京津冀一次区域性暴雨特征分析

利用FNL再分析资料、卫星资料和自动站资料对2019年7月22~23日京津冀一次区域性暴雨过程进行了环流形势、卫星云图、动热力结构的分析。结果表明:此次暴雨发生在500hPa两槽一脊、副热带高压北抬、低空急流的大尺度环流背景下。西南方向的水汽输送和黄渤海的补充水汽为暴雨提供了良好的水汽条件,在河北中部的水汽辐合抬升则为暴雨提供了抬升条件。此次暴雨的产生受中尺度对流云团的连续生成合并影响,降水效率高。在暴雨中心整层表现为低层辐合、高层辐散,上升速度中心明显,使得高层的抽吸作用更强,更有利于上升运动的维持与发展,为降水强度增大提供了有力的动力条件,高空弱冷空气的入侵对能量锋区不稳定能量的释放起到了触发作用。     

Enhancement of sulfide auto-oxidation by metal ion in artificial seawater and a seawater which is a possible source of aoshio

SUMMARY: Aoshio is hypoxic milky blue-green seawater observed in some eutrophic bays. Previous studies have shown that colloidal sulfur causes the coloration and that the source of aoshio water is attributed to coastal anoxic bottom water. Occurrences of aoshio have been reported in limited areas of coastal seawater, although hypoxic transparent water seems rather universal. Promotion in auto-oxidation of sulfide by metal ions in seawater was investigated to explain the occurrences of aoshio. Artificial seawater containing 10 μM metal ion was assayed for the sulfide oxidation rate. The velocity constant which represents the oxidation rate within the initial 30 min and the amount of reacted sulfide in 2 h were determined by oxygen monitoring and sulfide quantification, respectively. Fe²⁺ and Cu²⁺ enhanced the initial 30 min reaction. Fe²⁺, Fe³⁺ and Ni²⁺ increased the amount of reacted sulfide in 2 h, forming whitish turbid water. Seawater from a suspected source of aoshio water was also assayed for the auto-oxidation rate of sulfide. The oxidation rate in water from 12 m depth was 13–19 times higher than the artificial seawater without an addition of heavy metal ions. More than 15% of the oxidation rate in 12 m deep seawater was explained by dissolved iron in the seawater.     

Study on Cultural Technologies and Salt-resistance of Nitraria sibirica in Coastal Areas with Serious Salt-affected Soil

In this research, five Nitraria sibirica provenances such as Dayilu were selected to do experiment of salt-resistance, combining fixed plots test with typical plot investigation, measuring survival rate and growth as main indicators. The experiments of main cultural technology were done on Nitraria sibirica in 4 types of site preparation, 3 types of planting, 3 designs for planting density. The Nitraria sibirica experiments for the effects of curbing salt and improving soil were done by testing soil nutrients, salt content, soil physical properties as focal points in typical site of 3-4 years woods. The experiment results showed that the Nitraria sibirica could survive well with soil salt content of 0.6%, and that survival rate declined distinctively as soil salt content exceeded 0.8%. However, high soil salt content did not influence growth in the year of planting. There were obvious differences in salt-tolerance among Nitraria sibirica provenances; Dayilu was the best on salt-tolerance, the other 4 pro     

The Effect of Lead and Zinc on Plant Growth and Chlorophyll Content of Holcus lanatus L.

Root length of Holcus lanatus L. declined rapidly with increasing lead and zinc concentrations in nutrient solution. In all used Pb and Zn concentrations root growth of genotypes coming from a Pb-Zn mine area, was greater than that of the control, suggesting that these genotypes evolved tolerance to Pb and Zn.
Negative correlation was also observed between chlorophyll content and increased heavy metal concentrations. The greater chlorophyll content found in tolerant genotypes, in different Pb and Zn concentrations, in comparison with the control, could be served to distinguish tolerant and non-tolerant genotypes.     

某些阳离子在大豆胞囊线虫生防系统中的作用

室内测定了不同浓度的 6种阳离子 :钼、硼、锌、铜、锰和铁对大豆胞囊线虫卵的孵化、大豆种子发芽和根系生长 ,以及对线虫生防菌———厚垣轮枝菌菌丝生长的影响。结果发现 ,在供试所有浓度下 ,铜、锰和铁明显抑制大豆胞囊线虫的卵孵化 ,锌具明显刺激作用 ;在供试浓度水平较低时 ,铜、锰和铁对大豆种子发芽及根系生长有轻微抑制 ,锰的抑制较为明显 ,但均不影响进一步发育 ;在供试浓度较低时 ,铜、锰和铁对厚垣轮枝菌菌丝生长无任何影响。铜可作为线虫生防制剂的添加剂。     

Determination and Analysis of Heavy Metal Content in the Soil from Beef Cattle Farms in Three Regions of Xinjiang

In order to study and evaluate the feeding environment of the beef cattle farms in Xinjiang, the contents of heavy mentals in the soil from 8 beef cattle farms in Xinjiang Aksu, Yili and Tacheng regions were tested according to the Field of Livestock and Poultry Environment Quality Standard (NY/T 388—1999).The atomic absorption spectroscopic method was used to determine the contents of As, Hg, Pb, Cd, and Cr.The mean contents of As, Hg, Pb, Cd, and Cr in 8 beef cattle farms soil were 0.389, 0.568, 22.708, 0.573 and 149.449 mg/kg, respectively, and they were all below the upper limit of NY/T 388—1999.The comprehensive heavy metal pollution index of 8 beef cattle farms were 0.577 to 0.994, and the index were 0.7 to 1 of two observation points in Yili and one observation point in Tacheng.The soil environment quality of these 3 farms were at the level of slight cleaning.The comprehensive heavy metal pollution index of other five observation points were ≤0.7, the soil environment was in a clean level.The soil environment of beef cattle farms in these three regions conformed to the standards of livestock for environment quality and safe products.     

农业重量物装卸机械应用现状及发展趋势

分析了目前国内外普遍采用的重量物装卸机械的应用及研究现状,介绍了它们各自的特点,并指出存在的问题,展望了未来农业重量物装卸机械的发展趋势。     

菜用睡莲营养成分及重金属含量测定与评价

对绿梗菜用睡莲(Nymphaea tetragona)及红梗菜用睡莲的15营养成分和4种重金属含量进行了测定与评价。结果表明,1与104~140种(品种)新鲜蔬菜已知数据比较,绿梗和红梗菜用睡莲均有较高含量的维生素C、钠及较低含量的干物质、蛋白质、钾、钙、镁、铜、锌、磷及硒;绿梗菜用睡莲有较高含量的粗纤维、锰及较低含量的铁,红梗菜用睡莲有较高含量的铁及较低含量的粗纤维。2菜用睡莲是一种含钠量较高的蔬菜。3绿梗菜用睡莲营养成分含量总体高于红梗菜用睡莲。4湖北产区菜用睡莲的铅、砷、镉及汞等重金属含量符合食品安全国家标准的规定。     

重金属污染土壤几种生物修复方式比较

土壤重金属污染是全球普遍存在的问题,生物修复因其环境友好且成本效益高而得到广泛关注。但不同生物修复技术有其优势和局限性,充分了解每种修复技术的特点,才能更经济、有效地对污染土壤进行修复。本研究阐述对比了目前的土壤重金属生物修复方法,包括植物修复（植物挥发、植物固定和植物提取）、转基因植物提取、螯合辅助植物修复、微生物辅助植物修复等技术的机制、优势、局限性和适用性等方面的差异。综述提出有效的生物修复技术需要土壤化学、植物生物学、遗传学、微生物学和环境工程等多学科的有机结合。根据污染土壤的特点,结合具有相应改良特性的转基因植物,是实现污染土壤大面积修复的有效方法。同时,农艺措施对天然超级积累植物的生物量和重金属提取能力的刺激作用还需要进一步挖掘。植物修复可以与其他几种传统修复技术有效结合,利用转基因技术建立土壤+植物+微生物的组合是未来修复技术发展的最佳途径。