测定模拟月壤物理和力学性质的室内试验方法研究

模拟月壤的物理和力学性质是月球科学研究的重要内容,但是由于模拟月壤具有含水率低、孔隙比大的特性,不易采用一般的室内土工试验方法进行测定。通过改进制样方法,即通过环刀和击实后试样高度严格控制模拟月壤试样的质量和密实度,得到了测定模拟月壤物理和力学性质较为准确的室内试验方法,并探讨了模拟月壤的抗剪强度指标与密实度和粒径的关系以及模拟月壤的含水率对其抗剪强度的影响。试验结果表明:模拟月壤的天然密度与粒径大小有关,其抗剪强度指标与密实度和粒径大小有关。该试验方法具有操作简单、准确性好、成本低的优点,也适用于其他与模拟月壤类似的低含水率、高孔隙比土样的物理和力学性质的室内测定。     

加拿大资源环境宏观管理经验的启示与若干建议

加拿大在资源环境宏观管理的经验和成就是多方面的 ,最重要的是政府支持 ,坚持实施可持续发展战略 ,要求各部门围绕这个中心制订相关的支持和激励政策 ,推动清洁生产的实施。作者在借鉴加拿大经验基础上 ,对我国的资源环境管理提出若干建议。     

F/M对活性污泥微生物生态网络的影响

为深入理解有机负荷率(F/M)对活性污泥(AS)微生物群落的影响,以F/M(以BOD/MLVSS计,下同)设计建议范围0.2～0.5 kg·(kg·d)-1为依据,将采集的AS样品分为3组,运用基于随机矩阵理论(RMT)的网络分析方法,解析了不同F/M条件下的AS微生物生态网络拓扑性质及结构特征.结果表明,较低的F/M...     

Distribution of alkylphenols in the Pearl River Delta and adjacent northern South China Sea, China

The occurrence of alkylphenols (APs) was investigated in surface water and sediments from the Pearl River Delta and adjacent northern South China Sea. Most of the water samples contained detectable amounts of APs, ranging up to 0.628 microg l(-1) for nonylphenol (NP) and 0.068 microg l(-1) for octylphenol (OP). APs were found in all of the sediment samples with concentrations ranging from 59 to 7808 microg kg(-1) for NP and from 1 to 93 microg kg(-1) for OP. The Zhujiang River showed the highest concentrations of APs in both water and sediments. Significant decrease of APs concentrations going from the Zhujiang River to the Shiziyang River was observed. The Xijiang River contained concentrations of APs slightly higher in water but relatively lower in sediments than the Lingding Bay, which might be attributed to their different hydrodynamic and sedimentary characteristics. There was a decreasing trend of APs in water from the rivers to the estuary and further to the sea on the whole. In the Lingding Bay and its outer waters, concentrations of APs in sediments increased to a maximum and then decrease seaward, which was consistent with the distribution trend of the sediment organic carbon contents. Linear regression analyses showed the concentrations of APs were markedly correlated with the sediment organic carbon contents, indicating that the sediment organic carbon is an important factor controlling the levels of APs in sediments.     

Assessing the anti-estrogenic activity of sodium pentachlorophenol in primary cultures of juvenile goldfish (Carassius auratus) hepatocytes using vitellogenin as a biomarker

Both pentachlorophenol and 2,3,7,8-tetrachlorodibenzo-p-dioxin （TCDD） had been studied widely because of their probable anti-estrogenic activity. Sodium pentachlorophenol （PCP-Na）, as a industrial product used in many fields, usually contains a trace of TCDD. The aim of this study was to assess the anti-estrogenic effect of PCP-Na in juvenile goldfish （Gurassius auratus） hepatocyte cultures using vitellogenin （VTG） as the biomarker. The ID50 of PCP-Na was investigated and then a series of concentrations （0.001 0.5 μg/ml） of PCP-Na were evaluated to estimate the anti-estrogenic activity. Results showed that PCP-Na was cytotoxic for hepatocytes even at very low concentration 〈1.21 μg/ml, and it could not induce VTG at any concentrations tested. Since it failed to stimulate VTG production, the possibility of its anti-estrogenic effect was tested, and a well-known anti-estrogenic compound-tamoxifen was used as positive control. PCP-Na caused a reduction in VTG synthesis in juvenile goldfish （Carassius auratus） hepatocytes at concentrations 〉0.1μg/ml when co-exposure with 1μg/ml 17β-estradiol （E2）, making its anti-estrogenic activity approximately as potent as tamoxifen. Our results indicate that PCP-Na can act as negative modulators of estrogenic function in juvenile goldfish （Carassius auratus） hepatocytes.     

全新世青藏高原东部西南季风的演变

本研究报道一组新的西南季风代用指标,即泥炭中单一种属植物———木里苔草残体纤维素和泥炭混合植物残体纤维素的δ13C时间序列,所记录的青藏高原东部全新世气候变化。两记录表明,该区全新世的下限年龄约11200aBP(14C年龄约9900aBP);从约11200aBP起该区迅速进入湿暖的全新世阶段,季风活动迅速增强;在约10800～5500aBP期间,季风总体保持在强盛状态,但其间有4次突然减弱,气候变干冷;约从5500aBP起季风活动在波动中逐渐减弱,其中有4次减弱最明显。所有这8次气候的突然变化都与北大西洋浮冰事件一一对应。这种密切的相关关系表明,西南季风强度的波动可能是对全球变化,特别是对海洋热盐环流引起的地球南北方气候波动的所谓"跷跷板效应"的响应。     

废水污染物总量监测中采样方法的研究

通过对21家有代表性的废水污染源进行现场采样、排放曲线分析、采样频率优化的研究,确定总量监测中采样频率优化结果,为污染源总量控制监测提供技术指导。     

规范土地--中国开始行动

土地是农民赖以生存的基础。然而,近年来部分地区不按客观规律盲目建设投资、圈地扩地,占用大量农田,使得耕地急剧减少,农民无地可耕。     

污泥的处理处置方法与资源化

城市污水污泥的处理处置已成为目前世界上环境科学研究领域中的重要问题。本文紧紧追踪世界技术前沿,详细介绍了目前污泥的减量化、处理处置与资源化方法,同时指出了目前我国污泥处理处置中存在的问题,并讨论了其解决方法。     

基于ARCGIS的水泥行业碳排放点源分布与变化分析

首先对水泥行业产能与产量数据进行调研,对不同的工艺采用不同的CO2排放因子系统地计算了2000—2009年各点源企业水泥生产的CO2排放量,在点源企业排放量数据的基础上分析计算了各省份及全国总排放量的年度增长趋势。其次利用ARCGIS绘制了全国水泥行业排放点源年度分布图并分析了其空间分布特征,调查分析了我国水泥企业CO2排放源点源分布与变化规律,对水泥工业节能减排、发展低碳经济的工作具有重要的意义。