Does the GreenWatch program work? Evidence from a developed area in China

The GreenWatch program has been implemented nationally in China. However, whether the program and its process have been effective in improving firms' environmental performance remains unclear. Based on the stakeholder theory, this paper conducts a comparative analysis between firms participating in the program and those that do not, all of which are based in Changshu City in the developed part of Jiangsu Province, China. Data suggest that GreenWatch encourages firms to improve and disclose their environmental performance. Through pressures imposed by different stakeholders—from the government, investors, and consumers, to the public, such as the community and media—this program has become the main driving force for improving the firms' environmental performance. The current study also provides substantial evidence that public disclosure in China opens up channels for effective public participation. Therefore, the GreenWatch program deserves to be promoted in China.     

货物列车空车直线地段脱轨机理分析与预防

对货物列车空车直线地段脱轨机理进行探讨 ,笔者认为脱轨是由于车辆蛇形运动波长与线路横向不平顺波长比例不合适或车辆蛇形运动频率与车辆轮对或转向架横向固有频率相等而产生横向共振导致。因此 ,提出提高线路横向不平顺标准 ,尤其是要消除连续性、周期性的反向波 ,对转 8A转向架结构上的缺陷进行改进 ,减小两钢轨间距以及从车辆部门获得轮对与转向架的横向固有频率等预防措施 ,设法避开根据上述机理所算得的列车共振临界速度 ,以尽量减少或消除货物列车脱轨事故。     

珍珠岩对蚯蚓同步处理污泥-狐尾藻的研究

本研究利用太平二号蚯蚓构建生物反应器,以污水处理厂脱水污泥和粉绿狐尾藻作为研究对象,探究添加不同比例的珍珠岩对蚯蚓动物反应器处理混合物的减量化、无害化和资源化效果.结果表明,添加珍珠岩能够显著提高蚯蚓动物反应器同步处理污泥-狐尾藻的效率,经反应器处理后,混合物减量化效果明显,处理后产物的pH、有机质、碱解氮和重金属含量(Cu、Pb、Cr)均表现为明显下降,电导率(EC)和速效磷显著上升.经反应器处理后,产物品质符合在pH6.5的中性和碱性土壤上的施用标准.结果显示,当珍珠岩添加比例为4%时,对动物反应器的实用性和经济性效果最佳.     

地震作用下土⁃结构相互作用的简化时程分析∗

基于黏弹性边界和将场地地震反应转化为等效荷载的有限元直接法是目前进行土?结构相互作用分析的常用时程分析方法之一。该方法具有严格的理论基础且计算精度较高,但在商业有限元软件中施加黏弹性边界和由场地反应确定的等效地震荷载时,需要使用者编制程序书写命令流文件。本文建议一种动力时程简化分析模型, 即计算模型侧边界采用滚轴或绑定边界、底边界强制自由场反应。首先基于一维等效线性化场地反应分析软件 EERA,明确了分别给定岩石地表记录、基岩记录和场地地表记录条件下,正确实现场地反应分析的做法,表明在相同地震下三种分析能够得到相同的场地反应结果;然后给出动力时程简化分析过程;最后通过一层两跨地铁车站的地震分析,表明该方法具有较高精度,满足工程需求。     

菹草和伊乐藻对水-沉积物界面磷迁移转化的影响

冬季沉水植物普遍凋亡,死亡残体易造成湖泊二次污染.为探究冬季耐寒性沉水植物对水-沉积物界面各形态磷迁移转化的影响,选取根系特征不同的冬季耐寒性沉水植物菹草（Potamogeton crispus L.）和伊乐藻（Elodea nuttallii）作为研究对象,测定其冬季生长期间上覆水、间隙水和沉积物中各形态磷的含量,并监测环境因子的变化.结果表明:①菹草、伊乐藻组生长期间水-沉积物界面各形态磷含量总体呈下降趋势,并在一定时期维持较低水平,菹草对沉积物和间隙水磷的吸收效果优于伊乐藻,而伊乐藻对上覆水磷的影响大于菹草.②试验第30天后,菹草、伊乐藻组上覆水和间隙水各形态磷质量浓度均显著低于对照组（P < 0.05）,上覆水中ρ（TP）最低值分别为0.057和0.041 mg/L,间隙水中ρ（DTP）（DTP表示溶解性总磷）分别维持在0.270~0.505、0.384~0.507 mg/L之间.③试验结束时,菹草组沉积物中w（TP）、w（IP）（IP表示无机磷）和w（NaOH-P）（NaOH-P表示NaOH提取态磷）分别低至643.68、415.79和120.17 mg/kg,分别下降了16.54%、18.37%和35.82%,伊乐藻组分别低至700.39、457.87和145.29 mg/kg,分别下降了10.24%、11.17%和24.67%;菹草、伊乐藻植株体内TP质量分别增加了588.94和464.59 mg.研究显示,菹草、伊乐藻在生长期间均能有效吸收磷,同时改变了pH、E_h等环境因子,从而影响磷在水-沉积物界面的迁移及磷形态的转变.      

格子玻尔兹曼方法(LBM)及其在微通道绕流中的应用

介绍了格子玻尔兹曼方法基本理论与计算方法,并建立了D2Q9计算模型,对宏观尺度及微通道中的非稳态绕流进行了数值模拟,得到了绕流过程的速度分布和涡量分布等信息,对流场结构、固体阻力、尾涡脱落等变化规律进行了分析。结果表明,格子玻尔兹曼方法以其计算稳定、效率高等优势能够应用于微反应器领域的数值模拟;同等液相停留时间条件下,微反应器中的圆柱绕流湍动程度明显降低,未形成周期性涡流,流动更加均匀稳定,有助于实现化学反应的精确控制。     

Optimization via response surface methodology of the synthesis of a dust suppressant and its performance characterization for use in open cut coal mines

To relieve dust pollution in open cut coal mines and reduce the hazards of coal dust pollution to the environment and workers we optimized the synthesis of a dust suppressant by graft copolymerization of environmentally friendly soy protein isolate with methyl methacrylate. This dust suppressant could effectively control dust pollution in open cut coal mines. The optimized conditions for graft copolymerization in this case were determined by a response surface experiment designed with Design-Expert 10 software. Characterization by scanning electron microscopy showed a significant morphology change of the dust suppressant and the generation of a rigid and dense layer on its surface after interacting with coal dust. The layer exhibited good bonding and dust suppression performance. The analysis with Fourier-transform infrared spectroscopy revealed the appearance of new absorption peaks near 1300, 1072, and 1631 cm⁻¹, demonstrating effective graft copolymerization. The proposed dust suppressant exhibited excellent wind erosion resistance, with a resistance that exceeded 90% at a wind speed of 6.5 m/sec. The successful graft copolymerization and effective bonding and curing of the dust suppressant on coal dust were experimentally verified. This is of great significance to the control of coal dust pollution.     

盐沼植物群落研究进展：分布、演替及影响因子

盐沼是全球温带及亚热带地区的主要滨海湿地类型之一,在我国分布广泛。盐沼湿地生态系统敏感、脆弱且具有重要的生态系统服务功能。理解盐沼植物群落时空分布动态的一般规律与生态学机制,是开展盐沼生态系统研究的基础与关键。海陆交界的特殊环境特征是影响盐沼湿地植物群落的空间分布及演替过程的主要因素。在海洋潮汐作用下,盐沼湿地中的盐度、水淹强度、氧化还原电位等非生物因子往往呈梯度分布,这也导致了生物群落中种内、种间关系的变化。在非生物及生物因子的共同作用下,盐沼植物群落也往往沿高程梯度呈带状分布。环境变化是盐沼植物群落演替的驱动因素,在海岸线相对较为稳定的盐沼,植物群落的演替多属自发演替,而在靠近的大型河口的一些持续淤涨的盐沼,植物群落演替通常属于异发演替。沿海地区的水产业、流域上游及沿海地区的工程、污染及生物入侵等直接或间接的人类活动已对盐沼湿地植物群落的产生了深刻影响。经过数十年发展,国际上盐沼植物群落学研究的热点领域主要包括盐沼植物群落与其他生物群落的相互关系、植物群落在盐沼生态系统过程中的作用等。在全球变化背景下,盐沼植物群落对气候变化与海平面升高也日益成为盐沼植物群落学相关的热点。     

‘Effortless Perfection:’ Do Chinese cities manipulate air pollution data?

This paper uses unique data on daily air pollution concentrations over the period 2001–2010 to test for manipulation in self-reported data by Chinese cities. First, we employ a discontinuity test to detect evidence consistent with data manipulation. Then, we propose a panel matching approach to identify the conditions under which irregularities may occur. We find that about 50% of cities reported dubious PM₁₀ pollution levels that led to a discontinuity at the cut-off. Suspicious data reporting tends to occur on days when the anomaly is least detectable. Our findings indicate that the official daily air pollution data are not well behaved, which provides suggestive evidence of manipulation.     

Toward efficient riparian restoration: integrating economic, physical, and biological models

This paper integrates economic, biological, and physical models to explore the efficient combination and spatial allocation of conservation efforts to protect water quality and increase salmonid populations in the Grande Ronde basin, Oregon. We focus on the effects of shade on water temperatures and the subsequent impacts on endangered juvenile salmonid populations. The integrated modeling system consists of a physical model that links riparian conditions and hydrological characteristics to water temperature; a biological model that links water temperature and riparian conditions to salmonid abundance, and an economic model that incorporates both physical and biological models to estimate minimum cost allocations of conservation efforts. Our findings indicate that conservation alternatives such as passive and active riparian restoration, the width of riparian restoration zones, and the types of vegetation used in restoration activities should be selected based on the spatial distribution of riparian characteristics in the basin. The relative effectiveness of passive and active restoration plays an important role in determining the efficient allocations of conservation efforts. The time frame considered in the restoration efforts and the magnitude of desired temperature reductions also affect the efficient combinations of restoration activities. If the objective of conservation efforts is to maximize fish populations, then fishery benefits should be directly targeted. Targeting other criterion such as water temperatures would result in different allocations of conservation efforts, and therefore are not generally efficient.