隔油–破乳–Fenton氧化–混凝工艺处理高浓度乳化液废水

针对某难处理高浓度乳化液废水,提出了隔油–破乳–Fenton氧化–混凝联合处理工艺.试验结果表明:乳化液废水静浮20 min除去上层浮油,在废水pH值8.0,PAC投加量8.0 g/L,0.1‰PAM投加量10 mL/L的条件下破乳效果较好.废水继续通过Fenton试剂氧化及混凝沉降处理,当Fenton氧化初始pH值3.5,H2O2(30%)投加量12 mL/L,[H2O2]/[Fe2+]=4∶1,一次性投加FeSO4·7H2O,反应时间45 min及混凝沉降pH值8.0,混凝剂投加量0.3 g/L时,处理效果令人满意.采用该工艺处理高浓度乳化液废水,其COD去除率为99.91%,浊度去除率为98.96%,石油类去除率为99.97%,处理后水质达到《污水综合排放标准》(GB8978-1996)二级标准.     

滑坡–堵江–涌浪灾害链模拟的DEM–CFD耦合分析方法及其应用

滑坡-堵江-涌浪灾害链的演化过程涉及复杂的滑坡-河流相互作用。为了真实再现这一演进过程,本文提出了一种扩展的离散元法（DEM）与计算流体动力学（CFD）耦合数值方法,通过在局部平均DEM-CFD耦合方法中引入流体体积法（VOF）建立了一套能够描述河流自由水面演化的扩展DEM-CFD耦合数值框架,实现了对滑坡涌浪形成及传播过程的追踪;并提出了一种新的局部孔隙率计算方法即虚拟球模型,来克服网格颗粒临界尺寸比的限制,从而实现复杂地形建模要求;进一步通过多个典型算例验证其准确性和有效性。在此基础上,开展了滑坡-堵江-涌浪灾害链演化模拟,并应用至白格滑坡坝形成过程复演,深入分析了滑坡-河流动态演化过程及耦合作用机理。结果表明：所提出的方法能够准确模拟滑坡-河流相互作用;滑坡-河流-河谷地形的耦合作用驱动了灾害演化,滑坡体驱动了涌浪的传播,而河流则增加了滑坡体的动能耗散,且对其沉积过程在河流流向上产生相反影响;模拟得到的白格滑坡运移路径、沉积形态及涌浪侵蚀面积与实地调查结果吻合度较高,成功再现了2018年10月11日白格滑坡堵江事件。本文所提出的扩展DEM-CFD耦合数值方法为深入研究滑坡-堵江-涌浪灾害链演化机制提供了有力的数值工具,对于灾害预测及防灾减灾策略的制定具有一定的参考价值。     

镍铁渣–黏土–水泥改性土力学特性试验及修正的邓肯–张模型

为研究镍铁渣-黏土-水泥(FNSCC)改性土的力学特性,开展了不同镍铁渣掺入比、含水率及养护时间下FNSCC改性土不固结不排水三轴压缩试验;获得了不同工况下FNSCC改性土试样的应力-应变关系曲线及割线弹性模量,分析了其力学特性影响机理及破坏模式,基于试验结果,建立了适用于FNSCC改性土的修正邓肯-张本构模型。研究结果表明：FNSCC改性土的应力-应变曲线具有明显的应变软化特征;其峰值强度随镍铁渣掺入比减小和养护时间增长而增大,随含水率的增加先增大而后减小。随着镍铁渣掺入比的增大,FNSCC改性土试样的破坏模式由鼓胀破坏向剪切破坏转变;含水率为15%左右的试样,鼓胀破坏特别明显;而随养护时间增长,其破坏模式则由鼓胀变形等塑性破坏向局部张裂等脆性破坏转变。FNSCC改性土的割线弹性模量随轴向应变增加而减小,轴向应变小于2%时,镍铁渣掺入比、含水率及养护时间对割线弹性模量的影响较大;而当轴向应变大于2%后,各因素对割线弹性模量的影响很小。修正的邓肯-张模型能较好地反映FNSCC改性土的应变软化现象;该模型中参数m、n及?与围压近似呈线性关系,模型参数m受FNSCC改性土配比的影响最大,养护时间次之,含水率最小。由修正邓肯-张模型计算得到的曲线与实测曲线吻合较好,验证了该模型拟合参数的合理性。     

赤泥–高炉矿渣–钢渣三元体系注浆材料试验研究

为解决地下工程灾害治理中大量消耗水泥造成的环境污染、造价高等问题,基于协同理论制备了赤泥–高炉矿渣–钢渣基三元体系全固废类注浆材料,系统研究了钢渣对赤泥–高炉矿渣二元体系工作性能、力学强度的作用规律,并结合X射线衍射、傅里叶变换红外光谱、扫描电镜、压汞仪等微观测试手段分析其作用机理。试验结果表明:钢渣对赤泥–高炉矿渣二元体系力学强度具有提升作用,当其掺量为10%时,28 d抗压强度可达12.78 MPa,增幅为59.84%。钢渣经机械粉磨和高温活化后,其协同作用可进一步提高,随着钢渣粒度的减小,浆液结石体力学强度逐渐增强;随着活化温度提升,结石体力学强度呈先增加后减小的趋势。钢渣在10%最优掺量下,活化温度为700℃,粒径为200目时,赤泥–高炉矿渣–钢渣基注浆材料结石体的力学强度最优,28 d强度达到15.1 MPa。此外,钢渣的掺入还可以促进赤泥–高炉矿渣基浆液的凝结,凝结时间缩短,浆液的流动性降低。微观分析表明:钢渣可参与赤泥–高炉矿渣体系的水化反应,而且钢渣微粒在浆液结石体中具有充填效应,使结石体更加密实,进而提高结石体力学强度;此外,在高温条件下,钢渣中生成钙芒硝、硅酸二钙、硅酸三钙、铝酸钙胶凝矿物,可促进钙矾石和水合铝酸钙的生成,对强度具有提升作用。     

基于模糊Petri网的“网–源–储–车”动态阈值能量管理策略研究

轨道交通作为电力系统的主要用能对象之一,每年消耗大量电能用于电力机车牵引。因此,降低牵引能耗、提升供能系统的弹性与效能对促进碳达峰、碳中和具有重要的现实意义。轨道交通“网–源–储–车”协同供能系统在传统牵引供电架构的基础上引入了储能系统与新能源发电系统,然而,如何实现牵引负荷、储能系统及新能源发电系统的高效能源自洽,减少双向波动性与不确定性对能量管理系统的影响成为了新的难题。为实现以上目标,减轻牵引负荷对牵引网的功率冲击,延长储能系统的使用寿命,本文提出了一种基于模糊Petri网（fuzzy Petri nets,FPN）的“网–源–储–车”动态阈值能量管理策略。该策略在“网–源–储–车”基本功率分配框架的基础上,设定了多工况下牵引供电系统与储能系统、新能源发电系统的动态能量交互规则,可适用于不同架构的“网–源–储–车”协同供能体系;在此基础上,以电力机车功率与储能系统寿命作为模糊Petri网的输入参数,经过模糊化、Petri网推理、反模糊化等操作后实现对放电阈值的自适应动态调整。本文以某牵引变电所实测数据作为测试案例,仿真结果表明：相较于基于固定阈值的能量管理策略,基于模糊Petri...     

Microstructures and Thermal Properties of Sn–Bi–Zn–Ga Alloys as Heat Transfer and Heat Storage Materials

Low melting point alloy is a potential high-temperature heat transfer medium because of the high thermal conductivity, low solidus temperature and wide range of use temperature. Consequently, we investigated the possibility of using Sn–Bi–Zn–Ga alloys as heat storage and heat transfer material. Moreover, we investigated the microstructure and phase compositions by electron probe micro-analysis(EPMA) and X-ray diffusion(XRD). Results show that the new structures and phases are formed in the alloy matrix with Ga additions, which lead to the improvement of the thermal properties. An extensive thermophysical characterization of the Sn–Bi–Zn–Ga alloys has been performed by differential scanning calorimeter(DSC) analysis. The addition of Ga lowers the peak temperature and increases the heat capacity of the alloys. The thermal expansion of the test alloys increases with increasing temperature and the densities decreases with Ga additions. As the density, specific heat capacity and thermal diffusivity change with temperature and physical state, the thermal conductivity of the alloys first decreases and then increases. These results demonstrate the feasibility of using Sn–Bi–Zn–Ga alloys as the high-temperature heat transfer fluid.     

2–UPR&2–RPU冗余并联机构动力学与功耗分析

提出一种新型2–UPR2–RPU结构冗余并联机构,其具有2个转动以及1个移动(2R1T)自由度。运用螺旋理论分析机构的自由度及其运动特性,并利用修正的G–K公式验证分析的准确性,得出该机构含有1个冗余支链的结论。分析机构运动的约束条件,建立各支链的闭环矢量方程,求解得出机构的位置反解。基于符号运算的微分变换法对机构的速度和加速度进行分析,得到动平台速度雅可比矩阵和2阶影响系数矩阵,在此基础上进一步求解得出各支链的雅可比矩阵。运用虚功原理构建该机构的动力学模型,然后根据冗余并联机构驱动力配置方式不唯一的特点,采用驱动力二范数的优化方法推导得出驱动力和驱动功率方程。在此基础上,使用MATLAB对所构建的数学模型编写计算程序,并通过具体数值算例对所构建的运动学及动力学模型进行仿真。最后,为了验证所构建数学模型的正确性,在ADAMS中建立机构虚拟样机并进行相同条件的仿真,将该结果与MATLAB仿真结果进行对比,两者的仿真结果基本一致,表明所构建数学模型的正确性。仿真得出各杆驱动力的最大误差分别为0.091%、1.83%、1.04%、1.40%。研究结果表明,在给定的运动规律的条件下,机构没有产生刚性冲击,在运动的起点和终点处,会产生一定的柔性冲击,整个运动过程中各杆的驱动力变化平缓,驱动力二范数解所做的总功为1 143.2 J。     

Effect of vanadium and chromium on the microstructural features of V–Cr–Mn–Ni spheroidal carbide cast irons

The objective of this investigation is to study the influence of vanadium（5.0wt%–10.0wt%） and chromium（0–9.0wt%） on the microstructure and hardness of Cr-V-Mn-Ni white cast irons with spheroidal vanadium carbides. The alloys＇ microstructural features are presented and discussed with regard to the distribution of phase elements. The structural constituents of the alloys are spheroidal VC, proeutectoid cementite, ledeburite eutectic, rosette-shaped carbide eutectic（based on M7C3）, pearlite, martensite, and austenite. Their combinations and area fraction（AF） ratios are reported to be influenced by the alloys＇ chemical composition. Spheroidized VC particles are found to be sites for the nucleation of carbide eutectics. Cr and V are shown to substitute each other in the VC and M7C3 carbides, respectively. Chromium alloying leads to the formation of a eutectic（γ-Fe ＋ М7С3）, preventing the appearance of proeutectoid cementite in the structure. Vanadium and chromium are revealed to increase the total carbide fraction and the amount of austenite in the matrix. Cr is observed to play a key role in controlling the metallic matrix microstructure.     

超高效液相色谱–四极杆飞行时间串联质谱测定牦牛肉中5'–肌苷酸和5'–鸟苷酸

建立了超高效液相色谱–四级杆飞行时间串联质谱快速测定牦牛肉中5'–肌苷酸、5'–鸟苷酸含量的分析方法。首先采用正交试验对5'–肌苷酸、5'–鸟苷酸提取工艺进行了优化;进一步采用串联四级杆飞行时间质谱对肌苷酸和鸟苷酸进行定性、定量分析。结果表明: 5'–肌苷酸和 5'–鸟苷酸在0.312 5~50.0 μg/mL质量浓度范围内线性关系良好,平均回收率分别为为101.53%、96.27%,|基质效应|分别为 26.21%、16.27%。本方法具有检测快速、灵敏度高和重现性好等优点,可以为牦牛肉中呈味核苷酸的检测提供技术支撑。     

初始损伤–载荷–冻融作用下红砂岩的孔隙结构及力学特性

中国寒区的岩体支护、边坡开挖等工程需要深刻认知、准确评估载荷和冻融诱发岩体的损伤情况,尤其是裂隙岩体的损伤。研究采用核磁共振技术测试含单裂隙红砂岩试样在初始、力学循环加载后、冻融循环后三个阶段的孔隙度、T2谱分布等微观孔隙参数,随后测试损伤后试样的力学参数,以量化、评估力学循环加载、冻融循环对试样孔隙参数及力学性质的影响。试验结果表明,荷载和冻融先后作用下不同试样的孔隙结构和力学性质有相似的变化规律。试样随着力学循环加载其孔隙度不断增大,随着冻融循环作用其孔隙度继续增大。循环载荷作用促使试样孔隙度的增大以原有孔隙扩展为主,冻融循环作用促使试样孔隙度的增大以新增小孔隙和原有孔隙扩展为主。载荷、冻融都将导致试样强度、弹性模量的损伤,单一冻融作用下红砂岩试样强度损伤在5%-10%,但载荷、冻融先后作用下试样强度损伤达到20%-30%,试样的初始强度越小其强度损伤越大。分析试样的微观孔隙和宏观力学之间的相关性,发现损伤试样的孔隙度增幅与试样的强度降幅呈正相关。     

Improved recovery of a low-grade refractory gold ore using flotation–preoxidation–cyanidation methods

In this work, different flotation–preoxidation–cyanidation methods are considered for treating a low-grade refractory gold ore. On the one hand, the results of selective flotation show that 22% and 31.1% of total Sb and As, respectively, remained in the final tailings and only about 28% of the total Au remained for further cyanidation processes. On the other hand, in bulk method of flotation the maximum Au recovery of 90.6% achieved after 60 min of flotation at the grind size with K80 of 146 micron. In addition, the bulk flotation method resulted in the concentrate with low concentrations of Sb and As elements. To improve the recovery of low-grade refractory gold ores, flotation should be followed by roasting, biological, or pressure oxidation processes so that the gold could be liberated prior to cyanidation processes. It is also found that the pressure oxidation pre-treatment of the concentrates prior to cyanidation may yield high gold recoveries of over than 83%. In these processes, recoveries are controlled by the temperature and the oxygen partial pressure in the solvent. However, by utilizing the bio-oxidation technique, the oxidation of sulfur to sulfate cannot be completed and, consequently, the gold recovery may be limited to only 72.2%.     

考虑预测不确定性的风–光–水多能互补系统调度风险和效益分析

风电、光伏与水电(简称风光水)互补发电系统是提高清洁能源整体利用效益的重要创新模式,随着风电、光伏发电渗透率的增加,如何解决大规模风光接入所带来的不确定性是多能互补系统研究的核心和难点。作者重点探讨日前风光出力预测的不确定性对于多能互补系统风险和效益的综合影响。首先,从可靠性、稳定性和经济性3个方面提出风光水多能互补系统调度运行风险和效益评价体系;建立多能互补系统短期优化调度模型,在日前风光出力预测结果基础上,编制系统日前发电计划;根据风光实际出力情况,滚动更新和模拟水电站实际调度过程。最后,对比分析各电站计划和实际调度运行情况,评价日前风光出力预测不确定性对于多能互补系统风险与效益的综合影响。以接入209万kW光伏和104.9万kW风电的雅砻江流域锦屏一级多能互补系统为实例进行研究。相比风光水独立运行,风光水互补后系统的发电效益提高了37.13%,且系统出力过程更为稳定。互补系统在年尺度上具有良好的可靠性,但在水库低水位时期,系统失负荷天数明显增多,占全年失负荷天数的96%以上,系统可靠性降低;在汛期,互补后水库的下泄流量最大增加了47.06%,出现水量集中下泄的情况,这给电力部门、下游用水部门以及防护对象带来一定的防洪风险。     

湿–载–热对粉质黏土持水性能的影响特征及预测模型

非饱和土的持水性能通常以土水特征曲线的变化规律来体现。荷载和温度等因素对土水特征曲线的重要影响已逐渐被认识,但综合考虑湿–载–热对土水特征曲线共同作用的研究鲜见报道,对其主导性影响因素的分析更为罕见。为了探究粉质黏土在湿–载–热共同作用下的持水性能,本文开展了在不同竖向应力和温度条件下粉质黏土的干湿循环实验,分析了各因素的影响机理、特征和重要性,并建立了反映多因素共同作用的预测模型。研究结果表明:1)随着竖向应力的增加,非饱和土的进气值增加、减湿率降低、干湿循环过程的滞回效果变强,且在各个温度下皆表现出相同的特征。2)对比在相同的竖向应力、不同温度下的实验曲线,发现在温度较高的状态下,土体的进气值相对略低。3)竖向应力对于土体持水性能的影响最大,但主要局限于低吸力阶段;干湿循环的作用排第2,且随着循环次数增加会快速衰减;温度的影响较小,且在吸力值或密实度较高时可忽略不计。4)基于Logistic曲线改进后的L模型比常用的V–G模型更适用于巴东粉质黏土的土水特征曲线拟合。综合研究结果得出:竖向应力引起特征值变化的根本原因在于内部孔隙结构的改变,进而导致持水性能产生差异;温度主要影响土体处于低应力低吸力状态时的持水性能;3种赋存条件对粉质黏土持水性能的影响程度呈竖向应力干湿循环温度分布;改进后的L模型可以有效反映粉质黏土在湿–载–热共同作用下的持水性能演变特征。     

An efficient method for train–track–substructure dynamic interaction analysis by implicit-explicit integration and multi-time-step solution

In this work, a method is put forward to obtain the dynamic solution efficiently and accurately for a largescale train–track–substructure(TTS) system. It is called implicit-explicit integration and multi-time-step solution method(abbreviated as m I-n E-MTS method). The TTS system is divided into train–track subsystem and substructure subsystem. Considering that the root cause of low efficiency of obtaining TTS solution lies in solving the algebraic equation of the substructures, the high-efficie...     

Electromagnetic interference assessment of a train–network–pipeline coupling system based on a harmonic transmission model

The harmonics and resonance of traction power supply systems(TPSSs) aggravate the electromagnetic interference(EMI)to adjacent metallic pipelines(MPs), which has aroused widespread concern. In this paper, an evaluation method on pipeline interference voltage under harmonic induction is presented. The results show that the Carson integral formula is more accurate in calculating the mutual impedance at higher frequencies. Then, an integrated train–network–pipeline model is established to estimate ...     

聚氨酯–橡胶复合阻尼材料减振优化设计

隔离自由阻尼是在传统的自由阻尼结构上建立的一种减振处理方法。以隔离自由阻尼理论为基础,提出以硬质聚氨酯泡沫作为隔离层、橡胶为阻尼层制备用于抑制结构振动的聚氨酯–橡胶隔离复合阻尼材料。利用模态叠加原理和Lagrange方程,在考虑阻尼层剪切变形的基础上,推导出隔离自由阻尼悬臂梁的控制方程。在钢板悬臂梁上敷设隔离层与阻尼层厚度比值为1～3以及具有分段式隔离层的聚氨酯–橡胶复合阻尼材料,并通过单点锤击实验从幅频曲线、复合损耗因子、模态频率等方面对悬臂梁模型的减振性能进行对比分析。结果表明:隔离层与阻尼层的厚度比值由1增加至3时,模型的振动响应峰值降低了13%～62%,同时损耗因子明显升高;当厚度比超过1.5时,材料对模型低阶模态的减振效果持续提高,而高阶模态的减振效果趋于稳定;分段式隔离层的设计降低了隔离层的抗弯刚度,扩大了阻尼层的处理面积,模型振动响应峰值降低了16%以上,且并未显著增加阻尼处理的附加质量。研究结果表明:在聚氨酯–橡胶隔离复合阻尼材料的阻尼层厚度不变的情况下,增大隔离层与阻尼层的厚度比有助于提高复合阻尼材料的减振性能;分段式隔离层的设计能够进一步改善复合材料的阻尼性能。     

Melting,sintering and wetting properties of ZnO–Bi_2O_3–B_2O_3 sealing glass

Glasses based on ZnO-Bi_2O_3-B_2O_3 system are expected to be a new kind of sealing glasses because of their low melting temperature and other properties.In order to reveal the effect of B_2O_3 on the rheological behavior of ZnO-Bi_2O_3-B_2O_3 system glass melt,the properties of viscosity,thermal expansion,fluxion property and wetting process between cylinder samples and stainless steel were investigated with the rotating crucible viscometer,dilato meter and high-temperature microscope.The structure of sintered glass samples was investigated with scanning electron microscope.The results show that the B_2O_3 content increasing in B_1-B_3 at the given temperature between 400 ℃ and 500 ℃ leads to the increasing of the sample viscosity.When the amount of B_2O_3 increases from 5.24%to 9.24%(mass fraction),the coefficients of thermal expansion of glass samples decrease smoothly from 10.94×10~(-6) to10.71×10~(-6) and 10.38×10~(-6) ℃~(-1) respectively.In the case of sealing temperature,its value increases from 453 ℃ to 494 ℃.ZnO-Bi_2O_3-B_2O_3 system low-melting glass powder sintering was with viscous liquid to participate,which could make the densification of glass sample more effective and more efficient.With the content of B_2O_3 increasing,the wetting angle between the glasses samples and stainless steel could also increase,and the resulting appropriate sealing temperature range is 460-490 ℃.     

Ultrahigh performance concrete–properties,applications and perspectives

Over the last twenty years,remarkable advances have taken place in the research and application of ultra-high performance concrete(UHPC),which exhibits outstanding mechanical properties and excellent durability.It has shown great potential for the next generation infrastructure construction from the sustainability point of view.This paper will give an overview on UHPC,with particular focus on the properties,applications and perspectives.After several decades of development,several types of commercial UHPC materials are available in the market,and the properties of UHPC have been characterized by numerous experimental and field tests.Generally speaking,the performance(e.g.mechanical properties and durability)of UHPC is much better than normal concrete(NC)and high performance concrete(HPC).Therefore,the uses of UHPC are growing all over the world,in both fields of new construction and retrofitting.Nevertheless,it is still a special material and technology,which is not worldwide accepted.So some application prospects of UHPC are briefly introduced in the paper,and the efforts,which have to be made to turn UHPC into a widespread‘regular’technology,are discussed.This paper aims to help designers,engineers,architects and infrastructure owners to know the capacities of UHPC and thus to increase the applications of this material.     

Carboniferous–Permian marine transgressions in the Jiyang Depression

In recent years, great attention has been paid to oil and gas exploration in the Carboniferous–Permian strata of the Bohaiwan basin, especially the Carboniferous–Permian marine transgression, using data from drilling, outcrops and carbonate acid-insoluble residue experiments together with the tectonic evolutionary history of the peripheral orogenic zones of the North China plate and the Tan-Lu fault zones. The study concludes that marine transgressions took place on six occasions during Carboniferous–Permian time in the Jiyang Depression. The marine transgressions were concentrated in the Late Carboniferous: two marine transgressions occurred in the early Late Carboniferous, and the scale of the first was smaller and the time was shorter than those of the second. The other four marine transgressions happened in the late Late Carboniferous, the first and the fourth of which were larger in scale and longer in time than the second and the third. The seawater came from the Jiaobei area, the eastward part of the Qinling–Dabie residual sea basin, and invaded progressively as a planar flow from south to north and from east to west. These findings have great significance for thorough analysis of the sedimentary characteristics and evolution of the Carboniferous–Permian strata in the Jiyang Depression.     

数控车床主轴热误差SHO–LSTM预测建模

在高精度加工过程中,数控机床主轴误差对加工精度的影响较为严重。数控机床热误差占总误差比例高达40%～70%,是主要的误差源之一。为了提高热误差预测的精度,本文提出一种使用海马优化算法（SHO）优化时序预测网络（LSTM）的精密车床主轴热误差预测建模方法。首先,利用羚羊优化算法（GOA）对模糊C均值聚类（FCM）的模糊矩阵常数、最大迭代次数、迭代终止条件进行优化并结合皮尔逊（Person）、斯皮尔曼（Spearman）和肯德尔（Kendall）相关分析方法优化温度测点,使用手肘法确定最优分组规模,根据DB(Davies–Bouldin)、BWP(Bregman Within–class Projection)和Silhouette(Silhouette coefficient)聚类评估指标评估温度测点聚类效果。其次,以车床主轴五点法获取的热误差数据和优化后的温度数据作为输入,使用海马优化算法（SHO）对时序预测网络（LSTM）的隐含层节点、全连接层节点、学习率、L2正则化常数进行优化,并使用S折交叉试验方法确定最优分组规模,建立主轴热误差SHO–LSTM预测模型。再次,在不同转速下对构建...