Effect of bis(tributyltin) oxide on reproduction and population growth rate of calanoid copepod Schmackeria poplesia

A full life-cycle toxicity test, combined with histology, on calanoid copepod Schmackeria poplesia was used to study the effect of bis(tributyltin) oxide (TBTO). The results indicate no sex-specific differences in TBTO toxicity. Long-term mortalities of the copepods exposed to concentrations higher than 20 ng TBTO L⁻¹ were significantly elevated compared with that of control, and larval development was inhibited when they were exposed to 40 and 60 ng TBTO L⁻¹. The percentages of ovigerous females were reduced compared with the control (P<0.01) after 24 days exposure to concentrations higher than 10 ng TBTO L⁻¹. Histological examinations suggest that exposure to TBTO might block the posterior end of the diverticula and inhibits the production of egg sacs. A modified Euler-Lotka equation was used to calculate a population-level endpoint, the intrinsic rate of natural increase (r _m), from individual life-table endpoints, i.e. mortality rate, time of release of first brood, sex ratio, the fraction of ovigerous females among all females as well as the number of nauplii per ovigerous female. Apart from the highest TBTO concentration (60 ng L⁻¹), where all females aborted their egg sacs, 20 ng TBTO L⁻¹ was the only concentration that significantly decreased r _m compared with that of control (an effect associated with decreased sex ratio). The results show that the S. poplesia is affected by prolonged exposure to low concentrations of TBTO. The full life-cycle toxicity test combined with histology experiments provides more integral understanding of the toxicity of endocrine disrupters.     

海底透水通道发育带隧道施工注浆技术研究

通过对海底透水通道的特征分析,采用裂隙超前预注浆和裂隙补充注浆方法成功地解决了裂隙注浆堵水难题,为海底隧道安全施工提供了保障。提出了适于海水条件下的裂隙注浆原则、参数、设备、方法、工艺、材料及注浆效果检查方法,并成功地应用于胶州湾海底隧道穿越断裂破碎带时裂隙岩体注浆实践,其研究结果可为类似工程提供参考     

乌什地震台伸缩仪资料影响因素分析

通过对乌什台伸缩仪资料的分析,总结了现阶段伸缩仪资料的影响因素,其中气压变化对观测数据有明显的干扰,两者呈正相关关系;仪器自身工作状态不正常、仪器间的相互检修也会影响数据稳定;突然停电、电压波动、瞬间的强雷电干扰等都会对仪器的工作状态产生较大的影响。     

功能可配制的GIS服务引擎

为解决基于软件即服务架构地理信息系统(geographic information system,GIS)的四级模型中有关功能可配置、可扩展和多用户效率的技术难题,提出了功能可配制的GIS服务引擎模型框架,并介绍了功能可配制的GIS服务引擎的核心技术——工作流技术、功能仓库技术、搭建与配置技术、权限管理技术等,同时给出了一个基于功能可配制的GIS服务引擎技术构建遥感影像系统的应用实例,为软件即服务这一新的软件应用模式提供了技术支撑.      

汶川地震(MS8.0)前的地磁低频峰值变化

以2008年5月12日发生的汶川地震(M_S8.0)为研究对象,选取震前2007年7月—2008年6月成都地磁台的观测数据每月计算一个低频段功率谱峰值,并对2011年7月—2012年6月和2012年7月—2013年6月两个时间段的资料作同样的数据处理。结果表明,成都台2007年7月—2008年6月的低频段功率谱峰值震前出现一些幅度较大的变化,而另外两个时段则显示较为平稳的低频段功率谱峰值。作为对照,对西昌台同时段资料也作相同的处理,其结果显示震前未出现和成都台类似的异常结果。结合其他研究结果,初步认为这种现象可能与汶川地震(M_S8.0)有关联,且这种现象的出现可能与震中距有关,但其发生机理尚需进一步研究。这一结果对于震磁关系的研究具有参考意义。     

On the accumulative contribution of CO2 emission from China to global climate change

A study of the contribution to global climate change from China’s CO₂ emission is conducted using the FIO-ESM v1.0 climate model. A series of sensitivity experiments are performed to identify two kinds of contributions to global climate change of China’s CO₂ emission due to fossil fuel combustion: one is the pure contribution which is the historical climate response from the sensitivity experiment forced only by China’s CO₂ emission, the other is the accumulative contribution which is proposed in this research and defined as the difference of historical climate responses between the experiments forced by all countries’ CO₂ emission and other countries’ CO₂ emission excluding China. The pure contribution approach considers the total CO₂ discharged by China, while the accumulative contribution approach considers not only the discharge amount of China but also the discharge order of China and other countries. The latter is a more realistic approach to quantify the contribution of CO₂ emission to the historical change of atmospheric CO₂ concentration, surface air temperature (SAT), sea surface temperature (SST) and sea ice coverage in the Arctic. Model results show that from the accumulative perspective, the ratio of the contribution of CO₂ emission from China for the increase of atmospheric CO₂ concentration, SAT and SST, and the decrease of the sea ice coverage in the Arctic to that from all other countries excluding China varies from 8% to 92%, 5% to 95%, 9% to 91% and 18% to 82%, respectively. Here we take the contribution of China’s CO₂ emission as an example, the contribution of CO₂ emission from any other country or area can be evaluated by the same approach.     

Diet breadth and mortality patterns from Laoya Cave: A primary profile of MIS 3/2 hunting strategies in the Yunnan-Guizhou Plateau,southwest China

Laoya Cave is a long-term occupation site of Late Paleolithic humans in the Yunnan-Guizhou Plateau, southwest China, where abundant lithic, bone materials were recovered. Dating by the AMS technique showed a significant depositional process during marine isotope stage (MIS) 3/2. In this study, the species spectrum was presented from the perspective of zooarchaeology and the mortality profile of large Cervidae was examined to help increase our understanding of the subsistence strategy of local people dealing with climate and environmental changes. The main part of the diet was focused on large Cervidae, and the dominance of Ungulates indicates effective management of the cave and local fauna. On the other hand, the mortality profiles of large Cervidae varied correspondingly with climate change. The evidence indicates a specialized hunting strategy that was also flexible, depending on the prevailing climate and environment.     

泊江海子矿白垩纪地层冻结软岩力学特性试验

针对泊江海子矿白垩纪地层中的砂岩和泥岩,分别进行了不同温度（-20~20℃）下的三轴压缩试验。试验结果表明：在-20~20℃之间,白垩纪地层软岩的峰值强度和弹性模量均随温度的降低及围压的升高而增加,其中中砂岩的峰值强度随温度的变化程度明显大于泥岩,即其对温度的敏感性更高;而岩石峰值处的轴向应变则随温度的下降而减小;另外,随着温度降低,两种岩石的峰值内摩擦角和黏聚力均有一定程度的提高,并且抗剪强度指标的增加主要集中在黏聚力上。通过对试验结果的整理和分析,掌握了白垩纪地层软岩在不同低温和围压下的力学特性和规律,为西部地区矿井冻结法设计与施工提供了可靠的依据。