The effects of ocean acidification on marine organisms and ecosystem

海洋酸化是CO2排放引起的另一重大环境问题.工业革命以来,海洋吸收了人类排放CO2总量的三分之一.目前,海洋每年吸收的量约为人类排放量的四分之一(即约每小时吸收100万吨以上的CO2),对缓解全球变暖起着重要的作用.然而,随着海洋吸收CO2量的增加,表层海水的碱性下降,引起海洋酸化.海洋酸化会引起海洋系统内一系列化学变化,从而影响到大多数海洋生物的生理、生长、繁殖、代谢与生存,可能最终导致海洋生态系统发生不可逆转的变化,影响海洋生态系统的平衡及对人类的服务功能.地球历史上曾多次发生过海洋酸化事件,伴随着生物种类的灭绝,其内在联系虽然不甚明确,却也可能暗示未来海洋酸化可能对海洋生态系统产生重大的影响.Ocean acidification is known as another global change problem caused by increasing atmospheric CO2.Since the industrial revolution, the oceans have absorbed more than one third of the anthropogenic CO2 released to the atmosphere, currently, at a rate of over 1 million tons per hour, totaling to about one quarter of all anthropogenic CO2 emissions annually.Uptake of CO2 by the ocean has played an important role in stabilizing climate by mitigating global warming.However, rising ocean carbon levels caused by the uptake of anthropogenic CO2 (acidic gas) leads to increased ocean acidity (reduced pH) and related changes in ocean carbonate chemistry, or "ocean acidification".Recent research has shown that ocean acidification affects the physiology, growth, survival, and reproduction of many, if not most marine organisms.Ultimately, future ocean acidification may lead to significant changes in many marine ecosystems, with consequential impact on ecosystem services to societies.Several ocean acidification events are known to have occurred during Earth’s history, each coinciding with high rates of species’ extinctions.Although the mechanisms involved in past massive species extinction associated with ocean acidification events, they certainly hint potential disastrous impacts on ecosystem functions in short future.中国科学院“百人计划”(2006-067); 国家自然科学基金(40872168)资

1978～2008年中国湿地类型变化

分别基于美国陆地卫星(Landsat MSS/TM/ETM+)和中巴资源卫星(CBERS-02B)影像数据,以人工目视解译为主,完成了中国1978～2008年4期(基准年分别为1978,1990,2000和2008年)湿地遥感制图,并进行了大量的室内外验证.在此基础上,对我国湿地现状及近30年来湿地变化进行了初步分析,得到以下主要结论:(ⅰ)截止2008年,中国湿地面积约为324097km2,其中以内陆沼泽(35%)和湖泊湿地(26%)为主.(ⅱ)1978～2008年,中国湿地面积减少了约33%,而人工湿地增加了约122%.过去30年里湿地减少的速度大幅降低,由最初5523km2/a(1978～1990年)降为831km2/a(2000～2008年).(ⅲ)减少的自然湿地(包括滨海湿地和内陆湿地),其类型变化由湿地向非湿地转化的比例逐渐降低.初期(1978～1990年)几乎全部(98%)转换为非湿地;在1990～2000年间减少的自然湿地约有86%转化为非湿地,而在2000～2008年,这一比例下降为77%.(ⅳ)气候变化和农业活动是中国湿地变化的主要驱动因素,湿地变化在中国分为三大不同特征区域,即西部三省/自治区(西藏、新疆和青海)、北部两省/自治区(黑龙江和内蒙古)和其他省市区.其中西部区域尤其是青藏高原,湿地变化的驱动因子以气候增温为主;新疆湿地由于气候增温和农业活动共同作用造成变化不大.北部省/自治区的湿地变化则主要由农业活动引起;而其他省市区的湿地变化几乎完全受控于人类的农业经济活动

A Study of the Threshold Values of Earnings Management of China’s Listed Companies: from the Perspective of Prospect Theory

文章从前景理论的视角对我国上市公司为了追求和超越市场阈值与政策阈值而实施的盈余管理行为进行研究,发现前景理论能较好的解释各种阈值两侧管理层的风险态度以及风险和收益之间的权衡关系,同时也检验了前景理论在我国的适用性。From the perspective of prospect theory,this paper tries to study the earnings management behavior carried out by the listed companies in China to seek and surpass the market threshold value and policy threshold value.It is found that the prospect theory can rationally interpret the risk attitude of the management on both sides of every threshold value and the trade-off relationship between risk and profit.At the same time,it is verified that the prospect theory is applicable in China.国家自然科学基金项目(70872096);教育部人文社会科学重点研究基地基金资助项目(05JJD630008

基于LMD排列熵和BP神经网络的行星齿轮箱故障诊断方法

针对行星齿轮箱故障诊断过程中的故障特征向量区分度差、诊断成功率不够高等问题，提出了一种基于局部均值分解（Local mean decomposition，LMD）排列熵和BP神经网络结合的方法。对原始信号进行LMD，获得包含主要信息的PF分量，计算排列熵值，构造特征向量，利用提取的特征向量训练BP神经网络，完成故障模式识别。以EMD排列熵方法和无量纲分析方法作为对比组，实验验证说明，提出方法提取到的不同工况的特征向量区分度更强，故障诊断效果更好；且当训练组数发生变化时，提出方法的综合表现更优秀

不同上方来水模式下工程堆积体坡面的植被调控

为揭示植被格局对工程堆积体坡面水沙调控的影响，采用野外模拟径流冲刷试验，分析了 4 种上方来水模式（均 匀型、峰值前型、峰值中型和峰值后型）下坡面 5 种覆草格局（裸坡、坡顶聚集、坡中聚集、坡底聚集和带状格局）的 侵蚀特征。结果表明：水流功率与土壤剥蚀率之间相关性最高且呈极显著幂函数关系（R2 =0.47～0.72，P&lt;0.01），是描述 堆积体侵蚀动力机制的最优参数。植被格局的减流效益在 12.23%～49.62%之间，减沙效益在 12.92%～80.54%之间，减 沙效益高于减流效益；带状和坡顶聚集格局的平均减流减沙效益分别为 43.87%、58.09%和 30.55%、54.41%，显著优于 其他植被格局，在治理堆积体水土流失时应优先考虑这两种植被格局。植被格局下侵蚀泥沙中砂粒含量较对照小区减小 了 18.79%～35.80%，黏粒含量增加了 3.56%～10.69%，表明植被对砂粒的拦截效果显著；侵蚀泥沙颗粒体积分形维数主 要由黏粒体积分数决定，两者呈极显著线性相关关系（R2 =0.90，P&lt;0.01）。植被格局的砂粒富集率较对照小区相对减小， 黏粒富集率相对增加，体积分形维数增大；侵蚀泥沙中黏粒和砂粒迁移方式以团粒为主，粉粒则以单粒为主。该研究可 为工程堆积体水土流失植被防控措施的配置提供参考。</div

2004年中国植物科学若干领域研究进展

中文核心期刊要目总览(PKU)中国科学引文数据库(CSCD)004385-39

不同垃圾焚烧设备中二噁英的排放特征和I-TEQ指示物的研究

分析了国内3种不同类型的垃圾焚烧设备中二噁英化合物的排放特征,不同PCDD/F单体与I-TEQ的相关性以及23478-PeCDF与I-TEQ的线性回归分析.得到了不同类型的垃圾焚烧设备中二噁英同系物的统计学分布特征.结果发现,生活垃圾、医疗垃圾和危废焚烧炉中二噁英（PCDD/F）同系物分布虽有一定差异,但变化不大,与生活垃圾焚烧炉和危废焚烧炉相比,医疗垃圾焚烧炉中噁英同系物的分布稍有区别.在3种焚烧炉的烟道气中体积分数最大的是OCDD和1234678-HpCDF,分别为12.3%-23.0%和15.0%-19.7%;而对I-TEQ贡献最大的则是23478-PeCDF,体积分数为33.1%-34.5%,远远高于其它的PCDD/F单体.通过对不同的PCDD/F单体与I-TEQ的相关性分析发现：23478-PeCDF与I-TEQ的相关性最好,相关系数R2为0.93-0.98;而毒性最大的2378-TCDD与I-TEQ的相关性较差,R2为0.29-0.49;体积分数最大的OCDD与I-TEQ的相关性很差,R2为0.03-0.12;体积分数较大的1234678-HpCDF与I-TEQ也有较好的相关性,R2为0.62-0.87,但依然次于23478-PeCDF.通过23478-PeCDF与I-TEQ线性回归的结果发现：即使I-TEQ的浓度范围为5-6个数量级,23478-PeCDF与I-TEQ也表现出很好的线性关系,对于不同的垃圾焚烧设备,回归曲线斜率为在1.16-1.40之间,相关系数R2在0.94-0.97之间

Unemployment and gender relations : occupational trajectories and the experience of job loss among women and men in the metallurgical sector in Campinas (2002 - 2012)

Orientador: Angela Maria Carneiro AraujoTese (doutorado) - Universidade Estadual de Campinas, Instituto de Filosofia e Ciências HumanasResumo: O desemprego está relacionado à existência de um excedente de força de trabalho, mas também à atuação das instituições que estruturam o mercado de trabalho para apoiar quem perde sua ocupação em cada sociedade. Além disso, tem importante dimensão subjetiva, pois o/a trabalhador/a sem trabalho pode ou não reconhecer-se como desempregado/a, sendo sua percepção da situação de desemprego e os sentimentos dela decorrentes influenciados pela trajetória profissional e de vida de cada um e cada uma (ou seja, pela relação que cada pessoa desenvolve com o trabalho assalariado, com o(s) coletivo(s) de trabalho e com as empresas por que passou). Neste sentido, as visões sobre o trabalho e sobre o desemprego apresentam diferenças entre mulheres e homens, relacionadas a formas diferenciadas de socialização, às políticas de recursos humanos das empresas (que segregam reiteradamente as mulheres a uma posição secundária no mercado de trabalho) e às políticas públicas que regulamentam o mercado de trabalho e oferecem suporte ao cuidado infantil. Nesta tese investigamos, na perspectiva das relações sociais de gênero, a experiência do desemprego entre os homens e mulheres de uma categoria profissional majoritariamente masculina: a categoria metalúrgica. Procuramos compreender como o desemprego impacta sobre o percurso ocupacional, sobre a vida pessoal, sobre as relações familiares, sobre as estratégias de reinserção no mercado de trabalho e sobre os modelos ideais de comportamento das mulheres e dos homens desta categoriaAbstract: Unemployment is related to the existence of a surplus of labor force, but it is also connected to the performance of institutions that structure the labor market to bolster those who lose jobs in each society. Furthermore, this phenomenon has important subjective dimension, since the unemployed worker may or may not recognized him or herself as such, and one¿s perception depends on each personal and professional path (i.e. it is influenced by the relation that each person develop with paid labor, collective work and also companies). In this sense, there are different points of view of women and men regarding different forms of interaction, gendered human resources policies (which insert women in bottom positions) and public policies that rule the labor market and support childcare. In this thesis we aim to investigate - through the perspective of gender relations - the experience of unemployment among men and women in an environment predominantly male: the metallurgical sector. We seek to understand how unemployment affects distinctively gendered roles of women and men in this sector, as occupational route, personal life, family relations, and strategies of reinsertion into the labor marketDoutoradoCiencias SociaisDoutora em Ciências Sociai

洱海蓝藻水华暴发期浮游植物群落变化及影响因素

对洱海水质和浮游植物进行了调查,分析了洱海藻类水华暴发季节水质营养水平及浮游植物多样性,并探讨了洱海浮游植物种群演替的环境机制。研究结果表明,洱海蓝藻水华在6—10月份大量暴发,蓝藻数量高达107 cells/L,水华种类为微囊藻(Microcystis)属的一些种,微囊藻在6—10月份占绝对优势,最高可达90%以上。分析5—11月洱海营养水平,其中7月营养水平最高,浮游植物生物量10月份最大(以叶绿素a表示)。使用SPSS里的pearson分析了浮游植物和各理化因子的关系,结果表明相对于其他浮游植物种类,总磷(TP)对微囊藻的影响比较大