刍议我国直流冷却电厂冷却用水生态危害与减损

根据我国滨海电厂发电现状与发展趋势,本研究评述了我国火电和核电厂直流冷却需水量以及电厂规模化直流冷却用水对海洋生态系统的影响,包括取水卷塞效应导致生物伤害及其机理,卷载和温排水对海洋生物和海洋生态系统的负面影响。本研究估算了取排水导致的卷塞和卷载损失量。同时,以大亚湾生态系统变化为例,探讨了取排水的可能影响,提出了底栖贝类食物链形成的假设。由于电厂取排水对海洋生态系统构成实际和潜在危害,因此,有必要采取措施缓解电厂取水造成的环境影响。在对电厂的取排水海洋环境评估的基础上,电厂可以利用最佳实践技术（Best Technique Available, BTA）,避免或减轻取排水对海洋生态系统的影响,维护冷却海水资源开发的可持续性。减损措施不仅有利于海洋生态保护,也有利于电厂的冷源安全。     

基于卫星和浮标数据的副热带西北太平洋反气旋型中尺度涡旋的个例观测研究

The comprehensive three-dimensional structures of an anti-cyclonic mesoscale eddy(AE) in the subtropical northwestern Pacific Ocean were investigated by combining the Argo floats profiles with enhanced vertical and temporal sampling and satellite altimetry data. The AE originated near the Kuroshio Extension and then propagated westward with mean velocity of 8.9 cm/s. Significant changes and evolutions during the AE's growing stage(T1) and further growing stage(T2) were revealed through composite analysis. In the composite eddy core,maximum temperature(T) and salinity(S) anomalies were of 1.7(1.9)°C and 0.04(0.07) psu in T1(T2) period,respectively. The composite T anomalies showed positive in almost whole depth, but the S anomalies exhibited a sandwich-like pattern. The eddy's intensification and its influence on the intermediate ocean became more significant during its growth. The trapping depth increased from 400×10~4 Pa to 580×10~4 Pa while it was growing up, which means more water volume, heat and salt content in deeper layers can be transported. The AE was strongly nonlinear in upper oceans and can yield a typical mean volume transport of 0.17×10~6 m~3/s and a mean heat and salt transport anomaly of 3.6×10~(11) W and –2.1×10~3 kg/s during the observation period. The Energy analysis showed that eddy potential and kinetic energy increased notably as it propagated westward and the baroclinic instability is the major energy source of the eddy growth. The variation of the remained Argo float trapped within the eddy indicated significant water advection during the eddy's propagation.     

济阳县土壤元素有效量及其影响因素研究

通过对济阳县生态地球化学调查研究,该区受成土母质来源、土壤类型、地形地貌及其理化性质等因素影响,土壤元素全量、有效量及有效度表现为：低平洼地土壤中K,P,N,Se,Mn,Fe,Zn,Cu和Mo全量较高,P,N,Se和Cu有效量较高,显示为低平洼地为黏质成分的沉积成因特点;而决口扇形地区土壤Cu,Mo,N,Zn,B有效量和全量均偏低。富含有机质,且pH相对较低的潮土中Se,Cu,Mo和B等元素有效度较高,贫有机质、pH相对较高的草甸风沙土中N,Fe,Cu,Mo,B和S等元素有效量较低,但K有效量和有效度均较高。统计分析表明,土壤中K,P,N,S和Cu等元素全量与有效量间具显著正相关性,表明全量是有效量的重要影响控制因素;有机质含量与K,P,Zn,Cu和B有效度间为显著正相关,说明有机质较高有利于土壤元素活化;Fe,P,S,Zn,B和Cu有效度与pH值为显著负相关,表明土壤酸性增强会增加这类元素的生物有效性。     

The vertical attenuation of irradiance as a function of turbidity: a case of the Huanghai(Yellow) Sea in spring

The planar photosynthetically available radiation (PAR), turbidity and concentration of chlorophyll a (chl a), were measured at 26 stations in the Huanghai (Yellow) Sea during a cruise of China SOLAS from 19 to 27 March 2005. Due to low chl a (<0.35 mg · m-3 ) in upper layers (above 5 m), suspended particulate matter became the major factor that influenced the turbidity in early spring. The calculated vertical diffuse attenuation coefficient of PAR, K PAR , varied with water depths with a maximum value in t...     

矿物风化对黄土区土壤有效硅含量的控制作用--以陕西省关中-陕北地区为例

利用XRD、粒度分析、土壤风化模拟试验等方法,对黄土区土壤有效硅含量分布、土壤机械组成、粘粒矿物种类及含量分布、土壤溶液pH值和土壤矿物风化过程中硅的析出规律进行研究。从陕北干旱区到关中半湿润区,土壤中蛭石含量从0.18%升高到1.60%;高岭石从0.45%升高到1.84%,相应的土壤有效硅含量从122.62×10-6升高到463.95×10-6。土壤有效硅含量与粘粒矿物总量呈正比,与土壤溶液pH值成反比,这与南方水田水稻土情况完全不同。模拟实验证实土壤中存在的游离硅是硅酸盐矿物异成分溶解的结果。研究区土壤风化作用强度规律性变化是造成区内土壤有效硅含量变化的主要原因。     

风蚀影响因子的敏感性试验

 对风蚀模式的各重要影响因子进行了敏感性试验，结果表明：①随风力的增大，跃动沙粒的粒径范围迅速增大，从而会使更多、更大的尘粒因受到更强烈的撞击作用而释放于空中。但随土壤水分和植被覆盖度的增加，跃动沙粒粒径范围会变窄，较大的粒子很难被激发到空中。②各种土壤沙流通量及尘粒释放率随粒径的变化趋势Q(d)和F(d)与相应的地表土壤有效粒度分布Ps(d)具有相似的特征，说明前人用近地层沙尘粒度分布来代表地表土壤的有效粒度分布是合理的。③若以总沙流通量Q>0.5 g·m^-1·s^-1为风蚀过程开始发生的标准，在干燥、裸露的情况下，沙土、沙壤土、壤土、黏土和粉黏土表面发生风蚀的临界摩擦速度都约为0.3 m·s^-1。相同风力条件下（u*=0.6 m·s^-1），若地表干燥（w=0）并忽略小于0.1 g·m^-1·s^-1的总沙流通量，则抑制5种土壤发生风蚀的最小植被覆盖度分别约为：沙土0.35、沙壤土0.45、壤土0.45、黏土0.55、粉黏土0.55；若地表裸露，抑制风蚀发生的最小水分含量分别为：沙土0.15、沙壤土0.18、壤土0.3、黏土0.36和粉黏土0.33。④通常情况下沙土最不易起尘，它在各个粒径的尘粒释放率比其他土壤均约小3~5个量级。粉黏土最易起尘，且粒径较小，较容易传输到下游很远处。⑤总尘粒释放率F和总沙流通量Q随风力、地表条件的变化一般是同相的，即Q增大，F也会增大。⑥一般情况下F随摩擦速度u*的增大或植被覆盖度cf和土壤水分w的减小而增大；土壤拖曳系数sx和弹性压力垂直分量pye的增加会大大降低尘粒释放率。⑦通常风蚀情况下，5种土壤中粉黏土和沙壤土因聚合粒子破碎产生的尘粒释放率Fc最大，Fc随风力、地表条件变化的敏感度也最强；沙土的Fc最小，其对风力、地表条件的敏感度也最弱。     

中国土壤有效含水量分布

1IntroductionAvailable soil water capacity (ASWC) is the volume of soil water that should be available to plants. It is commonly estimated as the amount of water held between field capacity (FC) and permanent wilting point (PWP) with corrections for salin…     

Surfactant and irrigation effects on wettable soils: runoff,erosion, and water retention responses

Surfactants are chemical compounds that can change the contact angle of a water drop on solid surfaces and are commonly used to increase infiltration into water repellent soil. Since production fields with water repellent soil often contain areas of wettable soil, surfactants applied to such fields worldwide will likely be applied to wettable soil, with unknown consequences for irrigation‐induced erosion, runoff, or soil water relations. We evaluated surfactant and simulated sprinkler irrigation effects on these responses for three wettable, Pacific Northwest soils, Latahco and Rad silt loams, and Quincy sand. Along with an untreated control, we studied three surfactants: an alkyl polyglycoside (APG) in solution at a concentration of 18 g active ingredient (AI) kg^?1, a block copolymer at 26 g kg^?1, and a blend of the two at 43 g kg^?1. From 2005 to 2009 in the laboratory, each surfactant was sprayed at a rate of 46·8 l ha^?1 onto each soil packed by tamping into 1·2‐ by 1·5‐m steel boxes. Thereafter, each treated soil was irrigated twice at 88 mm h^?1 with surfactant‐free well water. After each irrigation, runoff and sediment loss were measured and soil samples were collected. While measured properties differed among soils and irrigations, surfactants had no effect on runoff, sediment loss, splash loss, or tension infiltration, compared to the control. Across all soils, however, the APG increased volumetric water contents by about 3% (significant at p≤0·08) at matric potentials from 0 to ? 20 kPa compared to the control. With a decrease in the liquid–solid contact angle on treated soil surfaces, surfactant‐free water appeared able to enter, and be retained in pores with diameters ≥ 15 µm. All told, surfactants applied at economic rates to these wettable Pacific Northwest soils posed little risk of increasing either runoff or erosion or harming soil water relations. Moreover, by increasing water retention at high potentials, surfactants applied to wettable soils may allow water containing pesticides or other agricultural chemicals to better penetrate soil pores, thereby increasing the efficacy of the co‐applied materials. Copyright © 2010 John Wiley & Sons, Ltd.     

南疆柯坪强雷暴天气的分析

利用NCEP 1°×1°的6小时再分析资料和常规观测资料以及位于南疆阿克苏新一代C波段多普勒天气雷达资料,分析了2009年8月19日发生在南疆阿克苏地区柯坪县的强雷暴天气。分析显示,β中尺度切变线和地面中低压、辐合线是雷暴的直接影响系统,其水汽源于塔里木盆地东部和中部地区,水汽输送集中在低层,低空偏东急流为水汽输送发挥了重要作用,雷暴发生前对流有效位能有一个增大的过程。雷暴从暴雨雷暴发展为雹暴,持续时间超过1小时。在雷暴单体成熟期,雹暴中层反射率呈现回波悬垂和弱回波区。     

一次夏季雷暴天气过程中闪电活动特征分析

利用探空资料、多普勒天气雷达和闪电定位仪数据,分析了2009年7月30日发生在南京地区一次雷暴天气过程的雷达及闪电数据时空演变特征。结果表明：对流有效位能Ecap比起K指数（IK）等对于对流潜势预报具有更明显的指示作用,0 ℃层和-10 ℃层高度的降低有利于雷暴云的雷电活动;整个过程以负闪为主导,闪电强度越大,闪电频数也越高,每次闪电峰值后,都对应一次谷值;闪电数据与多普勒天气雷达回波叠加后分析发现,回波的生消演变对应着闪电频数和强度的生消演变,负闪主要落在强回波中心区域,正闪零星分布于回波强度梯度较大的区域;雷达径向速度图像特征变化更能揭示闪电发生发展的机制,逆风区对应雷暴中心区域,不仅是强降水的中心区也是闪电的中心区,对逆风区的识别监测能够更好的指导雷暴预警报工作;利用雷达数据计算的云底动能施力参量,能够很好的描述支持闪电起电的热动力特征,云底动能施力对雷电增长的贡献有一段持续传输过程,该参量峰值比频闪峰值和强度峰值都约有0.5 h的提前量。