Characteristics of inorganic ions and organic components in PM_(2.5) from biomass burning

为探讨生物质在明火和阴燃两种不同条件下PM_(2.5)及主要成分的排放差异,选取了7种具有代表性的生物质样品(小麦、水稻、马尾松叶、马尾松枝、杂; 草、玉米、棉花)进行了燃烧实验,并对PM_(2.5)样品中的7种主要水溶性离子(Na~+、NH_4~+; 、K~+、Ca~(2+)、Cl~-、NO_3~- 、SO_4~(2-))及有机碳(OC) 、元素碳(EC) 、水溶性有机碳(WSOC); 、有机酸和左旋葡聚糖(LG)等有机成分进行了分析.结果表明,明火和阴燃条件下PM_(2.5)的排放因子分别为2.82~ 7.74; mg·g~(-1)和3.24~ 22.56; mg·g~(-1),阴燃时的排放因子偏高,不同燃料类型也存在一定差异.燃烧排放PM_(2.5)中水溶性离子以Cl~-为最高,占总离子的比例为72; %~; 94%,且与NH_4~+存在显著正相关关系,水溶性离子整体表现为明火条件下的浓度显著高于阴燃条件下的浓度.受阴燃条件下氧气不足的影响,PM_(2; .5)中有机组分的浓度表现为阴燃高于明火,进而导致阴燃时PM_(2.5)的排放因子增加.水稻秸秆燃烧烟尘中3种来源特征比值(LG/PM_(2.5; )、LG/OC和LG/WSOC)仅为小麦和玉米秸秆燃烧排放相应比值均值的0.34、0.24和0.27倍,表明在不同农作物的收获季节采用上述特征比; 值进行生物质燃烧来源估算时,应区别对待.Seven kinds of biomass samples including masson pine needles and; branches,wheat,rice,grass,maize and cotton straw were burned under; flaming and smoldering conditions to investigate the emission factors of; PM_(2.5) and its associated major components including organic carbon; (OC), elemental carbon,water soluble ions,water soluble organ carbon; (WSOC),organic acids and levoglucosan (LG). The results showed that the; emission factors were in the range of 2.82 ~ 7.74 mg·g~(-1) and 3.24 ~; 22.56 mg·g~(-1) for PM_(2.5) from biomass burning in flaming and; smoldering conditions, respectively. The difference between the two; burning conditions varied in different kinds of biomass fuel. The; profiles of water soluble ions in PM_(2.5) were all dominated by; Cl~-,accounting for 72%~ 94% of the total water soluble ions.; Significant positive correlations were only observed between Cl~-and; NH_4~+. The concentrations of water soluble ions were generally higher; in flaming PM_(2.5) than those in smoldering PM_(2.5). The organic; components showed much higher levels in smoldering PM_(2.5) with respect; to those in flaming PM_(2.5) because of incomplete burning. The higher; emission factors of PM_(2.5) under smoldering conditions were mainly due; to the higher emission factors of organic species. Three source; characteristic ratios including LG/PM_(2.5),LG/OC and LG/WSOC in rice; straw burning PM_(2.5) were only 0.34,0.24 and 0.27 times of the mean; ratios in wheat and maize straw burning PM_(2.5),respectively.; Thus,different characteristic ratios are required to estimate biomass; burning contribution in different biomass burning seasons.国家自然科学基金; 国家重点研发计划; 福建省自然科学基金计划项

2017年厦门金砖会晤期间气象因素与管控措施对空气质量的影响

2017年厦门金砖会晤期间采取了大气污染临时管控措施,使AQI小时值和日均值均达到了双优的预期目标.本文根据管控措施实施的前、中、后阶段,厦门及周边城市大气污染物浓度的变化,对气象因素和人为因素的影响分别进行分析.结果发现,气态污染物对临时管控措施的敏感性最强,SO2和NO2的降幅（39.9%和25.6%）明显高于PM2.5和PM10的降幅（5.5%和4.8%）,台风外围带来的大风和降水可显著改变大气污染物的周期性变化规律.大气PM2.5组成及SO2/NO2、SO【math395z】/NO【math396z】、OC/EC和WSOC/OC等比值变化显示机动车（尤其是柴油货车）是本地区大气污染物的重要来源.控制变量分析显示,厦门金砖会晤期间气象因素对颗粒物和NO2削减的贡献更大（20.3%）,而临时管控措施对SO2的削减效果更明显（23.2%）,且有一半以上（51%～64%）的大气污染物来自外来源输送.国家重点研发计划(No.2016YFC0502901);;国家自然科学基金(No.41471390);;厦门大学校长基金本科生项目(No.20720162006)~

类泛素蛋白及其中文命名

泛素家族包括泛素及类泛素蛋白,约20种成员蛋白.近年来,泛素家族领域取得了迅猛发展,并已与生物学及医学研究的各个领域相互交叉.泛素家族介导的蛋白质降解和细胞自噬机制的发现分别于2004和2016年获得诺贝尔奖.但是,类泛素蛋白并没有统一规范的中文译名. 2018年4月9日在苏州召开的《泛素家族介导的蛋白质降解和细胞自噬》专著的编委会上,部分作者讨论了类泛素蛋白的中文命名问题,并在随后的\"泛素家族、自噬与疾病\"(Ubiquitinfamily,autophagy anddiseases)苏州会议上提出了类泛素蛋白中文翻译草案,此草案在参加该会议的国内学者及海外华人学者间取得了高度共识.冷泉港亚洲\"泛素家族、自噬与疾病\"苏州会议是由美国冷泉港实验室主办、两年一度、面向全球的英文会议.该会议在海内外华人学者中具有广泛影响,因此,参会华人学者的意见具有一定的代表性.本文介绍了10个类别的类泛素蛋白的中文命名,系统总结了它们的结构特点,并比较了参与各种类泛素化修饰的酶和它们的生物学功能.文章由45名从事该领域研究的专家合作撰写,其中包括中国工程院院士1名,相关学者4名,长江学者3名,国家杰出青年科学基金获得者18名和美国知名高校华人教授4名.他们绝大多数是参加编写即将由科学出版社出版的专著《泛素家族介导的蛋白质降解和细胞自噬》的专家

Survey on the Core Techniques of Cloud Computing

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Benefit-Aware On-Demand Provisioning Approach for Virtual Resources

基于虚拟机的资源重配置操作具有耗时长并伴随性能衰减的特点。已有的 Cost-Oblivious 和 Cost-Aware方法在面对Internet突变负载时存在因经常执行资源重配置操作而导致频繁QoS违约的不足。提出了一种收益敏感(benefi t-aware)的资源按需提供方法。该方法首先考虑了 Web 应用在配置稳定期内的 QoS 获益,并以此构建收益函数;然后,以收益率最大化原则作为资源重配置策略选择的依据。实验结果表明,该方法与Cost-Oblivious方法相比最多能 节约25%的资源成本,而与Cost-Aware方法相比则能有效减少Web应用在突变负载下的QoS违约次数。It is a challenging problem to provide QoS (quality of service) in the virtualization-based cloud computing environment. Existing efforts have addressed this challenge based on either Cost-Oblivious approaches, or Cost-Aware approaches. However, both approaches may suffer frequent QoS violations under typical flash crowd workload. For instance, both approaches ignore the benefit gained after configuration changes. In this paper, a benefit-aware approach according to the profit rate maximization principle is introduced to address this problem. Here, the benefit means the satisfaction percept of the duration that application continuously guarantees the QoS in the new configuration. Experimental results based on TPC-W benchmark show that this benefit-aware approach can save the costs of VM resources as much as 25%and can effectively reduce the QoS violations compared through a cost-aware approach

检测O<sub>2<-sub>·<sup>-<-sup>的荧光分子探针、其合成方法和应用

本发明公开了一种检测超氧阴离子自由基(O2·-)的荧光分子探针，其具有下式所示结构：式中，R为氨基烷基或C1～C12的直链烷基，n选自0～2中的任一整数。同时，本发明还提供了合成所述荧光分子探针的方法以及利用所述荧光分子探针检测超氧阴离子自由基的方法。本发明的荧光分子探针对于低浓度、活性高及寿命短的超氧阴离子自由基可以实现快速准确的响应，并且灵敏度(检测限可低至222nM)和选择性高，同时可以应用于水相体系，具有良好的应用前景，另外，本发明荧光分子探针的合成工艺简单，反应条件温和，适于规模化生产

Plasma assisted stabilization of a premixed methane-air flame by nanosecond repetitively pulsed discharges

Nanosecond pulsed discharges were applied to an experimental study of the temporal response of a premixed methane-air Bunsen flame.A nanosecond-gated schlieren system was employed to explore the microstructure and the dynamic response of flame to the discharges.At the meantime,time-resolved optic..