Diazocarbonyl and Related Compounds in the Synthesis of Azoles

Diazocarbonyl compounds have found numerous applications in many areas of chemistry. Among the most developed fields of diazo chemistry is the preparation of azoles from diazo compounds. This approach represents a useful alternative to more conventional methods of the synthesis of azoles. A comprehensive review on the preparation of various azoles (oxazoles, thiazoles, imidazoles, pyrazoles, triazoles, and tetrazoles) from diazocarbonyl and related compounds is presented for the first time along with discussion of advantages and disadvantages of «diazo» approaches to azoles.     

Optimal control strategy for COVID-19 concerning both life and economy based on deep reinforcement learning

At present, the global COVID-19 is still severe. More and more countries have experienced second or even third outbreaks. The epidemic is far from over until the vaccine is successfully developed and put on the market on a large scale. Inappropriate epidemic control strategies may bring catastrophic consequences. It is essential to maximize the epidemic restraining and to mitigate economic damage. However, the study on the optimal control strategy concerning both sides is rare, and no optimal model has been built. In this paper, the Susceptible-Infectious-Hospitalized-Recovered (SIHR) compartment model is expanded to simulate the epidemic's spread concerning isolation rate. An economic model affected by epidemic isolation measures is established. The effective reproduction number and the eigenvalues at the equilibrium point are introduced as the indicators of controllability and stability of the model and verified the effectiveness of the SIHR model. Based on the Deep Q Network (DQN), one of the deep reinforcement learning (RL) methods, the blocking policy is studied to maximize the economic output under the premise of controlling the number of infections in different stages. The epidemic control strategies given by deep RL under different learning strategies are compared for different reward coefficients. The study demonstrates that optimal policies may differ in various countries depending on disease spread and anti-economic risk ability. The results show that the more economical strategy, the less economic loss in the short term, which can save economically fragile countries from economic crises. In the second or third outbreak stage, the earlier the government adopts the control strategy, the smaller the economic loss. We recommend the method of deep RL to specify a policy which can control the epidemic while making quarantine economically viable.     

浅析老龄经济中的税收政策

本文放宽人口结构平稳假设,将总人口增长率与劳动人口增长率之差定义为老龄化率,在此基础上构建老龄经济模型,分析税收政策对老龄经济的影响。基于一定假设,老龄经济存在鞍型收敛路径,平衡增长路径上的人均收入增长率取决于技术进步率与老龄化率之差,技术进步率在积极应对人口老龄化方面至关重要。从税收角度看,资产收入税与企业利润税对老龄经济的扭曲程度较高,而劳动收入税与消费税的扭曲程度相对较低。通过削减政府支出与调整税收结构,减税不仅可以提高均衡的资本水平,若能够激励经济主体积极创新,还将会提高平衡路径上人均收入的增长速度。一定条件下,老龄经济中将会存在正的最优税率。     

Ruthenium‐Catalyzed Allylation–Cyclization Reactions of Cyclic 1,3‐Dicarbonyl Compounds with 1‐Vinyl Propargyl Alcohols

Ruthenium‐catalyzed allylation–cyclization reactions of cyclic 1,3‐dicarbonyl compounds with 1‐vinyl propargyl alcohols that lead to diverse carbo‐ or heterocyclic products in a one‐pot cascade process are reported. These mechanistically distinct reactions are catalyzed by a single ruthenium(0) complex that contains a redox‐coupled dienone ligand. The reaction pathway strongly depends on the substrate substitution pattern, which determines the mode of activation of the 1‐vinyl propargyl alcohol. The environmentally benign process, which generates water as the only waste product, is of wide scope and allows the atom‐economic synthesis of highly functionalized furans, pyrans, and spirocarbocycles.     

L-凸空间中一个新的连续选择及其不动点定理以及对抽象经济的应用(英文)

在L-凸空间中建立了一个新的连续选择及其不动点定理.作为应用,获得了L-凸空间中的极大元定理以及定性对策和抽象经济的平衡点存在定理     

能源价格变化对我国宏观经济及节能减排的影响研究——基于联立方程模型的分析

基于供给需求理论构建了能源——经济联立方程模型,定量研究各类能源价格变化对我国宏观经济的影响.结果发现,能源价格上涨可以降低能源消耗,通过供给渠道对潜在生产能力和GDP产生紧缩作用,对通货膨胀产生向上压力.石油价格上涨对主要经济指标的影响略小,煤炭价格与电力价格上涨对经济的影响较大,煤、电价格联合上涨对经济的影响最大.这与目前我国能源消费结构吻合.各种能源价格的持续上涨冲击对潜在产出、能源消费、能源强度和碳排放强度的负向影响有继续增强的趋势.     

黑龙江省总体经济预测——基于扩散指数模型

本文以Stock and Watson提出的"扩散指数"模型为基础,建立一个两步骤的"扩散指数"预测模型,并应用于黑龙江省经济增长率的预测。除了依循Stock and Watson的作法外,本文也将变量依其特性区分为商品市场变量与货币市场变量,再分别针对各市场变量估计其扩散指数,然后根据这些指数进行预测。实证结果显示,"扩散指数"预测模型具有相当好的预测绩效,也优于一般模型的预测,因此可以作为未来总体经济预测上的另一种选择。     

A model for speculation in a dynamic economy

The paper deals with speculation strategies in a dynamic economy, where “speculation” means participating in a market with the intention to gain a reward by first buying an item and thereafter selling it at a possibly higher price. By assuming that the states of the economy form a Markov chain the problem is modeled as a discrete time Markov decision process. The optimal strategies (which are pairs of stopping times) are identified. Under quite general conditions the optimal rule for the selling process turns out to be a control limit policy in both state of economy and time. Techniques for the computation of optimal strategies are presented; some numerical examples are also discussed. For a static economy closed-form solutions are given     

Chemoenzymatic Synthesis of Ramosetron Hydrochloride

A new method for the synthesis of ramosetron hydrochloride, the most wildly used 5-HT₃ receptor antagonist, was reported. The intermediate 8 was obtained in a high e.e. value via lipase catalyzed hydrolytic kinetic resolution. Then enantiomerically pure ramosetron hydrochloride was synthesized in two steps with excellent yield (the total yield is 24.6%). The method provides a new environment friendly and atom economy way to synthesize enantiomerically pure ramosetron.