矿井生产环境下光透过性实验研究

通过实验模拟巷道生产作业环境,分析了矿井生产环境下光照衰减的机理,研究了普通LED灯、金卤灯、荧光灯、头戴LED矿灯4种灯具在不同环境参数下的透射性,得出其在不同矿井因素（粉尘浓度、风速、相对湿度）下光的透过性影响规律,结果表明:在矿井中风速和相对湿度的增加均能降低光的透过率,相对湿度变化对光的透过率影响较大,且风速和相对湿度的增加对粉尘浓度有一定的积聚作用。研究结果为井下照明灯具的合理选用提供了依据。     

实验室条件下蓝藻结皮对低温光照胁迫的响应与微结构变化

低温光照是荒漠化地区蓝藻结皮经常面临的环境条件之一.报道了实验室条件下低温光照处理对蓝藻结皮形态、生理特性和超微结构的影响.本研究中,首先通过接种具鞘微鞘藻和爪哇伪枝藻形成人工蓝藻结皮,接着以人工蓝藻结皮为材料进行低温光照处理:28℃+60μE.(m2.s)-1(对照)、10℃+60μE.(m2.s)-1、2℃+60μE.(m2.s)-1和2℃+黑暗.在不同低温光照处理的第0、5和12 d分别测定蓝藻结皮光合活性(Fv/Fm)、叶绿素a、胞外多糖、伪枝藻素、类胡萝卜素和藻蓝蛋白的含量及藻蓝蛋白/叶绿素比值,同时采用扫描电镜观察低温光照处理下蓝藻结皮的微结构变化.此外,对结皮的表观形态特征如结皮颜色、厚度和干重等进行了测定.与对照结皮相比,低温光照下结皮的表观形态受到不利影响,所测定的结皮各项生理指标均呈现显著下降(P<0.05).在2℃+60μE.(m2.s)-1处理12 d时,结皮生物量、光合活性、胞外多糖含量、伪枝藻素含量、类胡萝卜素含量和藻蓝蛋白含量分别比同期对照结皮下降了61.48%、94.89%、66.37%、31.01%、59.38%和65.91%.电镜观察表明,低温光照导致蓝藻结皮的超微结构受到明显破坏,表现为结皮层出现大量蜂窝状空隙,藻丝体数量减少,呈网格状分布,对沙粒的束缚能力减弱等.研究表明低温光照对蓝藻结皮的形态和生理活性具有明显的抑制效应,而低温黑暗能较好地促进蓝藻结皮生理活性和结皮表观形态的恢复.本研究初步探索了蓝藻结皮对低温光照胁迫的耐受性,同时对于了解蓝藻结皮在野外极端环境条件下的生存状况具有一定的理论意义.     

几种化学物质对番茄幼苗耐低温弱光能力的影响

以4叶期番茄为试材,对叶面喷施不同浓度的CaCl_2、甜菜碱和ALA(5-氨基乙酰丙酸),用人工霜箱进行低温弱光胁迫处理,通过观测、计算冷害指数,测定净光合速率、气孔导度等指标,结果表明,CaCl_2、甜菜碱和ALA等几种化学物质能够提高番茄幼苗的耐低温弱光能力,其中CaCl_2的适宜浓度为0．4～1 mmol/L,甜菜碱的适宜浓度为2．5 mmol/L,ALA的适宜浓度为30mg/L。     

我国轻型汽车污染物排放因子的测试研究

采用底盘测功机按ＥＣＥ－１５规程测试了我国１３辆（１２种）正在使用的轻型汽车的ＣＯ、ＨＣ和ＮＯｘ的排放量分别为８７．２５±５６．３１、１１．３６±５．１３和８．２０±６．６８ｇ／ｔｅｓｔ;在相同测试条件下,测试了其中１１种轻型车在不同车速匀速行驶时的ＣＯ、ＨＣ和ＮＯｘ排放因子．测试结果表明、轻型汽车污染物排放因子随车速的变化有良好的规律性．用统计方法拟合了轻型汽车污染物排放因子的车速变化系数的计算公式。当车速＜９０ｋｍ／ｈ时,轻型车ＣＯ、ＨＣ排放因子随车速的增加而减小,当车速＞９０ｋｍ／ｈ时,又略有增加,而ＮＯｘ排放因子随车速的增加而增大。     

Combination of heterogeneous Fenton-like reaction and photocatalysis using Co-TiO2 nanocatalyst for activation of KHSO5 with visible light irradiation at ambient conditions

A novel coupled system using Co–Ti O2 was successfully designed which combined two different heterogeneous advanced oxidation processes, sulfate radical based Fenton-like reaction（SR-Fenton） and visible light photocatalysis（Vis-Photo）, for degradation of organic contaminants. The synergistic effect of SR-Fenton and Vis-Photo was observed through comparative tests of 50 mg/L Rhodamine B（Rh B） degradation and TOC removal. The Rhodamine B degradation rate and TOC removal were 100% and 68.1% using the SR-Fenton/Vis-Photo combined process under ambient conditions, respectively. Moreover, based on XRD, XPS and UV-DRS characterization, it can be deduced that tricobalt tetroxide located on the surface of the catalyst is the SR-Fenton active site, and cobalt ion implanted in the Ti O2 lattice is the reason for the visible light photocatalytic activity of Co–Ti O2. Finally, the effects of the calcination temperature and cobalt concentration on the synergistic performance were also investigated and a possible mechanism for the synergistic system was proposed. This coupled system exhibited excellent catalytic stability and reusability,and almost no dissolution of Co2＋was found.     

可见光下氮掺杂罗丹明B分子印迹TiO_2的选择性光催化性能

采用溶胶-凝胶法和分子印迹技术,以尿素为氮源、罗丹明B为模板分子制备了氮掺杂罗丹明B分子印迹TiO_2粉末(N-TiO_2-RhB),并对样品进行了XRD、UV-Vis DRS和BET表征。表征结果显示:氮掺杂和分子印迹一定程度改善了样品的孔隙结构和孔径分布,N-TiO_2-RhB的比表面积和孔体积分别为TiO_2的1.9倍和1.5倍;氮掺杂使TiO_2的光吸收带边发生红移,而分子印迹不能改变催化剂的光吸收带边。N-TiO_2-RhB具有最佳的可见光活性和选择性,对罗丹明B的降解率高达92.7%。对罗丹明B、罗丹明6G、甲基紫和甲基绿的降解过程均符合一级反应动力学方程。     

Modeling the current-voltage characteristics of thin-film silicon solar cells based on photo-induced electron transfer processes

Power conversion efficiency of p-i-n type microcrystalline silicon (c-Si:H) solar cells has been analyzed in terms of sequential processes of photo-induced electron transfer. The effect of the excitonic state on the charged carrier generation has been studied compared to a conventional scheme in which only charged carriers are taken into account for the operation of the solar cells. A numerical model has been developed to calculate current-voltage characteristics of solar cells on the basis of two types of charged carrier generation processes (exciton process and charged carrier process). The light trapping effect due to a textured back surface reflector (BSR) was embedded in the numerical model by using the effective medium theory in combination with the matrix method in the field of the electromagnetic theory of light. As an application of this modeling, it was found that the reported data of the power conversion efficiency were not explained by the conventional charged carrier process model and that the combined model of the charged carrier process with the exciton process well explains the performance of the p-i-n type c-Si:H solar cells. In this way, the typical power conversion efficiencies were estimated to be 10.5% for the device (i-layer thickness: 1.8 m) with the BSR (period: 600 nm; height: 250 nm) and 8.6% for the device with the flat reflector under the condition that the fractions of the exciton process and charged carrier process were 60% and 40%, respectively.     

烷烃条件下CF2ClBr的紫外光解离机理研究

以气相色谱、红外光谱为主要分析手段,对气态ＣＦ２ＣｌＢｒ在ＣＲ２ＣｌＢｒ－Ｃ６Ｈ１２体系中的紫外光解离进行了研究,结果表明,在２５３．７ｎｍ紫外光照射下,该体系的主要光解产物为ＨＣＶＦ２Ｃｌ、ＨＢｒ以及Ｃ６Ｈ１２的聚合物,体系中ＣＦ２ＣｌＢｒ的解离近似精同缀反应,解离反应的速率常数为２．８７７×１０＾－６ｓ＾－１表观量子产率约０．１,基于此,对该光解反应的机理做了分析。     

吸附-混凝-紫外光催化氧化法处理医药废水的研究

采用吸附—混凝—紫外光催化氧化法对医药废水进行处理。在废水pH为6.8、聚合氯化铝（PAC）和阳离子聚丙烯酰胺（PAM）的和量分别为400和12mg/L条件下，废水COD、色度去除率分别为37.8%、72.7%；在废水（混凝处理后）pH为3、分3次加入H2O2（投加量为2.5g/L）条件下，紫外光照射6h后，废水COD、色度去除率分别为97.6%、100%。用该法处理后的医药废水，其COD、色度去除率分别为99.1%、100%，出水水质达到医药行业废水二级排放标准。     

二次过街路口行人违反交通法规规律的研究

为了解在不同类型二次过街路口行人违反交通法规闯红灯的违法率,找出二次过街路口不同参数对行人违法率的影响,从而找出降低路口行人违法率的对策,保障路口行人交通安全和人车流畅通,本文选取上海市5种类型的二次过街路口调查行人在路口的违法率.通过分析调查数据,行人在路口一次穿越车道数为2～7,两次穿越车道总数为6～12,违法率随车道数的增加而降低.在红灯等待时间90 s之内,行人违法率随等待时间的升高呈一定的下降趋势.红灯等待时间在90～150 s之间,行人违法率没有确定的规律.安全岛、引导护栏、中继信号灯等设施具有明显降低行人违法率的作用.根据二次过街路口设置安全岛、引导护栏、中继信号灯、车道数以及是否从路边穿越5个影响因素的安全评价系数之和建立综合安全评价系数,得到行人在二次过街路口违法率随综合安全评价系数的增大而降低.研究表明,完善和优化二次过街路口的设施参数可以降低路口行人违法率.