Responses of Synechocystis sp. PCC 6803 (cyanobacterium) photosystem Ⅱ to pyrene stress

In order to explore the mechanism of acute toxicity for pyrene to cyanobacterial organisms, the responses of Synechocystis sp. PCC 6803 photosystem II (PS II) under pyrene stress were studied. The results showed there was no significant di erence about the oxygen evolution under 0.125 mg/L pyrene stress when compared with control, but it was significantly lower than control at 0.625 mg/L pyrene. Polyphasic chlorophyll-a fluorescence transients in cells of Synechocystis sp. PCC 6803 exhibited a typical increase including O, J, I, and P phases. Fluorescence yield at phases J, I and P declined slightly at 0.125 and 0.625 mg/L pyrene, and significantly lower than control at 3.125 mg/L. According to the parameters deviated from JIP-test, no modification was induced by pyrene both at the donor side and at the acceptor side of PS II, and the reaction centre of PS II is the primary damaging target. Based on the expressing of four key genes (psbA, psbB, psbC and psbO) of PS II, only psbA showed significant di erence at 3.125 mg/L pyrene when compared with control.     

花卉植物修复铅污染土壤的研究现状及展望

植物修复以其优良的社会、生态和经济效益,成为重金属污染土壤修复的首选措施。从花卉植物对铅的富集能力及其强化措施方面,阐述了利用花卉植物修复铅污染土壤的研究现状,提出了研究中存在的主要问题,并对今后的研究工作进行了展望。     

长春市主要街路代表性植物叶片铅含量分析

应用火焰原子吸收光谱法,对长春市14条主要街路交通密集地段两侧绿化带中采集到的12种代表性植物叶片的铅含量进行了分析。结果表明,植物叶片的铅含量范围在8.20 mg/kg～58.5 mg/kg之间,平均值为19.7 mg/kg。木本植物叶片的平均铅富集能力略低于草本植物,并且木本植物叶片平均铅含量的空间变异性较大;木本植物中杨树叶片的平均铅富集能力最强而榆树最低,草本植物中绣线菊的叶片平均铅富集能力最强而八宝景天最低;草本植物中绣线菊的叶片在所有供试植物叶片中平均铅富集能力最强,其次为木本植物中杨树的叶片,而草本植物中八宝景天的叶片平均铅富集能力最低。不同植物在同一街路以及同种植物在不同街路之间其叶片的铅含量都不同。     

江苏省土地后备资源持续利用研究

本文从土地可持续利用的要求出发,分析了江苏省土地后备资源的数量、分布特征和成因,提出了土地后备资源持续利用的对策     

Anaerobic treatment of fresh leachate from a municipal solid waste incinerator by upflow blanket filter reactor

This paper describes the feasibility of fresh leachate treatment by an upflow blanket filter (UBF). Through dilution and partial effluent recycling, the organic loading rates increased from 0.51 to 14.56 kg COD/(m³·d), meanwhile the corresponding hydraulic retention time decreased from 9.0 to 3.6 d. The reactor was able to achieve steady-state within 80 d. Based on the distribution of COD fluxes in the process, it was concluded that anabolism was the main pathway of COD removal in the initial phase (1–33 d), accounting for 57%–85% of total COD removed. As the anaerobic consortium of bacteria reached steady-state (after 70–86 d), the majority of COD removed was transformed into methane, because the specific methane yield was close to the theoretical value (0.36 L CH₄/(g COD_deg)).     

机场大气污染研究现状综述

经济的发展驱动着航空业的进步,同时带来了机场大气污染问题。概述了机场大气污染的危害、基本原理,认为飞机排放是大气温室效应的直接污染源。进而对国内外典型的机场大气排放评估模型进行对比分析,并分析研究了飞机尾气污染防治措施。     

上盖一体化地铁车站结构非线性地震响应分析∗

基于 ABAQUS 软件建立了地下地铁车站?土?上盖建筑一体化结构大型三维有限元数值模型,计算分析了上盖一体化地铁车站结构的地震响应规律和破坏机理,探讨了上盖一体化地铁车站结构与单体车站结构地震响应的差异。结果表明：地铁上盖一体化结构体系各阶自振频率与自由场地较为接近,地铁上盖结构的存在对场地动力特性的影响较小;强震作用下,一体化地铁车站结构的损伤破坏区域主要是车站各层楼板和墙柱的交接位置,尤其是中柱和侧墙顶底部的损伤最为严重;单体车站与上盖一体化地铁车站结构地震响应规律存在一定差异,上盖一体化地铁车站结构的地震反应略小,其中,上盖地铁车站结构的地震响应同时受上盖结构和周围土体介质的影响, 上盖结构对上盖地铁一体化区域的影响显著,周围土体对上盖地铁非一体化区域的影响显著。     

十溴联苯醚(BDE 209)孕哺期及出生后暴露对子代小鼠血液系统影响初探

本研究旨在探讨BDE 209长期暴露对出生后不同发育阶段子鼠血液系统的影响。将75只雌性昆明小鼠随机分为对照组、低剂量组(1.5 mg·kg-1·d-1)和高剂量组(225 mg·kg-1·d-1)。BDE 209暴露10 d后,将雌鼠与雄鼠合笼。选取怀孕时间相近(相差不过2 d)的10只孕鼠持续染毒直至自然分娩。出生后子鼠在哺乳期通过母乳染毒,断乳后则按照与母鼠相同的方式进行染毒,并在不同时间点进行外周血常规、外周血形态学、骨髓细胞形态学、骨髓细胞染色体组型和数目分析。血常规结果显示,低、高剂量BDE 209暴露对出生后不同发育阶段子鼠的白细胞计数没有影响,即白细胞、中性粒细胞、淋巴细胞及单核细胞的数量均无显著变化(P0.05);红细胞系统检查显示一定性别差异,即低剂量和高剂量BDE 209染毒的雄性小鼠在PND30出现红细胞(RBC)(P0.05)、血红蛋白(Hb)(P0.05或P0.01)及红细胞压积(P0.05或P0.01)的显著降低;而雌性小鼠只在PND 30出现红细胞压积的降低(P0.05);在PND 30,高剂量暴露组的雌性及雄性小鼠,低剂量暴露组的雌性小鼠均出现血小板计数的显著降低(P0.05或P0.01);而PND 60、PND 90的实验组血小板均未观察到显著改变(P0.05)。外周血形态学检查表明,低剂量组在PND 30、PND 60,及高剂量组在PND 90检测到典型异常结果多表现为白细胞数的增多。而低剂量组在PND 90检测到的典型异常结果多表现为异型深染淋巴细胞(P0.05)。骨髓形态学检测表明,低剂量组子代雄性及雌性小鼠在PND 60、PND 90骨髓涂片可检测到骨髓细胞的异常结果,表现为骨髓增生活跃,高剂量组雄性小鼠在PND 90观察到3例异常涂片,表现为骨髓增生异常(P0.05)。研究结果表明,BDE 209长期暴露可能导致出生子代外周血和骨髓的毒性,提示具有血液系统发育毒性。     

Ecological Survey of Coastal I Water Adjacent to Nuclear Power I Plants in Taiwan

A total of six nuclear reactors installed in three power plants, two along the northern and one along the southern coasts of Taiwan, started their operations one after another since October 1977. Owing to the large quantities of cooling water intake into and discharge from the plants, some environmental factors such as water temperature, chlorine, environmental radioactivity and nearshore currents may be significantly changed. Variations of these abiotic environmental factors may influence the biological activities in the ecosystem, particularly doing some kinds of damage to marine biological resources. Therefore, the possible environmental impact upon the biological systems including the fishery resources along the northern and southern coasts of Taiwan should be studied before and during the plant operation.

We have started the long-term programmes of biological, chemical and hydro-graphical surveys of the nuclear power plant sites on both northern (since July 1974) and southern (since July 1979) coasts of Taiwan. the survey items include ocean currents, physical and chemical properties of sea water, primary productivity, specific compositions and interspecific relationships among phyto- and zooplankton, algae, invertebrates, corals, and fishes; and radionuclides in water and biological specimens, and fishery statistics. in general, except for a few events, the operations of the six units of nuclear power plants have not produced detectable effects on the marine ecosystem. Radio activity levels and radionuclides in water and the biological specimens remained the same as background levels throughout the survey period. However, the events of coral bleaching and fish body anomalies caused by thermal discharges were observed respectively along the outlets of third and second Nuclear Power Plants. the purposes of this paper are to report and evaluate these two events during the operations of nuclear power plants in Taiwan.     

Runoff water management technologies for dryland agriculture on the Loess

SUMMARY

Arid and semi-arid environments undergo periodic seasonal agricultural droughts of varying extents and duration, erratic and ineffective rainfall of high intensity and short duration, with high surface runoff. High efficiency water-harvesting agriculture has been routinely used in the Loess Plateau agricultural production of China over the past 10 years. Localized habitat effect and regional water resource enrichment are the theoretical basis of high efficient water-harvesting agriculture. Features of this agricultural system are described, including: water harvesting of surface runoff from roads and collection in concrete yards on plastic sheets; water storage cellar tanks for harvesting runoff to provide life-saving/critical irrigation, with devices for water lifting and conveying such as hand pumps and pipelines; feasible methods of water use for limited supplies such as drip, hole, subsoil, and super-sheet irrigation; agronomic measures of high water use efficiency; and field micro-catchment for water harvesting and conservation to increase fallow efficiency in rainy seasons. Using the stored runoff water to irrigate the mulched winter wheat and spring corn, as well as vegetables and fruit trees, significant yield increasing and water use efficiency improvements have been achieved. Plastic mulching for increasing fallow efficiency in rainy seasons and improving yield of the next winter wheat crop have been developed and demonstrated. These techniques have provided obvious benefits in terms of soil and water conservation on slope farmland in the hill regions and remarkable effects of storing water and reducing drought in the dryland farming regions have been obtained.