有毒化学物质瞬时泄漏无风大气扩散的危害后果模拟分析

目的建立对有毒气体或高挥发性有毒化学品意外泄漏在大气扩散危害后果数值模拟与预测的方法,为突发化学危害性公共卫生事件应急处置提供事故危害分析信息和可供建设项目职业病危害预评价工作应用。方法利用国家环境保护行业标准推荐的描述有毒气体扩散的数学模型和中毒伤亡后果分析的概率函数法结合计算机软件开发技术,设计开发毒气扩散危害分析软件。结果在高斯气团模型基础上推导了对瞬时泄漏点源毒物在无风情况大气扩散的危害影响范围、危险期等危害后果的一系列定量计算公式,开发设计了实现相应的自动计算和绘图的计算机程序软件TDA2.0,TDA2.0可给出毒气扩散浓度的时空分布分析数据并自动根据中毒概率函数法给出总毒性负荷数值、人员中毒伤亡概率值及人员中毒死亡百分率的预测值。应用TDA2.0对一液氨槽罐车泄漏事故案例作了危害后果模拟分析,估算结果与案例情形基本相符。结论应用该文的危害后果分析定量计算公式和TDA2.0软件能快速得到毒气扩散对点、区间、区域面危害后果的数值模拟预报信息,使用简便有效。     

医院组织气氛与护士工作倦怠的关系研究

目的探讨医院组织气氛状况与护士工作倦怠二者之间的关系。方法采用自编的医院组织气氛问卷和工作倦怠问卷(MBI)对银川市340名护士进行问卷调查。结果①组织气氛各维度在不同医院属性上得分差异显著(P均<0.01);②已婚者在情感耗竭方面的得分显著高于未婚者,在人格解体方面边缘显著高于未婚者(P均<0.01);③医院组织气氛的5个层面与护士的情感耗竭呈负相关且非常显著,与护士的个人成就呈正相关且非常显著,工作责任、工作报酬、支持信任与人格解体呈负相关且非常显著(P<0.01)。结论医院组织气氛与护士工作倦怠之间关系密切。     

Fog and rain in the Amazon

The diurnal and seasonal water cycles in the Amazon remain poorly simulated in general circulation models, exhibiting peak evapotranspiration in the wrong season and rain too early in the day. We show that those biases are not present in cloud-resolving simulations with parameterized large-scale circulation. The difference is attributed to the representation of the morning fog layer, and to more accurate characterization of convection and its coupling with large-scale circulation. The morning fog layer, present in the wet season but absent in the dry season, dramatically increases cloud albedo, which reduces evapotranspiration through its modulation of the surface energy budget. These results highlight the importance of the coupling between the energy and hydrological cycles and the key role of cloud albedo feedback for climates over tropical continents.Tropical forests, and the Amazon in particular, are the biggest terrestrial CO₂ sinks on the planet, accounting for about 30% of the total net primary productivity in terrestrial ecosystems. Hence, the climate of the Amazon is of particular importance for the fate of global CO₂ concentration in the atmosphere (1). Besides the difficulty of estimating carbon pools (1–3), our incapacity to correctly predict CO₂ fluxes in the continental tropics largely results from inaccurate simulation of the tropical climate (1, 2, 4, 5). More frequent and more intense droughts in particular are expected to affect the future health of the Amazon and its capacity to act as a major carbon sink (6–8). The land surface is not isolated, however, but interacts with the weather and climate through a series of land−atmosphere feedback loops, which couple the energy, carbon, and water cycles through stomata regulation and boundary layer mediation (9).Current General Circulation Models (GCMs) fail to correctly represent some of the key features of the Amazon climate. In particular, they (i) underestimate the precipitation in the region (10, 11), (ii) do not reproduce the seasonality of either precipitation (10, 11) or surface fluxes such as evapotranspiration (12), and (iii) produce errors in the diurnal cycle and intensity of precipitation, with a tendency to rain too little and too early in the day (13, 14). In the more humid Western part of the basin, surface incoming radiation, evapotranspiration, and photosynthesis all tend to peak in the dry season (15–17), whereas GCMs simulate peaks of those fluxes in the wet season (10, 11). Those issues might be related to the representation of convection (1, 2, 4, 5, 13, 14) and vegetation water stress (6–8, 15–17) in GCMs.We here show that we can represent the Amazonian climate using a strategy opposite to GCMs in which we resolve convection and parameterize the large-scale circulation (Methods). The simulations lack many of the biases observed in GCMs and more accurately capture the differences between the dry and wet season of the Amazon in surface heat fluxes and precipitation. Besides top-of-the-atmosphere insolation, the simulations require the monthly mean temperature profile as an input. We demonstrate that this profile, whose seasonal cycle itself is a product of the coupled ocean−land−atmosphere dynamics, mediates the seasonality of the Amazonian climate by modulating the vertical structure of the large-scale circulation in such a way that thermal energy is less effectively ventilated in the rainy season.     

The future of airborne sulfur-containing particles in the absence of fossil fuel sulfur dioxide emissions

Sulfuric acid (H₂SO₄), formed from oxidation of sulfur dioxide (SO₂) emitted during fossil fuel combustion, is a major precursor of new airborne particles, which have well-documented detrimental effects on health, air quality, and climate. Another precursor is methanesulfonic acid (MSA), produced simultaneously with SO₂ during the atmospheric oxidation of organosulfur compounds (OSCs), such as dimethyl sulfide. In the present work, a multidisciplinary approach is used to examine how contributions of H₂SO₄ and MSA to particle formation will change in a large coastal urban area as anthropogenic fossil fuel emissions of SO₂ decline. The 3-dimensional University of California Irvine–California Institute of Technology airshed model is used to compare atmospheric concentrations of gas phase MSA, H₂SO₄, and SO₂ under current emissions of fossil fuel-associated SO₂ and a best-case futuristic scenario with zero fossil fuel sulfur emissions. Model additions include results from (i) quantum chemical calculations that clarify the previously uncertain gas phase mechanism of formation of MSA and (ii) a combination of published and experimental estimates of OSC emissions, such as those from marine, agricultural, and urban processes, which include pet waste and human breath. Results show that in the zero anthropogenic SO₂ emissions case, particle formation potential from H₂SO₄ will drop by about two orders of magnitude compared with the current situation. However, particles will continue to be generated from the oxidation of natural and anthropogenic sources of OSCs, with contributions from MSA and H₂SO₄ of a similar order of magnitude. This could be particularly important in agricultural areas where there are significant sources of OSCs.Airborne particles play an essential role in many serious environmental issues, including visibility reduction (1) and climate change (2), and have been linked to health problems associated with air pollution (3). On a global basis, sulfuric acid (H₂SO₄) is the most significant contributor to new particle formation in air, likely through reaction with ammonia and amines (4–6). In air, the dominant source for H₂SO₄ is the oxidation of SO₂ from combustion of sulfur-containing fossil fuels. Another source of new particle formation in air is the oxidation of organosulfur compounds (OSCs) generated by biological processes and agricultural activities (7–10). For example, oceans are a significant source of dimethyl sulfide (CH₃SCH₃, DMS) (10), whereas a variety of related species such as methanethiol (CH₃SH, MTO), dimethyl disulfide (CH₃SSCH₃, DMDS), and dimethyl trisulfide (CH₃SSSCH₃, DMTS) originate from livestock and farming practices (11–15). It has been shown that even human breath contains OSCs (16, 17). Atmospheric oxidation of OSCs generates not only SO₂ (which ultimately converts into H₂SO₄) but also methanesulfonic acid [CH₃S(O)(O)OH, MSA] (18), which also reacts with amines to generate new particles in air in the presence of water vapor (19, 20). Increasing regulations are driving the sulfur content and use of fossil fuels down (21), resulting in declining atmospheric SO₂ concentration and particulate sulfate concentrations. A key question for understanding future impacts of particles and for the development of cost-effective control policies is the extent to which atmospheric particulate matter can be controlled through regulation of fossil fuel combustion against a background of OSCs. We report here a distinctive multidisciplinary approach that integrates chemical mechanism development, quantum chemical calculations, field measurements, and 3D modeling to examine this issue in the context of a large, urban coastal area, the South Coast Air Basin of California (SoCAB).     

药品上市许可持有人制度试点对上海生物医药产业的影响分析

通过分析国内外药品上市许可人制度,结合上海生物医药创新所处的环境,通过查询行业数据统计和分析,研究在上海开展药品上市许可人制度试点的可行性和必要性,同时分析这项制度的执行将对上海生物医药产业未来格局产生影响。     

Spatial constraints in large-scale expansion of wind power plants

When wind turbines are arranged in clusters, their performance is mutually affected, and their energy generation is reduced relative to what it would be if they were widely separated. Land-area power densities of small wind farms can exceed 10 W/m², and wakes are several rotor diameters in length. In contrast, large-scale wind farms have an upper-limit power density in the order of 1 W/m² and wakes that can extend several tens of kilometers. Here, we address two important questions: 1) How large can a wind farm be before its generation reaches energy replenishment limits and 2) How far apart must large wind farms be spaced to avoid inter–wind-farm interference? We characterize controls on these spatial and temporal scales by running a set of idealized atmospheric simulations using the Weather and Research Forecasting model. Power generation and wind speed within and over the wind farm show that a timescale inversely proportional to the Coriolis parameter governs such transition, and the corresponding length scale is obtained by multiplying the timescale by the geostrophic wind speed. A geostrophic wind of 8 m/s and a Coriolis parameter of 1.05 × 10⁻⁴ rad/s (latitude of ∼46°) would give a transitional scale of about 30 km. Wind farms smaller than this result in greater power densities and shorter wakes. Larger wind farms result instead in power densities that asymptotically reach their minimum and wakes that reach their maximum extent.

In 2020, wind comprised a 6.1% share of electricity generated worldwide (1). This figure is expected to substantially grow as more renewable energy is used in the effort to limit carbon dioxide emissions and consequent global average temperature increases. Under some energy transition scenarios (2), wind energy provides more than one-third of global energy needs by 2050, indicating that the size of future wind farms may extend far beyond that of current installations.When wind turbines are clustered in large groups, their performance is mutually affected, and the rate at which they extract energy from the atmosphere is reduced (3). To better characterize how wind farms function and interact with the atmosphere, researchers have focused on the wakes that the turbines generate (4) and the turbines’ power production (5), given in terms of power density per unit of land area for very large wind farms (6). Wakes are regions of reduced wind speed resulting from the turbine energy extraction. They are a function of wind speed and direction (7, 8), atmospheric turbulence intensity (9) and stratification (10), turbine operating conditions (11), and terrain topography (12). Because farm performance is directly affected by wakes and atmospheric transport mechanisms, power production or power density in wind farms exhibits the same qualitative dependence on the wind resource, turbulence, and stratification (5, 13–15).Numerical- and observation-based studies have shown that there are substantial differences in wind farm performance and wake characteristics, depending on the horizontal size of the farm (16). For small wind farms, wind speed in wake regions recovers to undisturbed conditions within a distance of 10 to 15 times the rotor diameter (17), which corresponds to hundreds of meters, depending on the turbine dimensions. For large wind farms, wakes have been observed extending up to tens of kilometers downstream (18, 19), raising questions regarding the consequences that this could have on neighboring wind farms in terms of energy production and economic losses (20). As the number and density of turbines in a wind farm increase, so does their likelihood of being affected by an upstream turbine, diminishing energy generation. If wind farms are composed of a relatively small number of widely spaced turbines, the likelihood of a turbine being affected by an upstream one is low, and this likelihood can be further mitigated by optimal layout design (21, 22). For very large (mesoscale) wind farms, where all but the first row of turbines are mutually affected, a fully developed wind farm boundary layer is observed (6). At such scales, optimal siting of wind turbines is expected to have a more limited effect, with achievable gains in power generation of about 10%, depending on the layout (23). In fact, the power density reaches a limit that largely depends on the atmospheric pressure gradients and Coriolis forces, which ultimately control how much energy the turbines can extract from the atmosphere (24). While these limits are framed in terms of local pressure–gradient forces, these pressure–gradient forces are themselves a product of mesoscale processes that extend to global scale. These energy replenishment limits are reflected in the power density of wind farms at different scales: at small scales, it can exceed 10 W/m², but it is in the order of 1 W/m² at very large scales (25, 26).These substantial differences among various wind farm sizes show the importance of understanding at which spatial scale a transition of wind farm performance and wake characteristics occurs. Because of the lack of field experiments aimed at answering this question, researchers have used numerical experiments to characterize this transition. Results from large-eddy simulations showed that the transition from submesocale to mesoscale—that is, the scale at which the wind farm boundary layer is fully developed—occurs well beyond 10 km in conventionally neutral boundary layers (27), and potentially at a few tens of kilometers (28, 29). Formulas based on scaling analyses considering canopy flows have also been provided to estimate the adjustment length (30). These analyses however did not consider the role of large-scale atmospheric physics such as the Coriolis force and atmospheric pressure gradients, which become important in large wind farms and for the characterization of the submesocale-to-mesoscale wind farm transition.Here, we characterize spatial constraints in the large-scale expansion of wind power plants by identifying transitional scales in wind farm performance and wake characteristics. This will help determine how large a wind farm can be before its generation reaches lower mesoscale limits, and how far apart large wind farms must be spaced to avoid inter–wind-farm interference. In contrast to previous studies, we consider in our analysis the Coriolis and atmospheric pressure–gradient forces, which we show are important factors for a characterization of the transition. We run a set of idealized, atmospheric simulations with neutral atmospheric conditions using the Weather and Research Forecasting (WRF) model, in which the wind turbines are parametrized as momentum sinks. We give a physical explanation to the transitional scale, and we identify a timescale inversely proportional to the Coriolis parameter that defines at what length scale a wind farm can be said to have reached mesoscale characteristics (fully developed wind farm boundary layer). We also show the implications that this scale has on the power density and wakes when we consider different wind farm sizes. Ultimately, the goal of this study is to provide both mechanistic understanding and a quantitative rule of thumb, indicating when the primary factor reducing wind power generation would be shadowing by wakes from individual turbines, or the formation of the wake behind the wind farm as a whole.     

常压氧疗装置的研制及应用

介绍一种常压环境下的全新吸氧装置。它具有纯氧和混合氧的选择疗法以及高压氧舱的供、吸氧特点,并拓宽了氧疗的治疗范围。临床应用收到了满意的效果。     

规范化培训护士临床归属感及影响因素的混合研究

目的 了解规范化培训护士临床归属感及其影响因素。方法 采用一般资料调查表、临床归属感量表对214名规范化培训护士进行调查，并通过目的抽样法对其中12名护士就临床归属感的影响因素进行半结构访谈。结果 规范化培训护士临床归属感总分为132.00±16.83;多元逐步回归分析结果显示，工资福利满意度、休息时间及方式满意度是规范化培训护士临床归属感的主要影响因素(均P<0.05)。质性研究提炼出临床归属感的4个影响因素：职业价值及个人成就感，科室的工作氛围和人际关系，规培阶段的职业规划，培训医院的声誉。结论 规范化培训护士临床归属感处于中等偏上水平，建议护理管理者根据影响因素采取针对性管理措施，以提升规范化培训护士的临床归属感。     

引以为戒，恪守学术道德和科研诚信良好学风

目的目前,高校对于硕博士论文的要求是需要通过抄袭检测系统的检测才能过关。近年来随着学术界尤其是生物医药领域学术不端的现象接连被爆出后,高校及医药学专业科研院所在内的学术界更是对学术规范严加管控,允许论文重复率一降再降,对我们的学术规范提出了更高要求,鞭策学术界端正学术行为,坚持科研诚信,恪守学术道德。方法本文通过总结既往发生的国内外的学术不端行为,探讨学术不端行为问题的根源,尝试寻找正确引导规范学术道德的措施。结果文章所提出的一系列解决对策有望为医药领域科研单位的科研管理部门提供一些思路和解决措施。结论学者是知识群体、国家的后备力量。尤其从事生命科学学术活动的学者应以笃信诚实的原则从事科学研究,做名副其实的学术研究人员。