China Economic Quarterly,2020,Vol 19,No. 01
We used the micro data of Chinese manufacturing enterprises during 2004–2007 to identify the effect of the implementation of Provisions on Minimum Wages on labor factor allocation efficiency, and then discussed the transmission mechanisms. Our empirical results show that the Provisions on Minimum Wages reduced labor factor allocation efficiency by 3.61%–5.71%, and this conclusion still holds when we relax the pseudo-randomness assumption of regression discontinuity design. Additionally, factors’ over-adjustment is an important channel through which Provisions on Minimum Wages reduced labor factor allocation efficiency.
China Petroleum Exploration,2020,Vol 25,No. 01
As a typical representative of the continental fault basin in China, Jiyang depression has experienced three exploration stages from structure exploration of large anticlines, complex oil and gas accumulation belts to subtle oil and gas reservoirs. At present, exploration objectives in the Jiyang depression are more complex and subtle, which requires a finer degree of exploration research, deployment, and management. By strengthening the dynamic evaluation of remaining resource potential, continuously deepening the understandings of geological laws, and the research and application of exploration supporting technologies, scholars have carried out a fine evaluation of exploration targets in Shengli Oilfield to achieve the continuous and stable reserve increase in the Jiyang depression. This paper systematically summarizes the exploration practice in the Jiyang depression and presents “five fine and two innovative” exploration methods, which is of great theoretical and practical significance for the exploration and stable development of continental fault basins with high exploration degree in eastern China.
China Journal of Highway and Transport,2020,Vol 33,No. 06
For the precise and effective prevention of traffic accidents through preemptive warnings, an estimation method for the safety risk of urban road traffic is proposed based on driving behavior obtained from OBD data of vehicles and through information entropy theory. First, the relationship between locations with frequent abnormal driving behavior or places of traffic accidents was analyzed. Second, an estimation index system of the safety risk of road traffic was developed with road traffic safety entropy (RTSE) as the primary index and sudden acceleration and deceleration rates, sharp turning rate, speeding rate, and the rate of high-speed neutral taxiing as the secondary indexes. Thus, a calculation model of RTSE was developed based on the improved entropy weight method. Then, the number of safety levels of road traffic was determined through the combination of density clustering and K-means clustering. Furthermore, a method for calculating safety level thresholds was established through K-means clustering. The findings of the test results are in order. ① Locations with frequently abnormal driving behavior are consistent with the places traffic accidents. ② Modifications to the entropy weight method, such as optimization of selecting the base number of the logarithmic function, the processing of secondary indexes equal to zero, and the piecewise calculation of index weights can compensate for the limitation of the original logarithm with regard to entropy calculation with indexes equal to zero. In addition, it can avoid negative index weights and information inconformity between entropy values and index weights. ③ Two-step clustering may evade the influences of isolated data points on safety level division. A validation study was carried out on four urban roads in Chongqing with a total length of approximately 38 km. The results demonstrate that the RTSE is in accordance with the trend of the road safety state reflected by accidents, that the safety risk of road traffic can be divided into high and low levels, and that the optimal RTSE threshold is 0.042. Finally, the model achieves a risk division accuracy of 87.88%. This research can provide effective technical support for the identification of risky locations with regard to road traffic safety and preventing traffic accidents by providing preemptive warnings.
Disease Surveillance,2020,Vol 35,No. 06
Objective We give projections of the COVID-19 epidemic worldwide. Methods Based on a generic SEIR (susceptible-exposed-infectious-recovered/removed) model which incorporates the main epidemiological parameters and control efficacy, we thereby construct a web app EpiSIX and use it to forecast the possible tendency of the COVID-19 epidemic. Results Ideally, the epidemic worldwide would be stopped by the end of September 2020, with the outcomes of 7.0 million diagnosed cases worldwide and 2.5 million diagnosed cases in the US (currently 5.4 million worldwide and 1.67 million in US). Conclusion A Warning is given: Only the first wave of the epidemic was predicted. Be careful with the emerging of second wave.
China Journal of Chinese Materia Medica,2020,Vol 45,No. 10
To analyze the development of coronavirus disease 2019 (COVID-19), this study systematically retrieved relevant Chinese and English articles from both CNKI and Web of Science (WOS) database platforms. Bibliometric research method and CiteSpace 5.5.R2 were used to analyze and visualize the articles. A total of 695 Chinese and 446 English articles were included in this paper. Statistics showed that China published most of the articles and established close cooperation with the US and the UK. Through the analysis, it was found that Tongji Medical College of Huazhong University of Science and Technology and its affiliated hospitals published the largest number of articles. Moreover, the highly productive journals, Journal of Traditional Chinese Medicine and Lancet covered eight major fields, such as medicine, medical virology, radiation medicine, infectious diseases, and traditional Chinese medicine. Besides, a total of 35 special funds for COVID-19 have been recently established to sponsor these studies. The keyword and topic analysis indicated that the protein structure of 2019-nCoV, receptor targets and mechanisms of action, integrated Chinese and western medicine therapy, screening and development of antiviral drugs from Chinese and western medicine, vaccine research as well as epidemiological characteristics and prediction were current study hotspots. This study provides a reference for researchers to rapidly master the key study directions of COVID-19 and screen relevant articles.