Monitoring seasonal distribution of an endangered anadromous sturgeon in a large river using environmental DNA

Monitoring dynamic distribution is crucial to conservation management of anadromous sturgeons, but traditional survey methods are less efficient for low-density populations in a large river. Natural propagation of Chinese sturgeon has been monitored annually mainly at the spawning ground using netting for eggs and hydroacoustics for broodstock. However, absence of spawning was observed sporadically in recent years, indicating further crises for the declining population. We analyzed eDNA of water samples collected from 24 sites across 1360 km of the migratory route of anadromous Chinese sturgeon in the middle and lower reaches of the Yangtze River. Chinese sturgeon was detected at 9 sites during the spawning season and 14 sites after the spawning season. We found that positive eDNA detection rates remained constant in the middle reaches but dramatically changed in the lower reaches, reflecting seasonal migration pattern of Chinese sturgeon. Invasive sturgeons were detected in the river, indicating their possible escape from aquaculture facilities. This study established a protocol for the use of eDNA to monitor distribution of Chinese sturgeon and could be valuable in making better policies for the conservation of this endangered species.     

The combination of subsoil and the incorporation of corn stover affect physicochemical properties of soil and corn yield in semi-arid China

ABSTRACT

The main objective of this study was to investigate the effects of combining subsoil and incorporation of corn stover on soil profile, soil physicochemical properties, and corn yield. A five-year field trial was conducted that consisted of two treatments arranged in a completely random design and replicated three times. Two soil management operations were tested: subsoil + corn stover incorporation (plow construction [PC] treatment) and conventional rotary tillage (control check [CK] treatment). Compared with rotary tillage, it was found that combining subsoil and corn stover incorporation significantly affected corn grain yield in all seasons. Further, combining subsoil and corn stover incorporation significantly increased the thickness of the plow layer, quantity of plow layer soil, thickness of the plow pan and soil bulk density, as well as soil organic matter, available nitrogen, available phosphorus, and available potassium. Evidence indicates that reconstructing the soil plow layer through combination of subsoil and corn stover incorporation improved soil structure, nutrient content, and corn yield. It is of interest that farmers are now applying subsoil and returning crop straw instead of solely relying on rotary tillage.     

空心壳聚糖微球对二甲酚橙的吸附性能研究

以生物可降解的壳聚糖为原料,采用反相悬浮交联法制备了具有空壳结构的壳聚糖微球,通过控制反应条件得到单分散性的微米级微球.通过分光光度法探讨了溶液初始pH、吸附时间、二甲酚橙初始浓度、壳聚糖微球用量及其直径对壳聚糖微球吸附二甲酚橙的影响.结果表明,常温下壳聚糖微球对二甲酚橙的最佳吸附条件为:溶液初始pH为5,吸附时间为2.0 h,二甲酚橙初始质量浓度为32 mg/L,壳聚糖微球用量为0.3 g/L(以每升二甲酚橙溶液计),壳聚糖微球直径为74 靘;在此最佳吸附条件下,采用分光光度法对二甲酚橙模拟废水进行测定,相应的回收率误差均在-1%～1%.     

浅论环境保护公众参与信息发布系统的构建

公众参与是环境保护工作一项重要内容。从中国实际情况来看，公众参与信息发布方式与手段已不能适应经济、社会发展的要求。本文主要介绍了基于应用信息网络技术改进公共服务，重组公共组织，提高公共参与的原理和涉及的相关技术。讨论了利用面向对象的分析和设计方法、分布式数据库技术、三层结构的网站建设技术、C／S和B／S网络技术结合移动通讯和网络接口技术的公众参与信息发布系统设计，探讨利用互联网及移动通讯技术实现公众便捷地参与对专项规划和建设项目环境影响评价的模式。     

论水工程设施收集的水资源的所有权归属

雨水收集设施等水工程日益得到应用,需要解决雨水收集设施等水工程设施收集的水资源的所有权。因大气降水是一种自由资源,不属于《宪法》中的"水流"或《水法》中的"水资源"的范畴,雨水收集设施等水工程设施收集的水资源所有权不能适用《宪法》、《水法》的规定,而是取决于雨水收集设施等水工程设施的所有权。雨水收集设施等水工程设施不是土地的组成部分,所有权包括国家所有、集体所有、其他组织和个人所有等形式,因此,雨水收集设施等水工程设施收集的水资源所有权自然包括国家所有、集体所有、其他组织和个人所有。但水工程设施不是公益性、大中型的水利设施,允许其他投资主体投资,其所有权应以集体、个人所有为主要形式     

防灾减灾的基础研究及应用研究进展概况

人类社会是在对自然灾害的不断斗争中得到发展。近代由于全球人口的迅速增长和城市化程度的提高，自然灾害的损失也在急剧增加。防灾减灾是减轻灾害损失、保障社会可持续发展的系统工程。当前灾害监测技术、灾害的形成和发展规律、灾情评估方法、灾害管理及灾害对社会经济的影响等方面的基础研究及应用研究已有了不小的进展。本文概括地介绍了这些进展，并指出了防灾减灾工作中存在的一些问题及对策     

从醇后气中回收淡甲醇

在甲醇分离器后设置淡甲醇回收装置回收醇后收醇后的中甲醇，其回收率达到８７．５％，同时大大降低了排放地沟的稀氨水中的甲醇含量，减轻了稀氨水对环境的污染，有较好的经济效益和环境效益。     

乙烯撑二氨基苯磺酸生产中磺化废酸的处理

对乙烯撑二氨基苯磺酸生产过程中产生的磺化废酸采用浓缩法进行处理,得到的浓硫酸顺生产中使用。废酸浓缩装置的工艺简单,投资少,建设周期短,运行平稳,１年内即可收回投资,经济效益显著。该装置的建成投产,大大改善了周围环境,具有明显的环境效益。