The transport and retention of CQDs-doped TiO2 in packed columns and 3D printed micromodels

CQDs-doped TiO₂（C-TiO₂） has drawn increased attention in recent because of its excellent catalytic performance.Understanding the transport of C-TiO₂ in porous media is necessary for evaluating the environmental process of this new nanomaterial.Column experiments were used in this study to investigate ionic strength（IS）,dissolved organic matter（DOM）and sand grain size on the transport of C-TiO₂.The mobility of C-TiO₂ was inhibited by the incr...     

硝基苯在傍河地下水源地迁移转化的模拟实验

以黑龙江省佳木斯市傍河地下水源地为主要模拟对象，进行了硝基苯迁移转化的室内模拟实验。结果表明：吸附与生物降解作用是影响硝基苯在含水屡中迁移转化的主要因素。淤泥介质对硝基苯的除去能力较高，砂砾介质对硝基苯的除去能力相对较弱。实验过程中，从进水口至出水口的各取样点依次出现硝基苯浓度峰值，并且随着硝基苯迁移路径的延长其浓度峰值相应变小。硝基苯的浓度峰值在含水介质中的持续时间并不很长，但由于硝基苯解吸附作用的存在，在此后相当长的一段时间里都存在较为明显的拖尾现象。     

胜利油田废钻井液固液分离技术研究实验

针对胜利油田勘探与开发特性以及钻井过程中产生大量的高含水量的废钻井液,在固化处理技术的基础上对其分离技术进行了研究与实验,经现场实验,处理后主要污染物指标均能达到国家《污水综合排放标准》(GB8978—1996)中的二级标准。     

Estimating the population size with a behavioral response in capture-recapture experiment

A new estimating procedure is suggested to estimate the population size in a capture-recapture experiment. The capture intensities for first-capture and recapture are allowed to be different and time dependent but they are assumed to be proportional. It is shown that the information on the proportionality constant is crucial to the estimation of the population size. Sensitivity analysis with a misspecification of the proportionality constant is conducted. The method has also been extended to the case with an unknown proportionality. A real example is given.     

考虑礼让规则与出口切分的瓶颈处行人动力学规律研究*

为研究礼让规则和出口切分对瓶颈处行人微观行为及通行效率的影响,充分调研并设计行人动力学规律实验,使用图像识别技术从采集的实验视频中获取行人运动轨迹与坐标数据。研究表明:行人平均速度与视野内行人平均最近距离呈正相关、与视野内平均人数、相对角度呈负相关;同向从众、反向避让的行人行为特征导致行人在通过瓶颈时会出现明显分层现象,平均层间距150 mm。考虑礼让规则时,通行效率与初始人员数量呈负相关,但行人反应时间间隔的不确定性导致瓶颈整体通行效率下降,适当瓶颈宽度可避免“成拱”现象发生并提高瓶颈空间利用率,进而提高通行效率;非拥挤状态下竞争规则比礼让规则的通行效率更高;将宽2 m的瓶颈划分多个出口瓶颈整体通行效率变化不大,但单个出口通行效率明显提高,且面对多出口选择时行人表现出右侧出口选择倾向性。     

高压输电线路抗冰灾的研究现状与发展趋势

从导地线和输电塔的覆冰模型、覆冰断线倒塔破坏机理、覆冰气象条件下塔-线体系可靠性等方面,全面分析了高压输电塔-线体系抗冰灾的研究现状和发展趋势,系统总结了国内外有关高压输电线路抗冰灾的研究成果。指出了目前高压输电塔-线体系抗冰灾研究中存在的问题和不足,具体从导地线和输电塔的覆冰模型、覆冰断线冲击的动力学分析理论、模型实验和数值模拟方法、塔-线体系覆冰可靠性等方面提出了当前迫切需要进行研究的内容与方向,以揭示高压输电线路覆冰断线以及倒塔破坏的机理,增强抵抗冰荷载灾害性破坏的能力及完善高压架空输电线路设计的标准。     

轻骨料混凝土组合楼板的火灾响应及火灾后性能研究

对一组具有不同参数的轻骨料混凝土组合楼板开展了火灾响应及火灾后承载力试验研究。试验用轻骨料为一种烧制陶粒,楼板的制作主要考虑了板厚的变化及栓钉的设置。对承载条件下的4块简支陶粒混凝土组合楼盖进行了火灾行为试验,分别得到了其火灾响应温度及位移响应。为了考察该类组合楼盖火灾后的受力性能,进一步进行了火灾后的承载力试验研究,并与一块未受火灾作用的楼盖进行了对比试验。结果表明,增加楼板厚度不仅能提高轻骨料组合楼板的抗火性能,也能提高其在火灾后的承载力。但是,在楼板内部设置焊接栓钉会减弱组合楼板的抗火性能,降低组合楼板在火灾后的承载力;压型钢板-陶粒混凝土组合楼盖受火后整体刚度虽然有明显下降,但仍具有较高的承载力,且塑性性能良好;陶粒混凝土组合楼盖的热响应温度沿楼板板厚方向的变化呈明显的非线性,但可近似为两个线性变化段。     

紧密型栅栏对风沙流影响的实验研究

开展了紧密型栅栏阻沙的野外观测实验,探讨栅栏对风沙流粒度组成及输沙量的影响。结果表明:受栅栏影响风沙流中大粒径沙粒含量降低,小颗粒含量增加;沙粒越过栅栏继续随气流运动的能力与其粒径相关,以0.1mm~0.075mm粒径穿越能力最强,随着粒径的增大或减小这种能力逐渐减弱;粒径1mm的沙粒则很难通过栅栏;沙粒沉积主要发生在在栅栏前端,以粒径0.1mm沙粒为主,占沉积沙土总量的80%强。     

LC-MS/MS method validation for determination of selected neonicotinoids in groundwater for the purpose of a column experiment

The work was carried out to develop and validate a method based on liquid chromatography tandem mass spectrometry (LC-MS/MS) for the simultaneous detection and quantification of five neonicotinoid insecticides: acetamiprid, clothianidin, imidacloprid, thiacloprid and thiamethoxam in groundwater samples for the purpose of a further column experiment. This experiment will be used to analyze breakthrough curves of neonicotinoids under a saturated water flow to set transport parameters, where the reliability of the results of chemical analysis plays an important role. The validation was performed in a concentration range from 0.09?µg L^?1 to 100?µg L^?1 using an Infinity 1290 (Agilent, USA) chromatograph coupled with a QTrap 5500 mass spectrometer (Sciex, Canada). The calibration curves were obtained on the basis of the results of six standard solution analyses. Linearity was not lower than 0.998. The limit of detection was set at the lowest concentration which can be determined with an acceptable accuracy and precision. All pesticides had recoveries in the range 85–109% with relative standard deviation values less than 8.1%. The estimated measurement uncertainty did not exceed 30%, so the LC-MS/MS method fits for the intended purpose.     

泡沫镍负载Pr-N共掺杂TiO2的制备及其光催化性能

以泡沫镍为载体,钛酸丁酯为原料,采用溶胶-凝胶法制备Pr-N共掺杂TiO2光催化剂。利用X射线衍射(XRD)、紫外-可见漫反射光谱(DRS)、扫描电镜(SEM)对催化剂进行表征,结果表明,Pr和N的掺杂抑制了TiO2从锐钛矿晶型向金红石晶型的转变,提高了催化剂在可见光区的吸收能力。以孔雀石绿为目标模型化合物,利用正交实验得出当n(Pr)∶n(N)∶n(Ti)为0.0020∶0.2∶1、焙烧温度为400℃时制得的催化剂活性最高。同时,考察了Pr-N共掺杂、Pr掺杂、N掺杂及TiO2对孔雀石绿降解并利用傅立叶红外光谱对降解产物进行分析,实验表明,Pr-N共掺杂之后催化剂对孔雀石绿的降解率较改性之前提高了1.6倍。