辽宁省经济发展与环境关系的实证研究

维持经济的持续稳定增长是我国的重要政策目标,然而面对日趋严峻的资源、环境制约,大力推进生态文明建设已刻不容缓。相应地,在理论方面,研究经济增长与环境污染的双向作用机制也非常必要。利用VAR模型,研究了辽宁省经济发展与环境之间的关系,发现两者之间的关系并不是EKC理论中所说的倒u型曲线,而是呈现w型、N型等更加复杂的曲线形状。实验结果也表明辽宁省环境与经济存在双向作用机制,其中,废气与废水对辽宁省经济增长影响最大。     

生物过滤塔净化甲醛废气的动力学研究

选用榛子壳作为反应器的填料,利用沈阳北部污水处理厂的活性污泥对填料进行挂膜,由低到高通入甲醛气体进行驯化。在系统稳定后进行了生物过滤塔净化甲醛气体的实验研究,并建立了生物过滤塔降解甲醛气体的动力学模型。结果表明,入口气体浓度在低于25mg/m3时,甲醛废气的净化效率可保持在97％以上,超过此浓度值时,效率明显下降。随着进口气体流量的增加,净化率逐渐下降,由入口流量为0．2m3／h时的97．25％下降到入口流量为0．8m弧时的57．2％。根据现有动力学模型及本实验得出数据所建立的生物过滤塔净化甲醛气体的动力学模型,可以较好地模拟系统处理甲醛废气的实验结果,验证了模型的正确性。     

一株抗Cd~（2＋）菌株的筛选及其吸附性能

Cd2＋为一种毒性金属元素,为了实际解决污水中低浓度重金属污染,实现污水达标排放,通过12C6＋重离子束辐照诱变技术筛选到一株耐受Cd2＋的菌株C2,研究其对Cd2＋的抗性和低浓度Cd2＋的吸附性能表明,Cd2＋浓度≤100 mg/L时,C2菌株可以生长繁殖,但随Cd2＋浓度升高受到抑制;SEM分析表明,受到Cd2＋胁迫时,C2产生大量胞外产物与Cd2＋形成络合物;吸附过程中菌粉表面空隙得到填充,形成凸起;红外光谱分析表明,吸附过程中的主要作用基团为醇羟基O—H键、氨基和酰胺基团;C2菌粉和固定化菌球都对Cd2＋有较好的吸附能力,菌粉吸附效果比固定化菌球稍好;菌粉和固定化吸附剂的最佳吸附初始pH值为5~6.0,最佳投加量分别为1.0 g/L和10 g/L（实际含菌量为1.0 g/L）;Cd2＋浓度在2~20mg/L时,在最佳吸附条件下,菌粉和固定化吸附剂对Cd2＋的吸附率均在90%左右;2种吸附剂吸附过程与Langmuir等温模型和拟二级动力学模型拟合最佳;热力学研究表明吸附反应均能自发进行。以上研究结果表明,C2菌粉和固定化吸附剂均可用于污水中低浓度Cd2＋的去除。     

Modeling channel management impacts on river migration: a case study of Woodson bridge state recreation area,Sacramento river,California, USA

Understanding how hydraulic factors control alluvial river meander migration can help resource managers evaluate the long-term effects of floodplain management and bank stabilization measures. Using a numerical model based on the mechanics of flow and sediment transport in curved river channels, we predict 50 years of channel migration and suggest the planning and ecological implications of that migration for a 6.4-km reach (river miles 218–222) of the Sacramento River near the Woodson Bridge State Recreation Area, California, USA. Using four different channel management scenarios, our channel migration simulations suggest that: (1) channel stabilization alters the future channel planform locally and downstream from the stabilization; (2) rock revetment currently on the bank upstream from the Woodson Bridge recreation area causes more erosion of the channel bank at the recreation area than if the revetment were not present; (3) relocating the channel to the west and allowing subsequent unconstrained river migration relieves the erosion pressure in the Woodson Bridge area; (4) the subsequent migration reworks (erodes along one river bank and replaces new floodplain along the other) 26.5 ha of land; and (5) the river will rework between 8.5 and 48.5 ha of land in the study reach (over the course of 50 years), depending on the bank stabilization plan used. The reworking of floodplain lands is an important riparian ecosystem function that maintains habitat heterogeneity, an essential factor for the long-term survival of several threatened and endangered animal species in the Sacramento River area.     

乡镇环境保护的“角直模式”

本文分析了江苏省角直镇乡镇经济腾飞与环境保护协调同步的发展过程,总结出了“统一规划、合理布局、集中控制、全面管理、环境保护与经济建设协调发展”的“角直模式”,并就模式的优缺点作了一定程度的探讨.     

The Impact of Increased Environmental Stochasticity Due to Climate Change on the Dynamics of Asiatic Wild Ass

Abstract:  Theory proposes that increased environmental stochasticity negatively impacts population viability. Thus, in addition to the directional changes predicted for weather parameters under global climate change (GCC), the increase in variance of these parameters may also have a negative effect on biodiversity. As a case study, we assessed the impact of interannual variance in precipitation on the viability of an Asiatic wild ass ( Equus hemionus ) population reintroduced in Makhtesh Ramon Nature Reserve, Israel. We monitored the population from 1985 to 1999 to determine what environmental factors affect reproductive success. Annual precipitation during the year before conception, drought conditions during gestation, and population size determined reproductive success. We used the parameters derived from this model to assess population performance under various scenarios in a Leslie matrix type model with demographic and environmental stochasticity. Specifically, we used a change in the precipitation regime in our study area to formulate a GCC scenario and compared the simulated dynamics of the population with a no-change scenario. The coefficient of variation in population size under the global change scenario was 30% higher than under the no-change scenario. Minor die-offs (≥15%) following droughts increased extinction probability nearly 10-fold. Our results support the idea that an increase in environmental stochasticity due to GCC may, in itself, pose a significant threat to biodiversity.     

基于24Model-D-ISM的地铁站火灾疏散影响因素研究

为预防地铁站火灾事故,深入了解地铁站火灾人员疏散影响因素间的内在联系与层次结构,基于第6版“2-4”模型(24Model)分析63起地铁站火灾疏散事故,充分考虑各个因素之间的交互作用,提取19个影响地铁站人员疏散的关键因素,建立地铁站火灾人员疏散影响因素指标体系;采用算子客观赋权法(C-OWA)改进决策试验与评价实验法(DEMATEL),确定地铁站火灾人员疏散的重要影响因素;在此基础上,采用解释结构模型(ISM)分析各个因素间的层次结构及相互作用路径,构建地铁站火灾人员疏散影响因素的多级递阶结构模型。研究结果表明：疏散引导、恐慌从众行为、人员拥挤为地铁站火灾人员疏散的关键影响因素;地铁站火灾人员疏散受表层因素、中间层因素、深层因素共同作用的影响,其中,疏散教育与培训、设施维护与检查、疏散预案等因素是根源影响因素,重视根源影响因素的改善有利于从本质上预防和控制事故的发生。     

河套灌区土壤砷含量的季节变化特征模拟

土壤砷（As）是河套灌区粮食安全生产的潜在风险,开展土壤As含量的时空分异机制研究具有重要意义.基于随机森林（RF）和SHAP模型,利用气候、遥感和地形等特征变量对河套灌区秋季采样点土壤As含量进行模拟和解释,并根据气候因子和遥感因子等特征变量的季节变化,对夏季土壤As含量进行预测.结果表明：河套灌区土壤As含量主要受潜在蒸发量、植被指数和高程影响;在中部和东部地势较平缓的地区, 与夏季相比,秋季大部分样点土壤As含量增加;而在地势较高的西部,与夏季相比,秋季土壤As含量降低.本研究结果能够为大尺度土壤As的季节变化预测提供科学依据.     

基于土地利用回归模型的场地土壤污染特征分析

通过在广东韶关凡口铅锌矿向外辐射8 km²范围内布设25个采样点,监测土壤中Pb、Zn、As、Cu、Cr和Hg的质量比,构建土地利用回归(LUR)模型模拟该6种元素质量比的空间分布。结果表明：不同土壤元素质量比受地理要素影响差异较大,Pb和As的空间分布受道路影响较大,其高值区沿道路呈带状分布;Zn和Cu受自然因素与土地利用的综合影响,高值分布相对零散;Cr的空间分布主要受地形降水等自然因子的影响。研究区整体元素质量比偏低,西部地区元素质量比低于东部地区,南部地区低于北部地区。     

“因商而游”亦或“寻文而至”？

客观评估“一带一路”倡议对中国入境旅游业影响效应,系统梳理该影响的作用机制对推动中国入境旅游发展具有指导意义。文章以“一带一路”倡议实施为准自然实验,使用104国2010—2019年的国际面板数据,建构双重差分模型,并基于经济联系与文化交流视角,使用中介效应和文本挖掘与分析的方法检验作用机制,借鉴调节效应的思路探索机制内可能的交互影响。结论如下：①“一带一路”倡议显著增加了15.03%~30.10%的沿线国家来华旅游人次,促进了中国入境旅游发展。②国际贸易在此促进中发挥中介效用,且相比于进口贸易的中介效应占比39.17%,沿线各国出口贸易中介效应占比为47.05%,对中国入境旅游业影响更大。③文化认同在此促进中发挥中介效用,且“一带一路”倡议对文化认同的影响呈现“三核六调众要素”的方式,热点集中于汉语学习、教育、艺术、中医、电影、出版等方面。④“因商而游”和“寻文而至”的机制并存,且存在着正向的交互影响,沿线各国出口贸易下两者的交互影响大于进口贸易。