Vegetation and carbon sequestration and their relation to water resources in an inland river basin of Northwest China

In the Heihe River Basin in the arid inland area of northwest China, the distribution of water resources in vegetation landscape zones controls the ecosystems. The carbon sequestration capacity of vegetation is analyzed in relation to water resources and vegetation growing conditions. During the last 20 years, the vegetation ecosystems have degenerated in the Heihe River Basin. Simulation using the C-FIX model indicates that, at present, the total amount of NPP of vegetation accounts for about 18.16 TgC, and the average value is 106 gC/m(2)/yr over the whole basin. NPP has generally the highest value in the upperstream mountain area, middlestream artificial oases area, downstream river bank area, alluvial fan and the terminal lake depression where vegetation grows relatively well. The lowest value is found in the vast downstream desert and Gobi area. Protection of vegetation ecosystems and enhancement of carbon sequestration require such inland river basins as the Heihe River Basin to be brought under management in a comprehensive way, taking water as a key, to carry out a rational and efficient allocation and utilization of water resources.     

Grazing greatly reduces the temporal stability of soil cellulolytic fungal community in a steppe on the Tibetan Plateau

Excessive livestock grazing degrades grasslands ecosystem stability and sustainability by reducing soil organic matter and plant productivity. However, the effects of grazing on soil cellulolytic fungi, an important indicator of the degradation process for soil organic matter, remain less well understood. Using T-RFLP and sequencing methods, we investigated the effects of grazing on the temporal changes of cellulolytic fungal abundance and community structure in dry steppe soils during the growing months from May to September, on the Tibetan Plateau using T-RFLP and sequencing methods. The results demonstrated that the abundance of soil cellulolytic fungi under grazing treatment changed significantly from month to month, and was positively correlated with dissolved organic carbon (DOC) and soil temperature, but negatively correlated with soil pH. Contrastingly, cellulolytic fungal abundance did not change within the fencing treatment (ungrazed conditions). Cellulolytic fungal community structure changed significantly in the growing months in grazed soils, but did not change in fenced soils. Grazing played a key role in determining the community structure of soil cellulolytic fungi by explaining 8.1% of the variation, while pH and DOC explained 4.1% and 4.0%, respectively. Phylogenetically, the cellulolytic fungi were primarily affiliated with Ascomycota (69.65% in relative abundance) and Basidiomycota (30.35%). Therefore, grazing substantially reduced the stability of soil cellulolytic fungal abundance and community structure, as compared with the fencing treatment. Our finding provides a new insight into the responses of organic matter-decomposing microbes for grassland managements.     

我国黑土地农田土壤除草剂残留特征研究及展望

粮食安全是“国之大者”.东北黑土地作为我国重要的粮仓,是保障国家粮食安全的“压舱石”.但黑土地农田除草剂的长期高强度施用,导致除草剂在土壤中积累和迁移,影响土壤质量、作物产量和品质,阻碍黑土地可持续利用和农业可持续发展.解决黑土地农田除草剂残留问题,既要从源头管控除草剂的施用,也要掌握除草剂的残留特征、时空演变和驱动因素,才能做到科学防控、精准施策.系统总结了我国黑土地农田除草剂的施用状况和存在的问题,全面梳理了除草剂的残留现状,指出了当前在黑土地农田除草剂残留特征、空间分布和污染诊断等研究上的不足,提出了我国黑土地农田除草剂残留诊断与风险管理研究思路与重点方向,为保障我国黑土地农田土壤健康、粮食安全和生态系统安全提供科技支撑.     

城市发展质量的综合评价--以江苏省13个省辖市为例

在城市发展质量评价指标体系构建的基础上,依据一定的规则确定各评价指标的目标值,根据综合评价方法,对江苏省13个省辖市2000-2002年各城市发展质量进行综合分析.提出测算城市质量系统间协调发展程度的一般计量模型,根据此模型及城市发展质量综合评价的结论,分别研究了13个城市在近三年的城市化进程中,城市质量系统发展的协调性.     

生物操纵方法对水绵(Spirogyra)的调控效应

为探究安全高效调控水绵生长的方法,本研究利用养殖水桶开展了两次生物操纵实验,分别观测了鲤(Cyprinus carpio)、鲫(Carassius auratus)和鲢(Hypophthalmichthys molitrix)在没有营养加富条件下,以及鲫和日本沼虾(Macrobrachium nipponense)在营养加富条件下,对水体中浮游态和固着态水绵(Spirogyra)生长的抑制效果.结果表明,在没有营养加富的水体中,鲤和鲫对水绵不仅没有调控效应,反而会促进水绵的生长.建议在水绵生长旺盛的水体中,一定程度上移除水体中这些鱼类反而可以有效控制水绵的生长.在营养加富条件下,日本沼虾对水绵的控制效应明显.鲫对水绵发挥的作用与水体营养状态存在交互作用,日本沼虾对水绵的抑制效应是否受水体营养状态的影响值得进一步探究.     

印染废水RO浓水水质分析

以江苏某印染废水处理厂反渗透（RO）浓水为研究对象,采用多种分析手段分析了RO浓水的水质特征.首先采用IC和ICP-MS对水中的无机离子进行了定性和定量分析,采用GC-MS对废水中的半挥发性有机物进行定性和定量分析.结果表明,RO浓水中无机离子以Na⁺、Cl^-和SO₄^2-为主,半挥发性有机物邻苯二甲酸二（2-乙基己）酯（DEHP）为主要成分,其浓度为1.452mg/L.为分析RO浓水中的溶解性有机物（DOM）特征,进一步采用超滤膜分子量分级法和树脂亲疏水分离技术对废水中的DOM进行分离解析,分析了不同组分的溶解性有机碳（DOC）、UV₂₅₄、SUVA含量和分布情况,应用三维荧光光谱对各组分物质进行了定性分析.超滤分级表明,RO浓水中相对分子量<1k的有机物占56.98%,相对分子质量5~10k有机物仅占2.19%,但其芳香化程度较高.树脂分离结果表明,RO浓水中亲水性物质（HPI^*）、疏水性物质（HPO^*）和过渡性物质（TPI^*）的DOC含量差异不大,其中HPO^*的芳香构造化程度最高,含有较多的色氨酸类芳香族蛋白质,而HPI^*中含有较多的溶解性微生物代谢产物类物质.     

Visible-light-driven photocatalytic inactivation of bacteriophage f2 by Cu-TiO2 nanofibers in the presence of humic acid

Pathogenic viruses in drinking water are great threats to public health. Visible-light-driven photocatalysis is a promising technology for virus inactivation. However, the existing photocatalytic antiviral research studies have mostly been carried out in single-component systems, neglecting the effect of natural organic matter, which exists widely in actual water bodies. In this paper, electrospun Cu-TiO₂ nanofibers were prepared as photocatalysts, and their photocatalytic antiviral performance in the presence of humic acid (HA) was comprehensively studied for the first time. The properties of the reaction mixture were measured during the reaction. In addition, the safety, reliability and stability of photocatalytic disinfection in the mixed system were evaluated. The results showed that the virus removal efficiency decreased with the increase of the HA concentration. The type of reaction solution, such as PBS buffer solution or water, did not affect the removal efficiency noticeably. Under acidic conditions, the electrostatic forces between photocatalysts and viruses were strengthened, leading to higher virus removal efficiency. As the reaction time went on, the pH value in the solution increased first and then tended to be stable, the conductivity remained stable, and the dissolved oxygen increased first and then decreased. The safety test showed that the concentration of Cu ions released into the solution was lower than specified by the international standards. No photoreactivation was observed, and the addition of HA significantly reduced the reutilization efficiency of the photocatalysts.     

Source identification and trends in concentrations of gaseous and fine particulate principal species in Seoul, South Korea

Ambient measurements were made using two sets of annular denuder system during the four seasons (April 2001 to February 2002) and were then compared with the results during the period of 1996-1997 to estimate the trends and seasonal variations in concentrations of gaseous and fine particulate matter (PM2.5) principal species. Annual averages of gaseous HNO3 and NH3 increased by 11% and 6%, respectively, compared with those of the previous study, whereas HONO and SO2 decreased by 11% and 136%, respectively. The PM2.5 concentration decreased by -17%, 35% for SO4(2-), and 29% for NH4+, whereas NO3- increased by 21%. Organic carbon (OC) and elemental carbon (EC) were 12.8 and 5.98 microg/m(-3), accounting for -26 and 12% of PM2.5 concentration, respectively. The species studied accounted for 84% of PM2.5 concentration, ranging from 76% in winter to 97% in summer. Potential source contribution function (PSCF) analysis was used to identify possible source areas affecting air pollution levels at a receptor site in Seoul. High possible source areas in concentrations of PM2.5, NO3-, SO4(2-), NH4+, and K+ were coastal cities of Liaoning province (possibly emissions from oil-fired boilers on ocean liners and fishing vessels and industrial emissions), inland areas of Heibei/Shandong provinces (the highest density areas of agricultural production and population) in China, and typical port cities (Mokpo, Yeosu, and Busan) of South Korea. In the PSCF map for OC, high possible source areas were also coastal cities of Liaoning province and inland areas of Heibei/Shandong provinces in China. In contrast, high possible source areas of EC were highlighted in the south of the Yellow Sea, indicating possible emissions from oil-fired boilers on large ships between South Korea and Southeast Asia. In summary, the PSCF results may suggest that air pollution levels in Seoul are affected considerably by long-range transport from external areas, such as the coastal zone in China and other cities in South Korea, as well as Seoul itself.     

基于SIL评估的LNG加气站安全仪表系统问题分析及改进建议*

为分析LNG加气站安全仪表系统的功能完备性与可靠性,以3座典型的三级LNG加气站为研究对象,全面开展安全仪表功能辨识、安全完整性等级（SIL）定级与验证,进而提出针对性的改进建议。结果表明:3座LNG加气站的安全仪表系统均存在功能不完备、设备组件缺少失效数据的问题;为满足风险控制要求,三级LNG加气站需设置15个安全仪表功能,其中1个应达到SIL2等级,14个应达到SIL1等级;LNG加气站的安全仪表系统应选用获得功能安全认证的设备组件,并在设计阶段开展SIL评估工作。研究结果可为今后LNG加气站安全仪表系统的设计与管理提供重要参考。