Toxicity Study of Anti-HABs Agents on Penaeus chinensis     

孙晓霞  张波  俞志明 《海洋通报(英文版)》2001,3(1)

In order to study the effect of anti-HABs agents on Penaeus chinensis, the toxicity experiments on clay, Ca(ClO)2, FeCl3, and AlCl3 to Penaeus chinensis are carried out. The results show that: (1) the clay isn't toxic to Penaeus chinensis; (2) Ca(ClO)2 has no toxicity to Penaeus chinensis at low levels, but has acute and chronic toxicity at high levels; (3) Penaeus chinensis can accumulate Fe and Al. The toxic effect needs further study.  相似文献   

Ledgers and landscapes: Indicators of rural landscape change in southern New Zealand, 1878–1919          下载免费PDF全文

Peter Holland  Sherry Olson 《New Zealand geographer》2017,73(1):45-56

Our objective was to develop and calibrate numerical measures to represent the timing and magnitude of landscape change between 1878, and 1919 using information in a stock and station agency's ledgers. Relative expenditures on fencing materials peaked in the 1880s, were lowest in the early 1900s, and rose to one‐fifth of annual expenditures from 1914 onwards. In contrast, relative expenditures on soil preparation, cropping and harvesting grew steadily after 1879, peaked in 1900, and declined from then until 1919. This research found that periods of intensive landscape investment between 1878 and 1919 were separated by longer intervals of landscape maintenance.  相似文献   

多智能体系统的群集行为研究综述     

胡鸿翔  梁锦  温广辉  虞文武 《南京气象学院学报》2018,10(4):415-421

近些年来,多智能体系统的群集行为分析已成为复杂网络领域的一个研究热点.本文从个体内部动力系统与个体间的拓扑结构这两个因素出发,对多智能体系统的群集行为问题的发展现状进行概述,并对相应的分布式协议、收敛速度以及实现的条件做了介绍和分析.最后,结合目前的研究现状,讨论了群集行为未来的研究方向.  相似文献   

粉土及其稳定土的三轴试验研究   总被引：9，自引：1，他引：8  

朱志铎  刘松玉  邵光辉  郝建新 《岩土力学》2005,26(12):1967-1971

以粉土和4 %石灰、2 %水泥+2 %石灰、4 %SEU-2型固化剂、8 %SEU-2型固化剂处理的粉土为研究对象,通过不固结不排水三轴剪切试验(UU)和固结不排水三轴剪切试验(CU)对变掺量、变龄期条件下粉土及稳定土的强度和变形特性进行了研究。试验结果表明：粉土及其稳定土的应力-应变曲线主要为软化型。SEU-2型固化剂在改善粉土的凝聚力方面起了很好的作用,综合考虑了不同稳定方法的强度指标,表明掺SEU-2型固化剂是稳定粉土的最有效的方法。  相似文献   

Factors Controlling Localization of Unconformity-related Uranium Deposits in the Proterozoic Athabasca Basin, Canada     

CHI Guoxiang  CHU Haixi  Ryan SCOTT  LI Zenghu  Kathryn BETHUNE 《《地质学报》英文版》2013,87(Z1):687-688

  相似文献   

Bioconcentration of triclosan and methyl-triclosan in marine mussels (Mytilus galloprovincialis) under laboratory conditions and in metropolitan waters of Gulf St Vincent,South Australia     

Rai S. Kookana  Ali Shareef  Milena B. Fernandes  Sonja Hoare  Sam Gaylard  Anu Kumar 《Marine pollution bulletin》2013

The anti-microbial agent triclosan (TCS), and its derivative methyl-triclosan (Me-TCS), are discharged with treated effluents from wastewater treatment plants to receiving environments. We investigated the bioconcentration of TCS and Me-TCS in mussels (Mytilus galloprovincialis) exposed to TCS (100 ng L⁻¹) for 30 days in seawater aquaria (19 ± 2 °C) with fresh phytoplankton as a food source. Bioconcentration increased with time reaching a steady-state around 24–30 days. The bioconcentration factor (log BCF) for TCS were 2.81 L kg⁻¹ (dry weight) and 4.13 L kg⁻¹, when lipid normalised concentrations were used. Mussels were also deployed in cages at four marine locations receiving effluents from WWTPs. The mean (±SD) TCS and Me-TCS concentrations for mussels from these sites were 9.87 (±1.34) and 6.99 (±2.44) μg kg⁻¹. The study showed that mussels can be a useful tool for monitoring pollution of TCS and Me-TCS in marine and estuarine environments.  相似文献   

滨海盐渍土的固化方法及固化土的偏应力-应变   总被引：2，自引：0，他引：2  

王沛  王晓燕  柴寿喜 《岩土力学》2010,31(12):3939-3944

滨海盐渍土可使用水泥、石灰、粉煤灰和高分子材料SH固土剂单独及联合固化,以提高土的强度、抗变形能力和水稳性。为研究各种固化方法固化盐渍土的抗变形能力和偏应力-应变特征,通过三轴UU压缩试验得到盐渍土和6种固化盐渍土的偏应力-应变曲线。曲线显示：水泥＋石灰类固化土呈应变软化型、石灰＋粉煤灰类固化土呈应变软化型、石灰类固化土呈应变硬化型。掺入SH固土剂,提高了固化土的浸水前后的强度,同时也增强了固化土的水稳性。掺入SH固土剂使固化土达到偏应力峰值所需的应变增加,即抗变形能力增强;0.9%SH固土剂+12%石灰+36%粉煤灰固化土具有适中的强度、良好的弹性变形和水稳性的优点,作为轻质路堤填料使用,还可减少滨海地区软土路基的沉降量,这使其成为滨海盐渍土的6种固化方案中的最适宜方案。  相似文献   

水泥基渗透结晶型防水材料对硫铝酸盐水泥固化土性能影响及机制分析     

杨康辉  欧忠文  肖寒冰  莫金川  刘晋铭 《岩土力学》2016,37(2):477-486

水泥土固化过程中Ca2+浓度会随水化反应的进行而逐步降低,导致水泥颗粒未完全水化,固化土强度增长受限,而水泥基渗透结晶型防水材料（CCCW）中活性物质能催化未水化水泥颗粒反应。选择硫铝酸盐水泥（SAC）为胶凝材料、CCCW为添加剂,通过单掺与复掺的方式,结合X射线衍射（XRD）、电镜扫描（SEM）表征,分析了固化土的无侧限抗压强度、水稳定性、耐干湿循环性能及微观结构。结果表明,复掺16%混合料（4%CCCW+12%SAC）的固化土强度是同掺量下单掺SAC固化土强度的1.5倍,且比单掺20%SAC的固化土强度高1.41 MPa;复掺16%混合料（4%CCCW+12%SAC）的固化土泡水2～8 d软化系数平均达0.97,而同掺量下SAC固化土平均仅为0.73;单掺的固化土强度随干湿循环次数增加逐级降低,而复掺混合料的固化土强度呈波浪式发展;CCCW中活性物质能增加固化土中钙矾石生成量并修复微裂缝,钙矾石长径比显著增大,可直接连接两个甚至多个土颗粒,形成三维网状结构,显著提高结晶体的微观加筋、骨架及填充作用,改善SAC固化土强度、水稳定性及耐干湿循环性能。  相似文献   

社区视角下的农业文化遗产保护与旅游发展（英文）   总被引：1，自引：0，他引：1  

孙业红  王静  刘某承 《资源与生态学报(英文版)》2013,4(3):258-266

农业文化遗产中蕴含的丰富生物多样性和文化多样性是在当地社区的传统生活中不经意间保留下来的。这些生物多样性和文化多样性同时也是很好的旅游资源,通过旅游发展既能维持当地居民的生计,同时也可以有效保护农业文化遗产。本文以全球重要农业文化遗产——贵州从江县稻鱼鸭复合系统为例,讨论了农业文化遗产保护与旅游发展中的社区参与问题。构建了基于社区的农业文化遗产保护及旅游发展的概念模型,其核心观点为农业文化遗产在保护和社区适应方面是一个动态的过程。模型中的6个主要因子分别为:农业文化遗产社区、传统农业系统、生物多样性、文化多样性、可持续旅游发展、社区生计和社区文化身份。几个因子之间的作用是互相影响的,因此支持了农业文化遗产的保护以及农业文化遗产地的旅游发展。  相似文献   

A new mixing technique for solidifier and dredged fill in coastal area     

Wenhui Shi  Sanjay Nimbalkar  Wenbai Liu 《Marine Georesources & Geotechnology》2017,35(1):52-61

One of the major drawbacks of the conventional method of land reclamation, which involves mixing cement with the dredged soils at the disposal site, is the high cost associated with its manufacturing and transportation. In this study, a new solidified dredged fill (SDF) technique and a new additive are proposed and their practical applications are discussed. Unlike the conventional approach, the dredged marine soils were mixed with the solidifiers using a newly designed mixing technique prior to its transport to site, which would significantly reduce the cost of site machinery and effectively reclaim land with adequate engineering properties necessary for the construction of infrastructure. To evaluate the performance of the reclaimed land using the proposed technique, a series of laboratory and field tests (namely, static and dynamic cone penetration tests, and plate load tests) were conducted on grounds filled with and without solidified dredged marine soils, respectively. The results showed that the engineering behavior of the reclaimed land with dredged marine soils using SDF technique had significantly improved. The SDF technique combined with the newly designed mixing system improved the performance of ground and has thus proved to be both cost-effective and safe.  相似文献