Perception of risk

Studies of risk perception examine the judgements people make when they are asked to characterize and evaluate hazardous activities and technologies. This research aims to aid risk analysis and policy-making by providing a basis for understanding and anticipating public responses to hazards and improving the communication of risk information among lay people, technical experts, and decision-makers. This work assumes that those who promote and regulate health and safety need to understand how people think about and respond to risk. Without such understanding, well-intended policies may be ineffective.     

Cardiac activity preparatory to overt and covert behavior

The heart rates of 17 women subjects were recorded as they prepared to make both overt (key press) and covert (silently thinking the word "stop") responses. A very reliable preparatory cardiac response was obtained regardless of whether the overt or covert response mode was employed. The temporal development of this cardiac response faithfully reflected the speed with which the subjects were asked to respond, suggesting that in the covert condition heart rate could be used to detect the time at which a mental event was being generated.     

两种自然保护区设计方法——数学建模和计算机模拟

传统的自然保护区设计方法是打分法和Gap分析法,这两种方法简单易行但可靠性不高;地理信息系统(GIS)在保护区设计领域的应用也为人熟悉。关注近年来快速发展而国内使用不多的两种方法——数学建模和计算机模拟。数学建模主要用来从一组备选地块中选择一部分组成自然保护区,包括线性和非线性模型,用启发式算法或最优化算法求解。启发式算法具有速度快、灵活等优点,但解通常不是最优的,不能保证稀缺资源的最优化利用。最优化算法运算效率低,变量较多比如数百时就可能遇到计算困难,但解是最优的。预计两种算法都将继续发展。计算机模拟主要用于保护区评价、功能区划分、预测特定环境比如空间特征和气候变化对物种的影响等,多用启发式算法,与其它软件结合把结果以图画显示出来。两种方法特别是计算机模拟均要求保护区设计者有较强的专业知识。讨论了两种方法面临的问题和新的研究方向,至少包括:1)基础数据依然需要完善;2)一些新的因素比如动态性和不确定性如何在模型中考虑并与其它因素结合;3)气候变化预景下模拟参数如何评估和调整;4)如何协调保护与发展的关系;5)方法的实际应用需要研究者与决策者之间建立交流机制;6)多领域专家和相关利益方应有机会参与保护区设计。     

Policies designed for self-interested citizens may undermine "the moral sentiments": evidence from economic experiments

High-performance organizations and economies work on the basis not only of material interests but also of Adam Smith's "moral sentiments." Well-designed laws and public policies can harness self-interest for the common good. However, incentives that appeal to self-interest may fail when they undermine the moral values that lead people to act altruistically or in other public-spirited ways. Behavioral experiments reviewed here suggest that economic incentives may be counterproductive when they signal that selfishness is an appropriate response; constitute a learning environment through which over time people come to adopt more self-interested motivations; compromise the individual's sense of self-determination and thereby degrade intrinsic motivations; or convey a message of distrust, disrespect, and unfair intent. Many of these unintended effects of incentives occur because people act not only to acquire economic goods and services but also to constitute themselves as dignified, autonomous, and moral individuals. Good organizational and institutional design can channel the material interests for the achievement of social goals while also enhancing the contribution of the moral sentiments to the same ends.     

基于森林空间收获问题的模拟退火算法邻域搜索技术比较

邻域搜索是当前提高启发式算法求解效率的核心技术之一,然而近期关于该搜索策略的性能却产生了较大争议。模拟退火算法作为一种典型的启发式算法,已广泛应用于一系列的林业规划问题。为此,本研究以模拟退火算法为例,系统评估2种不同邻域搜索技术在森林空间收获安排问题中的应用效果。规划模型以50年规划周期(10个规划分期)内的最大化木材收获为目标函数,以蓄积均衡收获、蓄积期末存量、单位限制模型和绿量限制等为主要约束条件。测试方法以模拟退火算法为原型,以每次优化过程中随机选择的小班数量为标准,共包括1-邻域和2-邻域2种不同的搜索技术。模拟规划数据由3个假设的栅格数据集组成,其共产生了3293个(林分Ⅰ)、29536个(林分Ⅱ)和81625个(林分Ⅲ)0-1型决策变量。研究结果表明:模拟退火算法2-邻域搜索技术能够提高各规划问题的最大目标函数值;但当规划问题的决策变量数(或小班数量)较大时(即林分数量≥3600),单纯增加邻域范围并不能提高规划问题的平均目标函数值。因此,鉴于模拟退火算法的优化结果对规划问题具有较高的敏感性,因此森林经营决策人员应慎重选择模拟退火算法邻域搜索作为相关规划问题的优化求解技术。      

有机肥的不同配置对烤烟生长的影响

通过田间试验研究不同有机肥料(腐熟猪粪、菜籽饼和腐熟秸秆)前作和当季施用对烤烟生长的影响。结果表明:前作和当季施用有机肥对烤烟生长有促进作用。前作施用腐熟猪粪对促进烟株的生长,上部烟叶叶面积比较明显,但烟叶中上等烟叶比例和均价下降。施用秸秆在小春季养分矿化比油枯和腐熟猪粪慢,养分矿化率低,至当季土壤中的硝态氮含量较高,施用油枯则相反。前作施用油枯烟叶产值量比当季好,施用秸秆可以提高烟叶中上等烟比例和均价,但不能提高烟叶的产值量。当季化肥和腐熟猪粪合理混施可以提高烟叶的产值量。     

Genetic and somatic effects of carbon-14

On the basis of information about carbon-14 given by Libby, calculations are made of the predicted genetic and somatic effects of the carbon-14 produced by the testing of nuclear weapons. It is concluded that 1 year of testing (30 megatons of fission plus fusion) is expected to cause in the world (stimated future number of births per year 5 times the present number) an estimated total of about 55,000 children with gross physical or mental defects, 170,000 stillbirths and childhood deaths, and 425,000 embryonic and neonatal deaths. (There is an unknown amount of overlap of these three categories.) These numbers are about 17 times the numbers usually estimated as the probable effects of the fallout fission products from 1 year of testing. In addition, the somatic effects of bomb-test carbon-14 are expected to be about equal to those of fission products, including strontium-90, with respect to leukemia and bone cancer and greater than those of fission products with respect to diseases resulting from radiation damage to tissues other than bone tissue and bone marrow. All of the estimated numbers are subject to great uncertainty; they may be as much as 5 times too high or 5 times too low. The uncertainty in the estimation of the relative effects of carbon-14 and fission products in world-wide fallout is not so great.     

印度洋长鳍金枪鱼CPUE权重配置对资源状态指标的影响

单位捕捞努力量渔获量（catch per unit effort,CPUE）权重问题对于渔业资源评估而言至关重要。本研究使用印度洋长鳍金枪鱼（Thunnus alalunga）的渔业独立和非独立数据,构建了年龄结构资源评估模型（ASAP）。利用评估模型估计得出的参数,使用年龄结构种群模拟器（PopSim）模拟“真实”的资源种群动态以及相应的捕捞动态。针对不同序列的CPUE数据赋予不同的权重因子,同时考虑种群关键参数（自然死亡系数M和陡度h）的错误设置,进行敏感性分析,阐述CPUE权重的错误设置对评估结果的影响。结果表明,当估算模型中的M和h被正确指定或被低估时,若给具有较高准确性或较长时间序列的CPUE分配更多的权重,模型估算的捕捞死亡系数F和产卵亲体生物量B具有较小的相对误差（RE）和相对均方根误差（RMSE）,即估算更为准确。同时,对不确定性较高的CPUE赋予更大的权重会使Flast/Fstart的估计值过高,而Blast/Bstart的估计值准确性较低。因此,当使用多组CPUE数据时,对具有较高准确性或较长时间序列的CPUE分配更高的权重,或可提高资源状态指标估算的准确性。同时,在CPUE权重的分配中应考虑重要生物学参数（例如M和h）的准确性,至少应进行敏感性分析,以涵盖潜在的模型或参数的错误设置对CPUE权重的影响。     

Symmetric NAT的穿越问题研究

《礼记质疑》是郭嵩焘最主要的礼学专著，历来学者对其褒贬不一。文章在对《礼记质疑》进行较深入的研究后，不赞成对该书过分地贬斥,认为该书虽有不少疏失，但其中言之成理的意见亦不在少数，甚至可以说，该书于治礼发表了一些较好的意见(观点)。     

树月季砧木引种驯化与快繁

该文首先从树月季的历史出发 ,概述了树月季砧木在各国的使用情况及其引种驯化的可能性 .树月季在北美洲和欧洲的应用已经相当普遍 ,但由于各国蔷薇资源和育种进展情况的不同 ,对树月季砧木的应用也不大相同 .北美洲主要应用Rosamultiflora的品种或变种作为树月季砧木 .欧洲主要利用Rosarugosa和Rosacanina‘Pfander’作为树月季砧木 .该文进一步概述了目前繁殖树月季砧木的两种主要方法 ,即组织培养和扦插繁殖的方法 .生产上常利用扦插的方法繁殖树月季的砧木 ,特别是全光雾插 ,已经广泛应用于商业性大规模的生产 .最后简略介绍了树月季培育的途径 .     

The group self

Although people often tend to consider themselves and others as unique individuals, there are many situations in which they think, feel, and act primarily as group members. This can bring out the best in them, as when they are inspired to help fellow citizens in need, or the worst, as when they show hostility against others simply because they represent another religious or ethnic group. Understanding when and why the group self becomes more important than the individual self, and how this affects people's thoughts, feelings, and behaviors, can help to prevent and redirect unwelcome aspects of human behavior by addressing them at the appropriate level of self.     

一类不确定网络控制系统的鲁棒H SymboleB@ 控制

基于一类具有网络时延和参数不确定性的离散系统，考虑系统的网络时延小于一个采样周期，传感器是时间驱动，控制器和执行器是事件驱动。根据文中描述的系统建立模型，运用Lyapunov稳定性理论、鲁棒控制理论和线性矩阵不等式处理方法，推导出闭环控制系统渐近稳定的充分条件，并且得出鲁棒H 控制律和其性能指标γ。最后用数值例子对所得结果加以验证，通过MATLAB LMI工具箱求解，说明文中结果的正确性。     

花人同化 畅神乐生

道家的畅神自然审美观主张赏花人在清新自然的赏花审美环境中,动用五官和肺腑,全身心投入地与花融为一体,人的身心均获得了自然美的滋补、疗养与慰藉,实现了天人合一、花人合一的最高自然审美境界——这正是道家赏花审美所追求的在天地大化中寻求"畅神"的自由境界!道家在中国古代赏花审美实践中所体现出的以赏花审美为畅神之情、养生之艺、乐生之趣的民族花文化传统精华,理应继承借鉴并使之发扬光大。     

对天然气流量测量不确定度问题的认识

列出了国内部分计量现场流量测量的惯用方法及相应的测量参数,探讨了流出系数的计算不确定度,孔板孔径及测量管内径的测量不确定度,真实相对密度的测量不确定度,气流温度和静压及差压的测量不确定度等问题,指出任何时刻或任何环节产生的测量不确定度地影响累计流量测量不确定度。     

蛋黄胆固醇的研究进展

鸡蛋因其含有丰富而全面的营养物质,一直深受人们垂青。但是由于它的胆固醇(cholesterol , CHOL)含量之高,又使人们谈蛋色变。CHOL是导致心血管疾病的重要因素。一直以来,世界范围内的广大科研工作人员以及蛋鸡业内人士致力于生产低CHOL鸡蛋的研究。为此,对影响蛋黄中CHOL含量的各种因素进行了大量的试验与分析。这里对这些因素仅作简要的介绍。同时,还简要总结了测定及脱除蛋黄中CHOL的一些方法。     

Consciousness and anesthesia

When we are anesthetized, we expect consciousness to vanish. But does it always? Although anesthesia undoubtedly induces unresponsiveness and amnesia, the extent to which it causes unconsciousness is harder to establish. For instance, certain anesthetics act on areas of the brain's cortex near the midline and abolish behavioral responsiveness, but not necessarily consciousness. Unconsciousness is likely to ensue when a complex of brain regions in the posterior parietal area is inactivated. Consciousness vanishes when anesthetics produce functional disconnection in this posterior complex, interrupting cortical communication and causing a loss of integration; or when they lead to bistable, stereotypic responses, causing a loss of information capacity. Thus, anesthetics seem to cause unconsciousness when they block the brain's ability to integrate information.     

Analysis of plant nutrient management strategies: Conventional and alternative approaches

During times of economic uncertainty, such as the current period, all costs of agricultural production become important and worthy of close scrutiny if the threat of farm foreclosures is to be minimized. This concern particularly applies to the cost of plant nutrients, which, under conventional approaches, typically represents 24%–30% (or more) of the total variable costs of production [Lu et al. (2000) Food Reviews International 16(2): 121–157; Bullen and Brown (2001) Economic Evaluation of UNR Cotton, NC State University, Raleigh, North Carolina]. The purpose of this paper is to examine, via a review of the literature, the economics and profitability of various plant nutrient management strategies–both conventional and alternative ones–in an attempt to identify those strategies that can lead to financial resource optimization and, ultimately, maximum profits for farm enterprises. The results of this analysis are as follows: In a meta-analysis of 120 studies, conventional nutrient management systems, using commercial fertilizers, showed higher profit for most grain crops (with the exception of corn and sorghum), than organic nutrient management systems. Both cover crop and animal manure-based systems show considerable promise as alternative nutrient management strategies for increasing farm profitability. A cover crop system produced the highest average corn yield and gross margin per hectare with the smallest coefficient of variation compared to no-tillage conventional, manure-based, or crownvetch systems. Manure-based systems that do not require purchase or transport of the manure (as in combined animal and crop production systems) can be considerably more profitable than conventional systems. Both manure-based and cover crop systems that do not include the use of commercial fertilizers (i.e., organic systems), hold particular promise due to the output price premiums typically garnered by the organic crops grown under such conditions.     

Butterfly-Plant Coevolution: Has Passiflora adenopoda Won the Selectional Race with Heliconiine Butterflies?

Hooklike trichomes of Passiflora adenopoda provide a specific, effectively absolute defense against heliconiine butterfly larvae, a major class of Passiflora herbivores. It is suggested that since mechanical defenses are usually more selective in their action against herbivores, they usually are evolved by a plant only after it has accumulated a series of chemical defenses.     

Negative linear compressibility and massive anisotropic thermal expansion in methanol monohydrate

The vast majority of materials shrink in all directions when hydrostatically compressed; exceptions include certain metallic or polymer foam structures, which may exhibit negative linear compressibility (NLC) (that is, they expand in one or more directions under hydrostatic compression). Materials that exhibit this property at the molecular level--crystalline solids with intrinsic NLC--are extremely uncommon. With the use of neutron powder diffraction, we have discovered and characterized both NLC and extremely anisotropic thermal expansion, including negative thermal expansion (NTE) along the NLC axis, in a simple molecular crystal (the deuterated 1:1 compound of methanol and water). Apically linked rhombuses, which are formed by the bridging of hydroxyl-water chains with methyl groups, extend along the axis of NLC/NTE and lead to the observed behavior.