黄连炉甘石洗剂盐酸小檗碱含量测定的研究

目的建立黄连炉甘石洗剂盐酸小檗碱含量的质量控制标准。方法采用高效液相色谱法测定处方中盐酸小檗碱的含量。结果建立高效液相色谱法测定处方中的盐酸小檗碱含量的方法。盐酸小檗碱的进样量在10~100μg/ml范围内呈良好的线性关系(R2=0.9996),平均回收率为102.01%,RSD为0.49%(n=6)。结论本方法专属性强、准确、重现性好,可用于黄连炉甘石洗剂盐酸小檗碱含量的质量控制标准。     

A dynamic general equilibrium model of pollution abatement under learning by doing

In 2013, Beladi et al. constructed a dynamic general equilibrium model of pollution, and characterized a steady-state equilibrium. In this paper, we extend Beladi et al.’s model to an even more general model in which the pollution abatement costs under learning by doing are taken into account. In our model, the instantaneous abatement costs depend on both the rate of abatement and the experience of using a technology. Our objective is to apply optimal control theory to investigate the dynamic general equilibrium model of pollution abatement, and derive the steady-state equilibrium properties and optimal levels of emission permits and pollution treatment.     

中国企业研发国际化影响因素研究——计算机、通信及其它电子设备制造业上市公司实证分析

研发国际化是企业提升技术能力的重要途径。为了深入研究企业研发国际化动因,基于中国200家计算机、通信及其它电子设备制造业上市公司的调查数据,运用多元回归分析法,从公司规模、研发能力、盈利水平、产品出口、境外股权以及高管受教育程度等方面,实证研究了我国企业研发国际化影响因素。结果表明,企业规模、研发能力、产品出口、高管受教育程度对企业研发国际化有显著正向影响,境外股权对企业研发国际化无显著影响,盈利水平对企业研发国际化有显著负向影响。该结果对于理解和指导中国企业研发国际化工作具有较高的参考价值。     

管理会计实地研究述评:比较与借鉴

实地研究作为管理会计领域的主流研究方法之一,被西方学者广泛采用并取得了突出的成果,而中国管理会计实地研究仍处于探索阶段.鉴于此,本文对过去20年间发表于国内外顶级会计学术期刊的管理会计实地研究文献进行系统地梳理和述评,归纳出管理会计实地研究的定义、理论、方法、研究问题及其研究贡献,对国内外研究现状进行比较,在此基础上讨论国际经验对于开展中国情境下管理会计实地研究的借鉴启示.本文对管理会计实地研究问题的讨论和相关建议,有助于会计学者了解相关的理论和方法、开展对中国企业的实地研究.     

融入ESG因素的企业债券信用风险预警研究

选取2018年第四季度至2020年第四季度发生违约和信用评级下调的企业债券为样本,利用Logistic模型探究企业ESG表现在债券信用风险预警中的应用,研究发现:(1)ESG表现越好的企业,其债券发生违约或信用评级下调的可能性越低.(2)在预警模型中加入ESG因素能够显著提升模型的敏感性、特异性和预测准确性.(3)利用ESG评级构建的预警指标有助于预测企业债券信用风险.(4)进一步考察ESG的分项指标发现,违约企业在环境表现和公司治理方面存在尤为明显的缺陷.研究结论为发债企业提升自身ESG表现,投资者充分认识ESG评级的"排雷"作用和监管部门将企业ESG表现作为审核发债的重要参考提供了支持证据.     

Optimizing EV-based P&R subsidy policies for commuting corridor based on cross-nested logit model

The promotion of electric vehicles (EVs) is restricted by cruising range limitation and charging station deficiency. Given the mature development of Park and Ride (P&R) mode, which is used in many cities worldwide to attract more travelers to use public transit, a new travel mode, i.e., EV-based P&R is introduced as an alternative for commuters’ daily travel. This seems quite attractive to expand the use of EVs and further increase their market share. This paper aims to investigate the impact of EV-based P&R introduction on travel mode choice along commuting corridor, and further aid in the optimal subsidy policies decision for the government. A bi-level model is proposed to model the presented problem. The lower level describes commuters’ joint mode and transfer choice behavior through a cross-nested logit (CNL) model, while the upper level minimizes the system cost. A genetic algorithm is developed to solve the formulated model with a partial linearization algorithm for solving the lower level model. And a numerical example is then used to demonstrate the effectiveness of the methodology and illustrate how the network flow pattern reshapes due to the introduction of EVs into the P&R mode and the change of corresponding subsidy policies. As the results show, improving the EV hardware, applying the intelligent supporting service system, developing new technologies for EV fast charging, appropriately improving the parking space capacity, and increasing the parking fee of transfer stations near the central business district (CBD) are all helpful to save the social cost and promote the usage of EVs.     

Diamond model for the transfer of world science and technology centres

Since the end of the Middle Ages, Italy, the United Kingdom, France, Germany and the United States, has successively become the world’s science and technology centre. The combination of societal factors, such as economic prosperity, ideological emancipation, education development, and government’s strong support, and timely appearance of scientific achievements, jointly lead to the formation, evolution and transfer of the centre whilst a diamond model composed of these five elements can be utilized to analyse of this process. The innovation of global science and technology has entered an unprecedented period featured by its intensity, providing a perfect "window of opportunity" for China to become a world science and technology centre. It is vital for china to emancipate the mind, improve the personnel system, create an innovation-friendly environment, speed up the establishment of a world education centre, enhance government’s support, solve problems occurring during development, preemptive frontier research and subversive technological innovation.     

磁热按摩理疗仪的制作

分析了利用电子技术产生磁、振、热3种物理因子的方案。选取通用数字芯片,设计、分析了一种针对亚健康人群的磁、振、热理疗仪,通过选择不同的电压档位实现了不同振动强度和磁场强度的按摩与治疗,具有10 min、20 min、30 min、40 min、50 min、60 min 6个时间计时选择档位,最后依据设计原理制作了理疗仪的控制器样机。通过初步实验表明该理疗仪的功能符合设计要求,能很好地满足临床和家庭等多种需求。     

Stochastic convergence in per capita energy consumption and its catch-up rate: evidence from 26 African countries

Using annual data from 1971 to 2014, we examine stochastic conditional convergence in per capita energy consumption for 26 low income, lower middle-income and upper-middle-income African countries. To do so, we use panel unit root tests that allow for cross-sectional dependence and structural breaks as well as the recently developed univariate Residual Augmented Least Squares-Lagrange multiplier (RALS-LM) unit root test with structural breaks. Although for most countries our evidence suggests stochastic conditional convergence, we find divergence for four countries including DR Congo, Senegal, Egypt and Botswana. Consistent with the neoclassical growth models we also examine the catch-up rate between energy consumption levels of African economies and that one of China and investigate its convergence properties. As African economies continue to grow, regional energy consumption disparity narrows, African energy consumption levels will catch up to the ones in China.