Nonlinear beam optics with real fields in compact storage rings

We analyze the proposed Karlsruhe electron storage ring for X-ray in-depth lithography using the 3rd order charged particle beam transport code MARYLIE 3.0. The ring features four 90° superconducting bending magnets. A numerical calculation of their field provides the longitudinal dependence of the multipole expansion coefficients. These are used by the code SCB to compute the Lie algebraic transfer map. Subsequent particle tracking with MARYLIE is employed to find dynamic apertures. Two different magnet designs which both lead to satisfactory dynamic apertures are presented.     

基于ARIMA和Prophet的水质预测集成学习模型

将时间序列模型ARIMA和Prophet作为基学习器,结合BP神经网络模型构建了水质预测集成学习模型。选取长江流域某断面2019—2020年的DO、COD_Mn、NH₃-N、TP和TN等5个水质指标的监测数据对该模型的有效性进行了检验,结果表明：5个水质指标集成学习模型预测结果的平均绝对百分比误差比时间序列模型的预测误差分别低35.0%、29.9%、4.1%、40.6%和17.1%,模型预测值和监测值的皮尔逊相关系数大于0.8。集成学习模型预测精度高于单一模型,可以更精确地进行水质预测。     

Experimental study of high temperature particle dropping in coolant liquid

A series of experiments of the premixing stage of fuel-coolant interactions (FCI), namely the particles falling into water, were carried out. The force on the particles during the course of falling has been studied. The dropping character of hot particle was influenced by three main parameters, i.e., particle temperature, particle diameter and coolant subcooling that varied over a wide range. A high-speed camera recorded the falling speed of the particle and the moving curves were obtained. The experimental results showed that for the film boiling on the surface of particle and water, the temperature increase of either particle or coolant would slow down the particle falling velocity. The falling velocity of particle in small diameter is lower than that of the bigger particle. The present work can provide an experimental foundation for further investigation of high-speed transient evaporation heat transfer.     

Investigation of conformation of polyvinyl alcohol chain at oxide/electrolyte interface

An attempt to evaluate the surface area of hematite and rutile occupied by an adsorbed molecule of polyvinyl alcohol(PVA) was made. The surface area occupied by a PVA molecule was evaluated from the changes of surface charge density of the oxides before and after PVA addition in the presence of Cs⁺, Mg²⁺, and Ca²⁺ ions. The desorption of an inorganic ion caused by PVA adsorption was taken into account. The configuration of the PVA chain at the solid — liquid interface is also discussed in the light of the results obtained.     

Phosphate removal in marine electrolytes by zeolite synthesized from coal fly ash

The aim of this study was to examine the influence of seawater electrolytes on removal of phosphate by zeolite synthesized from fly ash (ZFA). A low-calcium ZFA was initially saturated with Na⁺, Mg²⁺, Ca²⁺, Al³⁺, and Fe³⁺. Al- and Fe-ZFA showed nearly complete removal of phosphate regardless of the major seawater electrolytes, pH, and salinity. This result was explained primarily on the basis of the adsorption mechanism through the formation of inner-sphere complexes. The remaining ZFAs showed lower phosphate removal performance, in general with the order of Ca-ZFA > Mg-ZFA > Na-ZFA. Compared with pure water, increase of electrolyte concentration or salinity initially enhanced phosphate uptake but then reduced phosphate removal. The individual presence of major seawater electrolytes all facilitated the retention of phosphate, with CaCl₂ being the most effective. The mechanism for phosphate removal by Na-, Mg-, and Ca-ZFA was due mostly to precipitation. Repeated batch equilibration experiments indicated that, compared with pure water, ZFA had greater sorptive capacity for phosphate (except for Ca-ZFA, whose capacity decreased slightly) and had lower reversibility for sorbed phosphate in marine electrolytes. In conclusion, our results suggest that presence of seawater electrolytes had roughly no effect, or even positive effects, on the removal of phosphate by ZFA.     

高密度聚乙烯/铅硼复合材料屏蔽性能和力学性能研究

研究了高密度聚乙烯/铅硼复合材料的屏蔽性能和力学性能,通过屏蔽仿真比较了密度及碳化硼（B4C）含量对屏蔽性能的影响,通过试验比较了B4C含量对屏蔽性能、弯曲强度及冲击强度的影响。仿真结果表明,随聚乙烯/铅硼复合材料密度升高,快中子屏蔽性能下降,热中子屏蔽性能和γ屏蔽性能提高;保持聚乙烯/铅硼复合材料密度不变,随B4C含量的提高,中子屏蔽性能提高而γ屏蔽性能下降;实验数据表明,随B4C含量的升高,高密度聚乙烯/铅硼材料的快中子屏蔽性能、热中子屏蔽性能升高,γ屏蔽系数下降,冲击强度和弯曲强度下降明显,屏蔽性能测试结果和仿真结果规律性相符;综合仿真结果和实验数据表明,含B4C 2 %左右的高密度聚乙烯/铅硼复合材料同时具有较好的屏蔽性能和力学性能。     

An experimental approach to produce hydrogen and methane from food waste using catalyst

Anaerobic co-digestion of food waste, cow dung, and sludge solution is experimented in the presence of calcium peroxide (CaO₂) as the catalyst to produce hydrogen and methane as a source of renewable energy. The substrate to inoculum ratios (v/v) of 1:1(S1), 1:2(S2), 1:3(S3), 1:4(S4) and 1:5(S5) are investigated in separate fermentative and methanogenic reactors. The result from the fermentative reactors indicate maximum hydrogen concentration of 26.34% with cumulative yield of 114.1 mL/g total solid (TS) in S3 compared to the other samples. Methanogenic reaction shows the highest methane concentration of 54.13% in S3. The highest daily (average) and cumulative biogas yield of 5.36 mL/g TS and 201.9 mL/g TS respectively are identified in S3. A maximum carbon dioxide concentration of 63.11% is found in S1. Overall, the substrate to inoculum ratio of 1:3 is spotted to be optimal for effective hydrogen and methane production during the anaerobic co-digestion process.     

带压作业配合水力喷射分段酸压技术在塔里木油田的应用

笼统酸压、多个压裂封隔器+压裂滑套及裸眼封隔器+压裂滑套等这些传统的储层改造手段在塔里木超深井储层改造工艺及效果方面均存在一些缺憾.在此背景下,塔里木油田决定引进带压作业配合水力喷射分段酸压技术用于奥陶系碳酸盐的改造.该技术采用不压井作业机配合施工,全过程无需压井,应用该技术完成5口井32个层段的现场分段酸压试验,工艺成功率为100％,单层改造效率大幅度提高,取得了很好的增油效果,为塔里木油田超深井分段改造提供了新的有效的方法.