城市化与国民经济发展之关系的理论分析

城市化水平与人均国民生产总值的统计关系在８０年代被建立,从理论上分析这个统计关系能加深对城市与经济发展之关系的理解。从经济学的要素替代和需求收入弹性原理概括了城市化的发展机制,认为任何一个国家或地区的城市化都遵从它。并构造了全国人均国民生产总值与城市人均国民生产总值、乡村人均国民生产总值、城市化水平的关系,它是普适的。如果假设城市、乡村人均国民生产总值的增长分别引起的全国人均国民生产总值的增长总是占据了一个不变的份额,同时,城市人均国民生产总值与乡村人均国民生产总值之差与全国人均国民生产总值成正比,那么,就可以据此演绎出这个统计关系。第二个前提暗示了一个城乡发展差距的倒“Ｕ”字型过程     

Coupling mechanism of activated carbon mixed with dust for flue gas desulfurization and denitrification

To clarify the effect of coking dust, sintering dust and fly ash on the activity of activated carbon for various industrial flue gas desulfurization and denitrification, the coupling mechanism of the mixed activated carbon and dust was investigated to provide theoretical reference for the stable operation. The results show that coking dust had 34% desulfurization efficiency and 10% denitrification efficiency; correspondingly, sintering dust and fly ash had no obvious desulfurization and denitrification activities. For the mixture of activated carbon and dust, the coking dust reduced the desulfurization and denitrification efficiencies by blocking the pores of activated carbon, and its inhibiting effect on activated carbon was larger than its own desulfurization and denitrification activity. The sintering dust also reduced the desulfurization efficiency on the activated carbon while enhancing the denitrification efficiency. Fly ash blocked the pores of activated carbon and reduced its reaction activity. The reaction activity of coking dust mainly came from the surface functional groups, similar to that of activated carbon. The reaction activity of sintering dust mainly came from the oxidative property of Fe₂O₃, which oxidized NO to NO₂ and promoted the fast selectively catalytic reduction (SCR) of NO to form N₂. Sintering dust was activated by the joint action of activated carbon, and both had a coupling function. Sintering dust enhanced the adsorption and oxidation of NO, and activated carbon further promoted the reduction of NO_x by NH₃; thus, the denitrification efficiency increased by 5%-7% on the activated carbon.     

GdFeO3上CO氧化的Redox机理动力学

ＧｄＦｅＯ３用柠檬酸络合制备。用ＸＲＤ测定ＧｄＦｅＯ３为钙钛矿结构。用ＣＯ还原脉冲及用Ｏ２再氧化脉冲证实在ＧｄＦｅＯ３上ＣＯ氧化为Ｒｅｄｏｘ机理。用外循环流动无梯度反应顺研究了ＣＯ氧化稳态动力学。用正交设计法估计动力学方程中的参数。还原催化剂再氧化为控制步骤。     

The impact of government subsidy and tax policy on the competitive decision-making of remanufacturing supply chains

In this paper, we consider a two-period competition model of a remanufacturing supply chain consisting of three members: a new product manufacturer, a recycler and a remanufacturer. The manufacturer supplies new products in the first period and the remanufacturer participates in the competition in the second period. We consider three scenarios in the second period: (1) there is no government subsidy in the competition; (2) there is only government subsidy in the competition; (3) there are both government subsidy and tax in the competition. First, we give the optimal decision-making of the manufacturer, the remanufacturer and the government in the three scenarios; second, we analyse changes in the decision-making of the manufacturer and remanufacturer in the three scenarios and compare their results. We analyse the effects of government subsidy and tax and their asymmetric use on manufacturers’ and remanufacturers’ decision-making variables and competitive performance. We also take consumer awareness of environmental protection into account and examine its impact on subjects’ decisions. Lastly, we operate a numerical example to show the results.     

嘉陵江有毒鱼类的分布研究

为了丰富人们对有毒鱼类的认知,结合8年的调查数据和已有资料对嘉陵江中有毒鱼类的种类、分布和食性进行研究。研究结果发现:在嘉陵江中有毒鱼类共计18种,隶属于4目6科17属,随着分类水平的变化(从目、科、属到种),有毒鱼类在不同分类级别下所占的比例逐渐降低。嘉陵江有毒鱼类中仅圆口铜鱼(Coreius guichenoti)和鳜(Siniperca chuatsi)分布于中下游,其余16种有毒鱼类分布于整个嘉陵江干流。Jaccard’s相似性分析表明各江段有毒鱼类分布的相似性极高,卡方(χ~2)检验结果显示各江段有毒鱼类分布无显著性差异(p0.05)。嘉陵江分布的有毒鱼类共4类,包括卵毒鱼类2种,血清毒鱼类1种,胆毒鱼类9种以及刺毒鱼类7种,其中鲇(Silurus asotus)既属于卵毒鱼类也属于刺毒鱼类,胆毒鱼类全部来源于鲤科鱼类,暂没有发现皮肤黏液毒鱼类。这18种有毒鱼类共包含7种食性类型,主要以杂食性和肉食性类型为主,分别占有毒鱼类种类数的38.89%和33.33%。通过本研究可知,有毒鱼类在嘉陵江中分布广泛,有毒鱼类种类和类别较多。该研究促进了人们对嘉陵江有毒鱼类相关知识的了解,为进一步研究嘉陵江有毒鱼类奠定了基础。     

忻州市土地利用现状的环境敏感区分析

随着新一轮土地利用规划修编展开,针对忻州市土地利用存在的环境问题,利用调查资料和相关研究成果,有效管理土地利用空间向环境敏感地区伸展,减缓环境敏感地区的环境压力和生态胁迫,为市域土地利用方式和分区方案制定提供环境敏感性依据.从规划方案与面临的土地生态问题入手,划分生态环境、水源保护、污染影响、优质农田以及煤矿塌陷五类环境敏感区,并进行忻州市环境敏感地综合评价,明确其空间分布范围.研究结果表明,极高敏感、高敏感区占全市总面积的4%,较高敏感区和一般敏感区分别占10.5%和7.5%,低敏感区和非敏感区分别占40%和38%.通过分析规划土地利用功能分区方案与环境的协调性, 在土地利用规划过程中,提出土地利用方式和空间布局优化对策.     

不同日摄氟量居民罹患氟斑釉的研究

人和动物体内的硬组织（牙齿、骨骼等）是氟化物作用的主要部位,严重者可引起氟骨症和氟斑釉,其中氟斑釉是慢性氟中毒的一项特异指标。通常日摄氟量高的居民其氟斑釉率和斑釉指标均增高。本文用日摄氟量作指标评价环境氟对居民牙齿的影响。研究结果揭示,当地居民的斑釉率和斑釉指数均与日摄氟量呈非常显著的正相关,r＝0.9084,P<0.01。     

杭州西湖底泥释磷的初步研究

为了探讨杭州西湖底泥的释磷状况,通过对钱塘江引水前后西湖水体中总磷浓度的测定,根据物质平衡原则,求得西湖底泥平均释磷速率为3.49mg/m²·d,全湖年释磷量达7.22t。此外用实验室模拟法对底泥释磷的影响因素进行研究,结果表明,温度、pH值和扰动均能不同程度地对底泥释磷产生作用,其中尤以pH值的改变和扰动影响较大;结果还显示,微生物在底泥释磷过程中具有重要的作用。     

用于污水再生利用的生物活性炭床的有机物降解特性

以微生物增殖动力学的基本方程-莫诺方程为出发点,通过氮同位素分析比较了具有同源性微生物的生物陶粒滤床和生物活性炭床的有机物生物降解规律,建立了生物活性炭床的有机物生物降解动力学方程,提出在污水再生利用过程中生物活性炭床符合高基质有机物降解动力学模型,即有机物降解呈一级反应动力学方程。以此方程为基础,分析计算了生物活性炭床沿炭床深度的吸附性能,结果表明,在生物活性炭床中,随生物功能的减弱,生物活性炭床对有机物的吸附能力逐渐加强。     

模拟降雨作用桩锚-加筋土组合结构加固边坡研究

桩锚—加筋土组合支挡结构在治理大型复杂滑坡中发挥越来越重要的角色。以某高填方山区机场滑坡为原型,进行降雨作用对桩锚—加筋土组合支挡结构加固边坡稳定性的模型试验研究。结果表明:①桩顶位移随注水时间产生三个阶段的变化:初期平缓发展阶段、突变增加阶段、再次平缓发展阶段。后排悬臂式桩桩顶位移变化量明显大于前排埋入式桩,因此,多排锚索抗滑桩加固边坡设计时,在后排桩悬臂情况下,宜考虑后排桩比前排桩截面尺寸大、锚索间距小来减小其桩顶位移,增强坡体稳定性;②填方边坡位移随注水时间变化,坡顶一级边坡位移量最大,随边坡级数增加,位移量减小,因此多级边坡加固可适当增加边坡锚索框架;③填方坡体沉降量随注水时间表现出后缘大、前缘小的趋势;④加筋土的变形与边坡坡体的变形一致,表明加筋土能够增强填方边坡的整体性;⑤各监测曲线最终均趋于平缓,表明桩、锚和加筋土组合支挡结构体系性能发挥良好。