Predictive Model for Corrosion Rate of Oil Tubes in CO_2/H_2S Coexistent Environment Part Ⅰ: Building of Model

Introduction　　Sincethecorrosionofoiltubesinbrinesolutionscontainingcarbondioxide (CO2 )andhydrogensulfide(H2 S)gasesisasevereprobleminengineering ,itisveryurgenttobuildapredictivemodelofthecorrosionrate(rcorr)foroiltubesinCO2 /H2 Scoexistentenvironment …     

二次空气喷射系统结构与检修

发动机二次空气喷射系统是一种新型的排气净化装置．它利用空气泵将新鲜空气经空气喷管喷入排气管或催化转化器．使排气中的CO和HC进一步氧化或燃烧成为二氧化碳（CO2）和水（H2O）。通过探讨二次空气喷射系统的结构原理、故障现象，掌握二次空气喷射系统的检测与维修。     

A study on synthesis and oxidation mechanism of mono-alkyl phosphate

Oxidation of white phosphor, us by peroxides to produce mono-alkyl phosphate in the alcoholic solution has been studied under non-and catalytic conditions. In this paper, the mechanism of the oxidation process was analyzed. The content of mono-alkyl phosphalte in the product is affected by different types of alcoholic solution and peroxide solvent. The result shows the availabulity of the following order for the activity of the peroxide solvent and alcoholic solutions-tert-butyl hydroperoxide>(di) benzoyl peroxide>hydroperoxide; methanol> n-butyl alcohol> phenol. Under optimized reaction conditions: n (a white phosphorus) : n( tert-butyl hydroperoxide) : n (methanol)= 1:10:12, reaction temperature 80 ℃, reaction time 2.5 h, products of 80.0% mono-alkyl phosphonates can be provided when white phosphorus undergoes oxidation by tert-butyl hydroperoxide in the methanol solutions. When Cu (I), and Cn(Ⅱ) complexes are used as catalysts, it is possible to significantly enhance the oxidation of white phosphorus with the increase in the reaction rate. Th'e order for activity of catalysts is Cu(acac)2>Cu (CH3COO)2>Cu (C3 H7COO)2:>CuI>CuCI2. Noticeably, with Cu(acac)2 as catalyst, the selectivity for mono-alkyl phusphonates can reach 95% under adequate reaction conditions.     

基于机器学习的网约车合乘出行碳减排状态预测

网约车合乘出行可有效提高车辆运输效率,与常规网约车出行相比具有显著的碳减排潜力。然而,现实中网约车合乘出行能否真正减少碳排放受多方面因素影响,往往存在较大差异与不确定性。为识别碳减排潜力较大的网约车合乘订单,提出一种基于机器学习的网约车合乘出行碳减排状态预测模型,并解析其碳减排机理。首先,基于成都市真实的网约车合乘订单与轨迹数据,应用COPERT(COmputer Program to calculate Emissions from Road Transport)排放模型分别计算合乘出行碳排放量及其替代的独乘出行碳排放量,进而得到合乘出行相比独乘出行的碳减排量。然后,基于历史的合乘行程碳减排及其订单特征数据,训练XGBoost(eXtreme Gradient Boosting)模型以预测未来潜在合乘出行的碳减排状态。最后,采用ALE (Accumulated Local Effects)分析方法对预测模型进行特征变量解析,以识别影响合乘出行碳减排状态的关键因素。结果显示：研究区域内平均每次网约车合乘出行可减少碳排放307.23 g,但仍有15%的网约车合乘行程未能实现减碳;XGBo...     

Research on modeling and fuzzy control of magneto-rheological intelligent buffer system for impact load

So far the magneto-rheological (MR) effect mechanism of MR damper has not been known completely, especially in the impact load, and the problem becomes more complicated and difficult for analyzing. A set of characteristic tests and parameters?? identification are made to the MR damper by the experimental platform. The dynamical model of the damper is constructed based on the Bingham plastic model, and the buffer control strategy of aircraft undercarriage based on MR technology is established. Finally, the fuzzy control algorithm is applied to the process of automatic control for landing buffer of aircraft undercarriage. The simulation results show that the proposed MR damper pulley buffer can effectively recognize the impact energy. The research has a better application in the engineering.     

火电厂化学吸收CO2捕获工艺的应用与能耗分析

从火力发电厂烟气特性出发,分析了化学吸收CO2捕获工艺流程,评估了醇胺吸收剂和改进型吸收剂的特点及适用性,总结了吸收剂在国内外CO2捕获示范工程中的应用情况,提出了化学吸收工艺能耗分析参数体系,通过工程和理论研究两个路径对化学吸收CO2捕获工艺的能耗水平进行了分析.分析结果表明化学吸收工艺吸收剂以胺和混合胺为市场主导,CO2捕获吸收剂的再生能耗一般介于3.0～4.2GJ/t之间.     

水分子在Sn02（110）表面吸附特性的密度泛函计算

根据密度泛函理论,采用广义密度近似,建立了水分子在SnO2（110）面不同吸附位的周期平板模型,研究了水分子在SnO2（110）表面的吸附特性．结果表明：发生在Sn5C吸附位的水分子平行于表面和水分子以H原子向上垂直于表面的两种吸附方式为稳定吸附．对两种稳定吸附方式下电子态密度及电荷转移进行了分析,发现两种吸附方式均使体系费米能向高能量方向移动,同时两种方式下水分子向SnO2表面提供的电子数分别为0．09e和0．08e．提出水分子与CO分子对表面同一吸附点存在着竞争吸附,是湿度影响CO气体传感器电导灵敏度的主要原因．     

城市客车燃用沼气的生命周期分析

应用生命周期分析方法建立了城市垃圾厌氧发酵车用沼气燃料的生命周期能 耗和环境排放模型,对车用沼气在原料阶段、燃料生产阶段和车辆运行阶段的能耗和环 境排放进行了分析计算,并将城市客车燃用沼气和柴油的生命周期能耗和排放指标进行 了对比分析.结果表明,在车用沼气的全生命周期内,燃料的总能源消耗比传统柴油低 9.5%,全生命周期HC、CO、NOX、PM10、SO2、CO2等6 种排放物都比柴油低.从降低生命周 期能耗和环境排放角度看,城市垃圾厌氧发酵车使用沼气是一种较好的新能源燃料;从 城市垃圾处理方式看,城市垃圾厌氧发酵车用沼气为城市垃圾处理寻找了新的途径.     

Prevention of Seepage of Unsaturated Clay by Chemical Treatment

Introduction　　Asanimperviousbarrier ,clayiswidelyusedinmanyfieldssuchaswasteisolation .Theimperviousnessofclayisstableinzoneofsaturation ,butnotstableinzoneofaerationasaresultofalternatewettinganddrying ,whichinducesstructuralporeanddryingfractureandrai…     

Fe{O(CH_2CO_2)_2}(H_2O)_2(NO_3)电子结构和磁性的第一性原理研究

采用第一性原理计算研究了Fe{O(CH2CO2)2}(H2O)2(NO3)晶体的电子结构及磁性。该计算采用密度泛函理论(DFT)结合投影缀加波(PAW)方法。计算结果表明,化合物Fe{O(CH2CO2)2}(H2O)2(NO3)具有反铁磁基态,这种反铁磁相互作用来自于最近邻的铁离子;每个分子的自旋磁矩是4.99μB,这和实验结果也是相吻合的。     

Experimental investigation of a cryogenic filter for separating solid carbon dioxide particles from liquid nitrogen

This paper presents an investigation of a new method of purifying cryogenic liquid using sintered metallic wire-mesh filter, which has the advantages of high purifying efficiency and preferred strength at absolutely low temperature. Experiments are conducted to purify solid CO2 particles from liquid nitrogen. Temperature and pressure in the upstream and downstream of the filter, and the flow rate of carbon dioxide (CO2) gas and liquid nitrogen are measured, with the gas content of filtrate analyzed using a CO2 concentration detector. It is illustrated that after filtration, the purity of liquid nitrogen (volume fraction) is higher than 99.99%, which means that the volume fraction of CO2 is less than 0.01%. Effects of operation parameters on the performance of the filter, such as pressure drop △p and filtration efficiency E are analyzed quantitatively. The present conclusions will provide a guideline to the optimumal design and operation of sintered metallic wire-mesh filter in cryogenic application.     

Modeling and control of the pulley buffer system of arresting cable for shipboard aircraft based on magneto-rheological fluid

Taking the MK7-3 of USA hydraulic buffer arresting device as the research subject, the dynamical model for the shipboard aircraft arresting system is established, and the magneto-rheological (MR) damper is applied to pulley shock absorbers for shipboard aircraft block system. Due to the effect of the MR damper has not been known completely and so far MR damper model has not been defined, we use a set of characteristic test of the MR damper, through the process of parameters identification, to establish the dynamical model for the MR damper based on the Bingham plastic model. Then, the fuzzy control rules are designed, the buffer control for the pulley buffer of shipboard aircrafts is completed in touchdown moment based on MR technology. Compared with blocking device of hydraulic pulley buffer in the same condition, the simulations results show that the proposed MR pulley buffer can effectively recognize the impact energy for shipboard block system and reduce the pull peak of arresting cable. It improves significantly safety during landing of the air vehicles and lowers the risk of accidents.     

秦巴山区精神发育迟滞儿童生物医学因素分析

目的　确定秦巴山区宁强、柞水、安康调查点精神发育迟滞 (MR)儿童的生物医学因素。方法　由心理学专业人员对调查点儿童做智力筛查 ,对筛出的可疑儿童做适应行为评定、智力诊断、相关的实验室检查及病史调查 ,最后由小儿神经科、妇产科及心理学专家进行病例讨论 ,确定MR儿童的病情程度和病因结构。结果　调查 0～ 14岁儿童共计 74 87人 ,发现MR儿童 2 38人 ,其患病率为 3.18% ,显著高于 1987年全国平均水平 (P <0 .0 0 5 ) ;在MR病情轻重构成方面 ,除安康调查点缺乏统计学意义外 (P >0 .10 ) ,宁强、柞水两点主要以轻度MR占大多数 ,分别为 76 .8%、73.9% ,较全国平均水平 (6 0 .6 % )高 (P <0 .0 5 ) ;在已明确病因的MR病因构成方面 ,宁强、安康两点的情况和全国平均水平相似 ,均以产前及产后原因为主 ,而柞水调查点则主要以产时因素为主 (P <0 .0 1) ;在参与构成MR病因的家庭文化环境方面 ,母亲因素占主导地位 :在母亲为智力低下或文化程度低的家庭中 ,MR的患病率显著增高 (P <0 .0 0 5 )。结论　秦巴山区的MR发生情况仍较严重 ,加强围产期保健 ,规范培训乡村医师 ,改善家庭经济文化状况 ,提高母亲的文化素质是改变这一现状的主要措施     

流动注射-化学发光法测定氢化可的松

目的确定以高锰酸钾-亚硫酸钠体系测定氢化可的松的流动注射-化学发光分析方法。方法在酸性条件下,氢化可的松对高锰酸钾-亚硫酸钠体系发光反应具有明显的增敏作用。据此,建立了流动注射化学发光测定氢化可的松的分析方法。结果在优化的实验条件下,氢化可的松质量浓度在1.0×10-9-1.0×10-6g/mL范围内与发光强度呈良好的线性关系,检出限(3R)为4.0×10-10g/mL,对氢化可的松进行11次平行测定,其相对标准偏差为2.2%。结论本方法应用于注射液中氢化可的松含量的测定,快速、准确、简便,灵敏度高、线性范围宽。     

微电解-双氧水处理模拟染料废水的实验研究

研究了铁炭微电解一双氧水氧化工艺处理模拟染料废水的效果。结果表明，对于色度为1000倍，COD为40mg·L^-1的次甲基蓝模拟废水，在铁炭比1．5：1、反应时间1h、pH值2．0的条件下处理，色度去除率达到94．7％，COD增长到734．4mg·L^-1.双氧水与Fe^2＋摩尔比10：1，pH值2～5，反应50min的条件下处理后，COD去除率达到93．1％，色度去除率达到62．5％。经两步处理后，色度降低为3倍，COD为51．2mg·L^-1。同时对反应机理进行了探讨。     

Measurement of Swarm Parameters of c-C4F8/CO2 and Its Insulation Characteristics Analysis

In c-C4F8 and c-C4F8/CO2 mixtures, the swarm parameters including ionization coefficient, attachment coefficient and effective ionization coefficient were obtained at the ratio of the electric field strength to the gas density between 150-550 Td by the steady-state Townsend (SST) method. Static breakdown voltages at each ratio were also measured at the SST condition. The limiting field strengths were obtained by two methods:computing the density-normalized effective ionization coefficient as a function of the overall density-reduced electric field strength; and measuring static breakdown voltages as a function of the product of gas density and electrode separation. Good agreement was obtained by these two methods, which ensures the correctness of the former method. The limiting field strengths of c-C4F8 and c-C4F8/CO2 mixtures were compared with those ofpure SF6, SF6/CO2 mixtures and pure c-C4Fs. It is found that buffer gas CO2 does not reduce the limiting field strengths of c-C4F8 greatly, the limiting field strengths of c-C4F8/CO2 mixtures are higher than those of SF6/CO2 mixtures or even pure SF6, and so c-C4F8/CO2 mixtures are suggested to be possible substitutes for SF6.     

碳达峰目标下中国民航CO2与NOx减排协同效益分析

民用航空作为交通运输的重要组成部分，对落实国家碳达峰和碳中和战略具有重大意义。本文构建了一套符合民航特征的大气污染物与CO2排放综合预测模型，针对民航飞机未来增 长情况和2019—2050年民航CO2和NOx排放量开展预测分析，并利用协同控制坐标系和协同减 排弹性系数评价产生的减排协同效益。结果表明，未来民航飞机年增量呈现出不断增长的趋势， 与GDP、潜在产出及劳动效率的发展关联密切。燃油效率的提高并不能改变民航CO2和NOx排放量持续增长的现状，可持续航空燃料的发展使民航CO2排放量于2045年达峰，约为3.18×108 t，并会促进NOx排放量持续增长。通过技术改进与新动力飞机的进入可消除此影响，使民航CO2排放量达峰时间提前到2040年，排放量约为2.65×108 t，在此基础上，推进可持续航空燃料的应用可使民航CO2排放量在2037年达峰，约为2.47×108 t，可见民航业无法实现2030碳达峰愿景，且研究表明，适当引进可持续航空燃料，加快对民航技术的改进和新动力飞机的应用是强化民航CO2与 NOx协同减排的最佳选择。因此短期内着力提高飞机燃油经济性；中期加速推进可持续航空燃料 的应用比例；长期依靠新型动力飞机实现零碳飞行，是民航业实现双碳的最佳路径。     

Improvement of collaborative optimization

This paper presents a new improved collaborative optimization (CO) model that provides solution capabilities for multiobjective multidisciplinary optimization problems. Reasons that cause computational difficulties in CO algorithm are firstly analyzed. Then a new system level objective function is advised to minimize relative value between the collaborative objective function and single disciplinary objective function. And it eliminates the effect of dimensions and magnitude orders among objectives. A new s...     

中国货运结构优化的碳减排效应测度

管理部门和学界高度重视货运结构优化问题，因为过高的公路货运量导致货运碳排放居高不下，不利于早日实现“碳达峰、碳中和”目标。除货运结构外，货运碳排放受诸多因素影响，但研究者大多仅关注部分重点因素影响，对于货运结构优化的碳减排效应缺乏准确理解。为解决上述问题，本文利用“自上而下”法测算1999—2019年中国货运碳排放量，并构建综合考虑社会经济变量(如人均GDP)与货运特征变量(如货运分担率)的偏最小二乘回归模型，通过调整不同货运方式使用费用，模拟2030年不同政策刺激情景下货运结构优化的碳减排效应。结果表明：1999— 2019年，社会经济变量对货运碳排放增长的年均贡献度为73%，显著高于货运特征变量；公路、铁路和水路货运分担率变化对货运碳排放增长的年均贡献度分别为1.81%、-0.01%和-0.26%；2030 年公路货运量全部转为铁路或水路货运量的极端情景，难以实现单位GDP货运碳排放较2005年下降65%的标准；增加高碳货运方式使用费用的碳减排效应比降低低碳货运方式使用费用更显著。     

Finite Element Methods for Coupled Stokes and Darcy Problems

We derived and analyzed a new numerical scheme for the coupled Stokes and Darcy problems by using H(div) conforming elements in the entire domain. The approach employs the mixed finite element method for the Darcy equations and a stabilized H(div) finite element method for the Stokes equations. Optimal error estimates for the fluid velocity and pressure are derived. The finite element solutions from the new scheme not only feature a full satisfaction of the continuity equation, which is highly demanded in scientific computing, but also satisfy the mass conservation.