乌鲁木齐市耕地面积变化态势及驱动机制分析

[目的]耕地资源是我国乃至世界重要的土地资源,保护耕地数量不减少、质量不降低是我们每个公民义不容易的责任和义务。当前国内外对耕地保护的研究大多仅停留在时间上的比较以及定量的分析,很少对指标因素和时间进行横纵向比较。[方法]文章基于乌鲁木齐市2004~2013年耕地面积,从全市人口、经济、政策投资及科技与城建等4个大类出发,选取18个指标,分析了乌鲁木齐市耕地面积的变化态势和规律。采用主成分和多元回归的分析方法,揭示了耕地面积变化的驱动机制;采用相应的指标体系构建耕地面积变化驱动模型。[结果]研究表明:近10年乌鲁木齐市耕地面积呈减少-增多-减少趋势,而GDP、居民储蓄存款、市区总人口及财政支出是影响耕地面积变化的主要因素。[结论]鉴于此,该研究为乌鲁木齐市土地资源的合理配置、土地利用规划以及耕地资源的科学利用提供决策依据,为实现当地资源、环境与经济的可持续发展提供了新的思路。     

基于DEA-Malmquist的沿海港口转型升级测度及趋势研究

从港口全要素生产效率视角出发,采用Malmquist全要素生产率指数对传统数据包络分析(DEA)方法进行改进,克服了传统DEA方法不能处理不同时期面板数据的缺点,通过构建基于规模报酬可变的DEA-Malmquist模型,可以掌握港口转型升级程度及发展趋势。以山东沿海港口为实例,利用DEA-Malmquist模型进行分析,结果表明:山东省沿海港口的总体效率在2014—2018年整体呈上升趋势;各个港口发展并不平衡;全省港口的Malmquist生产力指数虽然受到了规模效率的制约,但仍呈上升趋势。最后,提出了山东沿海港口转型升级发展的对策建议。     

基于遥感数据的郑州市植被覆盖度变化研究

植被覆盖度是衡量某一地区植被覆盖状况的指标,某一地区的植被覆盖状况会直接影响到该地区的土壤、水分和气候等自然环境要素。随着中原经济区的快速发展,郑州市作为中原经济区的增长极,发展速度很快,城市扩张迅速。为了研究郑州市的快速发展给生态环境带来的影响,选取植被覆盖度这一指标为研究对象,利用不同时间阶段的遥感影像估算郑州市不同时期的植被覆盖度,通过分析植被覆盖度变化来研究郑州市的快速增长对植被覆盖度造成的影响。结论如下:(1)2000年郑州市的植被覆盖度主要以低植被覆盖为主,2014年以中低植被覆盖度为主,高植被和较高植被覆盖度略有提高;(2)从植被覆盖度变化来看,2000—2014年整个研究区植被覆盖度主要以轻微增加为主。     

Discussion of “Information Asymmetries about Measurement Quality”

This article discusses Glover and Levine (2019). It summarizes Glover and Levine's model, its contributions, and practical implications. It also suggests empirical extensions based on the predictions of the model.     

Recombinant Urbanization: Agrarian–urban Landed Property and Uneven Development in India

This article develops the concept of recombinant urbanization to show how agrarian landed property and land‐based caste/class relations shape the production of post‐liberalization urban real estate markets in India. I focus on two interrelated but differentiated agrarian property regimes in western Maharashtra to argue that real estate development is building on prior uneven agrarian land markets, which were themselves sociotechnically produced by colonial and postcolonial development politics. Through an examination of the organizational form of sugar cooperatives, which mediated agrarian capitalism in an earlier era, I track how these primary agricultural cooperatives are now being reorganized into real estate companies, sometimes with former sugarcane growers as company shareholders. The same caste‐based political and social capital that made sugar cooperatives possible in a capitalist agrarian society is now being leveraged by agrarian elites to ease their own and their constituents’ entry into an urbanizing economy. The concept of recombinant urbanization opens new methodological entryways to analyze the entangled agrarian and urban question in predominantly agrarian and late liberalizing societies.     

多壁碳纳米管增强水泥基复合材料力学性能的研究

采用球磨法将多壁碳纳米管均匀分散在水泥基体中,制备出多壁碳纳米管/水泥基复合材料,重点研究碳纳米管的掺量对水泥基复合材料力学性能的影响。实验结果表明:当多壁碳纳米管掺量为0.10 wt%时,多壁碳纳米管/水泥基复合材料3 d的抗压强度和抗折强度较空白对照组分别提高了22.00%和25.36%。在一定组成范围内,分散性良好的多壁碳纳米管,显著改善了水泥基复合材料的力学性能。     

Final production-based emissions of regions in China

Existing studies focus on either direct emissions of each province in China using production-based accounting (i.e. direct emitters) or emissions caused by the final consumption of each province using consumption-based accounting (i.e. final consumers), but overlook provinces whose final sales drive large amounts of upstream emissions (i.e. final producers). Improving the production efficiency of the latter can help to reduce national emissions. Here we use a final production-based accounting framework to identify critical final producers. Results show that the major final producers leading to China’s emissions are Hebei, Shandong, Jiangsu, Zhejiang, and Guangdong, which are the major manufacturing centers in China. China should encourage the production efficiency improvement of dominant firms in industries of these provinces. The final production-based accounting framework can also help to define and allocate emission responsibilities of Chinese provinces. It can complement production-based and consumption-based accounting frameworks to guide environmental policy-making in China.     

我国抵押权立法之完善

在《担保法》中禁止重复抵押有失科学性 ,设置提前清偿制度也不尽合理。完善我国抵押权立法应规定抵押权行使的除斥期间 ,并设置抵押合同的担保期限。     

Why Do Firms Enter into a New Niche Market? An Integrated View of Objective and Subjective Antecedents of Strategic Decisions

This study is based on behavioral theories and has the purpose of determining the predictors and contingencies of strategic decision making within the strategic tripod framework and CEO age effect. Furthermore, we focus on the effect of the interaction of these aspects on strategic decisions. Multiple theories and concepts are applied in this paper, such as the institution-, industry-, and resource-based view, upper echelons theory, socio-emotional wealth, empathy, and so on. Specifically, we focus on why Chinese real estate firms decide to enter the aged housing market. By conducting an empirical study using panel data from 134 listed Chinese real estate companies, we make the following conclusions: Institutional pressure and competitor numbers positively affect, whereas slack harms, the likelihood of entry. Ceteris paribus, the resource effect is strongest when the institutional effect is the most significant. When facing institutional pressure, a firm with a CEO older than 50 is significantly more likely to enter the aged housing market than firms with a CEO that is younger.Relieving institutional pressure and avoiding cutthroat competition are helpful in making strategic decisions but not for digesting slack resources. The CEO makes strategic decisions by replying to institutional pressure but likely not from engagements in resource or competitive affairs.     

我国税收政策对经济增长的非线性效应研究——基于总量与结构效应双重视角的实证分析

全面分析与科学把握我国税收政策方向与节奏不仅事关政府宏观调控与驾驭经济能力的提升,更是实现有质量、有效益、可持续经济增长的关键。文章首先基于创新驱动经济增长的内生增长模型构建税收对经济增长影响的理论分析框架,然后采用MS-VAR模型与利用中国季度数据,从总量与结构双重视角实证考察我国税收政策对经济增长的影响,结果发现：一是当处于区制1时,无论是税收的总量抑或结构效应,均表现出非凯恩斯主义特征,但并不显著;二是当位于区制2时,税收对经济增长的总量影响表现为凯恩斯效应,而商品税与所得税对经济增长的影响存在显著差异。其中商品税与经济增长正相关,所得税与经济增长负相关。另外无论是税收的总量效应抑或结构效应,在继续维持各自区制内的稳定性方面表现都非常强,从一个区制向另一个区制发生转换的概率非常小。文章研究结论对于创新政府宏观调控方式与增强税收政策调控的前瞻性、针对性与有效性具有非常重要的理论与实际意义。