毛竹水溶性多糖提取工艺的优化及结构表征

采用响应面法优化毛竹水溶性多糖的提取工艺,分析其成分,并进行结构表征。研究结果表明,优化的毛竹多糖(BSP)提取条件为:料液比1∶27(g/mL)、提取温度78 ℃、提取时间4 h,该条件下BSP提取率为(5.18±0.07)%,提取物中多糖含量为(72.14±0.02)%,糖醛酸含量为(9.76±0.03)%;BSP具有酸性多糖典型的官能团特征吸收峰,其单糖组成及摩尔比为n_甘露糖∶n_葡萄糖∶n_阿拉伯糖∶n_木糖∶n_鼠李糖∶n_半乳糖=62.52∶23.05∶10.35∶2.78∶0.79∶0.51;BSP由两个主峰组成,相对分子质量分别为91.11、4.55 kDa。BSP是一种混合酸性多糖。     

Do environmental regulations hamper small enterprises' market entry? Evidence from China

Due to the serious increase of environmental pollution in China, environmental regulations have become significantly stringent. Such regulations are playing an increasingly important role in the development of small enterprises (SEs) in China, especially in SEs' market entry. However, existing studies pay little attention to this issue. This paper investigates for the first time the effect of environmental regulations on SEs' market entry and the mechanism of environmental regulation effects in China. We consider two sets of panel data for the periods 2003–2010 and 2012–2015 in China. We also use the fixed effect model and the instrumental variable method to explore the role of environmental regulations in SEs' market entry. The results show that, overall, environmental regulations play a significantly positive and robust role in SEs' market entry. However, the mechanisms associated with the effect of environmental regulations on different innovative types of SEs differ. Environmental regulations promote the market entry of SEs with product innovation, but this impact is not significant for SEs with research and development (R&D) activities and R&D institutions. Our findings indicate that China's SEs prefer product innovation, which is a lower level innovative type, over R&D innovation, as a means to avoid the negative impact of stringent environmental regulations.     

The ABC mechanism: an incentive compatible payoff mechanism for elicitation of outcome and probability transformations

When it comes to experiments with multiple-round decisions under risk, the current payoff mechanisms are incentive compatible with either outcome weighting theories or probability weighting theories, but not both. In this paper, I introduce a new payoff mechanism, the Accumulative Best Choice (“ABC”) mechanism that is incentive compatible for all rational risk preferences. I also identify three necessary and sufficient conditions for a payoff mechanism to be incentive compatible for all models of decision under risk with complete and transitive preferences. I show that ABC is the unique incentive compatible mechanism for rational risk preferences in a multiple-task setting. In addition, I test empirical validity of the ABC mechanism in the lab. The results from both a choice pattern experiment and a preference (structural) estimation experiment show that individual choices under the ABC mechanism are statistically not different from those observed with the one-round task experimental design. The ABC mechanism supports unbiased elicitation of both outcome and probability transformations as well as testing alternative decision models that do or do not include the independence axiom.

     

The effects of COVID-19 containment measures on the Asia-Pacific region

As the COVID-19 pandemic spread across the world, governments introduced significant containment measures to control the spread of the virus. In this paper, we leverage inputs from IMF desk economists to construct a novel narrative index of containment measures for 11 countries in the Asia-Pacific region. A key innovation in our index is that it distinguishes between economic sectors (services, industry, retail), thus providing a more granular view of restrictions related to economic activity. Using this index, along with other high-frequency data, we find that containment measures have been successful in reducing the spread of the virus (though with some heterogeneity) but have also been associated with large short-term economic costs. Furthermore, exploiting the granularity of our index, we find that differences in strategies across countries regarding the closing of the industrial sector have mattered: imposing less severe restrictions on industry has been associated with lower economic costs without leading to worse health outcomes, possibly reflecting the less contact intensive nature of industrial activity.     

National response strategies and marketing innovations during the COVID-19 pandemic

During the COVID-19 pandemic, different nations have adopted a variety of response strategies to fight and contain the new coronavirus. Such national response strategies can be classified into three categories based on their underlying philosophy: strict control with unlimited resources, relentless contribution with limited resources, and rough rationality with limited resources. We discuss the philosophies, characteristics, and performances of the three response strategies and when they should be adopted. We also examine what marketing innovation strategies enterprises should adopt to survive and grow their businesses in both the short and long term. This study provides important strategic implications for national policymakers and enterprises on the use of response strategies as well as marketing innovation tactics and strategies to be used both during and after the pandemic.     

Rewriting China’s Recent History: Fluctuations in State Economic Control, 1949–1984

China's political and economic systems are often discussed in combination. It is generally believed that under the political system of centralization, the economic system had to be a state monopoly. This article challenges that view by providing an economic perspective. The period 1949–1984 is selected to explore the causes of successive periods of strengthening and weakening of the state's monopoly power over the economy. Scholars have generally assumed that the period of state monopoly originated from socialist ideology or the personal will of the leaders. But economic conditions severely limited the options available. After the new China was established, the Chinese Communist Party (CCP) did not try to create a fully socialist economy in the short run. Instead, the CCP formulated a New Democracy platform that pragmatically allowed many types of enterprise to function side by side, including private industry, household ventures, and state‐owned enterprises. The original plan of the CCP was to allow private enterprise to develop in order to build up capital to rebuild the war‐damaged economy so that a strong foundation could be established for creating a socialist economy. But the Korean War from 1950 to 1953 and an influx of Soviet capital caused a shift from a mixed economy to state capitalism by 1956. From that point on, Mao Zedong and other Chinese leaders had to change course again and again as fiscal crises limited available options. A reversal occurred in 1958 when the Soviets withdrew both their advisors and their capital subsidies, leaving the state capitalist system weakened. The crisis in the Chinese economy from 1959 to 1961 required decentralization of economic authority and efforts to promote rural capital formation. The next shift occurred after 1963 as the economy was organized to prepare for a possible military invasion. The required mobilization of industrial resources in remote regions of China inevitably reinforced state management of the economy. The final reversal occurred in the late 1970s, when imports of Western technology and equipment created another fiscal crisis for the central government, which then had to shift the burden of capital formation from the state to private entities. The reform of the rural household contract system, the adjustment of economic structures, and an increase in exports to gain foreign exchange all took place as part of “de‐monopolization” reforms. The reforms that occurred after 1979 were not an aberration or a radical break from the past. They were part of a pattern that evolved from 1949 to 1984, with fluctuations dependent on the weakening and strengthening status of state finances. The shifts that occurred during this period have either been ignored by observers, or they have been misinterpreted as being motivated by ideology. In fact, new policies were created to enable the government to adjust to changes in the internal and external environment.     

Covariance breakdowns and connectedness of crude oil futures markets with non-synchronous data

ABSTRACT

This article identifies the breakdowns in the covariance of three benchmark crude oil futures markets (WTI, Brent and Dubai) and investigates the changes of market connectedness across the breakdown periods. As the crude oil futures are traded in different regions, this article eliminates the non-synchronous trading data by employing the Vector Moving Average structure and the Bayesian data augmentation approach, which keeps the integrity of original data without changing its properties. The results show that there are significant breaks in the covariance structure of crude oil futures markets. The breakdown periods are consistent with the periods when the market volatilities are at high level and the returns are volatile. The changes of market connectedness are independent of the covariance states, which supports the globalization hypothesis for the crude oil market. The results also suggest that there is more information flow out of the WTI than to the WTI during the sample period, particularly during the breakdown periods in 2008–2009.     

乡村振兴背景下乡村旅游环境正义实现途径

［目的］为改变乡村旅游非生态化发展的现状，全面实现乡村振兴。［方法］结合使用文献综述法和实地调研法，基于环境正义理论，将环境问题与社会正义结合起来分析乡村旅游环境问题产生的根源。［结果］一直以来，乡村旅游作为实现乡村振兴的重要方式都过于追求经济效益，而忽视了给乡村旅游地及其周边区域带来的环境污染和生态破坏，造成乡村旅游种际环境非正义和人际环境非正义。［结论］代内人际环境正义的实现是解决乡村旅游环境问题的关键，确保未来乡村旅游发展的环境正义导向和矫正当前存在的环境非正义是必须同时兼顾的两个方面。实现乡村旅游环境正义，一方面应增强主体的环境正义意识、构建公正的环境相关制度以确保乡村旅游未来发展的环境公正导向，另一方面应探索建立乡村旅游生态补偿制度对已经造成或现阶段无法避免的环境非正义结果进行矫正，实现补偿正义。     

环境公平感知、社会信任与农户低碳生产行为*——以农膜、秸秆处理为例

［目的］研究旨在探讨环境公平感知和社会信任与农户低碳生产行为之间的关系，为促进农户生产行为向低碳化方向转变提供对策建议。［方法］基于陕西和甘肃两省的村域调查数据，以农膜和秸秆处理为例，运用二元logistic模型探讨环境公平感知和社会信任对农户低碳生产行为的影响，并结合分层回归分析了社会信任在环境公平感知和农户低碳生产行为间的调节效应。［结果］（1）在环境公平感知维度中，人际公平感知正向影响农户的农膜和秸秆处理行为； （2）对社会信任来讲，人际信任对农户农膜和秸秆处理行为均有显著的促进作用，而制度信任仅对农户秸秆处理行为具有正向影响； （3）人际信任在种际公平感知和农户农膜处理行为之间具有显著的正向调节效应，而制度信任在两者之间具有显著的负向调节效应； 同样，人际信任在人际公平感知和农户秸秆处理行为之间具有正向调节效应，而制度信任弱化了人际公平感知对农户秸秆处理行为的影响。［结论］环境公平感知和社会信任是影响农户低碳生产行为的关键因素，且社会信任在种际公平感知和农户农膜处理行为之间以及在人际公平感知和农户秸秆处理行为之间具有显著的调节作用。     

军民融合协同创新驱动产业园区高质量发展研究

军民融合产业园区高质量发展对于推进军民深度融合、在全国形成可复制可推广经验具有重要意义。军民融合协同创新通过促进新知识涌现、推进新产业集聚发展，最终汇聚经济发展新动能，驱动园区高质量发展。在提出军民融合协同创新驱动园区高质量发展的机理与组织框架基础上，将发展模式归纳为以分享经济为背景的资源共享模式、以新型研发机构为核心的第三方模式、以产业联盟为核心的产业链拓展模式和以交易平台为核心的“PPP”模式，最后提出相关对策建议。