroxydisulfate reactions, and investigated their effects on the improvement of sludge dewaterability. It was found that ZVI particles with smaller sizes (100 and 400 meshes) led to slightly higher enhancement of sludge dewaterability (69.1%–72%) than the larger size particles (20–40 meshes) with the reduction rate of CST by 64%. However, after the treatment, the recycle rate of larger size ZVI particles was obviously higher than the small sizes ZVI particles: 98.3% vs. 87.6–89.7%. Different surface areas of the ZVI particles with different sizes might contribute to the phenomenon. For the small ZVI particles with the sizes of 100 and 400 meshes, no obvious differences of oxidization effects and the improvements of sludge dewaterability were found between them, which might be because an oxide layer could have been formed on the surface of fine ZVI particles and led to agglomeration. According to the economical analysis, the small particles (100 and 400 meshes) of ZVI were more economically favorable for the oxidative conditioning process with ZVI-peroxydisulfate than large ZVI particles (20–40 meshes).     

杂原子掺杂生物质基炭材料的研究进展

生物质基炭材料具有低成本、来源广泛、导电性良好和电化学稳定性好等优点,通过杂原子掺杂,生物质基炭材料的性能得到进一步的提升。本文总结了杂原子引入生物质基炭材料的方法(原位掺杂和扩散掺杂)及其各自的优缺点,简述了杂原子掺杂的种类(氮掺杂、氧掺杂、磷掺杂、硫掺杂、卤素掺杂和多元素共掺杂)及杂原子掺杂对生物质基炭材料结构与性能的影响,综述了目前杂原子掺杂炭材料在能源存储、吸附分离、催化氧化等领域的应用状况,并对杂原子掺杂生物质基炭材料的发展方向进行了展望。     

Study on SO2 Poisoning Mechanism of CO Catalytic Oxidation Reaction on Copper–Cerium Catalyst

CuO–CeO₂ (Cu–Ce) catalyst with a CuO/CeO₂ mass ratio of 1 prepared by a sol–gel method is used in the CO catalytic oxidation reaction in the actual industrial sulfur-containing atmosphere. At a reaction temperature of 200 °C, the catalyst exhibits quite different stability under sulfur-containing and sulfur-free conditions. When 30 ppm SO₂ was added to the feed gas, the Cu–Ce catalyst had an initial CO conversion rate of 100%, gradually decreasing after 26 h, and this catalyst completely deactivated at about 50 h. However, the CO conversion rate of the catalyst under sulfur-free conditions could be nearly maintained at 100% within the measured time range (60 h). The results of IR, Raman, and XPS characterizations proved that the accumulation of cerium sulfate on the Cu–Ce catalyst would cover the active sites of the catalyst, eventually leading to the complete deactivation of the catalyst, which provides favorable evidence for the actual industrial anti-sulfur application.

Graphical Abstract

     

Synthesis,Structure and Photoluminescence Properties of Mixed-Valent Trinuclear Copper Complex Assembled from Bis(<Emphasis Type="Italic">N</Emphasis>-imidazolyl)methane

In this work, [Cu₃I₂(PPh₃)₆(L₁)₂]∙2DMSO∙Cl₂ (1) (L₁ = bis(N-imidazolyl)methane) complex was synthesized by solvothermal method. The crystal and complexes were characterized by X-ray diffraction (XRD) analysis, Fourier Transform infrared (FTIR) spectroscopy, elemental analysis and photoluminescence (PL) measurements. XRD and FTIR analysis indicated that the complex 1 is a trinuclear compound, in the compound there are two kinds of copper atoms, i.e. monovalent, and divalent copper cations. For the copper(I) center, it is surrounded by two P, one N, and one iodide atoms to complete its tetrahedron geometry. While the copper(II) center is surrounded by two P and two nitrogen atoms, the chloride anions existed as free counter anions. The copper(II) atom and the copper(I) atoms were bridged by exobidentate L₁ ligand. The PL spectrum showed that the complex displays intense blue emission related to shallow holes.