基于IVE模型重型柴油车尾气排放时空特征分析

该研究基于国际机动车排放(IVE)模型结合GPS轨迹点密度和道路长度的方法,建立了昆明市主城区重型柴油车大气污染物和温室气体的高分辨率网格化排放清单,量化了重型柴油车的行驶特征,确定了车辆的VSP bin分布特征、环境变量和车辆技术特征,改进了污染物空间分配方法。结果表明,昆明市主城区的CO_(2)、NOx和PM日排放总量分别为373.481、2.43和0.193 t。驾驶模式工况主要向VSP bin12趋近,其后逐渐降低;污染物的排放因子随车速变化而有规律的变化。从时间分布来看,污染物的小时排放模式均呈现出双峰趋势,表明交通拥堵和通勤高峰时段是污染物排放的主要时段;将轨迹点密度和网格道路长度作为污染物空间分配的权重因子,能够更真实地反映污染物排放强度的分布模式。

Astragaloside IV Ameliorates Inflammatory Damage in Mice with Acute Liver Failure

Acute liver failure is a life-threatening clinical syndrome with a high mortality rate. Currently, the research on Astragaloside IV in liver diseases primarily focuses on liver cancer, and there is limited understanding of its mechanism in acute liver failure’s innate immunity. Therefore, this study aims to investigate the potential protective effect of Astragaloside IV on acute liver failure and its impact on innate immune cells. The study employed D-GalN/LPS-induced acute liver failure mouse models and employed various techniques such as a range of molecular and analytical techniques. The experimental results demonstrated that treatment with Astragaloside IV significantly reduced the inflammatory response, alleviated liver injury, and improved the survival rate of mice with acute liver failure induced by D-GalN/LPS. Further investigations revealed that AS-IV played a beneficial role by regulating the proportion of CD11b+Ly6Chi monocytes and the secretion of inflammatory cytokines and anti-inflammatory metabolites. These findings suggest that the pharmacological mechanism of AS-IV may involve targeted regulation of CD11b+Ly6Chi monocytes in both peripheral blood and liver. The implications of this study’s results are twofold. Firstly, they provide a basis for the clinical application of AS-IV in treating liver failure, offering potential therapeutic benefits. Secondly, they serve as a reference for further development of safer and more effective modified compounds.

应用IVE模型计算上海市机动车污染物排放

为了解上海市机动车污染现状,建立上海市机动车源排放清单,分别选择上海市中心城区、商业区和收入相对较低区域中的主干道、快速道和次干道3种共9条典型道路,开展机动车技术水平参数、比功率(VSP)分布状况、启动状况等测试,并在此基础上将InternationalVehicleEmission(IVE)模型本地化.调查结果表明,上海市区实际道路上轻型客车、出租车、公交巴士、卡车和摩托车(包含助动车)分别占道路总车流量的41.0%、30.8%、15.6%、6.9%和5.7%;从技术组成看,约85%的轻型客车和97%的出租车均安装有三元催化装置,约30%的公交巴士和90%的卡车没有达到欧I标准;机动车的VSP分布主要集中在-2.9～1.2kW·t-1.模式计算结果表明,2004年上海市机动车CO、VOC、NOx和PM排放量分别为57.06×104t、7.75×104t、9.20×104t和0.26×104t;20%的高排放车对总排放量的贡献占到25%～45%;启动过程中排放的CO、VOC和PM占总排放量的15%～25%,NOx仅占总排放量的4.5%.

IVE机动车排放模型应用研究

对IVE模型进行了系统分析和介绍,以北京市为研究对象给出了模型的主要输入参数的确定方法和思路,运用IVE模型对北京市不同车型车队的排放进行计算.结果表明:公交车和卡车的排放因子明显较高,特别是颗粒物排放因子,分别为普通轻型车的14倍和44倍.北京市机动车的CO、VOC、NOx和PM的平均日排放总量分别为2767.4、182.5、353.8和7.1t.对于CO和VOC,普通轻型车的分担率分别为42.0%和34.7%;对于NOx和PM而言,卡车的贡献率最高,分别达到66.3%和83.0%.此外,比较了IVE模型与MOBILE6模型的方法和计算结果,讨论了IVE模型在我国的主要应用优势.

Role of Calcination Temperature on Isosorbide Production from Sorbitol Dehydration over the Catalyst Derived from Ce(IV)Sulfate

Isosorbide is a multi-purpose chemical that can be produced from renewable resources.Specifically,it has been investigated as a replacement for toxic bisphenol A(BPA)in the production of polycarbonate(PC).In this study,the synthesis of isosorbide by sorbitol dehydration using a cerium-based catalyst derived from calcined cerium(IV)sulfate(300°C,400°C,450°C,500°C,and 650°C)was investigated.The reaction occurred in a high-pressure reactor containing nitrogen gas.Advanced instrumental techniques were applied to analyze the characteristics of the calcined catalyst.The results showed that the calcined catalysts demonstrated different crystalline structures and sulfate species at different temperatures.However,the acidic properties(strength and amount)of the catalyst did not change with the calcination temperature.The cerium(IV)sulfate calcined at 400°C exhibited the best catalytic performance,achieving the highest isosorbide yield(55.7%)and complete conversion of sorbitol at 180°C,20 bar of N2,and 6 h using CeSO-400.The presence of a sulfate group on the catalyst was the most important factor in determining the catalytic performance of sorbitol dehydration to isosorbide.This work suggests that CeSO-400 catalysts may play an important role in reducing reaction conditions.

基于IVE模型的杭州市机动车实际行驶工况下排放因子的研究

首先,利用台架试验对IVE模型中的基础排放率进行地域性差异的修正;然后,利用GPS系统获得杭州市机动车在不同道路类型和时间下的实际行驶工况;最后,应用修正后的IVE模型确定杭州市实际行驶工况下轻型车和出租车的CO和NOx综合排放因子。结果表明,对IVE模型基础排放率的修正能较好地提高模型的模拟精度;在杭州市区高峰期实际行驶工况下,轻型车CO和NOx综合排放因子分别是2.92和1.03g/km,出租车的排放因子分别为轻型车的2.0和1.7倍。

一种汽车源排放模型——IVE模型简介

系统介绍了美国环保局应用于汽车源排放计算的IVE模型,分析了模型的结构和理论基础,着重介绍了模型中使用的VSP的概念以及Bin的划分,为模型及其参数的修正提供了理论指导,同时讨论了模型的发展及其适应性。

基于IVE模型的重庆市主城区机动车排放清单研究

对IVE排放模型进行了分析和介绍;以重庆市主城区为研究对象给出了IVE排放模型主要数据的调查方法及排放量的计算方法;利用IVE排放模型建立了2011年重庆市主城区机动车的排放清单。为以后的重庆市主城区的交通环境治理提供了参考依据。

利用IVE模型进行公交车尾气排放分析

介绍了IVE尾气排放模型并与MOBILE模型进行了比较分析。使用GPS对上海市公交车多条运行线路进行了实时运行速度测量,得到上海公交车运行模式的BIN分布,对上海市CNG公交车和柴油公交车的尾气排放进行了模拟计算。结果表明使用CNG公交车代替柴油公交车后,NOX和PM的排放均有显著的降低,但采用不同技术的CNG公交车尾气排放仍有很大的差异,无催化转化和尾气再循环的CNG公交车的CO排放量远高于同类型柴油公交车的排放量。认为IVE模型的模拟结果具有较好的可靠性,其计算模式适用于我国机动车尾气排放清单分析的研究。

利用柴油车车载排放测试对IVE模型的修正及模型应用

IVE模型是国内外应用较为广泛的机动车排放模型之一,为了使该模型在计算机动车排放时更为符合当地实际情况,本文首先将13辆我国道路上典型柴油车的车载排放测试数据与IVE模型基本排放因子进行了对比研究,获得了模型基本排放因子的修正系数,然后将修正后的IVE模型应用于宁波市机动车污染物排放因子的计算,获得宁波市各类型车辆的排放因子.结果表明,模型基本排放因子与排放测试结果相接近的污染物顺序依次为CO、NOX、HC;宁波市机动车CO的启动排放因子远远高于其他污染物,相当于HC和NOX启动排放因子的20倍左右;宁波市机动车运行排放因子中,公交车污染物排放因子最大,其次是重型货车和乘用车,最后是轻型货车.

Clinical usefulness of biochemical markers of liver fibrosis in patients with nonalcoholic fatty liver disease

AIM: Nonalcoholic steatohepatitis (NASH) is a severe form of nonalcoholic fatty liver disease (NAFLD), and progresses to the end stage of liver disease. Biochemical markers of liver fibrosis are strongly associated with the degree of histological liver fibrosis in patients with chronic liver disease. However, data are few on the usefulness of markers in NAFLD patients. The aim of this study was to identify better noninvasive predictors of hepatic fibrosis, with special focus on markers of liver fibrosis, type VI collagen 7S domain and hyaluronic acid. METHODS: One hundred and twelve patients with histologically proven NAFLD were studied. RESULTS: The histological stage of NAFLD correlated with several clinical and biochemical variables, the extent of hepatic fibrosis and the markers of liver fibrosis were relatively strong associated. The best cutoff values to detect NASH were assessed by using receiver operating characteristic analysis: type VI collagen 75 domain ≥5.0 ng/mL, hyaluronic acid ≥43 ng/mL. Both markers had a high positive predictive value: type VI collagen 7S domain, 86% and hyaluronic acid, 92%. Diagnostic accuracies of these markers were evaluated to detect severe fibrosis. Both markers showed high negative predictive values: type VI collagen 7S domain (≥5.0 ng/mL), 84% and hyaluronic acid (≥50 ng/mL), 78%, and were significantly and independently associated with the presence of NASH or severe fibrosis by logistic regression analysis. CONCLUSION: Both markers of liver fibrosis are useful in discriminating NASH from fatty liver alone or patients with severe fibrosis from patients with non-severe fibrosis.

基于IVE的校园网SSL VPN安全接入研究

针对华南师范大学基于IVE系统平台的校园网SSL VPN安全接入进行研究。简述了SSL VPN技术及网络部署环境,剖析了IVE系统结构和工作原理,重点对用户访问请求处理过程进行了说明,最后给出了SSL VPN安全接入校园网的详细配置和实现。研究表明基于IVE平台的SSL VPN技术实现了校外用户对校园网的远程接入,使得广大师生可以不受时间和空间的限制访问校内网络资源,为广大师生的工作和学习提供了极大的便利。

IVE中虚拟人行为控制模型的研究与设计

对IVE中虚拟人行为控制模型这一新的交叉课题的研究进行阐述,并对虚拟人模型的关键技术进行了讨论,分别提出了虚拟人简单行为建模与智能行为建模的方法,利用3DSMax和Virtools三维开发平台设计实现了一个的虚拟人行为控制模型实例,验证了提出的方法。

从车辆排放特性曲线研究IVE模型对我国城市车辆的适应性

为研究IVE模型在国内的适应性,利用车载排放检测仪器OBS-2200,在天津市典型道路上对随机获得的74辆不同类型车辆进行测试,并利用IVE模型附带模版对车载排放数据进行处理,得出了天津市不同技术类型车辆的排放特性曲线。通过与模型标准排放特性曲线对比,得出了该模型对我国城市车辆排放CO2的排放特性曲线符合性较好,对HC排放符合性较差等一系列结论。

IVE模型中区间划分方法对排放因子估算的影响

利用便携式排放测试系统(Portable Emission Measurement System,简称PEMS)和GPS系统(Global Position System,简称GPS)选取多辆天津市机动车进行了道路测试,并对其排放及行驶数据进行了研究,分析了在IVE(International Vehicle Emissions,简称IVE)模型中不同区间的划分方法下,机动车比功率(Vehicle Specific Power,简称VSP)与排放相关系数的差异.CO、CO_2、NO_x排放与VSP相关系数在Paps(Preaverage Power Stress,前平均比功率负载,简称Paps)方案下进行划分时的平均值从原有的引擎负载(Engine Stress,简称ES)方案下的0.1以下上升到0.4以上;但是HC排放与VSP相关系数在ES方案下的均值为0.0370,在Paps方案下却为-0.0766.分别计算污染物实测排放因子与IVE模型改进前和改进后的污染物排放因子的比值,发现采用Paps区间划分方法计算得出的排放因子数据比ES区间划分方法得出的数据显著接近于实测排放因子,显示Paps区间划分方法有助于改善机动车排放估算的准确度.

dead不“死”,live不“活”

我们都知道,dead的意思是“死的”,形容词live的意思是“活的”。但它们的意思决不局限于此,同名词结合后能产生许多新义,若稍不注意便会误译,因此要特别注意。

Valence Stabilization of Polyvalent Uranium Ions in Presence of Some Organic Additives during Extended Gamma Irradiation of Their Aqueous Acidic Solutions

In gamma irradiated aqueous acidic uranium solutions, tetravalent uranium ions are easily oxidized while U(VI) ions remain unchanged. In general, valence change of polyvalent metallic ions during chemical reprocessing of spent nuclear fuel solutions can lead to undesirable effects under the influence of the existing gamma radiations. Consequently, studies on valence stabilization of Uranium ions during chemical treatment in strong gamma irradiation fields seem to be highly interesting. It has been reported before that some organic compounds proved to be effective in stabilizing the valence of Fe(II) ions during extended gamma irradiation of their acidic solutions. In the present work, valence stabilization of Uranium ions in acidic solutions in presence of different classes of organic compounds has been studied. The results showed that in case of U(IV), methanol or formic acid are capable of providing about 80% protection while ethanol or acetaldehyde can provide about 70% protection. Propanol has the least protective effect i.e. about 54%. On using U(VI) instead of U(IV) in the irradiated solutions, the uranium ions were reduced and the formed U(IV) was protected as follows: formic acid or methanol can provide 69% or 63% protection respectively while ethanol, acetaldehyde or propanol can provide 50%, 35% and 24% respectively. In any case, protection exists as long as the organic additives were not completely consumed.

Evaluation of the International Vehicle Emission (IVE) model with on-road remote sensing measurements

Intemational Vehicle Emissions （IVE） model funded by U.S. Environmental Protection Agency （USEPA） is designed to estimate emissions from motor vehicles in developing countries. In this study, the IVE model was evaluated by utilizing a dataset available from the remote sensing measurements on a large number of vehicles at five different sites in Hangzhou, China, in 2004 and 2005. Average fuel-based emission factors derived from the remote sensing measurements were compared with corresponding emission factors derived from IVE calculations for urban, hot stabilized condition. The results show a good agreement between the two methods for gasoline passenger cars＇ HC emission for all 1VE subsectors and technology classes. In the case of CO emissions, the modeled results were reasonably good, although systematically underestimate the emissions by almost 12%-50% for different technology classes. However, the model totally overestimated NOx emissions. The IVE NOx emission factors were 1.5-3.5 times of the remote sensing measured ones. The IVE model was also evaluated for light duty gasoline truck, heavy duty gasoline vehicles and motor cycles. A notable result was observed that the decrease in emissions from technology class State II to State I were overestimated by the IVE model compared to remote sensing measurements for all the three pollutants. Finally, in order to improve emission estimation, the adjusted base emission factors from local studies are strongly recommended to be used in the IVE model.

High matrix metalloproteinase-9 expression induces angiogenesis and basement membrane degradation in stroke-prone spontaneously hypertensive rats after cerebral infarction

Basement membrane degradation and blood-brain barrier damage appear after cerebral infarc- tion, severely impacting neuronal and brain functioning; however, the underlying pathogenetic mechanisms remain poorly understood. In this study, we induced cerebral infarction in stroke- prone spontaneously hypertensive rats by intragastric administration of high-sodium water （1.3% NaC1） for 7 consecutive weeks. Immunohistochemical and immunofluorescence assays demonstrated that, compared with the non-infarcted contralateral hemisphere, stroke-prone spontaneously hypertensive rats on normal sodium intake and Wistar-Kyoto rats, matrix metalloproteinase-9 expression, the number of blood vessels with discontinuous collagen IV expression and microvessel density were significantly higher, and the number of continuous collagen IV-positive blood vessels was lower in the infarct border zones of stroke-prone sponta- neously hypertensive rats given high-sodium water. Linear correlation analysis showed matrix metalloproteinase-9 expression was positively correlated with the number of discontinuously collagen IV-labeled blood vessels and microvessel density in cerebral infarcts of stroke-prone spontaneously hypertensive rats. These results suggest that matrix metalloproteinase-9 upregula- tion is associated with increased regional angiogenesis and degradation of collagen IV, the major component of the basal lamina, in stroke-prone spontaneously hypertensive rats with high-sodi- um water-induced focal cerebral infarction.

基于IVE模型乌鲁木齐机动车大气污染物排放因子研究

本文通过对乌鲁木齐市主城区机动车车型、燃料和运行工况的信息调查,得到主城区机动车现状。在此基础上,采用IVE模型进行模拟,结合统计分析,计算得到了2010年乌鲁木齐市主城区机动车基于行驶里程的启动和运行排放因子。将有助于掌握乌鲁木齐市主城区机动车技术状况、车龄分布、年均行驶里程、在路行驶车型比例以及各型在用机动车排放状况,为制定主城区机动车排气污染管理措施,改善大气环境质量提供科学依据。