Defending young biparentally: female risk-taking with and without a male in the burying beetle, <Emphasis Type="Italic">Nicrophorus pustulatus</Emphasis>

A positive correlation between the parental effort of a male and female should promote stable biparental care. Risk-taking (as assessed by injuries) against infanticidal intruders by Nicrophorus pustulatus females was expected to be low when females had a low probability of successful defense of the young. I tested the hypothesis that when the presence of a male partner increased the probability of successful defense from low to moderate that female risk-taking would increase. Single females and pairs with first instar larvae were confronted by potentially infanticidal male and female conspecific intruders. Male intruders routinely took over nests from unpaired females (30 of 36 trials). Unpaired females and male intruders were injured infrequently, indicating less intense fights despite the high probability of infanticide. A resident female defending against a male intruder was injured more often when paired than unpaired, suggesting greater risk-taking. A male parent that delays desertion, therefore, receives fitness benefits not only from his own defense of the young, but from greater female defense against male intruders as well. It is hypothesized that the threat of infanticidal takeovers by males promotes extended biparental care in burying beetles. When the intruder was female, on the other hand, a female parent on her own had a moderate probability of successfully defending the brood (22 of 36 trials). The presence of a male partner against female intruders almost guaranteed successful defense (35 of 36 trials) and female intruders did not appear to contest pairs vigorously. Against female intruders the presence of a male partner did not significantly change injury rates of the defending female.     

Male care of infants in a siamang (Symphalangus syndactylus) population including socially monogamous and polyandrous groups

While male parental care is uncommon in mammals, siamang (Symphalangus syndactylus) males provide care for infants in the form of infant carrying. I collected behavioral data from a cohort of five wild siamang infants from early infancy until age 15–24 months to identify factors affecting male care and to assess the consequences of male care for males, females, and infants in a population including socially monogamous groups and polyandrous groups. There was substantial variation in male caring behavior. All males in polyandrous groups provided care for infants, but males in socially monogamous groups provided substantially more care than males in polyandrous groups, even when the combined effort of all males in a group was considered. These results suggest that polyandry in siamangs is unlikely to be promoted by the need for “helpers.” Infants receiving more care from males did not receive more care overall because females compensated for increases in male care by reducing their own caring effort. There was no significant relationship between indicators of male–female social bond strength and male time spent carrying infants, and the onset of male care was not associated with a change in copulation rates. Females providing more care for infants had significantly longer interbirth intervals. Male care may reduce the energetic costs of reproduction for females, permitting higher female reproductive rates.     

区域点源和非点源磷入河量计算的二元统计模型

基于流域或区域点源和非点源磷入河过程的水文学差异,以及影响河流持留作用的主要机制,建立了描述河流段末磷负荷量与流量和水温之间定量关系的二元统计模型;通过逐月的河流水文水质监测数据对模型中4个系数的有效校正和验证,实现了对点源和非点源磷入河过程的准确定量.与现行的水文估算法相比,该模型既考虑了河流磷的持留能力及其时间变异性,也考虑了上游水体输入的磷负荷量,推进了对磷污染过程的定量认识,满足了我国以行政区为主要水污染控制管理单元的现实需要.应用该模型,计算了浙江长乐江集水区2004～2009年的总磷(TP)入河量.结果表明,TP年入河总量为(54.6±11.9)t.a-1,其上游水体输入、点源和非点源的入河量贡献率分别为5%±1%、12%±3%和83%±3%.夏季5～6月和8～9月的非点源TP累计入河量占其全年的50%±9%,增加了引起下游水体藻类暴发的风险.河流TP持留量为(4.5±0.1)t.a-1,占年入河总量的9%±2%;5～9月的TP累计持留量占全年的55%±2%,表明河流持留能力对流域或区域磷素迁移转化过程的调控作用不容忽视.本研究建立的二元统计模型仅需常规的河流水文水质监测数据,无需专业软件知识,且计算结果直接来源于实际的河流水文水质测算值,为实施流域或区域磷污染总量控制策略提供了一种简便、实用、可靠的定量工具.     

Factor input structure,environmental policies,and the export quality upgrade: a perspective of heterogeneity

In the analysis of how environmental regulation affects the comparative advantage of trade, existing literature ignores industry’s inherent heterogeneity, which draws remarkably different conclusions. In view of this, the paper analyzed the mechanism of environmental regulation on the export quality of different industries from the perspective of factor input structure heterogeneity. Based on the panel data of China’s manufacturing industry, the paper used the system generalized method of moments method to examine the heterogeneity influence of environmental regulation on manufacturing export quality. The study found that, first, environmental regulation affected the export quality upgrade of the manufacturing sector through offset effect and compensation effect, and the direction of the impact would mainly depend on the industry’s factor input structure. Second, for industries with larger fixed-asset investment (FAI) ratio in the factor input structure, the current environmental regulation policy was not conducive to the export quality upgrading of the industries. However, there was a significant U-shaped dynamic relationship between them. As environmental regulations became stricter, when regulatory stringency went beyond the inflection point, the policy would promote the upgrading of export quality. But for industries with smaller proportion of FAI, environmental regulation exerted a favorable impact on the export quality upgrade, following a J-shaped marginal growth curve. Third, for industries with different factor input structure, their export quality had been effectively upgraded as expected by factors like human capital investment, independent R&D, technology introduction, and foreign direct investment; but raising per capita capital stock and expanding enterprise size did not produce significant direct impact on export quality upgrade. These conclusions remained robust after using different measurement methods and replacing with other variables. Therefore, this paper suggests that governments should take industry heterogeneity into consideration and formulate differentiated hierarchical environmental policies. Besides, they should strengthen the enforcement of the current environmental regulation policies. By doing so, enterprises are forced to improve their technology and product quality so that they can better cope with rising compliance costs, eliminate backward industries, and resolve excess capacity. In this way, the economic structure would be transformed and upgraded from the supply side.     

我国出口贸易中的碳排放转移测算研究

国际贸易中碳排放转移关系到贸易双方的碳权分配与碳排放责任,处理好贸易出口和碳排放关系非常重要。本研究应用投入产出法及模型,对我国2002—2011年出口贸易的碳排放进行测算。结果显示,出口贸易与出口贸易隐含碳排放呈现出同比增长关系,从出口规模和结构看,电气、机械及器材制造业,基本金属及金属制品业,通用、专用设备制造业,化学原料和化学制品制造业等行业的碳排放位居前列,行业高碳结构性特征明显;短期内出口贸易与出口隐含碳的正相关关系不会有明显变化,但从长期来看二者的正相关关系将会趋于减弱。本研究提出以碳减排为约束,转变出口贸易结构,促进传统制造业优化升级,发展低碳贸易产品和绿色产业等建议。     

动态群体安全投入博弈模拟*——以我国煤矿为例

为探究煤矿生产中的群体安全投入博弈特点,针对煤矿生产参与者面临的安全投入囚徒困境（SIPD）博弈,基于NetLogo模拟平台设计博弈模型,获取不同安全投入策略的工人群体变化、死亡情况和安全收益特征,探究不同安全环境对博弈结果的影响。研究结果表明:在低安全水平煤矿中,消极型工人（D-worker）可以利用积极型工人（C-worker）的安全投入,快速增加消极型群体规模,并攫取高达70%的安全收益,而在高安全水平煤矿中,在制裁型工人（T-worker）影响下,D-worker安全收益可被限制到20.4%。D-worker在恶劣安全环境中将成为主流,攫取最大安全收益,产生较高死亡率,并严重损害群体安全,扭转上述局面的短期方法为抑制群体消极心理,长期方法为逐步提高安全管理技术水平。研究结果可为我国煤矿安全水平提升提供安全投入策略参考。     

海河流域不同植物砣含量、地域分异及其输入、输出量研究

海河流域是我国农业发展的一个重要基地,由于不合理开发利用,造成某些地区土壤出现贫瘠化、盐渍化和沙漠化,土壤缺磷也很明显.为了寻找植物对磷的需求特点以及海河流域土壤磷分布规律,可以从植物指示的角度研究不同地区不同植物磷含量特征及其差异,研究植物每年从土壤中输出和输入的磷总量,从而寻找农业生态系统磷循环规律并科学指导施肥.     

淀山湖营养物输入响应关系的分位数回归分析

采用分位数回归方法研究了淀山湖富营养化输入(总氮和总磷)及响应指标(叶绿素a)之间的关系.结果表明,淀山湖营养物TP和TN(输入指标)对不同分位叶绿素a(响应指标)的影响不同.在低分位(0.10~0.50)时,淀山湖的藻类生物量(叶绿素a)主要受TP的控制;在高分位(0.60~0.90)时,淀山湖的藻类生物量同时受TP和TN的控制;TN对藻类生长的抑制作用随分位数升高而加强.0.60分位时是TP和TN对藻类增长影响发生变化的分位.普通最小二乘法(OLS)方法得到的经验方程,不能估计淀山湖多个因素不同变化速率对湖泊营养物输入响应关系的影响.     

投入产出模型在工业生态系统分析中的应用

应用投入产出模型构建出工业生态系统物质流分析的基本框架，在此基础上提出工业生态系统“关键种企业”的识别方法。以及工业生态系统企业能量消耗特征、累计污染排放特征的量化分析方法。这些分析方法将是辅助工业生态系统日常管理与维护的有力工具。     

三峡入库河流大宁河回水区浸没土壤及消落带土壤氮形态及分布特征

利用分级浸取分离法首次对三峡入库河流大宁河回水区表层浸没土壤、消落带土壤不同形态氮含量进行了测定,分析了各形态氮之间以及各形态氮与环境参数之间的相关性.结果表明,①浸没土壤总氮含量在436.0~921.6 mg/kg,消落带土壤总氮含量在1 253.5~2 439.8 mg/kg,与长江中下游浅水湖泊表层浸没土壤总氮含量相比,大宁河回水区表层浸没土壤总氮含量处于偏低水平.②浸没土壤可转化态氮含量在289.7~511.3 mg/kg,消落带土壤可转化态氮含量在271.6~595.1 mg/kg,有机态和硫化物结合态氮是可转化态氮的优势组分,离子交换态氮是可转化态无机氮的优势组分.③浸没土壤与消落带土壤中总氮、可转化态氮含量与有机态和硫化物结合态氮显著相关,表明样品中的可转化态氮含量的增加主要来源于有机态和硫化物结合态氮.