低附路面汽车动力学稳定性控制系统控制策略

分析低附条件下轮胎-路面的附着特性和轮胎力特性,建立基于HSRI轮胎模型的四轮2自由度模型,分析汽车在实际工况下的动力学稳定特性。应用β法分析汽车车身稳定性控制的可控区间,结合车身稳定特性、前后轴稳定特性、轮胎稳定特性,确定低附路面上汽车动力学稳定性控制系统对侧偏角、横摆角速度状态偏差的控制目标。基于上述分析开发出低附路面汽车动力学稳定性控制策略,并通过仿真和实车试验验证了控制效果。

基于CAN的汽车低附路面稳定性控制测试系统

基于汽车稳定性控制系统现场快速测试和控制策略调试的需要,搭建了由车身位置姿态模块、汽车稳定性控制器模块和CAN节点数据采集模块组成的低附路面试验测试系统。各模块间基于GPS接收机输出的秒脉冲同步信号完成数据同步,并通过CAN方式进行数据传输。详细给出了汽车侧偏角测试方法、惯性测量单元车上安装和初始对准方法、GPS惯性测量单元数据转换和传输延迟补偿方法,以及串口转CAN的快速实现方法。系统的道路试验验证了系统工作的可靠性。该测试系统构建CAN节点或基于车身CAN总线方式获取基于ESC和发动机管理系统配置传感器的信息,对了解汽车极限工况下的状态提供了真实数据,为汽车稳定性控制分析提供了有效手段。

基于转矩的低附路面机械式自动变速器控制策略

从机械式自动变速器控制系统所能获取的有限数据,判断行驶路面的附着系数以及车辆轮胎打滑情况,并进行驱动防滑控制;通过发动机转矩、变速器数据、整车状态等对车辆正常的加速度范围进行计算,并和轮速加速度进行比较,以确定车轮打滑情况。根据轮加速度的大小进一步判断路面附着系数。轮胎打滑时,通过对发动机的降扭和离合器的控制,实现驱动防滑的控制;在试验车辆上进行低附路面识别和控制的试验,能够正确识别出路面附着系数。在低附路面起步时,通过打滑时发动机转矩和离合器的控制,避免了车轮连续的滑转,大大提高了车辆的稳定性。这说明该低附路面识别和控制方法是可行的,能够在车上使用。

氯苯类易挥发有机污染土壤异位低温热脱附实例研究

针对南京市某大型化工企业退役场地,结合场地修复目标,使用生石灰对场地氯苯类挥发性有机污染物(VOCs)污染土壤进行异位低温热脱附处理。实验室试验结果表明,该方法可有效去除土壤中的VOCs,处理后各污染物去除率均达85%以上。在现场试验中,采用专业土壤修复设备KH200进行土壤破碎和药剂混合,处理过程全封闭运行,可有效降低扬尘等问题。通过投加生石灰提高土壤温度、降低土壤含水量的方法,有效地促进了土壤中VOCs的解吸和挥发,是一种高效率、低成本的土壤修复技术,经过KH200修复设备处理后土壤中各污染物均达到场地修复目标,具备工程应用可行性。

油基钻屑低温热脱附处理工艺模拟

为减少油基钻屑对环境的不良影响和危害,并最大限度地回收资源,提出采用低温热脱附的方式对其进行处理。通过钻井液油水固相分离装置并结合正交实验法对低温热脱附处理工艺进行模拟研究,选用热重分析仪及气相色谱研究油基钻屑热解失重规律以及回收油总石油烃分布。结果表明:低温热脱附处理油基钻屑的主要影响因素为处理温度,其次为停留时间,升温速率影响最小,350℃处理温度下,即可将油基钻屑热脱附残渣含油率降至0.3%以下,满足GB 4284—2018《农用污泥污染物控制标准》;油基钻屑中含水率的增加有利于提高低温热脱附效果,原料含水率在5%~10%时热脱附效果及经济性最好;低温热脱附回收油品质好,和原料总石油烃分布基本一致。

挥发性有机污染土壤异位低温热脱附中试研究

本文主要对某退役农药厂场地中挥发性有机污染土壤成分进行分析,针对其中挥发性有机污染物易挥发及难氧化的特点,采用异位低温热脱附工艺以及土壤修复机进行中试试验,分析试验中不同投加比的发热剂对于某退役农药厂场地中挥发性有机污染土壤修复效果及经济评价。

低温热解析对氧化铝系废弃脱汞剂中汞的回收

天然气脱汞净化工艺中产生的含汞废物,通常采用高温热解析（温度在800-1 000℃之间）回收其中的汞。这项技术存在一定的劣势,例如高温加热需要花费高成本,还可能破坏像脱汞剂这类材料的性质,导致失去再生性能。为克服这些缺点,研发出更加适合的低温热脱附回收技术,该技术加热温度250-350℃之间,并且在350℃下汞回收率可达到99.8%以上。

氯盐对汞化合物污染土壤热脱附过程的影响

对Hg Cl2、Hg S、Hg(NO3)2·H2O、Hg O、Hg SO45种试剂分别添加Mg Cl2、Ca Cl2和Na Cl 3种氯盐,采用热重分析法进行热挥发性对比研究,以期选择对汞化合物热脱附有促进作用的氯盐,并将其添加到内蒙古2块不同污染场地的汞污染土壤样品(A、B)中,进行低温热脱附修复研究.结果表明:5种汞化合物试剂热脱附温度由低到高依次为Hg Cl2<Hg S<Hg(NO3)2·H2O<Hg O<Hg SO4.在汞化合物中加入Mg Cl2、Ca Cl2和Na Cl后的热重分析发现,Mg Cl2对Hg S、Hg(NO3)2·H2O、Hg O、Hg SO4热脱附过程影响最大,降低了汞化合物热脱附的初始温度.A、B 2个污染土壤样品加入Mg Cl2热脱附后,汞的去除率分别从无药剂处理的65.67%、70.74%升至81.35%、84.91%.表明Mg Cl2可以促进汞污染土壤中汞化合物的转化,有利于土壤汞污染的热脱附修复,应用前景较好.

基于转向与制动协同的无人车辆轨迹跟踪控制

针对无人车辆轨迹跟踪控制在极端工况条件下的车辆失稳问题,提出一种考虑车辆横摆稳定性的前轮转向与差动制动分层协同轨迹跟踪控制策略。首先,顶层策略基于模型预测控制算法设计,控制输出为前轮转角,以实现常规工况下的期望轨迹跟踪控制;其次,底层策略基于滑模控制算法设计,得到车辆维持路径跟踪所需的附加横摆力矩,以提高极限复杂工况的横摆稳定性;进而,引入差动制动控制策略对单独车轮制动力矩进行动态分配。整车联合仿真结果表明,所提出的转向与制动分层协同轨迹跟踪控制策略及算法,在高速低附紧急避障工况下,能够有效避免车辆侧滑失稳,明显提高车辆稳定性及轨迹跟踪精度。

基于滑移率和ABS的电动商用车制动性能控制研究

针对电动商用车在低附路面ABS激活后制动平顺性较差的问题,设计基于滑移率和ABS的制动性能控制系统。系统在ABS激活前通过调节制动扭矩,降低ABS激活概率;在ABS激活后通过控制电制动取消速率,并耦合正常状态电制动MAP,从而改善制动平顺性。

关于医疗垃圾飞灰中二噁英在惰性气氛下的低温热脱附研究

以医疗垃圾焚烧炉布袋除尘器前管道内飞灰(BG)及布袋除尘器后飞灰(AG)为对象,研究不同温度及时间段下其在管式炉中的热脱附特性.结果表明,在低温氮气气氛下,热脱附作用较为明显,2种飞灰中的二噁英都有了不同程度的脱除,其中布袋前飞灰中二噁英的脱除率为82.9%～99.9%之间,毒性当量脱除率为77.3%～99.8%,布袋后飞灰中二噁英的脱除率为66.8%～99.8%之间,毒性当量脱除率为43.5%～99.6%.检测收集到的实验尾气,发现了二噁英的存在,且在300～350℃这个温度段生成量最多,且生成的有毒二噁英同系物中以OCDD为主.通过比较发现,当温度为400℃,加热时间为45 min时2种飞灰中的二噁英脱除效率最高.鉴于惰性气氛下的热脱附对处理飞灰中的二噁英具有较好的作用,可将其大规模应用于实际工程中.

Equilibrium Modeling for Hydrogen Isotope Separation by Cryogenic Adsorption

The separation of hydrogen and deuterium by cryogenic adsorption was conducted, using the molecular sieve 5A as adsorbent, helium as the carder gas in a fixed column. The breakthrough curves of hydrogen, deuterium and the mixture of two components in helium carder gas were measured, a separation factor, approximately 2, for the hydrogen-deuterium binary mixture was obtained. The equilibrium model was built for simulation of the concentration distribution for single hydrogen, deuterium and their mixture with helium carder in the fixed column, and the simulation compared well with the experimental results.

Preparation and properties of porous ceramics from spodumene flotation tailings by low-temperature sintering

Porous ceramics were prepared with spodumene flotation talings(SFT),kaolin and low-melting point glass(LPG)powder,whose pores were formed by the chemical reaction of hydrogen peroxide(H_(2)O_(2)).LPG was used to reduce the sintering temperature of porous ceramics and kaolin was used to realize the adsorption to methylene blue(MB)of porous ceramics.The average flexural strength,compressive strength,apparent porosity,water absorption and maximum MB adsorption capacity were 5.60 MPa,4.66 MPa,52.27%,44.32%and 0.7 mg/g,respectively.Moreover,the results of orthogonal experiments present that the sintering temperature and the dosage of H_(2)O_(2)had great influence on the mechanical properties and apparent porosity of porous ceramics,respectively.The main reason for the improvement of mechanical properties of porous ceramics was that LPG gradually became soft with increasing the sintering temperature,which made the mineral particles adhere to each other closely.Kaolinite was not completely converted into metakaolin at 550℃,which might be the main reason why porous ceramics had adsorption properties.

Improving collecting performance of sodium oleate using a polyoxyethylene ether in scheelite flotation

In order to improve the scheelite flotation with sodium oleate(NaOL),the effect of a non-ionic polyoxyethylene ether(JFC-5)on the floatability of scheelite was investigated through flotation experiments at10°C,compared with60mg/L NaOL alone,the recovery of scheelite is improved from22%to85%in the presence of JFC-5with a mass ratio of20%at pH10.Moreover,the resistance to Ca2+of NaOL is increased.The adsorption mechanism was analyzed by zeta potential measurement,contact angle measurement and X-ray photoelectron spectroscopy(XPS)analysis.The results show that the adsorption of NaOL on scheelite surface is enhanced after adding JFC-5due to the more negative zeta potentials and larger contact angles of scheelite.And the co-adsorption of NaOL and JFC-5is confirmed by XPS analysis,so it is indicated that the adsorption of JFC-5decreases the electrostatic repulsion between the oleate ions,resulting in the stronger adsorption of NaOL on scheelite surface.In short,the mixed NaOL/JFC-5collector can effectively improve scheelite flotation.

Adsorption of hexavalent chromium onto kaolin clay based adsorbent

A low-cost adsorbent modified kaolin clay(MKC) was synthesized and utilized for Cr(VI) removal from aqueous solution. Adsorption experiments were carried out as a function of adsorbent dosage, solution pH, Cr(VI) mass concentration, contact time, electrolyte, and temperature. It is found that the adsorption efficiency is high within a wide pH range of 2.5-11.5, and equilibrium is achieved within 180 min. Increases in temperature and electrolyte concentration decrease the adsorption. The adsorption follows the pseudo-second-order kinetic model. The Langmuir isotherm shows better fit than Freundlich isotherm. The maximum uptake capacities calculated from the Langmuir model are 15.82, 15.55 and 15.22 mg/g at 298, 308 and 318 K, respectively. Thermodynamic parameters reveals the spontaneous and exothermic nature of the adsorption. The FTIR study indicates that hydroxyl groups, NH4+ ions and NO3- ions on MKC surface play a key role in Cr(VI) adsorption. The Cr(VI) desorbability of 86.53% is achieved at a Na2CO3 solution. The results show that MKC is suitable as a low-cost adsorbent for Cr(VI) removal which has higher adsorption capacity and faster adsorption rate at pH close to that where pollutants are usually found in the environment.

Adsorption of dimethyl trisulfide from aqueous solution on a low-cost adsorbent:thermally activated pinecone

Thermally activated pinecone(TAP) was used for the adsorption of dimethyl trisulfide(DMTS)from aqueous solutions,which was proved to be the main odorous in algae-caused black bloom.The effects of adsorbent dosage,adsorbate concentration and contact time on DMTS biosorption were studied.The TAP produced at 600℃ exhibited a relatively high surface area(519.69 m^2/g) and excellent adsorption capacity.The results show that the adsorption of DMTS was initially fast and that the equilibrium time was6 h.Higher initial DMTS concentrations led to lower removal percentages but higher adsorption capacity.The removal percentage of DMTS increased and the adsorption capacity of TAP decreased with an increase in adsorbent dosage.The adsorption process conforms well to a pseudo-second-order kinetics model.The adsorption of DMTS is more appropriately described by the Freundlich isotherm(R^2=0.996 1) than by the Langmuir isotherm(R^2=0.916 9).The results demonstrate that TAP could be an attractive low-cost adsorbent for removing DMTS from water.

Pd-M-TiO_(2)(M=Mn,Cu,Ce and Fe)as passive NO_(x) adsorber(PNA)at low temperature

A series of transition metal Mn,Cu,Ce and Fe were loaded on TiO_(2) by sol-gel method with noble metal Pd as promotor for the application of passive NO_(x) absorber.Experiments on adsorption and desorption of NO_(x) were conducted and characterization methods such as X-ray diffraction(XRD),X-ray photoelectron spectroscopy(XPS),transmission electron microscopy(TEM)and in situ Fourier transform infrared spectroscopy(in situ DRIFTS)were involved.The experimental results show that Mn-contained catalysts,Mn-Ti and Pd-Mn-Ti,performed excellent NO_(x) adsorbing ability and appropriate desorption temperature window.On the other hand,Ce-and Cu-contained samples were not suitable for the purpose of PNA.In addition to the low adsorption capacity,these two series of catalysts released massive amount of NO below 150℃.Characterization results indicated that Pd was highly dispersed on all catalysts.The loading of Pd lowered not only the valence states of transition metals but surface oxygen percentage as well.From in situ DRIFTS tests,the Pd had little influence on the types of adsorbed substances for Mn,Ce and Cu series.However,the storage forms of NO_(x) were obviously different on Pd-Fe-Ti and Fe-Ti.

Kinetic and Thermodynamic Studies of Acid Scarlet 3R Adsorption onto Low-cost Adsorbent Developed from Sludge and Straw

A low-cost adsorbent was prepared from sludge and straw by pyrolysis in a dried state with the surface area of the adsorbent of 829.49 ma. g-l, micropore volume of 0.176 cm2·g-1 and average pore radius of 5.0 nm. The kinetic, equilibrium isotherm and thermodynamic characteristics of trisodium 1-（1-naphthylazo）-2-hydroxynaphthalene- 4＇,6,8-trisulphonate （acid scarlet 3R） onto the adsorbent from sludge and straw were investigated. The results indicated that the pseudo second order adsorption was the predominant adsorption mechanism of acid scarlet 3R. Thus, the adsorption phenomenon was suggested as a chemical process. The adsorption data were fitted better with Langmuir model than Freundlich model, indicating that the adsorption of acid scarlet 3R belonged to the monolayer adsorption and mainly occurred in micropores.

Pore characterization of different types of coal from coal and gas outburst disaster sites using low temperature nitrogen adsorption approach

To characterize the pore features of outburst coal samples and investigate whether outburst coal has some unique features or not, one of the authors, working as the member of the State Coal Mine Safety Committee of China, sampled nine outburst coal samples(coal powder and block) from outburst disaster sites in underground coal mines in China, and then analyzed the pore and surface features of these samples using low temperature nitrogen adsorption tests. Test data show that outburst powder and block coal samples have similar properties in both pore size distribution and surface area. With increasing coal rank, the proportion of micropores increases, which results in a higher surface area. The Jiulishan samples are rich in micropores, and other tested samples contain mainly mesopores, macropores and fewer micropores. Both the unclosed hysteresis loop and force closed desorption phenomena are observed in all tested samples. The former can be attributed to the instability of the meniscus condensation in pores,interconnected pore features of coal and the potential existence of ink-bottle pores, and the latter can be attributed to the non-rigid structure of coal and the gas affinity of coal.

Removal of Cu^2＋ Ions from Aqueous Solutions by Adsorption on Libyan Soil

Heavy metals are well recognized as potential health hazards as they can neither be degraded nor biologically detoxified. This experimental study aims to investigate the possible use of Libyan local soil, Ashkida soil, mined in the Southern Province of Libya as a low cost adsorbent to remove copper ions from aqueous solutions. In this work, the effects of various parameters such as adsorbent dosage, initial concentration of copper, agitation rate, contact time and solution pH level on the adsorption efficiency are investigated through batch experiments at room temperature. The results indicate that the optimum conditions for copper removal from aqueous solutions are 60 minutes contact time, 10 g/L adsorbent dose and 500 rpm agitation rate at natural pH value. The results are fitted to Freundlich, Langmuir, Temkin and Dubinin-Radushkevich isotherms. A satisfactory agreement between the experimental data and the model-predicted values is expressed by the correlation coefficient, r^2, and the total mean error, E%. Freundlich model offers the best representation of adsorption process revealing a monolayer adsorption capacity, qmax, of 27.03 mg/g. A comparison of kinetic models applied to the adsorption of copper ions on the adsorbent is evaluated by simple first order, pseudo first order and pseudo second order kinetic models. Kinetic parameters, rate constant, equilibrium sorption capacities and related correlation coefficients for each kinetic model are determined revealing that the pseudo second order kinetic model is in a better correlation with the experimental data in comparison with the other isotherms.