Large decrease of VOC emissions of Switzerland's car fleet during the past decade results from a hig
北京市典型城区餐饮业VOCs和PM_(2.5)排放量估算
中国环境科学 2021,41(5)：2090~2096 China Environmental S cience 北京市典型城区餐饮业VOCs和PM2.5排放量估算马殊琼1,2,林伟立1,夏建新1*(1.中央民族大学生命与环境科学学院,北京 100081；2.北京市西城区生态环境局,北京100055)摘要：以北京市餐饮企业分布密度最大的西城区为案例区,通过对研究区域内餐饮企业进行实地污染物检测及排放活动水平调查,计算得到基于就餐人数、就餐时间、烹饪油用量和灶头数4种核算基准的餐饮业VOCs和PM2.5排放因子,并利用排放因子法分别估算该区域在餐饮废气净化设备升级改造前后餐饮企业VOCs和PM2.5年排放量.结果表明: 本研究区域餐饮业废气净化设备升级改造前VOCs排放量范围为319.03 ~506.38t/a,改造后为92.14 ~109.89t/a;改造前PM2.5排放量范围为166.55 ~211.09t/a,改造后为30.22 ~36.05t/a,排放量明显减少.餐饮业废气净化设备改造后VOCs和PM2.5减排率分别为71%~82%和80%~86%,餐饮业废气净化设备升级改造减排效果良好.计算得到以街道为单元的餐饮源VOCs和PM2.5排放强度范围分别为1.45 ~4.32t/km2和0.47~1.42t/km2.通过PM2.5实测浓度(小时值)数据分析,餐饮业废气净化设备升级改造前、后PM2.5浓度平均减少了28.9%,最接近于用油量为核算基准的排放因子降低比例.关键词：北京典型城区；餐饮业；VOCs；PM2.5；排放因子；排放量中图分类号：X511文献标识码：A文章编号：1000-6923(2021)05-2090-07Estimation of VOCs and PM2.5 emissions from catering industry in a typical urban area of Beijing. MA S hu-qiong1,2, LIN Wei-li1, XIA Jian-xin1* (1.College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China；2.Beijing Xicheng Municipal Ecological Environment Bureau, Beijing 100055, China). China Environmental Science, 2021,41(5)：2090~2096 Abstract：Taking the Xicheng District, in which it has the highest distribution density of catering companies in Beijing, as the area of case study, four types of emission factors for VOCs and PM2.5 based on the number of people dining, dining time, edible oil consumption and number of stoves were obtained through on-site inspections and emission activity level surveys. The annual emissions of VOCs and PM2.5 from catering companies before and after the upgrading of exhaust gas purification equipment were estimated. Results showed that VOCs emission before and after the upgrading of exhaust gas purification equipment ranged from 319.03 to 506.38t/a and 92.14 to 109.89t/a, respectively. PM2.5 emissions also decreased from 166.55 ~211.09t/a to 30.22 ~36.05t/a. The VOCs and PM2.5 emissions were significantly reduced by 71%~82% and 80%~86%, respectively. Taking street as unit, the VOCs and PM2.5 emission intensities from catering sources were 1.45~4.32t/km2 and 0.47~1.42t/km2, respectively. Using the measured PM2.5 data, the average reduction in PM2.5 concentration was 28.9% by the upgrading of gas purification equipment, which is most coincident with the reduction ratio calculated from edible oil consumption.Key words：urban Beijing；catering industry；VOCs；PM2.5；emission factors；emissions为应对严重的大气污染,北京市自1998年开始连续实施大气污染综合治理,空气质量明显改善.但是,2017年PM2.5年均浓度仍超过国家空气质量标准66%.此外,挥发性有机物(VOCs)是大气环境中二次细颗粒物和O3的重要前体物,科学管控VOCs的排放对协同防控PM2.5和O3有重要作用[1].目前,北京大气污染已进入综合治理阶段,以能源结构调整和工业减排措施为主的治理效果逐步减弱,生活源大气污染物排放的贡献逐渐引起重视.近年来北京市餐饮业发展迅猛,对大气环境中VOCs和颗粒物等有重要的贡献,对城市局部大气质量及人体健康产生不利影响[2].餐饮行业是重要的大气污染源,但人们对其实际存在状况、活动水平及排放量的了解有限[3].餐饮业大气污染物排放因子及排放量核算是控制餐饮业大气污染的重要依据.准确可靠的排放因子的获取尤为重要,但存在较大的困难.近年来,北京市域内餐饮业大气污染物排放特征研究陆续涌现[4-5],但针对城区特定区域的餐饮业大气污染物排放情况研究聚焦较少,且尚未建立涵盖不同规模、不同核算基准的排放因子库. 因餐饮行业类型众多,排放污染物组分复杂,活动水平信息的获取也存在一定局限性,大部分餐饮业活动水平数据来自统计年鉴,部分收稿日期：2020-10-10基金项目：国家自然科学基金资助项目(91744206)* 责任作者, 教授,**************.com5期马殊琼等：北京市典型城区餐饮业VOCs和PM2.5排放量估算 2091数据仅有国家级数据或无数据[6],因此排放量估算存在较大的误差.本文基于北京市典型城区餐饮行业调查和实测数据,开展餐饮业废气中VOCs和PM2.5排放因子和排放量核算实证研究,建立北京市中心城区餐饮业废气中VOCs和PM2.5本地化排放因子并估算排放量.1方法与数据1.1监测数据选择北京市西城区为研究区域.研究区域总面积50.70km2,下辖15个街道,共计261个社区,常住人口117.9万人.该区域餐饮企业分布密集,平均密度约100家/km2,2018年营业额高达90.6亿元[7].2019年北京市全面推进餐饮业大气污染控制工程,各餐饮服务单位陆续开展废气净化设备升级改造.本研究在2019年先后检测2组餐饮企业废气样本,其中包括未进行废气净化设备升级改造(废气净化设备升级改造前)餐饮企业42家(小型餐饮8家、中型20家、大型14家)和完成废气净化设备升级改造(废气净化设备升级改造后)餐饮企业33家(11家、中型14家、大型8家).升级改造前、后餐饮样本选择同类型废气净化设备进行采样.每组样本中烧烤(含燃气烧烤、电烧烤、炭火烧烤)类、烤鸭类(含果木烤鸭、电烤鸭)、川湘菜、本帮江浙菜、家常菜、快餐(含中式、西式)、食堂餐饮占比均匀,检测样本类别的选取具有区域代表性.同时采集样本餐饮企业标态干废气流量(m3/h)和折算后实际使用灶头数(个)等相关指标.为构建本地化排放因子库,对研究区域内上述餐饮企业进行抽样检测,实地检测餐饮业废气中颗粒物和非甲烷总烃(NMHC)污染物浓度.参考北京市地方标准DB11/1488-2018[8],使用“非甲烷总烃(NMHC)”作为VOCs的综合控制指标.样品采集选择在餐饮废气排放单位作业(炒菜、食品加工或其他产生油烟的操作)高峰期进行,选择了在午餐高峰时段11:00~13:00,和晚餐高峰时段18:00~20:00进行采样.采样位置优先选择垂直管段,且避开烟道弯头和断面急剧变化部位.1.2采样方法使用TH-880F微电脑烟尘平行采样仪(武汉市天虹仪表有限责任公司)进行颗粒物采样,采样管由S型皮托管、热电偶或铂电阻温度计和采样头组成.使用从天津华翼科技有限公司采购的A型滤芯,其外壳材质为聚丙烯,内置双层滤膜,第一层滤膜为聚丙烯纤维滤膜,孔径1~3μm,第二层为超细玻璃纤维滤膜.此类型滤芯对于0.3μm标准粒子的截留效率≥99.95%.滤芯使用前经过101A-1E型电热鼓风干燥箱(上海实验仪器厂有限公司)干燥2h,干燥温度为(60±1)℃,自然冷却后,放入玻璃干燥器内,室温下干燥12h.将滤芯用来自梅特勒-托利多国际贸易(上海)有限公司的XS205型电子天平称量至恒重.采样前,将组合采样管放入烟道内测得排气静压、测点动压、温度等参数,使用湿度仪测得烟气水分含量,计算出采样嘴的内径.选择对应采样嘴内径的滤芯(滤芯采样嘴内径一般为6, 8, 10和12mm)进行采样,采样步骤按照DB11/T1485-2017[9]进行.采用气袋法采集非甲烷总烃样品,采样时将采样管加热并保持在(120±5)℃,10L的气袋用样品气清洗3次,连续采集3个样品,每个样品采集时间宜不少于20min,采气量均不小于10L.结束采样后样品应立即放入样品保存箱内保存,直至样品分析时取出,采样步骤按照《固定污染源废气挥发性有机物的采样气袋法》(HJ 732-2014)[10]进行.1.3分析方法颗粒物的分析方法采用手工称重法.根据DB11/T1485-2017[9],采用烟道内过滤的方式,按照颗粒物等速采样原理,使用滤芯采集餐饮废气中的颗粒物,通过101A-1E型电热鼓风干燥箱(上海实验仪器厂有限公司)除去水分后,由采样前后滤芯的质量差除以标干采样体积,计算出颗粒物的质量浓度.采样时间均不少于15min,每次平行采集3个样品.采样后滤芯运回实验室后,从密封袋中取出并放入玻璃干燥器内,在室温下干燥12h后,还用XS205型分析天平称量至恒重.采用气相色谱法对非甲烷总烃进行检测.根据HJ38-2017[11],将气体样品直接注入具备氢火焰离子化检测器的7820A型气相色谱仪(安捷伦科技(中国)有限公司),分别在总烃柱和甲烷柱上测定总烃和甲烷的含量,两者之差即为非甲烷总烃的含量.同时以除烃空气代替样品,测定氧在总烃柱上的响应值,以扣除样品中的氧对总烃测定的干扰.实验中色谱分析条件为:空气流速400mL/min;进样口温度2092 中国环境科学 41卷120℃;柱箱温80℃;检测器温度200.℃购买5个浓度梯度的甲烷标准气体分别绘制总烃、甲烷的校准曲线,进样量1.0mL.再取1.0mL待测样品测定样品中总烃和甲烷的峰面积,总烃峰面积应扣除氧峰面积后参与计算.1.4餐饮业活动水平调查数据餐饮业活动水平数据是污染物排放量计算的重要参数.本文中餐饮业主要的活动水平数据综合以下来源获得:①生态环境部门2019年对餐饮源污染物产生的普查数据;②相关行政管理部门、行业协会等公布的信息与资料.2019年北京市开展了《餐饮业大气污染排放标准》(DB11/1488-2018)[8]发布后的第一次对餐饮源污染物产生的普查,实现全区域餐饮服务单位清查.由于研究区域餐饮企业数量密度较大,普查工作制定了清查建库、入户调查、数据审核、质量抽查及汇总上报等一系列工作任务.最终建立的台账包括单位名称、详细地址、统一社会信用代码、经营面积(m2)、经营天数(d)、年度日均经营时间(h)、固定灶头数(个)、烹饪油使用量(kg/a)、客流量(人/a)、年营业额(当年价格, 万元)等指标.此次调查中的餐饮服务单位包括独立经营的餐饮服务机构,宾馆、酒店、度假村等场所内经营性餐饮部门,设于机关、事业单位、社会团体、民办非企业单位、企业等供应内部职工、学生等集中就餐的单位食堂和中央厨房等集体用餐加工服务机构,覆盖研究区域内所有产生餐饮大气污染物的服务单位.企业规模是影响餐饮企业PM2.5排放因子的重要因素[12].根据北京市《餐饮业大气污染物排放标准》(DB11/1488-2018)[8]中餐饮服务单位规模划分标准,选取其中较易获得的划分指标对所调查的餐饮服务企业进行规模划分(表1).其中,不同方式判断规模不一致的,餐饮服务单位的规模类别以大者计.表1餐饮服务单位规模划分Table 1 Division of catering scales划分指标小型餐饮中型餐饮大型餐饮基准灶头数(个) ≥1,<3 ≥3,<6 ≥6经营场所使用面积(m2)≤150 >150,≤500 >500 就餐座位数(座) ≤75 >75,≤250 >250 研究区域共有餐饮企业3400余家,按照表2划分餐饮业规模的标准,本研究区域有小型餐饮企业1300余家、中型餐饮企业1300余家、大型餐饮700余家.根据检测数据和餐饮服务单位普查数据,获取不同规模餐饮业的基础数据参数.本研究对样本数据进行了Shapiro-Wilk正态分布检验,随机变量服从对数正态分布则取几何平均值,不服从对数正态分布的则取中位数.抽样餐饮企业基本数据参数见表2和表3.表2废气净化设备升级改造前餐饮企业基本数据参数Table 2 Basic information on catering enterprises before the upgrading of exhaust gas purification equipment项目数量(家) 年经营天数(d) 年度日均经营时间(h)经营面积(m3)餐位数(个) 客流量(人/a)烹饪油使用量(kg)标态干废气流量(×10³ m3/h)折算后实际使用灶头数(个)小型8 300 9.28 120 54 24111 1467 6.34 1.66 中型 20 356 10.04 314 80 37707 1433 8.37 2.72大型14 365 9.25 664 193 73616 4287 20.98 10.16 总计42均值356 9.64 276 104 46748 1575 10.81 3.84表3废气净化设备升级改造后餐饮企业基本数据参数Table 3 Basic information on catering enterprises after the upgrading of exhaust gas purification equipment项目数量(家) 年经营天数(d) 年度日均经营时间(h)经营面积(m3)餐位数(个) 客流量(人/a)烹饪油使用量(kg)标态干废气流量(×10³ m3/h)折算后实际使用灶头数(个)小型11 330 10 52 23 19228 567 2.09 1.34 中型14359 9 185 53 50896 909 4.96 2.60 大型8 363 8 1047 195 88977 4154 9.28 7.27 总计33均值350 10 185 55 42129 1123 4.33 2.685期马殊琼等：北京市典型城区餐饮业VOCs 和PM 2.5排放量估算 20931.5 餐饮业大气污染物年排放总量估算方法根据《城市大气污染物排放清单编制技术手册》[13],餐饮油烟源排放清单污染物有PM 10、PM 2.5、BC 、OC 和VOCs.本文主要对PM 2.5和VOCs 排放总量进行估算.采用的核算方法为排放因子法.根据餐饮业行业特点,通常选取就餐人数、就餐时间、食用油用量和灶头数4项便于统计的指标为核算基准来计算相对应大气污染物排放因子[7].结合烟气排放量、污染物排放浓度以及餐饮企业的数量等进行污染物排放量估算[14-16].不同核算基准存在一定的不确定性,吴雪伟等[17]认为以用油量为基准的不确定性最小, 如PM 2.5和VOC S 的不确定性分别为31%和61%.吴芳谷等[18]对餐饮油烟研究发现,油烟中排出的颗粒物主要为细粒子,PM 2.5占餐饮废气颗粒物的76.91%.餐饮企业i 以第j 种核算基准的排放量E ij 计算采用下面的公式:1EF ij j i i E A ==×∑餐饮总数(1) 式中:A i 为餐饮企业i 活动水平,针对不同核算基准的排放因子取相对应的A i 值;EF j 为第j 种核算基准对应的排放因子,(g/kg)、(g/人)、(g/h)、[g/(h ⋅个)].本研究中,排放因子EF j 以不同核算基准分别计算获得.第j 种核算基准对应的排放因子EF j 计算公式如下: EF ()j j c U Y ×=用油量 (2)EF ()jj c U T×=用餐时间 (3)EF ()jj c U Z ×=灶头数 (4)EF ()jj c U R×=用餐人数 (5) 式中:c j 为第j 种污染物实测浓度,mg/m 3; U 为实测餐饮企业废气排放量,m 3/h; Y 为实测餐饮企业食用油年使用量,t; T 为实测用餐时间,h; Z 为实测餐饮企业基准灶头数,个; R 为实测餐饮企业用餐人数,人次.本研究中不同餐饮企业活动水平A 按餐饮规模计算统计得出,见表4.计算∑A 时,∑A (用餐时间)、∑A (用油量)和∑A (用餐人数)均需考量年均经营时间(h)范围.表4 不同餐饮规模餐饮企业活动水平 Table 4 The activity levels of catering enterprises withdifferent catering scales餐饮规模用油量(t/a)用餐时间(h/a) 灶头数(个) 客流量(万人次/a)小型 1428.893748547.14 1520 6110 中型 3759.184884655.56 3839 12602 大型 3793.462603358.96 5769 14108 总计 8981.5211236561.66 11128328212 结果与讨论2.1 餐饮业废气中VOCs 和PM 2.5排放因子通过(2)~(5)式计算得到分别以用油量、灶头数、用餐人数和用餐时间为核算基准的餐饮业废气VOCs 和PM 2.5排放因子,如表5所示.表6是按照不同规模餐饮企业核算的排放因子.可见,不同核算基准的排放因子差异较大.升级改造前,基于用餐时间的VOCs 和PM 2.5排放因子分别为42.35和17.66g/h,明显大于基于用餐人数的VOCs 和PM 2.5排放因子1.22和0.51g/人.因此,排放因子的参考基准不同影响了排放因子的值,且参考基准的实际情况因地域而异,需要获得不同核算基准下的本地化排放因子.本研究得到升级改造后以用油量为核算基准的VOCs 排放因子11.62g/kg 与秦之湄等[19]获得的成都市的值13.8g/kg 接近,但显著高于王秀艳等[20]获得的沈阳市的值5.03g/kg.因此,需获取本地化、易于计算并符合实际的排放因子[21],才能准确掌握餐饮企业排放对环境空气质量直接或潜在的影响.表5 基于不同核算基准的餐饮业污染物排放因子Table 5 Emission factors of VOCs and PM 2.5 in catering industry based on different accounting standardsVOCs 排放因子 PM 2.5排放因子核算基准升级改造前升级改造后降低比例(%)升级改造前升级改造后降低比例(%)用油量(g/kg) 35.52 11.62 67.3 14.81 3.81 74.3 用餐人数(g/人) 1.22 0.31 75.0 0.51 0.10 80.0 用餐时间(g/h) 42.35 7.56 82.2 17.66 2.48 86.0灶头数[g/(h·个)] 11.97 2.82 76.4 4.67 0.93 80.02094 中 国 环 境 科 学 41卷表6 不同规模餐饮业不同核算基准的排放因子Table 6 Emission factors of catering industries with variesscales and accounting standardsVOCs 排放因子 PM 2.5排放因子 餐饮业规模核算基准 升级改造前升级改造后降低比例(%)升级改造前升级改造后降低比例(%)小型 30.48 9.84 67.7 11.28 3.1672.0中型 36.40 19.08 47.6 16.05 7.2454.9大型 用油量(g/kg)37.44 6.14 83.6 15.42 1.6189.6小型 0.88 0.29 67.0 0.33 0.0972.7中型 1.00 0.34 66.0 0.44 0.1370.5大型 就餐人数(g/人)1.94 0.29 85.0 0.80 0.0890.0小型 17.512.50 85.7 6.57 0.8087.8中型 11.54 3.83 66.8 5.73 1.4674.5大型 灶头数[g/(h·个)] 8.32 1.95 76.6 3.59 0.5185.8小型 26.11 3.36 87.0 9.66 1.0888.8中型 29.90 9.98 66.6 13.18 3.7971.0大型 用餐时间(g/h)91.85 14.16 84.6 37.83 3.7190.0从表5可见,不论以何种核算基准计算得出的排放因子,废气净化设备升级改造后的餐饮业VOCs和PM 2.5排放因子均比改造前明显减小,分别降低了67.3%~82.2%和74.3%~86.0%.但是,不同规模餐饮企业油烟污染治理效果存在一定差异,如表6所示.调查数据表明,大型餐饮企业均已全部安装有油烟净化设施,污染物排放因子下降明显.中型餐饮企业VOCs 和PM 2.5排放因子下降幅度相对较小.中型餐饮企业数量占比和客流量较大,但存在未按要求启用净化设备,未定期清洗油烟净化设备,和未及时更换活性炭及分子筛等吸附材料等现象.穆桂珍等[22]研究也表明目前餐饮企业油烟净化设施“重安装,轻维护”的现象依然十分普遍.部分小型餐饮企业油烟净化装置缺乏专业及时的维护,排风量与灶头数量不匹配也导致静电油烟净化器处理效果大打折扣. 2.2 餐饮业废气VOCs 和PM 2.5排放量根据式(1)以及表5中的排放因子,核算出本研究区域全部餐饮企业2019年VOCs 和PM 2.5的排放量(表7).表7 餐饮废气净化设备升级改造前、后VOCs 和PM 2.5排放量(t/a)Table 7 VOCs and PM 2.5 emissions before and after upgrading of exhaust gas purification equipment (t/a)核算基准用油量就餐人次就餐时间灶头数污染物升级改造前升级改造后升级改造前升级改造后升级改造前升级改造后升级改造前升级改造后VOCs 319.03 92.76 399.54 101.63 506.38 92.14 457.27 109.89 PM 2.5 188.19 30.43 166.55 33.34 211.09 30.22 178.40 36.05本研究区域在餐饮业废气净化设备升级改造前,不同核算基准得到VOCs 排放量最大值为506.38t/a,最小值为319.03t/a;PM 2.5排放量最大值为211.09t/a,最小值为166.55t/a.其中,VOCs 和PM 2.5排放量最大值均是以就餐时间为核算基准计算获得的,但最小值分别是以用油量和就餐人次为核算基准计算获得.假定区域内餐饮业废气净化设备全部进行升级改造,则升级改造后,VOCs 和PM 2.5排放量范围分别为92.14 ~109.89/a 和30.22~36.05t/a.这时,最大值均是以灶头数为核算基准计算获得,最小值均是以就餐时间为核算基准计算获得.这表明净化设备改造后就餐时间不再是影响排放量主要的约束因素.在实际监督管理过程中,应督促餐饮企业及时进行餐饮废气净化设备升级改造,进行餐饮业用油量、灶头数量和就餐人次的管控.根据以上结果,餐饮废气净化设备升级改造后,餐饮源VOCs 减排率为71%~82%,PM 2.5减排率达到80%~86%.以街道为单元,对VOCs 和PM 2.5排放量贡献占比较大的街道为展览路街道(17.46%),月坛街道(12.68%),金融街街道(12.44%),德胜街道(8.73%).通过餐饮企业的位置、数量、排放量及地区占地面积,获得不同街道餐饮业VOCs 和PM 2.5年度排放强度分别为1.45~4.32t/km 2和0.47~1.42t/km 2.其中VOCs 排放强度最大的5个街道分别为陶然亭街道(4.32t/km 2)、大栅栏街道(4.23t/km 2)、新街口街道(4.03t/km 2)、月坛街道(3.90t/km 2)和金融街街道(3.08t/km 2).餐饮源PM 2.5排放强度最小的街道为广安门外街道(0.47t/km 2),排放强度最大为陶然亭街道(1.42t/km 2).为验证废气净化设备升级改造前后对大气中PM 2.5含量的影响效果,选择在7月(升级改造前)和10月(升级改造后)两个时间段,对研究区域中餐饮企业分布密集社区进行了PM 2.5监测.鉴于大气污染物存在明显的季节变化,把实测值减去当5期马殊琼等：北京市典型城区餐饮业VOCs和PM2.5排放量估算 2095月的平均值得到差值(∆PM2.5)进行对比(图1).从图1可看出,改造后∆PM2.5比改造前明显降低,尤其在早餐(05:30~08:30)、午餐(10:30~13:30)和晚餐(16:00~19:00)时段.此外,由于两次测值是在不同年段完成的,除排放外,大气污染物还会受到天气以及输送变化的影响,导致个别改造后的测值大于改造前的.将对应的改造前后早午晚餐时段∆PM2.5进行了差异性检验,两独立样本非参数检验结果显示各抽样社区∆PM2.5浓度实测值在净化设备改造前后变化呈现显著性差异(P<0.05),即区域∆PM2.5排放浓度经过餐饮废气净化设备升级改造后有明显的降低.通过实测值计算, 在月坛街道铁二二社区, 牛街街道东里社区, 金融街街道丰汇园社区和大栅栏街道煤市街东社区早中晚餐时段∆PM2.5分别减少了26.9%,25.1%,32.9%和30.8%.4个社区平均减少了28.9%,最接近于以用油量为核算基准的排放因子降低比例.a bc d图1 餐饮企业分布密集社区废气改造设备升级前后实测ΔPM2.5浓度比较Fig.1 Comparison of the measured ΔPM2.5 concentrations before and after the upgrading in communities with densely distributedcatering companiesa.月坛街道铁二二社区;b.牛街街道东里社区;c.大栅栏街道煤市街东社区;d.金融街街道丰汇园社区3结论3.1通过对研究区域内餐饮企业进行实地检测数据及活动水平调查,分别得到了基于就餐人数、就餐时间、食用油用量和灶头数4项核算基准的餐饮业VOCs和PM2.5排放因子,但4种核算基准的排放因子差异较大,需要进一步本地化检验.3.2本研究区域餐饮业废气净化设备升级改造前,VOCs排放量范围为319.03~506.38t/a,改造后为92.14~109.89t/a;PM2.5排放量范围改造前为166.55~ 211.09t/a,改造后为30.22~36.05t/a,经过餐饮业废气净化设备升级改造后VOCs及PM2.5排放量分别减2096 中国环境科学 41卷少了71%~82%和80%~86%.3.3计算得到以街道为单元的餐饮业VOCs及PM2.5排放强度,VOCs排放强度范围1.45~4.32t/ km2,PM2.5排放强度范围0.47~1.42t/km2.通过餐饮源VOCs和PM2.5排放强度情况的定量计算,便于有针对性的开展相应区域餐饮源大气污染物防治工作.3.4通过对典型社区PM2.5浓度(小时值)抽样检测,餐饮废气净化设备升级改造前、后∆PM2.5浓度平均减少比例为28.9%,最接近于用油量为核算基准的排放因子降低比例.进一步说明餐饮业废气净化设备升级改造对于PM2.5减排效果显著.参考文献：[1] 联合国环境规划署.北京二十年大气污染治理历程与展望 [R]. 内罗毕,肯尼亚:联合国环境规划署, 2019.United Nations Environment Programme. A review of 20 years’ air pollution control in Beijing [R]. Nairobi, K enya: United Nations Environment Programme, 2019.[2] 郑君瑜,王水胜,黄志烔,等.区域高分辨率大气排放源清单建立的技术方法与应用 [M]. 北京:科学出版社, 2014:124-161.Zheng J Y, Wang S S, Huang Z T, et al. The technical method and application of regional high resolution air emission source inventory [M]. Beijing: China Science Publishing& Media LTD, 2014:124-161.[3] 张洋,支国瑞,薛志刚,等.餐饮行业活动水平调查及大气污染物排放清单编制研究 [J]. 环境科学研究, 2019,32(6):929-937.Zhang Y, Zhi G R, Xue Z G, et al. Investigation of activity levels of catering service industry and construction of air pollutant emission inventory [J].Research of Environmental Sciences, 2019,32(6):929-937.[4] 孙成一,白画画,陈雪,等.北京市餐饮业大气污染物排放特征 [J].环境科学, 2020,41(6):2596-2601.Sun C Y, Bai H H, Chen X, et al. Emission characteristics of the catering industry in Beijing [J]. Environmental Science, 2020,41(6):2596-2601.[5] 何万清,王天意,邵霞,等.北京市典型餐饮企业大气污染物排放特征 [J]. 环境科学, 2020,41(5):2050-2056.He W Q, Wang T Y, Shao X, et al. Pollution characteristics of cooking fumes, particulates, and non-methane hydrocarbons in the exhaust of typical Beijing restaurants [J]. Environmental Science, 2020,41(5):2050-2056.[6] 熊桂洪,许丽萍,叶堤,等.我国餐饮油烟源排放清单建立方法研究进展 [C]. 北京:《环境工程》2019年全国学术年会, 2019:196-199.Xiong G H, Xu L P, Ye D, et al. Recent progress of cooking oil fumes emission inventory in China [C]. Beijing:“Environmental Engineering”2019 National Academic Conference, 2019:196-199. [7] 北京市西城区地方志编纂委员会办公室.北京西城年鉴 [M]. 北京:中华书局, 2019:438-447.Local Chronicles Compiling Committee Office of Beijing Xicheng District. Beijing Xicheng yearbook [M]. Beijing: ZhongHua Book Company, 2019:438-447.[8] DB 11/1488-2018 餐饮业大气污染物排放标准 [S].DB 11/1488-2018 Catering air pollutants emission standards [S]. [9] DB 11/T 1485-2017 餐饮业颗粒物的测定手工称重法 [S].DB 11/T 1485-2017 Determination of particulate matter in catering industry - Manual weighing method [S].[10] HJ 732-2014 固定污染源废气挥发性有机物的采样气袋法 [S].HJ 732-2014 Sampling of volatile organic compounds from stationarysource exhaust gas by air bag method [S].[11] HJ 38-2017 固定污染源废气总烃、甲烷和非甲烷总烃的测定气相色谱法 [S].HJ 38-2017 Stationary source waste gas-Determination of total hydrocarbon, methane and non-methane total hydrocarbon-Gas chromatographic method [S].[12] 王红丽,景盛翱,楼晟荣,等.餐饮行业细颗粒物(PM2.5)排放测算方法:以上海市为例 [J]. 环境科学, 2018,39(5):1971-1977.Wang H L, Jing S A, Lou S R, et al. Estimation of fine particle (PM2.5) emission inventory from cooking: case study for Shanghai [J].Environmental Science, 2018,39(5):1971-1977.[13] 贺克斌,王书肖,张强.城市大气污染物排放清单编制技术手册[M]. 北京:中华人民共和国环境保护部, 2015:65-145.He K B, Wang S X, Zhang Q. Technical manual for compilation of emission inventory of urban air pollutants [M]. Beijing: Ministry of Environmental Protection of the People's Republic of China, 2015:65-145.[14] He L Y, Hu M, Huang X F. Measurement of emissions of fineparticulate organic matter from Chinese cooking [J]. Atmospheric Environment, 2004,38(38):6557-6564.[15] Zhao Y, Hu M, Slanina S. Chemical compositions of fine particulateorganic matter emitted from Chinese cooking [J]. Environmental Science & Technology, 2007,41(1):99-105.[16] Ho S S H, Yu J Z, Chu K W, et al. Carbonyl emissions fromcommercial cooking sources in Hong Kong [J]. Journal of the Air & Waste Management Association, 2006,56(8):1091-1098.[17] 吴雪伟,陈卫卫,王堃,等.长春市餐饮源PM2.5和VOCs排放清单[J]. 中国环境科学, 2018,38(8):2882-2889.Wu X W, Chen W W, Wang K, et al. PM2.5 and VOCs emission inventories from cooking in Changchun City [J]. China Environmental Science, 2018,38(8):2882-2889.[18] 吴芳谷,汪彤,陈虹桥,等.餐饮油烟排放特征 [A]. 中国颗粒学会2002年年会暨海峡两岸颗粒技术研讨会会议论文集 [C]. 桂林:科学出版社, 2002:327-331.Wu F G, Wang T, Chen H Q, et al. Characteristics of catering lampblack emission [A]. Proceedings of 2002annual meeting of Chinese granule society and cross-strait symposium on granule technology [C]. Gui Lin: China Science Publishing& Media LTD, 2002:327-331.[19] 秦之湄,唐文雅,尹元畅,等.基于互联网大数据的成都餐饮源细颗粒物排放空间分配研究 [J]. 环境科学学报, 2017,37(12):66-73.Qin Z M, Tang W Y, Yin Y C, et al. Spatial distribution of PM2.5 emission from cooking sources in Chengdu based on internet big data method [J]. Acta Scientiae Circumstantiae, 2017,37(12):66-73.[20] 王秀艳,史建武,白志鹏,等.沈阳市烹饪油烟中VOCs排放特征分析[J]. 中国人口·资源与环境, 2011,21(S1):364-366.Wang X Y, Shi J W, Bai Z P. et al. Analysis on VOCs emission characteristics of cooking fume in Shenyang [J]. China Population Resources and Environment, 2011,21(S1):364-366.[21] 尹元畅,蒋燕,王波,等.成都餐饮源PM2.5及VOCs排放因子的探索 [J]. 环境监测管理与技术, 2015,27(5):63-67.Yin Y C, Jiang Y, Wang B, et al. The study on fine particles and VOCs emission factor of cooking activities in Chengdu [J]. The Administration and Technique of Environmental Monitoring, 2015,27(5):63-67.[22] 穆桂珍,卢清,钟志强,等.静电油烟净化器对餐饮油烟中醛酮类VOCs的去除 [J]. 中国环境科学, 2020,40(11):4697-4702.Mu G Z, Lu Q, Zhong Z Q et al. Removal of electrostatic fume purifiers on aldehydes and ketones compounds from cooking oil fume [J]. China Environmental Science, 2020,40(11):4697-4702.作者简介：马殊琼(1988-),女,甘肃临夏人,中央民族大学硕士研究生,主要从事大气环境污染与防治研究.发表论文1篇.。
油气田燃料天然气组分特征对实测碳排放因子的影响
油气田燃料天然气组分特征对实测碳排放因子的影响廉军豹付玥张鑫袁良庆刘宏彬李世熙谭小红（大庆油田设计院有限公司）摘要：通过实测碳排放因子计算公式理论分析及油气田典型燃料天然气实例分析，探索燃料天然气组分特征对实测碳排放因子的影响。
结果表明：各生产系统使用的油气田燃料天然气含碳原子数量较多的组分含量越多，实测含碳量碳排放因子及实测低位发热量碳排放因子越大，含碳原子数量较少的组分或H 2、O 2、N 2、He 不含碳的组分含量越多，实测含碳量碳排放因子及实测低位发热量碳排放因子越小；除实测方法系统性差异外，一定含量的CO 2，是导致油气田燃料天然气实测低位发热量碳排放因子与实测含碳量碳排放因子之间存在显著差异的重要原因；各类燃料天然气碳排放因子存在普遍性差异，干气的实测碳排放因子明显比湿气的小。
上述结论将为油气田燃料天然气碳排放核算提供技术支持。
关键词：油气田；燃料天然气；碳排放因子；组分特征；实测DOI :10.3969/j.issn.2095-1493.2023.11.016The influences of fuel natural gas composition characteristics on measured carbon emission factors in oil and gas fieldLIAN Junbao，FU Yue，ZHANG Xin，YUAN Liangqing，LIU Hongbin，LI Shixi，TAN Xiaohong Daqing Oilfield Design Institute Co ．，Ltd ．Abstract：The influences of fuel natural gas composition characteristics on measured carbon emission factors are explored through the theory analysis of measured carbon emission factors formula and the cas-es analysis of typical fuel natural gas in oil and gas field．The results show that the higher the content of components with more carbon atoms in the natural gas used as fuel of each production system in oil and gas fields，the greater the carbon emission factor from measured carbon content and that from measured low calorific value．The higher the content of components with less carbon atoms or components with-out carbon such as H 2，O 2，N 2，He in natural gas used as fuel in oil and gas fields，the smaller the car-bon emission factor from measured carbon content and that from measured low calorific value．What's more，in addition to systematic differences between measurement methods，a certain amount of CO 2is an important reason for the significant difference between the carbon emission factor from measured carbon content and that from measured low calorific value of natural gas used in oil and gas fields．In addition，there are universal differences in various carbon emission factors of fuel natural gases in oil and gas fields，and the measured carbon emission factors of dry gas are significantly smaller than those of wet gas．Most importantly，the above conclusions will be provided technical support for the carbon emis-sion accounting for fuel natural gas in oil and gas fields ．Keywords：oil and gas field；fuel natural gas；carbon emission factor；composition characteristics；measurement第一作者简介：廉军豹，高级工程师，硕士研究生，2010年毕业于中国地质大学（武汉）（应用化学专业），从事油气田碳资产研发技术研（碳控楼），163712。
2025届浙江“七彩阳光”新英语高三上期末学业水平测试模拟试题含解析
2025届浙江“七彩阳光”新英语高三上期末学业水平测试模拟试题注意事项:1．答题前，考生先将自己的姓名、准考证号码填写清楚，将条形码准确粘贴在条形码区域内。
2．答题时请按要求用笔。
3．请按照题号顺序在答题卡各题目的答题区域内作答，超出答题区域书写的答案无效；在草稿纸、试卷上答题无效。
4．作图可先使用铅笔画出，确定后必须用黑色字迹的签字笔描黑。
5．保持卡面清洁，不要折暴、不要弄破、弄皱，不准使用涂改液、修正带、刮纸刀。
第一部分（共20小题，每小题1.5分，满分30分）1．Tom’s sco re on the test is the highest in the class. He _____.A．should study last nightB．should have studied last nightC．must have studied last nightD．must study last night2．The Chinese people are kind and caring. If not, I _____ in China in the past 30 years. A．didn’t stay B．hadn’t stayedC．couldn’t stay D．couldn’t have stayed3．If you ___________ to my advice carefully, you wouldn’t have made such a terrible mistake.A．listened B．have listenedC．would listen D．had listened4．She is stubborn in resisting his enquiries about the Moonstone _____ the degree that she makes it seem as if she does not want the mystery ______.A．on; to solve B．with; solvingC．for; being solved D．to; to be solved5．Thanks to her determination and perseverance on the piano lesson, she has a ______ grasp of the subject.A．comprehensive B．confidentialC．conservative D．compulsory6．---Professor Li is wanted on the phone. Where is he?--- I saw him coming, but in a minute, he _____.A．will disappear B．has disappeared C．disappears D．disappeared7．There is no easy way to remember prepositions, as it is one area of English____ the rules seem very irregular.A．that B．whereC．whose D．which8．—The battery in my cell phone is running low.—I that last night before we went to bed.A．was noticing B．have noticed C．would notice D．had noticed9．Was it at the beginning _____ you made the promise ____ you would do all to help make it?A．that; that B．when; thatC．that; when D．when; when10．I would persuade her to make room for you ______it be necessary.A．could B．mightC．should D．would11．You can only be sure of _____ you have at present; you cannot be sure of something _____ you might get in the future.A．that; what B．what; / C．which; that D．/; that12．Could I speak to__________ is in charge of International Sales please?A．who B．whatC．whoever D．whatever13．______in painting, John didn’t notice evening approaching.A．To absorb B．To be absorbedC．Absorbed D．Absorbing14．—________! Somebody has left the lab door open.—Don’t look at me.A．Hi, there B．Dear meC．Thank goodness D．Come on15．At the meeting they discussed three different ________ to the study of mathematics. A．approaches B．meansC．methods D．ways16．________ your generous help, I do believe I have a better understanding of your country and culture.A．But for B．Out ofC．Thanks to D．As to17．The economy in big cities has continued to rise thanks to the local governments to increase ______.A．that B．themC．it D．those18．If you are feeling so tired, perhaps a little sleep would____．A．act B．helpC．serve D．last19．--- Did you watch the final match of China Open yesterday?---Sure. I it so attentively that I forgot to cook supper.A．watched B．had watchedC．was watching D．was to watch20．Children exposed to air pollution are more to suffering from different diseases.A．possible B．probable C．likely D．certainly第二部分阅读理解（满分40分）阅读下列短文，从每题所给的A、B、C、D四个选项中，选出最佳选项。
REDUCING_AGRICULTURAL_EMISSIONS
EmissionsCarbon emissions from agriculture and food systems account for a full third of the world’s total greenhouse gas emissionsemissions of the global food system.The second factor is the transformationof the mode of land use because 80percent of the global deforestationactivity is related to agriculturalactivities and causes 32 percent ofemissions. Agricultural supply chainsincluding retail, transportation,consumption, fuel production, wastemanagement, industrial processing,and packaging account for 29 percentof total emissions. In other words, evenif all fossil fuel emissions stopped now,growing emissions from agricultureand food systems would still preventthe world from achieving a climatetarget of 1.5-2 degrees Celsius abovepre-industrial levels. Agriculture isaccounting for a large share of the globalcarbon emissions. If we can facilitatethe transformation of agricultureand food systems, carbon reductionin the agricultural sector alonewould undoubtedly be an enormous contribution to global carbon neutrality.China Report ASEAN: The 2023 China Agriculture and Rural Low Carbon Development Report (released by the Chinese Academy of Agricultural Sciences on March 31) noted that the agricultural sector has created about a tenth of China’s GDP with one sixteenth of its carbon emissions and that the carbon emission intensity of major agricultural products in China is on a downward trend. Does that mean that we can be optimistic about agricultural carbon emissions in China?Fan: No, we cannot. The percentage of China’s agricultural carbon emissionsis not high because the volume ofour overall carbon emissions is huge.China’s agricultural carbon emissionsaccount for 10 percent of its domesticcarbon emissions but 30 percent ofthe world’s total. Although China hasmade some progress in agriculturalcarbon emissions reduction in recentyears, there is still a long way to go toaccomplish the goal of carbon neutralityby 2060. In the meantime, a large partof our grain consumption comes fromimported grain, which also generatescarbon emissions not included in thevolume of China’s agricultural carbonemissions.China Report ASEAN: SeveralSoutheast Asian countries have setgoals of carbon reduction and carbonneutrality and introduced correspondingagricultural decarbonisationpathways and policies. What are somerepresentative measures for reducingagricultural carbon emissions? Whatare the urgent problems to be solved?Fan: Vietnam is currently promotingcultivation of low-carbon rice with aplantation of 1 million hectares of low-carbon high-quality rice in the MekongDelta. Malaysia has imposed tougherpenalties to protect its rainforestsfrom illegal loggers. The Singaporeangovernment has advocated changes inpeople’s dietary structure. It has urgedconsumers to include more wholegrains, fruits, and vegetables in theirdiets to reduce 15 percent of food wastefrom refined food processing. These areall very good practices.Of course, some situations areless optimistic, like persisting illegallogging in Indonesia, Myanmar, Laos,Cambodia, and other countries, andthere is an urgent need to transformthe relatively backward agriculturalproduction mode in SoutheastAsian countries. If the problems ofagricultural carbon emissions inSoutheast Asia are not solved, the UNSustainable Development Goals willnot be achieved. And importantly,in the harsh circumstances of hightemperatures, hunger, and poverty,many people might cross nationalborders legally or illegally to survive,which can result in instability in theinternational situation or even conflict.Therefore, it is necessary to reshapeglobal agriculture and food systemsand promote the transformation of thesystems.China Report ASEAN: At thebeginning of this year, the ASEANSecretariat organized a regionalworkshop on decarbonizing the ASEANagriculture and forestry sector, whichproduced some initial recommendationson the topic including reducing the useof chemical-intensive farms, enhancingefficient utilization of resources (water,land, and fertilizer), and promotingsustainable land managementon May 3, 2023. (VCG)Southeast Asia’s Green Economy 2021Report released by Bain Capital showed that inthe ASEAN region, agriculture accounted for 10percent of the region’s gross domestic product aswell as 15 percent of its greenhouse gas emissions.10%15%techniques. Are these effective measures?Fan: The volume of Southeast Asia’s livestock emissions is smaller than that of China, and the degree of agricultural commercialization is relatively low. Therefore, carbon emissions from the region’s agricultural industry chain are not very high. However, rice is a major crop in Southeast Asia, and the agricultural production mode is backward. Transplantation cultivation, flood irrigation, and the unreasonable use of chemical fertilizers result in emissions of large amounts of greenhouse gases such as methane. And transformed modes of land use are also a major source of greenhouse gas emissions in Southeast Asia. The initial recommendations very much align with the actual needs of sustainable agriculture in the ASEAN region at this stage. Of course, it will take the concerted efforts of all parties to accomplish the tasks.First, at the top level, central governments should formulate scientific, systematic, and long-term agricultural carbon reduction strategies and management systems, establish a set of evaluation indexsystems to measure the progress of the transformation of agriculture and food systems, and strengthen oversight and accountability to ensure the effective implementation of relevant measures. Secondly, preferential policies for agriculture should be adjusted. Subsidies for water, electricity, and fertilizer for agricultural production are no longer feasible. More should be invested in scientific research, development of the industrial chain, and production of nutritious, healthy, low-carbon and sustainable food to build an eco-friendly and low-carbon agricultural system.And more efforts should be made to adjust dietary structure. Business enterprises, government departments, and consumers should all realize that the change in dietary habits will impact not only personal nutrition and health, but also the environment of the Earth.China Report ASEAN: What practices and experience can China share with other developing countries, including ASEAN countries, to ensure food supply while reducing carbon emissions?Fan: First, chemical fertilizerreduction. In 2015, China introduced the idea of zero growth of chemical fertilizers and pesticides followed by the abolishment of chemicalfertilizer subsidies and promotion of organic fertilizers, which was quite effective. Second, the national drive for afforestation. According to the Remote Sensing Assessment Report on Global Carbon Emissions and Carbon Budgeting compiled by the Chinese Academy of Sciences, over the last 40 years, China’s large-scale afforestation and ecological engineering efforts have sequestered an average of nearly 400 million tons ofcarbon dioxide a year through carbon sinks, effectively reducing global land-use carbon emissions. Third,agricultural technology. China has made many breakthroughs in agricultural carbon emissions reduction. Forexample, “perennial rice,” a crop variety cultivated by Professor Hu Fengyi’s team at Yunnan University, can be harvested continuously for three to four years without tilling once planted. This kind of new technology effectively saves production and labor costs, giving it huge potential for Southeast Asian countries highly dependent on rice cultivation.ASEAN has carried out discussions with Japan on agricultural carbon emissions reduction at the academic level. In contrast, China’s cooperation with ASEAN in this area is still in a preliminary stage. China should catch up in either investment and trade cooperation or knowledge sharing at the academic level and seize the chance to share agricultural carbon emissions reduction technologies, practices, and mechanisms with ASEAN countries. Personally, I would be overjoyed to join any endeavor to promote China-ASEAN cooperation on agricultural carbon emissions reduction.China’s agricultural carbon emissions account for 10 percent of its domestic carbon emissions but 30 percent of the world’s total.An intelligent airborne drone sprays pesticides and chemical manner, in Dalian, Liaoning Province, on June 18, 2023. (VCG)。
高三英语文章全球问题单选题50题
高三英语文章全球问题单选题50题1.Global warming is causing the sea level to rise. Which of the following is NOT a possible consequence?A.Loss of coastal landB.Increased frequency of hurricanesC.Decrease in air pollutionD.Disruption of marine ecosystems答案：C。
全球变暖导致海平面上升，会造成沿海土地流失、飓风频率增加以及海洋生态系统被破坏。
而海平面上升不会直接导致空气污染减少。
2.The depletion of the ozone layer is mainly caused by________.A.emission of carbon dioxideB.release of chlorofluorocarbonsC.burning of fossil fuelsD.cutting down of forests答案：B。
臭氧层的消耗主要是由释放氟氯烃引起的。
二氧化碳排放、燃烧化石燃料主要导致全球变暖；砍伐森林主要影响生态平衡等方面。
3.Which of the following is a measure to address climate change?A.Increasing the use of plastic bagsB.Building more coal-fired power plantsC.Planting more treesD.Dumping waste into the ocean答案：C。
种植更多的树可以吸收二氧化碳，有助于应对气候变化。
增加塑料袋使用、建设更多的燃煤发电厂、向海洋倾倒废物都会加剧环境问题。
4.Deforestation can lead to________.A.increased biodiversityB.more fertile soilC.flooding and soil erosionD.cooler climate答案：C。
2024年高一英语气候科学研究进展练习题40题
2024年高一英语气候科学研究进展练习题40题1.Climate change is mainly caused by the increase in _____.A.greenhouse gasesB.pollutionC.wasteD.noise答案：A。
“greenhouse gases”是温室气体，气候变化主要是由温室气体增加引起的。
“pollution”污染，范围太广，不一定直接导致气候变化。
“waste”废物，和气候变化关系不大。
“noise”噪音，与气候变化毫无关系。
2.Scientists are studying ways to reduce _____.A.climate changeB.global warmingC.pollution levelsD.carbon emissions答案：D。
“carbon emissions”是碳排放，科学家正在研究减少碳排放的方法。
“climate change”气候变化是结果不是要减少的对象。
“global warming”全球变暖也是结果。
“pollution levels”污染水平，比较宽泛，不如减少碳排放具体针对气候变化。
3.The melting of glaciers is a result of _____.A.rising temperaturesB.polluted airC.waste disposalD.noise pollution答案：A。
冰川融化是温度上升的结果。
“polluted air”污染的空气，不是冰川融化的直接原因。
“waste disposal”废物处理，与冰川融化无关。
“noise pollution”噪音污染，和冰川融化毫无关系。
4.One way to combat climate change is to increase the use of _____.A.fossil fuelsB.renewable energyC.nuclear powerD.coal答案：B。
和碳排放峰值相关的英语作文
和碳排放峰值相关的英语作文英文回答：The challenge of climate change requires global cooperation to mitigate greenhouse gas emissions and pursue a sustainable future. Carbon neutrality, achieved by balancing carbon emissions with carbon removal, is acritical goal in this endeavor. To achieve carbon neutrality, countries have set targets for peaking their carbon emissions, marking the point at which emissions reach their maximum level before declining.Carbon Emissions Peak and Mitigation Strategies.Reaching carbon emissions peak requires comprehensive strategies that address key sectors contributing to greenhouse gas emissions. These sectors include energy, transportation, industry, agriculture, and forestry. By adopting clean energy technologies, promoting energy efficiency, and transitioning to low-carbon transportation,countries can significantly reduce their carbon footprint.In the energy sector, renewable energy sources such as solar, wind, and hydroelectricity can replace fossil fuels, minimizing carbon emissions. Energy-efficient technologies, such as LED lighting and smart building systems, conserve energy and reduce demand for non-renewable resources.Transportation accounts for a substantial portion of global carbon emissions. Promoting public transportation, electric vehicles, and walking or cycling can reduce emissions from this sector. Governments can implement policies that encourage these sustainable transportation modes.Industry emits greenhouse gases through manufacturing processes and energy consumption. By adopting cleaner production methods, using energy-efficient equipment, and implementing carbon capture and storage technologies, industries can mitigate their emissions.Agriculture and forestry can contribute to carbonsequestration. Sustainable farming practices, such as no-till farming and cover cropping, can enhance soil carbon storage. Reforestation and afforestation projects can absorb carbon dioxide from the atmosphere and create carbon sinks.International Cooperation and Carbon Markets.Achieving carbon emissions peak is an international responsibility. Countries must collaborate through international agreements and carbon markets to share best practices, coordinate emissions reduction efforts, and ensure a just and equitable transition to a carbon-neutral economy.Carbon markets provide a platform for countries and businesses to trade carbon credits, incentivizing emissions reductions and financing clean energy projects. By pricing carbon emissions, carbon markets create a financial incentive for polluters to reduce their emissions.Benefits of Emissions Peak and Carbon Neutrality.Reaching carbon emissions peak and achieving carbon neutrality offer numerous benefits, including:Improved air quality and human health.Reduced climate change impacts, such as extreme weather events and sea-level rise.Transition to a sustainable and low-carbon economy.Creation of new jobs and economic opportunities.Enhanced energy security and resilience.中文回答：碳排放达峰与减排策略。
the use of soil to reduce carbon题目
the use of soil to reduce carbon题目Using Soil to Reduce Carbon Emissions: A Promising SolutionAbstract: The excessive emission of carbon dioxide (CO2), a major greenhouse gas, has contributed significantly to global warming. To combat this pressing issue, scientists and environmentalists have proposed various strategies, one of which is the use of soil as a means to sequester, or store, carbon. This paper explores the potential of soil as a tool for reducing carbon emissions and examines the different approaches that can be employed for maximum effectiveness.1. Introduction1.1 Background1.2 Objective1.3 Scope2. Carbon Sequestration in Soil2.1 Role of Soil Organisms2.2 Mechanisms of Carbon Storage3. Enhancing Soil Carbon Sequestration3.1 Conservation Agriculture Practices3.2 Agroforestry and Intercropping3.3 Cover Crops and Crop Rotation3.4 Biochar Application3.5 Carbon Farming4. Challenges and Limitations4.1 Soil Conditions and Types4.2 Land Use and Management Practices4.3 Measurement and Monitoring5. Benefits and Impacts5.1 Climate Change Mitigation5.2 Soil Health and Fertility5.3 Biodiversity Conservation5.4 Economic Opportunities6. Case Studies and Success Stories6.1 Project Drawdown6.2 Soil Carbon Restoration at Scale Initiative6.3 Farmer-Led Regenerative Agriculture7. Policy and Implementation Considerations7.1 Government Initiatives and Incentives7.2 Land-use Planning and Management7.3 Scientific Research and Data Collection8. Conclusion8.1 Summary of Findings8.2 Recommendations for Future ActionBy harnessing the power of soil, we can effectively reduce carbon emissions and mitigate climate change impacts. With the adoption of appropriate soil management practices, governments, farmers, and individuals can play an essential role in combating global warming. This paper highlights the significance of soil in the carbon cycle and provides insights into various strategies for carbon sequestration in soil.。
Threshold Resummed Spectra in B - Xu l nu Decays in NLO (I)
a rXiv:h ep-ph/57285v315Se p25ROME1/1407/05DSFNA1/25/2005THRESHOLD RESUMMED SPECTRA IN B →X u lνDECAYS IN NLO (I)Ugo Aglietti 1Dipartimento di Fisica,Universit`a di Roma “La Sapienza”,and I.N.F.N.,Sezione di Roma,Italy.Giulia Ricciardi 2Dipartimento di Scienze Fisiche,Universit`a di Napoli “Federico II”and I.N.F.N.,Sezione di Napoli,Italy.Giancarlo Ferrera 3Dipartimento di Fisica,Universit`a di Roma “La Sapienza”,and I.N.F.N.,Sezione di Roma,Italy.Abstract We evaluate threshold resummed spectra in B →X u lνdecays in next-to-leading order.We present results for the distribution in the hadronic variables E X and m 2X /E 2X ,for the distribution in E X and for the distribution in E X and E l ,where E X and m X are the total energy and the invariant mass of the final hadronic state X u respectively and E l is the energy of the charged lepton.We explicitly show that all these spectra (where there is no integration over the hadronic energy)can be directly related to the photon spectrum in B →X s γviashort-distance coefficient functions.1Introduction and summary of the resultsA long-standing problem in particle physics is the understanding of strong interactions at low energies.While at very low energies,of the order of the hadronic scaleΛ≈300MeV,perturbative QCD is of no use and alternative methods have been developed in decades(such as quark models,chiral lagrangians,lattice QCD, etc.),at intermediate energies,of the order of a few GeV,perturbative computations can be combined with non-perturbative models to predict a variety of cross sections and decay rates.Among these moderate hard scale phenomena is beauty physics,which is indeed characterized by a hard scale of a few GeV.The measured decay spectra often receive large contributions at the endpoints—in the case of the hadron energy spectrum, in the middle of the domain—from long-distance effects related to soft interactions between the heavy quark and the light degrees of freedom.The main non perturbative effect is the well-known Fermi motion,which classically can be described as a small vibration of the heavy quark inside the B meson because of the momentum exchange with the valence quark;in the quantum theory it is also the virtuality of the heavy quark that matters.This effect is important in the end-point region,because it produces some smearing of the partonic spectra.These long distance effects manifest themselves in perturbation theory in the form of series of large infrared logarithms,coming from an“incomplete”cancellation of infrared divergencies in real and virtual diagrams.The probability for instance for a light quark produced in a process with a hard scale Q to evolve into a jet with an invariant mass smaller than m is written in leading order as[1]:J(m)=1+A1αS 10dωθ2Θ m2ω 10dθ2αS log2 Q22hadronic subprocess in(2)is characterized by the following three scales:m b,E X and m X(m b≥E X),(3) where m X and E X are the invariant mass and the total energy of thefinal hadronic state X q,respectively.We are interested in the so-called threshold region,which can be defined in all generality as the one havingm X≪E X.(4) The region(4)is sometimes called radiation-inhibited,because the emitted radiation naturally producesfinal states with an invariant mass of the order of the hard scale:m X∼O(E X).It is also called semi-inclusive because experimentally,to satisfy the constraint(4),most hadronicfinal states have to be discarded.The processes we are going to consider are the well-known radiative decay with a real photon in thefinal state,B→X s+γ(5) and the semi-leptonic decay,4B→X u+l+ν.(7)In perturbative QCD,the hadronic subprocess in(2)consists of a heavy quark decaying into a light quark which evolves later into a jet of soft and collinear partons because of infrared divergencies.In leading order, one only considers the emission of soft gluons at small angle by the light quark(see eq.(1));thefinal state X q consists of a jet with the leading(i.e.most energetic)quark q originating the jet itself.In next-to-leading order one has to take into account two different single-logarithmic effects:(a)hard emission at small angle by the light quark q and(b)soft emission at large angle by the heavy quark.Because of(a),thefinal state consists of a jet with many hard partons and,in general,the leading parton is no longer the quark q which originated the jet itself.Because of(b),thefinal state does not contain only an isolated jet,but also soft partons in any space direction.The main result of[3]is that the large threshold logarithms appearing in(2)are conveniently organized as a series of the form:∞n=12n k=1c nkαn(Q)log k Q2m2X +c11α(Q)logQ2m2X+c23α2(Q)log3Q24The results for the semileptonic decay are easily extended to the radiative decay with the photon converting into a lepton pair,B→X s+l+This takes us into aneffectivetheoryin whichthebeauty quark is replaced bya static quark,as recoil effects are neglected in the limit (10).If we write the beauty quark momentum as pb =m b v +k ,where k is a soft momentum,the infinite mass limit of the propagator is easily obtained as:S F (p )= 1+ˆv 2m 121E X (ordinary QCD),(12)which diverge in the limit (10)(γ0is a constant).If one takes the limit (10)ab initio ,i.e.before integrating the loop,some divergence is expected in the loop integrals,as it is indeed the case.Technically,that occurs because the static propagator is of the form 1/(k 0+iǫ)(see eq.(11))and,unlike the ordinary propagator,has no damping for | k |→∞.It can be shown that the b →u vector and axial-vector currents are no more conserved or partially conserved in the static theory.Therefore,unlike the QCD case,the O (α)virtual corrections are ultraviolet divergent in the static theory and produce,after renormalization,terms corresponding to (12)of the form γ0αlogµm 2b +m 2Xm 2b≃m b .(16)This case corresponds to the radiative decay(5).In this case,thefinal hadronic energy is always large and of the order of the heavy-flavor mass:Q≈m b(radiative decay).(17) On the other hand,in the semi-leptonic decay(7)7,the lepton pair can have a large invariant mass,q2∼O m2b ,(18) implying a substantial reduction of the hard scale:Q≪m b.(19) This fact is one of the complications in the threshold resummation of the semileptonic decay spectra:while in the radiative decay(5),the hard scale Q is always large in the threshold region,and of the order of m b,this is no longer true in the semileptonic decay.The hadronic subprocesses have in general different hard scales in the two decays.If one integrates over q2,for example because of undetected neutrino momentum,there is a mixing of hadronic contributions with different hard scales in the semileptonic case.However,it turns out by explicit computation that the contributions from a large q2,i.e.with a small hard scale in the hadronic subprocess,are rather suppressed(see sec.4).Atfixed Q,the large logarithms in(2)can be factorized into a QCD form factor,which is universal in the sense that it depends only on the hadronic subprocess.The differences between,let us say,the radiative decay(5)and the semileptonic decay(7)only enter in the specific form of a short-distance coefficient function multiplying the QCD form factor(and in the form of a remainder function collecting non factorized,small contributions,see next section).The discussion above can be summarized as follows.The hard scale Q=2E X in(2)appears in the argument in the infrared logarithms as well as in the argument of the running coupling.In the radiative decay,because of kinematics,the hard scale is always large and of the order of the beauty mass:Q≈m b,while in the semileptonic case kinematical configurations are possible with Q≈m b as well as with Q≪m b.The main complication in semileptonic decays is that by performing kinematical integrations(for example over the neutrino energy), one may integrate over the hard scale of the hadronic subprocess.While in radiative decays the hard scale is fixed,in the semileptonic decays there can be a mixing of different hadronic subprocesses.A non-trivial picture of some semileptonic decay spectra emerges:there are long-distance effects which cannot be extracted by the radiative decay,related to a smallfinal hadronic energy,but their effect turns out to be small at the end because of a kinematical suppression of the states with a small hard scale.The decay spectra in(7)can therefore be divided into two classes:1.distributions in which the hadronic energy E X is not integrated over.These distributions can be related viashort-distance coefficients to the photon spectrum in the radiative decay(5).In particular,the structure of the threshold logarithms is the same as in decay(5).In this paper we restrict ourselves to these simpler distributions;2.distributions in which the hadronic energy is integrated over and therefore all the hadronic energiescontribute.These are for instance the hadron mass distribution or the charged lepton energy distribution.In all these cases,the structure of the threshold logarithms is different from that one in(5)and by far more complicated.The analysis of some of these distributions,which present novel features with respect to B→X sγ,is given in[5].Let us make a simple analogy with e+e−annihilation into hadrons.In the center-of-mass(c.o.m.)frame, thefinal state consists of a qq→J q+J7The same is also true for the radiative decay with the photon converting into a lepton pair(6).Roughly speaking,thefinal state X q in(2),consisting in a single jet,is“half”of that in(20),consisting of the two jets J q and Jq pair cannot occur and thefinal state consists of two narrow jets around the original qm2H andα(Q)logQ2dm2H(Q=m Z)(24) and the integral of this quantity over Q from a small energyǫ∼m H up to m Z with some weight functionφ(Q):dˆσdm2H(Q).(25) Radiative B decays(5)and semileptonic spectra(7)in class1.are the analog of the former distribution(24), while semileptonic spectra in class2.are the analog of the latter case(25).The analog of the suppression in the semileptonic spectra2.of the contributions from large q2is the suppression of the weight functionφ(Q)for Q≪m Z.Many properties of the distributions we are going to derive in this work can be understood with a qualitative discussion on the hadron energy spectrum,dΓ2.(28) In lowest order,thefinal hadronic state consists indeed of the up quark only:X u=u.To orderα,a real gluon is radiated and thefinal hadronic state is a two-particle system:X u=u+g.Thefinal hadronic energy is not restricted anymore to half the beauty mass but can go up to the whole beauty mass:E(1)X=E u+E g≤m b.(29)For example,just consider an energetic up quark recoiling against the gluon,with a soft electron and a soft neutrino.The relevant case for us is afinal state with the up quark of energy≈m b/2and a soft and/or a collinear gluon.Such a state has a total energy slightly above m b/2and the matrix element is logarithmically enhanced because of the well-known infrared singularities.Such logarithmic enhancement cannot be cancelled by the O(α)virtual corrections,because of their tree-level kinematical limitation(28).We are left therefore with large infrared logarithms,of the formαlog2 E X−m b2 E X≥m bE X=m b/2,because the lowest order spectrum has a discontinuity in this point, above which it vanishes identically because of kinematics.This infrared singularity is integrable,asm b/2+δm b/2dE Xαlog k E X−m bIn sec.(6)we derive the double distribution in the hadron and electron energies,i.e.in the two independent energies.A peculiarity of this spectrum is that it is characterized by the presence of two different series of large logarithms,which are factorized by two different QCD form factors.Another peculiarity is that this double differential distribution contains partially-integrated QCD form factors instead of differential ones.That implies that the infrared singularities occurring in this distribution are integrable,as in the case of the Sudakov shoulder which we have discussed before;Finally,in sec.(7)we present our conclusions together with a discussion about natural developments.2Triple differential distributionThe triple differential distribution in the decay(7)is the starting point of our analysis.It has a resummed expression of the form[3]:81dxdudw=C[x,w;α(w m b)]σ[u;α(w m b)]+d[x,u,w;α(w m b)],(33) where we have defined the following kinematical variables:w=2E Xm b(0≤x≤1)(34)and9u=E X− E X+1−4y1−4y,(36) withy=m2X(1+u)2.(38) The functions entering the r.h.s.of eq.(33)are:•C[x,w;α(w m b)],a short-distance,process-dependent coefficient function,whose explicit expression will be given later.It depends on two independent energies x and w and on the QCD couplingα;•σ[u;α(w m b)],a process-independent,long-distance dominated,QCD form factor.It factorizes the thresh-old logarithms appearing in the perturbative expansion.At orderα:σ(u;α)=δ(u)−C Fαu +−7C Fαu++O(α2),(39)where C F is the Casimir of the fundamental representation of SU(3)c,C F=(N2c−1)/(2N c)with N c=3 (the number of colors)and the plus distributions are defined as usual as:P(u)+=P(u)−δ(u) 10du′P(u′).(40) The action on a test function f(u)is therefore:10du P(u)+f(u)= 10du P(u)[f(u)−f(0)].(41)The plus-distributions are sometimes called star-distributions and can also be defined as limits of ordinary functions as:P(u)+=limǫ→0+ θ(u−ǫ)P(u)−δ(u) 1ǫdu′P(u′)=limǫ→0+ θ(u−ǫ)P(u)−δ(u−ǫ) 1ǫdu′P(u′)=limǫ→0+−dΓRdΓRm2b.(46)In this simpler case,the coefficient function C R(α)does not depend on any kinematical variable but only on the QCD couplingαand has an expansion of the form11:C R(α)=1+αC(1)R+α2C(2)R+O(α3),(47)where C(i)R are numerical coefficients.Basically,going from the2-body decay(5)to the3-body decay(7),the coefficient function acquires a dependence on the additional kinematical variables,namely two energies.The remainder function in eq.(45)depends on the(unique)variable t s and has an expansion of the form:d R(t s;α)=αd(1)R(t s)+α2d(2)R(t s)+O(α3).(48) The main point is that the QCD form factorσin the same in both distributions(33)and(45),explicitly showing universality of long-distance effects in the two different decays.By universality we mean that we have the same function,evaluated at the argument u in the semileptonic case and at t s in the radiative decay.This property is not explicit in the original formulation[11],in which the form factors differ in subleading order(see next section).Since,as shown in the introduction,w∼1in the radiative decay,we can make everywhere in eq.(45)the replacementα(w m b)→α(m b)(radiative case only),(49) to obtain:1dt s=C R[α(m b)]σ[t s;α(m b)]+d R[t s;α(m b)].(50) The distribution contains now a constant coupling,independent on the kinematicsα(m b)≃0.22.The replace-ment(49)cannot be done in the semileptonic case.In[3]the triple differential distribution was originally given in terms of the variable y instead of u,with the latter u=1−ξbeing introduced in[10].The variables u and y coincide in the threshold region in leading twist, i.e.at leading order in u in the expansion for u→0,as y=u+O(u2).Going from the variable y to the variable u only modifies the remainder function.The advantages of u over y are both technical and physical:•u has,unlike y,unitary range;•when we impose the kinematical relation between hadronic energy E X s and hadronic mass m X s of the radiative decay(5),u exactly equals t s:u|EX s=m b/2(1+m2X s/m2b)=t s.(51)This property suggests that some higher-twist effects may cancel in taking proper ratios of radiative and semileptonic spectra.Let us now give the explicit expression of the coefficient function in the semileptonic case:C(x,w)+αC(1)(x,w)+O(α3),(52) whereC(0)(x)(1+x,w)=12C Fx) (1+2log w−w log w8 ++2(1−w) (54)with x=xν=1−xνand xν=2Eν/m b.Unlike the coefficient function,the remainder function d(x,u,w;α)has an expansion starting at O(α):d(x,w,u;α)=αd(1)(x,w,u)+α2d(2)(x,w,u)+O(α3).(55) Omitting the overall factor C F/π,we obtain:13d(1)(x)x)x)2x)2x+20w x+8x2x−40w x−16x264(1+u) 640w−368w2−200w3−16w4+3w5−384x+528w2x−16w4x2−48w x2+24w364(1−u) −256w+528w2−200w3−16w4+3w5+512x++528w2x−16w4x2−48w x2+24w34(1+u)6+9w5log u x)2log ux)2log ux−2w x2 log ux−2w x2 log u64(1+u)2w −144w+208w2+16w3+w4−64x−16w2 x+48x2+16w264(1−u)2 −256w+624w2−304w3+16w4+w5+512x+ +944w2x−8w4x2−464w x2+16w3x.du (u)+C(0)(x,w)C Fu−log y(u)+7/4du(u) .(56)This function can also be obtained with a direct matching with the O(α)triple differential distribution computed in[8]after a change of variable(see the end of this section for a discussion about matching).The main point about the semileptonic decay(7)is that it has—unlike the radiative decay(5)—q2=0 and consequently the form factor depends not only on u but also on the hadronic energy w through the running coupling:σ=σ[u;α(w m b)].(58)The form factor is therefore a function of two variables.We work in next-to-leading order(NLO),in which only the O(α)corrections to the coefficient function and remainder function are retained(see next section).Since the difference betweenα(w m b)andα(m b)is O(α2), we can set w=1in the argument of the coupling entering the coefficient function and the remainder function. We then obtain the simpler expression:1=C[x,w;α(m b)]σ[u;α(w m b)]+d[x,u,w;α(m b)](NLO).(59) dxdudwNote that we cannot set w=1in the coupling entering the form factor,because in the latter caseαis multiplied by large logarithms,which“amplify”O(α2)differences in the couplings(see next section).Let us make a few remarks about thefinal result of this section,eq.(59):•it describes semi-inclusive decays,in which the internal structure of the hadronicfinal states is not ob-served,but only the total mass and energy are measured.Less inclusive quantities,such as for instance the energy distribution of thefinal up quark(i.e.the fragmentation function of the up quark),cannot be computed in this framework;•it constitutes an improvement of thefixed-order O(α)result in all the cases in which there are large threshold logarithms.In all the other cases,where there are no threshold logarithms,such as for example the dilepton mass distribution[12],there is not any advantage of the resummed formula over thefixed-order one.In the next sections we integrate the resummed triple-differential distribution to obtain double and single (resummed)spectra.There are two methods to accomplish this task which are completely equivalent:1.Thefirst method involves the direct integration of the complete triple-differential distribution.Schemati-cally:(spectrum)= C·σ+ d.(60) Large logarithms come only from thefirst term on the r.h.s.of(60),while non-logarithmic,“small”terms come both from thefirst and the second term.To obtain a factorized form for the spectrum analogous to the one for the triple-distribution,in which the remainder function collects all the small terms,one rearranges the r.h.s.of(60):the small terms coming from the integration of C·σare put in the remainder function;2.In the second method,one integrates the block C·σonly and drops the small terms coming from theintegration.The remainder function is obtained by expanding the resummed expression in powers ofαand comparing with thefixed-order spectrum.3Threshold ResummationIt is convenient to define the partially integrated or cumulative form factorΣ(u,α):Σ(u;α)= u0du′σ(u′;α).(61)Performing the integrations,one obtains for the O(α)form factor:Σ(u;α)=1−C Fα4πL+O(α2),(62)whereL=log1where G nk are numerical coefficients.Let us note that the sum over k extends up to n+1in(70),while it extends up to2n in the form factor in eq.(66).This property is a generalization of the simple exponentiation of the O(α)logarithms which holds in QED and is called generalized exponentiation.In general,this property holds for quantities analogous to the semi-inclusive form factors,in which the gluon radiation is not directly observed.One sums therefore over all possiblefinal states coming from the evolution of the emitted gluons (inclusive gluon decay quantities).The property expressed by eq.(70)does not hold for quantities in which gluon radiation is observed directly,as for example in parton multiplicities,where different evolutions of gluon jets give rise to different multiplicities.3.1N-spaceA systematic resummation is consistently done in N-moment space or Mellin space,in which kinematical constraints are factorized in the soft limit and are easily integrated over[14].One considers the Mellin transform of the form factorσ(u;α):σN(α)≡ 10du(1−u)N−1σ(u;α).(71) The threshold region is studied in moment space by taking the limit N→∞,because for large N the integral above takes contributions mainly from the region u≪1.For example,the Mellin transform of the spectrum ineq.(50)is of the form 10(1−t s)N−11dt sdt s=C R(α)σN(α)+d R,N(α),(72)whered R,N(α)→0for N→∞.(73) The total rate in Mellin space is obtained by taking N=1.It can be shown[15,1,16]that the form factor in N-space has the following exponential structure:σN(α)=e G N(α),(74) whereG N(α)= 10dz z N−1−1k2t A α(k2t) +B α(Q2(1−z)) +D α(Q2(1−z)2) .(75)Let us note that a prescription has to be assigned to this formula since it involves integrations over the Lan-dau pole[17].The functions entering the resummation formula have a standardfixed-order expansion,with numerical coefficients:A(α)=∞n=1A nαn=A1α+A2α2+A3α3+A4α4+ (76)B(α)=∞n=1B nαn=B1α+B2α2+B3α3+ (77)D(α)=∞n=1D nαn=D1α+D2α2+D3α3+ (78)The known values for the resummation constants read:A 1=C Fπ2 C A 672 −5π3 C 2A 24524z (3)−678z (4) −C A n f 20912z (3)−596−z (3)108 ;(81)B 1=−3π;(82)B 2=C F 864+112z (3) −C F32z (3)−3432−z (2)π;(84)D 2=C F 108−92 +n f MS scheme for the coupling constant 14.To this approximation,the first three orders of the β-function are also needed [19,20]:β0=13C A −224π2 17C 2A − 5C A +3C F n f ;(87)β2=154C 3A − 141518C A C F −C 2F n f + 799C F n 2f .(88)As is well known,β0and β1are renormalization-scheme independent,while β2is not and has been given in thed log µ2=−β(α)=−β0α2−β1α3−β2α4−···.(89)The running coupling reads:α(µ)=1β30log log µ2/Λ2 β50log 2 log µ2/Λ2 −log log µ2/Λ2 −1β40114Adiscussion about the scheme dependence of the higher order coefficients A 2,B 2,etc.on the coupling constant can be found in [18].leading term A1is the coefficient of that piece of the matrix element squared for one real gluon emission, which is singular in the small angle and small energy limit:A1αdωθ2∼=A1αdωk2t,(91)where k t≃ωθis the transverse momentum of the gluon.In(91)we have given the representation of the integral both in the angleθand in the transverse momentum k t.The subleading coefficients A2,A3,etc. represent corrections to the basic double-logarithmic emission.The function A(α)“counts”the number of light quark jets in different processes,i.e.we can writeA(P)(α)=n q A(α),(92) where n q is the number of primary light quarks in the process P.For example,in e+e−annihilation into hadrons n q=2,while in the heavyflavor decays(2)n q=1.Since soft gluons only couple to the four-momentum of their emitters and not to their spin,the function A g(α)for gluon jets is obtained from the quark one A(α)simply taking into account the change in the color charge,i.e.multiplying by C A/C F [23];•the function B(α)represents emissions at small angle with a large energy from the light quark.B1is the coefficient of that piece of the matrix element squared which is singular in the small angle limit:B1αdωdθ2k2t.(93)The non logarithmic integration over the gluon energyωhas been done and does not appear explicitly in eq.(75);the integration over the angleθor the transverse momentum k t is rewritten as an integral over z.The function B(α)counts the number offinal-quark jets,i.e.B(P)(α)=n l B(α),(94) where n l is the number of primaryfinal quarks in the process P.For example in e+e−annihilation into hadrons n l=2,while in DIS or in the heavyflavor decays(2)n l=1.Since hard collinear emissions are sensitive to the spin of the emitting particles,the gluon function B g(α)is not simply related to the quark one B(α)[23];•the function D(α)represents emissions at large angle and small energy from the heavy quark.D1is the coefficient of that piece of the matrix element squared which is singular in the small energy limit:D1αdω15Let us remember however that only two of the three functions appearing in eq.(75)are independent[16].contributions from all the hard partons in the process,i.e.it describes global properties of the hadronicfinal states.Let us observe that A2and D2,unlike B2,do not have a C2F contribution.That is a consequence of the eikonal identity,which holds in the soft limit[2].According to this identity,the abelian contributions simply exponentiate the lowest order O(αC F)term,just like in QED.That means that there are no higher order terms in the exponent G N.Because of similar reasonings,A3does not have a C3F contribution.Despite its supposed asymptotic nature,the numerical values of the coefficients show a rather good conver-gence of the perturbative series.Note that all the double-logarithmic coefficients A i are positive,implying an increasing suppression with the order of the expansion(up to the third one)of the rate in the threshold region. On the contrary,the single-logarithmic coefficients B i and D i–with the exception of B2—are all negative and therefore tend to enhance the rate in the threshold region[24].We have:A1=+0.424413;(96) A2=+0.420947−0.0375264n f=0.308367;(97) A3=+0.592067−0.0923137n f−0.000398167n2f=0.311542;(98) B1=−0.318310;(99) B2=+0.229655+0.04020n f=0.350269;(100) D1=−0.424413;(101) D2=−0.556416+0.002502n f=−0.548911.(102)With our definition,theβ-function coefficients are,as well known,all positive.β0=+0.87535−0.05305n f=+0.71620;(103)β1=+0.64592−0.08021n f=+0.40529;(104)β2=+0.71986−0.140904n f+0.003032n2f=+0.324436.(105) In the last member we have assumed3activeflavors(n f=3).Let us now discuss the computation of the coefficients entering the resummation formula.The occurrence of a Sudakov form factor in semileptonic B decays was acknowledged originally in[25],where a simple exponentiation involving A1and B1+D1was performed.The coefficient A2was computed for thefirst time,as far as we know, in[26].It was denoted A1K since it was considered a kind of renormalization of the lowest-order contribution:A1α→A1α(1+Kα).(106) The coefficient A2was obtained from the soft-singular part of the q→q two-loop splitting function[27],that is as the coefficient of the1/(1−z)term16.A2was subsequently recomputed in[29]in the framework of Wilson line theory,where the function A(α)has a geometrical meaning:it is the anomalous dimension of a cusp operator,representing the radiation emitted because of a sudden change of velocity of a heavy quark,Γcusp(α)=∞n=1Γ(n)cuspαn=Γ(1)cuspα+Γ(2)cuspα2+ (107)Indeed,it has been explicitly checked up to second order that these two functions coincide:A(α)=Γcusp(α).(108) Let us note that:•the theory of Wilson lines and Wilson loops;。
全球气候异常的作文英语
Climate change is one of the most pressing issues facing our planet today. The global climate is experiencing anomalies that have farreaching implications for ecosystems, economies, and human societies.Firstly, the increase in global temperatures, often referred to as global warming, has led to the melting of polar ice caps and glaciers. This not only contributes to rising sea levels but also disrupts the habitats of countless species that rely on these icy environments.Secondly, climate anomalies have resulted in unpredictable weather patterns. Droughts, floods, hurricanes, and other extreme weather events are becoming more frequent and intense. These events can lead to crop failures, which in turn affect food security and contribute to economic instability.Thirdly, the changing climate is causing shifts in ecosystems. Some species are migrating to cooler climates, while others are struggling to adapt to the new conditions. This can lead to a loss of biodiversity, which has cascading effects on the health of the entire ecosystem.To address these climate anomalies, it is crucial for nations to work together to reduce greenhouse gas emissions. This can be achieved through the adoption of renewable energy sources, improving energy efficiency, and promoting sustainable practices in agriculture and forestry.Moreover, investing in climate change adaptation and resilience is essential. This includes developing infrastructure that can withstand extreme weather events, as well as implementing early warning systems to help communities prepare for and respond to climaterelated disasters.Education and awareness campaigns are also vital in combating climate change. By informing the public about the causes and consequences of climate anomalies, we can encourage individuals to make lifestyle changes that contribute to a more sustainable future.In conclusion, the global climate anomalies we are witnessing today are a call to action. It is up to all of us to take responsibility for our actions and work towards a more sustainable and resilient world. By doing so, we can help mitigate the impacts of climate change and preserve our planet for future generations.。
雅思小作文co2排放量
雅思小作文co2排放量英文回答：CO2 emissions have become a major concern in today's world. The excessive release of carbon dioxide into the atmosphere has led to numerous environmental issues, such as global warming and climate change. In this essay, I will discuss the causes of CO2 emissions and their impact on the environment, as well as potential solutions to reduce them.One of the main causes of CO2 emissions is the burning of fossil fuels for energy production. Industries, transportation, and households heavily rely on fossil fuels like coal, oil, and natural gas. These fuels release large amounts of CO2 when burned, contributing to the greenhouse effect. For example, cars emit carbon dioxide through their exhaust pipes, and power plants release CO2 when generating electricity.Another significant source of CO2 emissions isdeforestation. Trees play a crucial role in absorbing CO2 and releasing oxygen through photosynthesis. However, when forests are cleared for agriculture, urbanization, or logging, the carbon stored in trees is released back into the atmosphere. This process contributes to the overall increase in CO2 levels.The impact of CO2 emissions on the environment is far-reaching. Global warming, caused by the greenhouse effect, leads to rising temperatures, melting ice caps, and more frequent extreme weather events. For instance, the increased CO2 levels in the atmosphere have resulted in the acidification of oceans, endangering marine life and coral reefs. Additionally, higher levels of CO2 contribute to air pollution, which poses health risks to humans and animals.To mitigate CO2 emissions, various solutions can be implemented. Firstly, transitioning to renewable energy sources like solar and wind power can significantly reduce CO2 emissions. These sources are clean, abundant, and do not produce greenhouse gases. Secondly, promoting energy efficiency in industries, transportation, and buildings canhelp reduce the demand for fossil fuels. For example, using energy-efficient appliances and insulation can lower energy consumption and subsequently decrease CO2 emissions.Furthermore, afforestation and reforestation programs can help absorb CO2 from the atmosphere. Planting trees not only sequesters carbon but also provides habitats forwildlife and improves air quality. Moreover, adopting sustainable agricultural practices can reduce deforestation and minimize CO2 emissions from land-use changes.中文回答：CO2排放量已成为当今世界的一个重大问题。
GRE考试《阅读理解》练习题及答案(8)
GRE考试《阅读理解》练习题及答案(8)GRE阅读题目解析:机动车尾气排放导致空气污染Although, recent years have seen substantial reductions in noxious pollutan ts from individual motor vehicles, the number of such vehicles has been steadil y increasing, consequently, more than 100 cities in the United States still hav e levels of carbon monoxide, particulate matter, and ozone (generated by photoc hemical reactions with hydrocarbons from vehicle exhaust) that exceed legally e stablished limits. There is a growing realization that the only effective way t o achieve further reductions in vehicle emissions—short of a massive shift awa y from the private automobile—is to replace conventional diesel fuel and gasol ine with cleaner-burning fuels such as compressed natural gas, liquefied petrol eum gas, ethanol, or methanol.All of these alternatives are carbon-based fuels whose molecules are smalle r and simpler than those of gasoline. These molecules burn more cleanly than ga soline, in part because they have fewer, if any, carbon-carbon bonds, and the h ydrocarbons they do emit are less likely to generate ozone. The combustion of l arger molecules, which have multiple carbon-carbon bonds, involves a more compl ex series of reactions. These reactions increase the probability of incomplete combustion and are more likely to release uncombusted and photochemically activ e hydrocarbon compounds into the atmosphere. On the other hand, alternative fue ls do have drawbacks. Compressed natural gas would require that vehicles have a set of heavy fuel tanks—a serious liability in terms of performance and fuel efficiency—and liquefied petroleum gas faces fundamental limits on supply.Ethanol and methanol, on the other hand, have important advantages over oth er carbon based alternative fuels: they have a higher energy content per volume and would require minimal changes in the existing network for distributing mot or fuel. Ethanol is commonly used as a gasoline supplement, but it is currently about twice as expensive as methanol, the low cost of which is one of its attr active features. Methanol’s most attractive feature, however, is that it can r educe by about 90 percent the vehicle emissions that form ozone, the most serio us urban air pollutant.Like any alternative fuel, methanol has its critics. Yet much of the critic ism is based on the use of “gasoline clone” vehicles that do not incorporate even the simplest design improvements that are made possible with the use of me thanol. It is true, for example, that a given volume of methanol provides only about one-half of the energy that gasoline and diesel fuel do; other things bei ng equal, the fuel tank would have to be somewhat larger and heavier. However, since methanol-fueled vehicles could be designed to be much more efficient than “gasoline clone” vehicles fueled with methanol, they would need comparativel y less fuel. Vehicles incorporating only the simplest of the engine improvement s that methanol makes feasible would still contribute to an immediate lessening of urban air pollution.1. According to the passage, incomplete combustion is more likely to occur with gasoline than with an alternative fuel becauseA. the combustion of gasoline releases photochemically active hydrocarbonsB. the combustion of gasoline involves an intricate series of reactionsC. gasoline molecules have a simple molecular structureD. gasoline is composed of small molecules.E. gasoline is a carbon-based fuel2. Which of the following most closely parallels the situation described in the first sentence of the passage?A. Although a town reduces its public services in order to avoid a tax incr ease, the town’s tax rate exceeds that of other towns in the surrounding area.B. Although a state passes strict laws to limit the type of toxic material that can be disposed of in public landfills, illegal dumping continues to incre ase.C. Although a town’s citizens reduce their individual use of water, the to wn’s water supplies continue to dwindle because of a steady increase in the to tal population of the town.D. Although a country attempts to increase the sale of domestic goods by ad ding a tax to the price of imported goods, the sale of imported goods within th e country continues to increase.E. Although a country reduces the speed limit on its national highways, the number of fatalities caused by automobile accidents continues to increase.3. It can be inferred from the passage that a vehicle specifically designed to use methanol for fuel wouldA. be somewhat lighter in total body weight than a conventional vehicle fue led with gasolineB. be more expensive to operate than a conventional vehicle fueled with gas olineC. have a larger and more powerful engine than a conventional vehicle fuele d with gasolineD. have a larger and heavier fuel tank than a “gasoline clone” vehicle fu eled with methanolE. average more miles per gallon than a “gasoline clone” vehicle fueled w ith methanol4. The passage suggests which of the following about air pollution?A. Further attempts to reduce emissions from gasoline-fueled vehicles will not help lower urban air-pollution levels.B. Attempts to reduce the pollutants that an individual gasoline-fueled veh icle emits have been largely unsuccessful.C. Few serious attempts have been made to reduce the amount of pollutants e mitted by gasoline-fueled vehicles.D. Pollutants emitted by gasoline-fueled vehicles are not the most critical source of urban air pollution.E. Reductions in pollutants emitted by individual vehicles have been offset by increases in pollution from sources other than gasoline-fueled vehicles.1Although, recent years have seen substantial reductions in noxious pollutants from individual motor vehicles, the number of such vehicles has been steadily increasing, consequently, more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone (generated by photochemical reactions with hydrocarbons from vehicle exhaust) that exceed legally established limits.尽管近年来单体机动车的有害排放物显著降低，但机动车总数一直稳步增加，结果是，美国超过 100 座城市的一氧化碳，有害悬浮颗粒，臭氧(机动车尾气与碳氢化合物发生光化学反应的产物)水平超过法定标准。
碳排放峰值英语作文
碳排放峰值英语作文英文回答：Carbon emissions have become a growing concern for the global community. Countries around the world have pledged to reduce their carbon emissions in order to mitigate the effects of climate change. One key target is to achieve carbon neutrality, which means that a country's net carbon emissions are equal to zero. To achieve carbon neutrality, countries need to implement a variety of measures,including reducing their reliance on fossil fuels,investing in renewable energy, and improving energy efficiency.The carbon emissions peak is the point at which a country's carbon emissions reach their highest level. After the carbon emissions peak, a country's emissions should begin to decline. The carbon emissions peak can be an important milestone in a country's transition to a low-carbon economy.There are a number of factors that can affect acountry's carbon emissions peak. These include thecountry's economic growth, its energy mix, and its population growth. In general, countries with high economic growth and a reliance on fossil fuels are more likely to have a high carbon emissions peak.Reaching a carbon emissions peak is a significant challenge. It requires a long-term commitment to reducing carbon emissions. However, it is an essential step in the fight against climate change. Countries that are able to achieve carbon neutrality will be better equipped to adapt to the effects of climate change and to create a more sustainable future.中文回答：碳排放峰值是碳排放量达到的最高点。
和碳排放峰值相关的英语作文
和碳排放峰值相关的英语作文English:The concept of reaching peak carbon emissions has gained increasing attention in the global effort to combat climate change. Peak carbon emissions refer to the point at which greenhouse gas emissions, particularly carbon dioxide, reach their maximum and begin to decline. Achieving peak carbon emissions is crucial in the fight against climate change as it marks a turning point towards a more sustainable and environmentally friendly future. By setting a clear peak emissions target, countries and industries can work towards reducing their carbon footprint and transitioning towards cleaner energy sources and more sustainable practices. This can ultimately help to limit global warming and its associated impacts on the planet. Additionally, reaching peak carbon emissions also signifies the potential for economic growth and development through the advancement of clean energy technologies and investments in renewable energy infrastructure. It provides an opportunity for countries to lead the way in innovation and create new jobs in the green economy.Translated content:达到碳排放峰值的概念在全球应对气候变化的努力中越来越受到关注。
2012职称英语理工阅读理解终极版
第一篇Ford Abandons Electric Vehicles1) What have the Ford motor company, General Motor’s and Honda done concerning electric cars?2) According to Tim Holmes of Ford Europe, battery-powered cars3) Which auto manufactures are still producing electric vehicles?4) According to the eighth paragraph, hybrid cars5) Which of the following is true about the hope of car manufacturers according to the last paragraph?1. Ford Abandons Electric Vehicles（理C）1) They have given up producing electric cars.2) Will not be the main transportation vehicles in the future.3) Toyota and Nissan.4) run more miles than petrol driven cars.5) The legislation will allow more low-emission to produced.1.针对电动汽车，通用汽车公司和本田汽车公司采取了_____________。
2.据福特欧洲区的Tim Holmes反应，电池动力汽车________。
3._________等汽车生产商仍在生产电动车。
4.混合动力汽车______________。
5.汽车生产商希望____________。
碳排放峰值英语作文
碳排放峰值英语作文Title: Achieving Carbon Emission Peak: A Crucial Step towards Sustainability.As the world grapples with the challenges posed by climate change, achieving a carbon emission peak has become a critical milestone. The concept of carbon peaking refers to the point in time when a country or region reaches its highest level of carbon dioxide emissions, marking the beginning of a downward trend. This transition is crucial for mitigating the adverse effects of climate change and ensuring a sustainable future.The need for carbon peaking is urgent. The scientific community has long warned about the perils of unchecked carbon emissions, which are the primary driver of global warming. Rising temperatures, melting ice caps, extreme weather events, and loss of biodiversity are just some of the consequences of climate change. To avert these disasters, we must reduce our carbon footprint andtransition to renewable energy sources.To achieve a carbon emission peak, we must adopt amulti-pronged strategy. Firstly, we need to increase our investment in renewable energy sources such as solar, wind, and hydroelectric power. These clean energy sources are not only sustainable but also cost-effective in the long run. By phasing out fossil fuels and transitioning to renewable energy, we can significantly reduce our carbon emissions.Secondly, we need to improve energy efficiency and conservation measures. This can be achieved through technological advancements and behavioral changes. For instance, we can adopt energy-efficient appliances, improve building insulation, and promote public transportation to reduce individual car usage. These measures will not only help us reduce our carbon emissions but also lower our energy bills.Thirdly, we need to promote sustainable land use and forestry practices. Deforestation and land degradation are major contributors to carbon emissions. By promotingsustainable land use, reforestation, and forest protection, we can absorb carbon dioxide from the atmosphere and offset our emissions.Fourthly, we need to strengthen international cooperation and policy frameworks. Climate change is aglobal challenge that requires collective action. Byworking together, sharing best practices, and implementing common policies, we can accelerate the transition to a low-carbon economy.In conclusion, achieving a carbon emission peak is a crucial step towards sustainability. It requires aconcerted effort from governments, businesses, communities, and individuals. By adopting a multi-pronged strategy, investing in renewable energy, improving energy efficiency, promoting sustainable land use, and strengthening international cooperation, we can reduce our carbon emissions and secure a sustainable future for ourselves and our planet.The road ahead is challenging, but it is not impossible.We have the technology, the resources, and the know-how to make a difference. It is time for us to rise to the challenge and take bold action to protect our planet. Let us work together to achieve a carbon emission peak and create a better, more sustainable world for future generations.。
电子教案与课件：《化工专业英语》 unit6
Auto emissions control has a long history.
汽车尾气的控制排放也具有悠久的历史。
Exhaust emission standards for new cars were first set in 1968 (1965 in California), after which the standards for exhaust emissions became steadily stricter every couple of years until the early 1980s.
由盛行风输送的高臭氧水平的光化学烟雾造成的大规 模区域问题也变得越来越明显。
with ozone concentrations in rural areas often reaching about half the urban peaks.
农村地区的臭氧浓度通常是城市峰值的一半。
Air quality measurements in the United States show that urban ozone levels have decreased by about 12 percent over the 1984-1993 decade, and incidents when the ozone National Ambient Air Quality Standard is exceeded have decreased by 60 percent.
为减少烟雾而采取的策略主要是减少未燃烧的碳氢化 物排放，却不能消减氮氧化物的排放量。
Emissions standards for engines in large vehicles (gasoline and diesel) have steadily become stricter too, though lagging in time.
2019年catti笔译二级试题：碳排放量
【导语】备考正当时，每⽇⼀练题⽬以知识点为单元，针对知识点做深⼊解析，让⼤家每天进步⼀点点。
以下为“2019年catti 笔译⼆级试题：碳排放量”，欢迎阅读参考！更多相关讯息请关注！ 2016年，中国的⼀个三⼝之家的碳排放量平均为2.7吨。
⽬前，这个数字已升⾄3.5吨。
⽽在北京、上海、⼴州等⼤城市，每个家庭的平均碳排放量已接近10吨。
碳汇(Carbon Sink)主要是指森林吸收并储存⼆氧化碳的能⼒。
森林是陆地⽣态系统中的碳汇库。
在降低⼤⽓中温室⽓体浓度、减缓全球⽓候变暖中具有⼗分重要的独特作⽤。
In 2016, the carbon emission of a family of three in China averaged 2.7 tons. At present, this figure has risen to 3.5 tons. In major cities such as Beijing, Shanghai and Guangzhou, the average carbon emission of each household is close to 10 tons. Carbon Sink function refers to the capability of forests to absorb and store carbon dioxide. Forests are the largest carbon sinks in the terrestrial ecosystem, which play an important and unique role in reducing the concentration of greenhouse gases in the atmosphere and mitigating global warming. 据统计数字，每⼈每年只需要种3棵树，就可以吸收个⼈当年排放的⼆氧化碳。
theozonelayer
Q.42Changes in solar radiation and increases in stratospheric particles from volcanic eruptions both affect the abun-dance of stratospheric ozone. Over the last three decades, global total ozone has decreased over the globe and is now about 3.5% below pre-1980 values (see Q13). The depletion is attributed to changes in reactive halogen gases, which are rep-resented by changes in equivalent effective stratospheric chlo-rine (EESC). EESC values account for stratospheric chlorine and bromine abundances and their different effectiveness in destroying ozone (see definition in Q16). A comparison of the smooth year-to-year changes in ozone and EESC shows that the quantities are inversely related to each other, with ozone first decreasing while EESC increases (see Figure Q14-1). After the mid-1990s, the annual changes in both quantities are sharply reduced. Changes in solar output and volcanic activity do not show such smooth long-term changes, as dis-cussed below, and therefore are not considered to be the cause of long-term global ozone depletion.Total ozone and solar changes. The formation of stratospheric ozone is initiated by ultraviolet (UV) radia-tion coming from the Sun (see Figure Q2-1). As a result, an increase in the Sun’s radiation output increases the amount of ozone in Earth’s atmosphere. The Sun’s radiation output and sunspot number vary over the well-documented 11-year solar cycle. Observations over several solar cycles since the 1960s show that global total ozone levels vary by 1 to 2% between the maximum and minimum of a typical cycle. Changes in incoming solar radiation at a wavelength of 10.7 cm are often used as a surrogate for changes in solar output at UV wavelengths. The long-term changes in the 10.7-cm output in Figure Q14-1 clearly show alternating periods of maximum and minimum values in total solar output separated by about 5–6 years. If changes in solar output were the cause of global ozone depletion, a gradually decreasing output would have been observed around 1980 or earlier, slowing sharply in the mid-1990s. Since such a decrease was not observed, nor is expected based on longer-term solar observations, the long-term decreases in global ozone cannot result from changes in solar output alone. Most analyses presented in this and previous international scientific assessments quantitatively account for the influence of the 11-year solar cycle on long-term variations in ozone.Total ozone and past volcanoes. Explosive volcanic eruptions inject sulfur gases directly into the stratosphere, causing new sulfate particles to be formed. The particles ini-tially form in the stratosphere downwind of the volcano and then spread throughout the hemisphere or globally as air is transported by stratospheric winds. One method of detect-ing the presence of volcanic particles in the stratosphere uses observations of the transmission of solar radiation through the atmosphere (see Figure Q14-1). When large amounts of new particles are formed in the stratosphere over an extensive region, solar transmission is measurably reduced. The erup-tions of Mt. Agung (1963), El Chichón (1982), and Mt. Pina-tubo (1991) are the most recent examples of sulfur injections that temporarily reduced solar transmission.Laboratory measurements and stratospheric observations have shown that chemical reactions on the surfaces of vol-canically produced particles can increase ozone destruction by increasing the amounts of the highly reactive chlorine gas chlorine monoxide (ClO). The ozone response depends on the total abundance of EESC after the eruption (see Q16). At times of relatively low EESC, such as the early 1980s, ozone is not very sensitive to stratospheric injection of volcanic sulfate particles. At times of higher EESC amounts, such as from 1980 to the present, global ozone is expected to decrease significantly following large explosive eruptions. The most recent large eruption was that of Mt. Pinatubo, which resulted in up to a 10-fold increase in the number of particles available for surface reactions. Both El Chichón and Mt. Pinatubo increased global ozone depletion for a few years (see Figure Q14-1). EESC was too low for ozone depletion to occur after the Mt. Agung eruption in 1963. The effect on ozone diminishes during the years following an eruption as volcanic particles are graduallyYes, factors such as changes in solar radiation, as well as the formation of stratospheric particles after volcanic eruptions, do influence the ozone layer. However, neither factor can explain the average decreases observed in global total ozone over the last three decades. If large volcanic eruptions occur in the coming decades, ozone depletion will increase for several years afterwards.Do changes in the Sun and volcanic eruptions affect the ozone layer?Q1420 Questions: 2010 Update Section III: STRATOSPHERIC OZONE DEPLETIONremoved from the stratosphere by natural air circulation. As particles are removed, solar transmission is restored. Based on the short residence time of volcanic particles in the strato-sphere, the two large eruptions in the past three decades cannot account directly for the continuous long-term decreases in global total ozone observed over the same period.Reactive chlorine from volcanoes. Explosive volcanic plumes generally contain large quantities of reactive chlorine in the form of hydrogen chloride (HCl). HCl is a reactive hal-ogen gas that can be converted to ClO, which rapidly destroys ozone (see Figure Q8-3). The plumes also contain a consider-able amount of water vapor, which forms rainwater and ice in the rising fresh plume. Rainwater and ice efficiently scavenge and remove HCl while it is still in the lower atmosphere (tro-posphere). As a result, most of the HCl in explosive volcanic plumes does not enter the stratosphere. After recent e xplosiveSection III: STRATOSPHERIC OZONE DEPLETION 20 Questions: 2010 UpdateQ.4320 Questions: 2010 Update Section III: STRATOSPHERIC OZONE DEPLETIONeruptions, observations of H Cl in the stratosphere have confirmed that increases are small compared with the total amount of chlorine in the stratosphere from other sources. Antarctic volcanoes. Volcanoes on the Antarctic conti-nent are of special interest due to their proximity to the Ant-arctic ozone hole. An explosive eruption could in principle inject volcanic aerosol and small amounts of HCl directly into the stratosphere over Antarctica, which could lead to ozone depletion. H owever, to be a possible cause of the annually recurring ozone hole beginning in the early 1980s, explosive Antarctic eruptions would need to have occurred at least every few years to maintain volcanic emissions in the stratosphere. This is not the case. Only the Mt. Erebus volcano is currently active in Antarctica. No explosive eruptions of Mt. Erebus or any other Antarctic volcano have occurred since 1980. There-fore, explosive volcanic eruptions in the last three decades have not caused the Antarctic ozone hole and, as noted above, have not been sufficient to cause the long-term depletion of global total ozone.Total ozone and future volcanoes. Observations and atmospheric models indicate that the record-low ozone levels observed in 1992–1993 resulted from the large number of par-ticles produced by the Mt. Pinatubo eruption, combined with the relatively large amounts of EESC present in the strato-sphere in the early 1990s. If the Mt. Pinatubo eruption had occurred before 1980, changes to global ozone would have been much smaller than observed in 1992–1993 because EESC values were much lower. EESC values will remain substantial in the early decades of the 21st century even as ODSs decline globally, with 1980 values reached by about 2050 (see Figures Q16-1 and Q20-2). Large volcanic eruptions in the interven-ing years will cause more ozone depletion. If an explosive eruption larger than Mt. Pinatubo were to occur, peak ozone losses could be larger than previously observed and substan-tial ozone losses could persist for longer time periods. As halogen gas abundances gradually decline to 1980 values, the effect of volcanic eruptions on ozone will lessen.Q.44。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
Analysis and simulation of “low-cost” strategies to reduce fuelconsumption and emissions in conventional gasoline light-duty vehicles Original Research ArticleEnergy Conversion and Management, Volume 50, Issue 2, February2009, Pages 215-222Carla Silva, Marc Ross, Tiago FariasClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThis paper focuses on technology analysis and simulation to mitigate the transportationimpacts on energy and environment, with the major goal of estimating the technologycontribution towards the 125 g/km CO2 target in Europe. The authors analyse cheap- andlow-complexity measures, while keeping the same power/weight ratio, for several vehiclecategories. The measures are: regenerative braking; fuel cut while coasting; enginestop/start; and engine downsizing and turbocharging. Simulation of these mechanisms forseveral road vehicles categories and driving cycles, allow us to conclude that with the lastthree mechanisms fuel consumption and CO2 emissions can be reduced by 15–49%,compared to the original vehicle. HC, CO and NO x emissions can be reduced by similar percentages. Regenerative braking is valuable only if the additional weight is compensatedby diminishing the body weight. The simulations confirm that the use of “slightly” modifiedconventional vehicles can reduce fuel consumption and carbon dioxide emissions, withoutthe complexity and high cost of full-hybrid powertrains.Article Outline1. Introduction2. Simulation model3. Vehicles and drive cycles3.1. Conventional vehicles4. Strategies for low fuel consumption and low CO2 emissions4.1. Regenerative braking4.2. Fuel cutPurchase$ 37.954.3. Stop–start4.4. Downsizing and turbocharging4.5. Combined effects5. Conclusions AcknowledgementsReferences227 A robust adaptive congestion control strategy for large scale networks with differentiated services traffic Original Research ArticleAutomatica, Volume 47, Issue 1, January 2011, Pages 26-38R.R. Chen, K. KhorasaniClose preview | PDF (891 K) | Related articles | Related reference workarticlesAbstract | Figures/Tables | ReferencesAbstractIn this paper, a robust decentralized congestion control strategy is developed for a large scale network with Differentiated Services (Diff-Serv) traffic. The network is modeled by a nonlinear fluid flow model corresponding to two classes of traffic, namely the premium traffic and the ordinary traffic. The proposed congestion controller does take into account the associated physical network resource limitations and is shown to be robust to the unknown and time-varying delays. Our proposed decentralized congestion control strategy is developed on the basis of Diff-Serv architecture by utilizing a robust adaptive technique.A Linear Matrix Inequality (LMI) condition is obtained to guarantee the ultimate boundedness of the closed-loop system. Numerical simulation implementations are presented by utilizing the QualNet and Matlab software tools to illustrate the effectiveness and capabilities of our proposed decentralized congestion control strategy.Article Outline1. Introduction2. Fluid flow model of a large scale diff-serv network 2.1. Fluid flow model of a single node 2.2. Fluid flow model of large scale diff-serv networks2.3. Network physical constraints2.4. Differentiated services (diff-serv) traffic3. Preliminary results3.1.Ultimate boundedness stability3.2. Stability of the perturbed switched time-delay systems4. Proposed decentralized robust congestion control strategy4.1. Premium traffic control strategy4.2. Ordinary traffic control strategy5. Performance evaluations and simulation results5.1. Performance metrics5.1.1. Packet loss rate (PLR)5.1.2. Average queueing delay5.2. Comparison results and discussion6. ConclusionsReferencesVitae228 Simulation of crash tests for high containment levels of road safety barriers Original Research ArticleEngineering Failure Analysis , Volume 14, Issue 8,December 2007, Pages 1711-1718M. Borovinšek, M. Vesenjak, M. Ulbin, Z. RenClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThis paper presents the results of computer simulations of road safety barrierbehaviour under vehicle crash conditions for high containment levels asPurchase $ 31.50mandated by the European standard EN 1317. Simulations were performedwith the explicit finite element code LS-DYNA, running on a multiprocessorcomputational platform. A very good agreement of simulation and real crash tests results was observed, which in turn justifies the use of computer simulations in the process of development and certification of road safety barriers.Article Outline1. Introduction2. Brief overview of the European standard EN 13173. Description of used computational models3.1. The vehicle models3.2. The safety barrier models3.3. Boundary conditions and contact description3.4. Dynamic analysis parameters4. Computational simulations4.1. Computational evaluation of different safety barrier reinforcements4.2. Comparison between the simulation and the large scale crash test5. ConclusionsReferences229 Spatial wildlife-vehicle collision models: A review of current work and its application to transportationmitigation projects Review ArticleJournal of Environmental Management , Volume 92, Issue 4, April 2011, Pages 1074-1082Kari E. Gunson, Giorgos Mountrakis, Lindi J. QuackenbushClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractPurchase$ 41.95In addition to posing a serious risk to motorist safety, vehicle collisions with wildlife are a significant threat for many species. Previous spatial modeling has concluded that wildlife-vehicle collisions (WVCs) exhibit clustering on roads, which is attributed to specific landscape and road-related factors. We reviewed twenty-four published manuscripts that used generalized linear models to statistically determine the influence that numerous explanatory predictors have on the location of WVCs. Our motivation was to summarize empirical WVC findings to facilitate application of this knowledge to planning, and design of mitigation strategies on roads. In addition, commonalities between studies were discussed and recommendations for future model design were made. We summarized the type and measurement of each significant predictor and whether they potentially increased or decreased the occurrence of collisions with ungulates, carnivores, small-medium vertebrates, birds, and amphibians and reptiles. WVCs commonly occurred when roads bisect favorable cover, foraging, or breeding habitat for specific species or groups of species. WVCs were generally highest on road sections with high traffic volumes, or low motorist visibility, and when roads cut through drainage movement corridors, or level terrain. Ungulates, birds, small-medium vertebrates, and carnivore collision locations were associated with road-side vegetation and other features such as salt pools. In several cases, results were spurious due to confounding and interacting predictors within the same model. For example, WVCs were less likely to occur when a road bisected steep slopes; however, steep slopes may be located along specific road-types and habitat that also influence the occurrence of WVCs. In conclusion, this review showed that much of the current literature has gleaned the obvious, broad-scale relationships between WVCs and predictors from available data sets, and localized studies can provide unique and novel results. Future research requires specific modeling for each target species on a road-by-road basis, and measuring the predictive power of model results within similar landscapes.In addition, research that builds on the current literature by investigating rareanomalies and interacting variables will assist in providing soundcomprehensive guidelines for wildlife mitigation planning on roads. Article Outline 1. Introduction2. Methods3. Results3.1. Landscape-related predictors3.2. Road-related predictors associated with wildlife-vehicle collisions4. Discussions4.1. Application of summary to mitigation planning4.2. Modeling considerations for mitigation planning5. ConclusionsAcknowledgementsReferences 230Energy for sustainable road transportation in China: Challenges, initiatives and policy implications OriginalResearch ArticleEnergy , Volume 35, Issue 11, November 2010, Pages4289-4301Xiaojun Hu, Shiyan Chang, Jingjie Li, Yining Qin Close preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesAbstractThis paper presents an overview of the initiatives launched in energy supplyand consumption and the challenges encountered in sustainable roadtransportation development in China. It analyzes the main energy challengesrelated to road transportation development arising in the context of economicPurchase $ 35.95development, rapid urbanization, and improvement in living standards. It also discusses technological- and policy initiatives needed to deal with these challenges, drawing comparisons with foreign experience: promoting the development and dissemination of alternative fuels and clean vehicles such as: LPG, CNG, EV, HEV, FCV, ethanol, methanol, DME, bio-diesel, and CTL, strengthening regulations relating to vehicle fuel economy and emission, improving traffic efficiency and facilitating public transport development, and strengthening management of the soaring motor vehicle population. If the current pattern continues, by the year 2030, the vehicle population in China will be 400 million and fuel demand will be 350 million tons. The potential energy saving capacity being 60%, the actual oil demand by 2030 from on-road vehicles might technically be kept at the current level by improving fuel economy, propagating use of HEV and diesel vehicles, improving supply of alternative fuels, and developing public transport. Several uncertainties are identified that could greatly influence the effect of the technical proposals: traffic efficiency, central government's resolve, and consumers' choice. Article Outline1. Introduction2. Road transportation development and energy consumption3. Major energy challenges for sustainable urban transport development3.1. Energy security3.2. Low efficiency3.3. Environmental challenges4. Policy initiatives and implications4.1. Promoting development and dissemination of clean vehicles and alternative fuels4.1.1. CNG and LPG4.1.2. EV, HEV and FCV4.1.3. Ethanol4.1.4. Bio-diesel4.1.5. Methanol4.1.6. DME4.1.7. CTL4.2. Strengthening vehicle fuel economy and emissions control4.3. Enhancing private vehicle management4.3.1. License bidding 4.3.2. Purchase rate4.3.3. Small displacement4.3.4.Fuel tax4.3.5. Parking and daily maintenance4.3.6. Motor cycles and electric bicycles4.4. Improving traffic efficiency and facilitating urban public transportationdevelopment4.4.1. Public transport infrastructure constructing4.4.2. Public transport fare5. ConclusionsAcknowledgementsReferences231 Reducing energy consumption in road transport through hybrid vehicles: investigation of reboundeffects, and possible effects of tax rebates OriginalResearch ArticleJournal of Cleaner Production , Volume 15, Issues 11-12, 2007, Pages 1076-1084 Peter de Haan, Anja Peters, Roland W. ScholzClose preview | Related articles | Related reference work articlesAbstract | Figures/Tables | ReferencesPurchase $ 41.95AbstractHybrid powertrains are considered to be a promising method to raise the overall fuel efficiency of passenger cars. They are predicted to enter the automobile markets in increasing numbers in the near future. This paper investigates 2 aspects relevant to the promotion of hybrid vehicles as part of an energy reduction strategy. First, are hybrid cars accompanied by rebound effects, which counteract their increased fuel efficiency? Second, do tax rebates indeed lead to higher sales numbers? We present results from a survey conducted with all 367 buyers of hybrid second-generation Toyota Prius in Switzerland in the first 9 months after market entry (response rate, 82.6%). As control group, questionnaires were also sent to 250 Toyota Corolla (61% returned) and 250 Toyota Avensis (52%) buyers. Among other items, the surveys asked for the car being replaced, if any. Main results are that the increase in car size for hybrid car buyers was lower than both, the market trend and the control group. Increase in car size was lower for hybrid car buyers than for both control group and market trend. 6% of hybrid car purchases did not replace a previously owned vehicle (control group 3%, P = 0.05), the Swiss market average being 20%. Hence rebound effects could be identified neither for vehicle size nor for vehicle ownership. As an energy policy measure, hybrid vehicles are eligible for tax rebates in parts of Switzerland. We found evidence that these tax rebates indeed lead to significant higher sales. We present a rough cost estimate of such tax rebates as CO2 abatement policy tool. Article Outline1. Introduction2. Possible side effects of hybrid car purchases2.1. Possible increase in car size2.2. Possible increase in vehicle ownership2.3. On the Toyota Corolla, Prius, and Avensis2.4. On the Swiss car market3. Surveys of new car buyers4. Analysis of car size evolution5. Analysis of household vehicle ownership evolution6. Effect of car ownership tax reductions7. Discussion, conclusions, and outlookAcknowledgementsReferences232 The Representations of inhabitants of Latvia about reasons of aggressive vehicle driving Original Research ArticleProcedia - Social and Behavioral Sciences , Volume 5, 2010, Pages 520-525Oksana JenenkovaShow preview |PDF (182 K)| Related articles | Related reference workarticles233 Environmental assessment of RAMseS multipurpose electric vehicle compared to a conventionalcombustion engine vehicle Original Research ArticleJournal of Cleaner Production , Volume 17, Issue 9, June 2009, Pages 781-790Hossein Mousazadeh, Alireza Keyhani, Hossein Mobli, Ugo Bardi, Ginevra Lombardi, Toufic el AsmarShow preview | Related articles | Related reference work articlesPurchase$ 41.95234 Development of comprehensive accident models for two-lane rural highways using exposure, geometry,consistency and context variables Original ResearchArticleAccident Analysis & Prevention , Volume 42, Issue 4, July 2010, Pages 1072-1079 Salvatore Cafiso, Alessandro Di Graziano, Giacomo DiSilvestro, Grazia La Cava, Bhagwant PersaudShow preview | Related articles | Related reference work articles Purchase $ 41.95235Visualization of road geometries based on CADD design standards Original Research ArticleAdvances in Engineering Software , Volume 41, Issue 4,April 2010, Pages 561-568Dahai Guo, Xuedong Yan, Janusz Zalewski, ClaudeVilliers Show preview | Related articles | Related reference work articlesPurchase $ 31.50 236 Development of a PC-based Open Architecture Software-CNC System Original Research ArticleChinese Journal of Aeronautics , Volume 20, Issue 3,June2007, Pages 272-281 Xiong-bo MA, Zhen-yu HAN, Yong-zhang WANG, Hong-ya FU Show preview | Related articles | Related reference work articlesPurchase $ 31.50 237Prolonged survival of mouse skin allografts after transplantation of fetal liver cells transduced withhIL-10 gene Original Research Article Transplant Immunology, Volume 13, Issue 1, June-July 2004, Pages 1-8Rachel Sembeil, Kamel Sanhadji, Geneviève Vivier, Jamel Chargui, Jean-Louis TouraineShow preview | Related articles | Related reference work articlesPurchase$ 31.50 238 Speed Character Study for Motor Vehicle and Bicycle at Non-barrier Section。