重庆典型灰霾天气下大气气溶胶的激光雷达探测

简要介绍了法国Losphere公司ALS300型偏振Mie散射激光雷达的基本结构、探测原理及反演算法,并通过在重庆主城区2009年11月23～27日一次典型灰霾天气条件下连续的气溶胶激光雷达探测结果分析得出,重庆冬季典型灰霾天气下PBL平均高度约为600米,AOD值在4及以上。     

安全监控系统的防雷技术研究

雷电对安全监控系统的电子设备是非常有害的，所以必须对其进行防御。为了科学系统地设计安全监控系统的防雷方案，本文从电磁兼容的角度对雷击种类及其破坏机理的分析，掌握了雷电的耦合途径及防雷关键所在，从切断电磁耦合途径的思路入手对安全监控系统的防雷技术进行了分析与设计。利用避雷针、避雷器及屏蔽接地等方法对安全监控系统的雷击防护进行了设计，经工程实践证明本文的避雷措施是行之有效的。     

行星位置与全球性灾害事件时间预测模拟

根据某类事件发生时的行星空间位置分布,可以从理论上建立该事件的时间预测模型.指出这一方法有可能通过计时历史资料的归算,提供未来灾害事件发生时刻的预测信息.以地震为例,给出了该方法的具体思路.处理了1900-1996年中国震级6.5及以上级的311次地震资料,据此:(1)统计得出了历史时期的地震时间与行星位置分布的相关性;(2)利用这种相关性并以7星组合作1997-2010年间6.5及以上级地震的模拟预测,给出了6个可能的危险日期;(3)采用1997年1月至2006年6月的35次M6.5级地震对模型作检验,表明总计14种单星和组合模型中日、月、水星、金星和天王星等五种模型稍好,而冥王星和海王星模型则不理想.(4)指出该模型不适用于较大区域,因其难以提供较精确的地点信息.此外,预测精度还与步长和确定的危险日期的数量有关.     

沙漠地区边界层高度的提高与尘卷风起沙量的变化

在YSU（Yonsei University）边界层参数化方案的基础上,采用一种经验修正边界层RYSU（Revised YSU）方案,其模拟的边界层高度与观测相吻合.同时利用尘卷风起沙方案,获得了2019年腾格里沙漠夏季尘卷风起沙量的时空分布,结果表明,在08：00~18：00时,RYSU方案模拟的整点尘卷风瞬时起沙量和起沙范围均高于YSU方案,前者的起沙量和范围最大的时刻是15：00时,较后者迟1h,它与腾格里沙漠观测的尘卷风出现频率更接近.采用RYSU方案6~8月研究区每日的总起沙量几乎是采用YSU方案的3倍左右,RYSU方案估算的最大瞬时起沙量比YSU方案更接近用观测的边界层最大高度计算的值.     

Can oligopsony power be measured? The case of U.S. old newspapers market

This paper uses an index analogous to Lerner-index in the input market to derive a price–cost margin that measures input exploitation by few large buyers. This paper identifies oligopsony characteristics associated with the old newspaper (ONP) input market for recycled-content newsprint manufacture and then examines the impacts of market performances on ONP input prices. The wastepaper recycling market, in particular, ONP has not been successful in utilizing the ONP generated. The existence of high sunk costs for entry to the market, along with the small numbers of buyers in the old newspapers market, were the reasons to believe that the waste paper industry had oligopsony elements among paper recycling mills. The regional oligopsony/oligopoly indices were derived and the impact of these market powers on ONP input prices were examined for period 1972–1995. The findings of this study were: oligopsony elements were present to certain degrees among the recycled-content newsprint manufacturers; and the oligopsony market power enabled these mills to exert a larger price–cost margin on ONP input market.     

可渗透反应墙对地下水中多氯联苯的处理

以还原铁粉、铸铁粉、铸铁粉与活性炭的混合物为可渗透反应墙(PRB)的主要反应介质,设计了三种反应体系,处理多氯联苯PCBs(1242)污染的地下水.在有效孔隙率为60%-65%,水力停留时间为12-14.4h的条件下,考察其对污染物的去除效果.结果显示:三个反应体系中,pH值从6.83分别升高到10.66,9.40和8.50;氧化还原电位从81mV分别降到-30mV,-18mV和12mV;PCBs(1242)的去除率分别为91.0%,93.9%,94.5%.     

河谷城市大气环境容量的研究

科学核算大气环境容量,对于合理确定污染物总量控制指标,进而实施大气污染管控措施、治理区域大气污染问题有重要意义.以河谷城市兰州市中心城区为研究区域,利用WRF模式模拟了研究区域的边界层高度及混合层平均风速,并根据地形条件,从污染气象角度给出了扩散单元面积,利用A值法（A为地理区域性总量控制系数）计算兰州市中心城区SO₂、NO_x及VOCs的大气环境容量;同时,将兰州市中心城区2016年SO₂和NO_x的排放总量与SO₂和NO_x的环境容量进行对比,结合区域环境质量监测资料说明大气环境容量设置的合理性.结果表明:①兰州市中心城区的A值具有季节性变化特征,其在春、夏两季较大,在秋、冬两季较小,春、夏两季A值较大的主要原因是边界层高度及边界层内的平均风速较大,而冬季则相反.②兰州市中心城区SO₂、NO_x和VOCs的大气环境容量分别为4.05×104、1.81×104和5.44×104 t/a.③2016年SO₂的实际年排放量（1.62×104 t）未超过大气环境容量限值（4.05×104 t）,尚有余量（2.43×104 t）,这与兰州市2016年4个环境空气质量监测点ρ（SO₂）年均值均达到GB 3095-2012《环境空气质量标准》二级标准的现状一致;NO_x的实际年排放量（3.16×104 t）已超过大气环境容量限值（1.81×104 t）,无环境容量（-1.35×104 t）,这与兰州市2016年4个环境空气质量监测点ρ（NO_x）年均值均超过GB 3095-2012二级标准值的现状一致.研究显示,采用A值法计算的兰州市大气环境容量符合区域污染扩散特征.      

Augmented hydrogen production by gasification of ball milled polyethylene with Ca(OH)2 and Ni(OH)2

PE ball milling pretreatment induces higher H₂ production and purity by gasification. Ca(OH)₂ reacts at solid state with PE boosting H₂ and capturing CO₂. Ca(OH)₂ significantly reduces methanation side-reaction. Polymer thermal recycling for hydrogen production is a promising process to recover such precious element from plastic waste. In the present work a simple but efficacious high energy milling pre-treatment is proposed to boost H₂ generation during polyethylene gasification. The polymer is co-milled with calcium and nickel hydroxides and then it is subjected to thermal treatment. Results demonstrate the key role played by the calcium hydroxide that significantly ameliorates hydrogen production. It reacts in solid state with the polyethylene to form directly carbonate and hydrogen. In this way, the CO₂ is immediately captured in solid form, thus shifting the equilibrium toward H₂ generation and obtaining high production rate (>25 L/mol CH₂). In addition, high amounts of the hydroxide prevent excessive methane formation, so the gas product is almost pure hydrogen (~95%).     

Bioleaching of copper from pre and post thermally activated low grade chalcopyrite contained ball mill spillage

Bioleaching of a low grade chalcopyrite (ball mill spillage material) was tested for copper recovery in shake flasks. The original samples (as received) were thermally activated (600°C, 30 min) to notice the change in physico-chemical and mineralogical characteristics of the host rock and subsequently its effect on copper recovery. A mixed culture of acidophilic chemolithotrophic bacterial consortium predominantly entailing Acidithiobacillus ferrooxidans strain was used for bioleaching studies and optimization of process parameters of both original and thermally activated samples. Mineralogical characterization studies indicated the presence of chalcopyrite, pyrite in the silicate matrix of the granitic rock. Field emission scanning electron microscopy coupled with Energy dispersive spectroscopy (FESEM-EDS) and X-ray Fluorescence (XRF) analysis indicated mostly SiO₂. With pH 2, pulp density 10% w/v, inoculum 10% v/v, temperature 30°C, 150 r·min^-1, 49% copper could be recovered in 30 days from the finest particle size (-1+ 0.75 mm) of the original spillage sample. Under similar conditions 95% copper could be recovered from the thermally activated sample with the same size fraction in 10 days. The study revealed that thermal activation leads to volume expansion in the rock with the development of cracks, micro and macro pores on its surface, thereby enabling bacterial solution to penetrate more easily into the body, facilitating enhanced copper dissolution.     

基于强度理论及虚拟仿真相结合的行星减速机构可靠性分析

基于破煤理论建立了采煤机的力学模型,采用ADAMS建立采煤机刚柔耦合模型,并解决了边界条件添加、接触法向力提取等技术问题,分析了行星轴、架的可靠性;基于行星减速机构强度校核基本原理,开发了行星齿轮强度校核软件,以虚拟仿真中的动态接触法向力为输入,对某公司两种行星减速机构设计方案中各齿轮的接触应力和弯曲应力进行研究。该方法解决了传统分析中齿轮受力无法确定以及采用有限元软件无法求解齿根弯曲应力、求解接触应力时间过长的不足。结果表明:二级行星减速机构采用4行星轮结构要优于采用3行星轮方案,传动更稳定、可靠。