Atmospheric Dispersion Modeling of the Emissions from the Logbaba Thermal Power Plant, Douala-Cameroon

Air quality in the vicinity of the thermal power plant of Logbaba in the town of Douala was investigated in this study using data collected in a 5-year period (2008-2012). The distribution of pollutants such as SO2, NOx, CO and the particle matter PM2.5 was analyzed using numerical modeling, based on physical and thermal characteristics, as well as the operating periods of the power plant. The American Environmental Regulator Model (AERMOD) that is an atmospheric dispersion model was used for simulation. The wind rose and others National Oceanic Atmospheric Administration (NOAA) in-situ data were used for the validation of the model. The pollutants distribution was evaluated at two locations: the exit of the power plant, considered as reference point, and at 330 m away from the exit where the first houses appeared. The results show that the relative concentration for each contaminant at the exit of the power plant is 7.2% for the PM2.5 during 24 hours of emission, 46.0% for CO over 8 hours of emission, and 17.5% for SO2 over one hour. The NOx is the highest pollutant with 259.1% over an hour of emission and 51.0% over one year. Beyond 330 m of the power plant, only NOx keeps a polluting character with a relative rate of 100%. These results show that the pollution level of the power plant is over the threshold for air quality set by the World Health Organization. Moreover, among all pollutants investigated, NOx appears to be the most critical for the population in the vicinity of the Logbaba thermal power plant. This information is therefore important for policy and decision makers in preventing the vulnerability of the population to air pollutants from such industrial settings.

Talking about Height and Quality of Life: A Content-Analysis of Focus Group Discussions with Short-Statured Children and Their Parents in the US

Background: To understand what life is like for US children with a diagnosis of Growth Hormone Deficiency or Idiopathic Short Stature, the impact of short stature on Health related Quality of Life (HrQoL) was qualitatively examined and needs for care from the young patients and their parents perspective were identified. Methods: Focus group discussions with 26 American-English speaking and nine American-Spanish speaking children and their parents were conducted, transcribed verbatim and subsequently qualitatively analyzed by two independent raters, using an existing coding guideline, based on the multidimensional HrQoL concept and a special software (VERBI-Software MAXQDA 10). Results: A total of 1313 statements for the English-speaking and 447 statements for the Spanish-speaking families were categorized. In the US, the strongest frequency of mention was found for the HrQoL dimension “Social” across respondents, followed by “Treatment” and “Emotion”. Conclusion: Conducting and analyzing data generated from focus groups ensure that young patients’ experiences of disease are represented in the measure of outcomes for use in clinical trials and patient care.

Self-care:A concept analysis

Objectives:There is extensive literature from various disciplines on self-care,an important aspect of nursing intervention via evaluation and education,but its meaning remains unprecise due to the difficulty integrating the diverse definitions developed over time across disciplines.Therefore,it is vital to clarify the meaning of self-care and formulate the defining attributes,antecedents,and consequences to self-care.Methods:Walker and Avant’s concept analysis approach was used to analyze the concept of self-care.A search of the literature was completed using the databases CINAHL,PubMed,and EBSCOhost for years 1975e2020;literature search included peer-review articles,full-text publications,and available in English.A total of 31 articles were reviewed,and saturation was reached.Results:An extensive review of the literature revealed salient characteristics that reflected the most frequently used terms associated with the concept.Guided byWalker and Avant’s method,three defining attributes emerged as common themes:awareness,self-control,and self-reliance.Conclusions:A clarified definition was identified:the ability to care for oneself through awareness,selfcontrol,and self-reliance in order to achieve,maintain,or promote optimal health and well-being.

从模拟研究看青藏高原的隆升形式与亚洲季风——干旱环境演化的区域差异（英文）

Tectonic uplift of the Tibetan Plateau(TP) is a major event in the recent geological history of the earth,which produced far-reaching impacts on the Asian and global climates and environments.Since the 1970 s,with the development of theories in planetary fluid dynamics and the improvement of computational environment,numerical simulation based on general circulation models(GCMs) has become an increasingly effective tool in investigations of the physical mechanisms and evolutionary processes of paleoclimate associated with the TP uplift.In this paper,we provide a timely review on representative works in the past four decades on the paleoclimatic responses to the plateau uplift.Numerical simulations to study the paleoclimatic effects of the plateau uplift experienced three stages with increasing complexity:1) plateau uplift as a whole in a single episode,as represented by the no-mountain/with-mountain experiments;2) phased uplift in which the uplifting process was divided into multiple stages and within each the plateau rose by a certain proportion of its current height;and3) sub-regional uplift,in which the focus was the effects of the uplift of a certain area within the TP,such as the northern Tibetan Plateau.These studies discovered the cause-effect relations between the plateau uplift and paleoclimate change,especially for the effects on the evolution of Asian monsoon system and aridification of inland Asia.In this review,we also included examples of current on-going studies,such as the relative impacts of the Himalayas vs.those of the TP as the rain barrier and comparative studies on the paleoclimatic effects of the uplifts of the TP and African highland.Toward the end,we identified five areas as the focus of future research regarding the TP uplift:1) the differences in the evolutionary processes of the South Asian and East Asian monsoons in response to the Himalayas-TP uplift at the regional and sub-regional scales;2) climatic feedbacks;3) long-distance effects(teleconnections) of the TP uplift;4) abrupt climatic changes;and 5) comparisons between the results of numerical simulations and geological evidences.

“女性之虹”——1977美国国际妇女年大会的多样性与统一性

1977纪念国际妇女年(International Women’s Year)全国妇女大会在诸多方面均标志着美国第二波女权主义已进入鼎盛时期,大会制定的《行动计划》是对女权运动理念的详尽声明。大会对反女权激进运动的发展、提升其可见度亦发挥了重要作用,把既是与会者又是《行动计划》起草者的有色人种女性和女同性恋者吸纳其中之举意义重大。2000余名代表构成的多元群体齐聚一堂,就27项建议纲领中的26项达成一致,这足以令世界瞩目,亦将一幅女权主义者同结一心的图画展现于美国民众面前。本文对大会的多样性及表面统一性的成因加以剖析,认为两大因素尤为关键:其一,反女权主义者所发出的威胁信号推动了女同性恋者的参会,使女权拥护者的反对之声最小化的策略得以形成;其二,众多华盛顿女权主义领导人全力支持广开言路,孜孜不倦于召开一个各色女性齐参与的盛会。与20世纪70年代末第二波女权运动中包容性政治相关的重要历史细节将在文中一一披露。

A Study on Dimension Synthesis for the Peaucellier Mechanism

Straight-line motion, albeit simple, manifests itself in numerous applications, from running steam engines and oil wells to manufacturing parts with straight edges and sides. The drive to maximize production creates a need for continuously running assembly-line manufacturing comprised of precise, individually optimized components. While there are many so-called straight-line generating mechanisms, few actually produces a true straight-line, most generate only approximate straight-line. Featured an eight-link rhomboidal system with length constraints,, the Peaucellier mechanism is one that actually produces a true straight line intrinsically. This paper presents a study on the dimension synthesis of the Peaucellier mechanism, namely by identifying the correct ratio of linkage lengths to produce the longest straight line stroke. In addition to designing for stroke, another objective of interest is to attain a desired velocity profile along the path. Kinematic analysis of the velocity profile on the mechanism will render the creation of input angular velocity standards based on desired stroke speed. Given the stroke and velocity specifications, specific steps to size the dimensions of the mechanism developed as result of this study will be presented.

Continental drift, plateau uplift, and the evolutions of monsoon and arid regions in Asia, Africa, and Australia during the Cenozoic

Monsoon and arid regions in the Asia-Africa-Australia(A-A-A) realm occupy more than 60% of the total area of these continents. Geological evidence showed that significant changes occurred to the A-A-A environments of the monsoon and arid regions, the land-ocean configuration in the Eastern Hemisphere, and the topography of the Tibetan Plateau(TP) in the Cenozoic. Motivated by this background, numerical experiments for 5 typical geological periods during the Cenozoic were conducted using a coupled ocean-atmosphere general circulation model to systemically explore the formations and evolutionary histories of the Cenozoic A-A-A monsoon and arid regions under the influences of continental drift and plateau uplift. Results of the numerical experiments indicate that the timings and causes of the formations of monsoon and arid regions in the A-A-A realm were very different. The northern and southern African monsoons existed during the mid-Paleocene, while the South Asian monsoon appeared in the Eocene after the Indian Subcontinent moved into the tropical Northern Hemisphere. In contrast, the East Asian monsoon and northern Australian monsoon were established much later in the Miocene. The establishment of the tropical monsoons in northern and southern Africa, South Asia, and Australia were determined by both the continental drift and seasonal migration of the Inter-Tropical Convergence Zone(ITCZ), while the position and height of the TP were the key factor for the establishment of the East Asian monsoon. The presence of the subtropical arid regions in northern and southern Africa,Asia, and Australia depended on the positions of the continents and the control of the planetary scale subtropical high pressure zones, while the arid regions in the Arabian Peninsula and West Asia were closely related to the retreat of the Paratethys Sea. The formation of the mid-latitude arid region in the Asian interior, on the other hand, was the consequence of the uplift of the TP.These results from this study provide insight to the important roles played by the earth's tectonic boundary conditions in the formations and evolutions of regional climates during geological times.

Tree ring-dated fluctuation history of Midui glacier since the Little Ice Age in the southeastern Tibetan Plateau

Fluctuation history of Midui glacier in the southeastern Tibet since the Little Ice Age(LIA) was reconstructed by the dating of lateral and terminal moraines using tree rings.Four conversions of glacier advance/stabilization to retreat were identified at around 1767,1875,1924 and 1964.The glacier reached its LIA maximum position at 1767.The fluctuations are consistent with those of other glaciers from the Tibetan Plateau,the Rockies and the Alps,suggesting high spatial coherency of glacier fluctuations in the Northern Hemisphere.Comparison with the summer temperature reconstruction in the southeastern Tibetan Plateau indicated that the Midui glacier fluctuation may be related to temperature variation on the centennial timescale.On the decadal scale,the fluctuation could correspond to cold/warm variation with an 8-year lag on average.

“人类世”的提出与争议

“人类世”(The Anthropocene)一词自2000年以来逐渐流行并越来越多地见诸于环境科学、地球科学以及社会和人文学科的各种期刊文章和书籍。本研究简要介绍有关“人类世”概念的提出、科学意义和相关的最新进展,特别是国际地层委员会第四纪地层分委员会的人类世工作组(Anthropocene Working Group)正在推进将“人类世”作为一个正式地质年代单位的工作;同时也介绍与之有关的争议,例如关于如何界定“人类世”的底界,以及“人类世”是否应当被看作是一个地质事件,而不是一个新的地质年代单位。分析认为,人类活动已经对地球环境造成极为深远的影响,但现今是否已经进入了一个新的地质年代尚待确定。学术界应当搁置争议,将注意力集中于研究人类活动对地球环境影响的事实和机制,为人类社会减缓和适应日益加剧的全球环境变化做出贡献。

1979～2005年青藏高原位势高度场变化趋势的时空特征

利用NCEP/NCAR位势高度再分析资料分析了1979～2005年青藏高原及其邻近地区30hPa、100hPa、300hPa和500hPa位势高度场变化趋势的时空特征。研究表明:(1)1979～2005年青藏高原区域平均位势高度场在对流层中层存在上升趋势,且主要发生在冷半年;随着等压面的升高,高度场上升趋势减弱;到平流层高度场呈显著降低趋势,且主要发生在暖半年。(2)从空间上看,平流层位势高度场年平均变化整体呈显著降低趋势,大致呈纬向分布,南部降低趋势强于北部,特别是高原东南、孟加拉湾北部降低趋势最强;对流层中层位势高度场变化趋势以上升为主,高原东北部上升趋势尤其显著。(3)尽管与高原各层位势高度值本身相比,变化趋势是一个小量,但国内外不同区域及不同空间尺度的研究都发现有类似现象,故对此应给予重视。今后应进一步加强青藏高原位势高度场时空变化趋势的驱动机制、影响及其对全球变暖的区域响应研究。(4)1979年以来NCEP/NCAR位势高度再分析资料用于青藏高原及其邻近地区的气候变化研究是有效的。

树轮揭示的藏东南米堆冰川小冰期以来的进退历史

利用冰川前端冰碛垄上的树轮年代学证据,对冰碛垄形成年代进行定年,重建了青藏高原东南部米堆冰川小冰期以来的进退波动历史.在对冰碛垄进行定年时,我们对树龄进行了髓心年龄估计和取样高度年龄校正,并考虑了先锋树种的定居期.最老树木的年龄显示,小冰期以来,米堆冰川至少经历了四次明显的冰川进退波动,分别为AD1767(TM1-LM1),AD1875(LM2),AD1924(LTM-LM3)和AD1964(TM2),其中AD1767(TM1-LM1)对应小冰期冰盛期,冰川前进达到最大规模.米堆冰川波动历史与中国和北半球其他地区冰川的波动呈现较高的空间一致性.与藏东南地区夏季温度变化重建的对比表明,百年时间尺度上米堆冰川进退波动与温度冷暖变化趋势相对应,在年代际尺度上,冰川进退波动与温度变化存在约8a的滞后期.

大陆漂移、高原隆升与新生代亚-非-澳洲季风区和干旱区演化

亚-非-澳洲季风区和干旱区的面积约占这三大洲陆地总面积的60%以上.基于新生代以来亚-非-澳洲季风和干旱环境以及东半球海陆分布和青藏高原等地形显著变化的地质事实,利用全球海-气耦合模式开展新生代5个特征地质时期气候模拟试验,系统探讨了新生代亚-非-澳洲季风区和干旱区形成演化及其受大陆漂移和高原隆升的影响.结果表明,亚-非-澳洲季风区和干旱区形成的时间和原因明显不同.北非与南非季风在古新世中期已经存在,南亚次大陆季风在始新世印度大陆移入北半球热带后开始出现,而东亚和澳大利亚北部季风在中新世才建立.北非、南非、南亚和澳大利亚热带季风的建立是大陆漂移的位置和热带辐合带季节性迁移共同决定的,而青藏高原的位置和高度则是东亚季风建立的关键因素.北非、南非、亚洲和澳大利亚副热带干旱区的存在取决于大陆的位置和行星尺度副热带高压的控制,阿拉伯半岛和西亚干旱区的发展与区域尺度海陆变迁,特别是古特提斯海的退缩密切相关,而亚洲内陆中纬度干旱区的形成则是青藏高原隆升的结果.这一研究揭示了地球构造边界条件在地质时期区域气候环境形成演化中的重要作用.

海洋对全球变暖的快慢响应与低温升目标

最新研究表明,为了实现《巴黎协定》制定的1.5或2℃低温升目标,温室气体浓度需要在增长到某个峰值后逐渐下降.利用第五次国际间耦合模式比较计划(CMIP5)中气候模式和理想的一维两盒模型的模拟结果,研究了全球变暖下海洋混合层的快速响应和深层海洋的缓慢响应及其对低温升目标的影响.多模式平均结果显示,在辐射强迫先增长后稳定情景(RCP4.5)下,全球表面平均温度(global mean surface temperature,GMST)会以先快后慢两种速率增长;而在辐射强迫先增长后减弱情景(RCP2.6)下,GMST会先快速增长,然后缓慢下降,且在2050~2100年间基本保持不变.这是由于不同情景下,GMST的变化特征由海洋快、慢响应在各个阶段的贡献比例所决定.RCP2.6情景下,GMST在2100年的温升值为1.83℃,对应辐射强迫下降阶段;而在RCP4.5情景下,GMST同样达到该温升值的时间为2033年,对应辐射强迫增长阶段.虽然两个时刻的GMST温升相同,气候系统在两种情景下的响应却有很大区别.其中,由热膨胀导致的全球海平面平均升高幅度在RCP2.6中要远高于RCP4.5,表面增温的空间结构也存在重要差异.在CMIP5使用的大多数未来情景中,多模式平均预估的1.5和2℃温升目标到达时间都远远早于2100年,这意味着如果利用这些情景下的结果来类比21世纪末低温升目标下的情况,会严重低估海洋慢响应过程的气候效应.

律师业忠诚:21世纪视野下言论自由及其义务

引言公司管制政策和法制内在化的新治理使行业规则焕然一新,雇员必须忠于企业并且遵守雇主设定的规则,但他们也必须认识到,雇佣关系意味着服务两个'主人':那就是他们的组织本身和设立组织所依据的法律管理体制。任何行业都要求组织成员在合理的职业理念下依法行事。一般的职业要求承担行业自身的责任也承担道德责任,不仅设立双重的成员资格并且向组织对成员的负责范围施加限制。