bluuebunny/crossref_metadata_2025 huggingface dataset:
Design and simulation optimization of cold storage and air conditioning system in LNG powered carrier by using cold energy of LNG based on HYSYS
Authors: Li Boyang , Yang Qianqian , Zhang Rui , Yang Sangyu
Published: April 2020

In order to solve the problem that the LNG (Liquefied Natural Gas) cold energy in LNG powered carrier is not used sufficiently, a set of system is designed. This cold storage and air conditioning system is used in LNG powered carrier. At the same time, the refrigerant required by the system is selected and simulate the process of the system by HYSYS. This paper describes the specific process and gives the simulation parameters of each node. The simulation results meet the expected requirements and accord with the actual situation. The main purpose of this system is to reduce energy consumption by using LNG cold energy as a cold source of cold storage and room air conditioning.
Investigation of instability on loop heat pipe with flat evaporator
Authors: Gai Dongxing , Yin Yang , Chen Chen
Published: April 2020

Loop heat pipes (LHPs) are heat transfer devices whose operating principle are based on the evaporation and condensation of a working fluid, using the capillary pumping forces to ensure the fluid circulation. A series of tests have been carried out with a loop heat pipe (LHP) with flat evaporator and a fin-and-tube type condenser. At some low heat loads, temperature oscillations were observed throughout the loop. Detailed study was conducted on the characteristics of temperature oscillation of the flat LHP at various heat loads. It is expected that the compensation chamber is the most critical component of the LHP; its hydrodynamic state dictates the extent and the characteristics of the temperature oscillations. The heat leakage from the evaporator to the compensation chamber, the heat loss to ambient and the subcooled liquid temperature dictate the vapor condition inside the compensation chamber, and the rate of vapor growth or dissipation dictated the nature of the temperature oscillation. The effects of different working fluid to the temperature oscillations were studied in detail.
Energy flow analysis of the multi-energy energy router
Authors: Li Shuo , Li Zichen , Li Pengfei , Zhang Yanchi , Xie Da
Published: April 2020

Energy routers have become a hot topic in recent years as a key link to realize the wide interconnection of multiple energy sources in the energy Internet. Firstly, this paper analyzed the operation mode of the multi-energy energy router and summarized its typical structure. Then based on the interaction between the energy router and the grid, the energy flow was analyzed from the energy router to the grid and the grid to the energy router. Finally, the energy interaction of the above two aspects was simulated, and the conclusion that the multi-energy energy router can realize various energy interactions in the energy Internet is obtained.
A calculation method of user response potential on demand side response in integrated energy system
Authors: Han Hanxian , Luo Jinman , Ye Ruijing , Liang Haobo , Zhang Zhilu , Deng Yingqi
Published: April 2020

The current Integrated Demand Response (IDR) strategies cannot accurately evaluate the user’s maximum response which ignore the user terminal equipment response model. At the same time, the optimization target of the current IDR strategies is mostly electric energy, and other energy response requirements such as natural gas are not considered. This paper establishes an IDR strategy model based on energy models for different equipment terminals of residential users. And calculate the theoretical maximum response potential value of different users according to the response strategy formulated by different energy response requirements with the GA-SQP hybrid algorithm. The example analyses the user response potential in typical scenarios and time periods. The results verify the effectiveness and feasibility of the proposed method.
Research and analysis of energy internet from the perspective of NSFC
Authors: Hu Congchuan , Wang Yongzhen , Liu Yuxuan , Zhang Jing , Li Yongtian
Published: April 2020

Energy Internet (EI) is an emerging discipline that integrates cooling, heating, power and gas in physical, information and value flows, so it has a very distinctive interdisciplinary feature. The current situation of EI needs to be sorted out and summarized in time, so as to provide a reference for its future development. To some extent, the National Natural Science Foundation of China (NSFC) reflects the research focus and trend of EI in China. Therefore, this paper tries to analyse the programs of EI from the perspective of NSFC, the results revealed that 1) EI becomes a research hot point of combined cooling, heating and power instead of electricity only after micro grid and smart grid. Also, this is one of the reasons that researches on EI mostly focus on the electrical science and engineering currently; 2) One of the purposes for EI is to solve the problem of abandoning wind and light energy;3) The number of NSFC supporting programs involving the topics of EI, multi-energy complementarity and integrated energy system accounts for 43% of 124 EI-related funds totally; 4) The distribution of the NSFC supporting programs about EI reveals the crossing and integration of multiple disciplines, such as electronics and information systems, computer science, automation, management science and engineering, mathematics.
Numerical simulation and analysis of enhanced heat transfer in corrugated tube heat exchanger
Authors: Jiang Jingzhi , Bo Lin , Chen Zhengjia , Cui Haiting , Zhu Hairong
Published: April 2020

At present, in many fields such as petrochemical industry, in order to make better use of heat energy and reduce energy consumption in the process of equipment operation, heat transfer enhancement of heat exchange equipment has attracted more and more attention. Corrugated tube has many advantages compared with other smooth tubes, which are enhancing heat transfer, strong anti-fouling ability and easy to clean. In this paper, a heat exchanger with corrugated tube is studied. The geometry is meshed with the software GAMBIT. It is used with Fluent software and the initial and boundary conditions are set. Heat transfer performance between smooth tube and corrugated tube at the same inner wall temperature and velocity. Then, the influence from inlet velocity on heat transfer performance is investigated. The variation of temperature field, pressure field and velocity field in corrugated tube heat exchanger with different inlet velocity is discussed. The results show that the enhanced heat transfer effect of corrugated tube is much better than that of smooth tubes. At three different inlet velocities (0.5m/s, 1m/s, 3m/s), the enhanced heat transfer effects of the corrugated tube heat exchanger are different. With the increase of inlet velocity, the heat transfer effects of corrugated tube heat exchanger are enhanced, but the extent of enhancement decreases. In the range of this paper, the optimal inlet velocity is 0.5m/s in order to obtain the more heat transfer quantity and lower operation cost.
Experimental research on the indoor thermal environment of the office buildings with solar energy heating in Xinjiang, China
Authors: Xu Xin , Li Jie , Jiang Shuguang , Wu Mengyun , Dai Jin , Qi Dianwei
Published: April 2020

In order to study the indoor thermal environment of solar heating of office buildings in Xinjiang, A rural office building in Shihezi was selected in this paper as the research object. Indoor temperature and relative humidity were monitored in field testing during the winter heating period. 4363 sets of effective data were collected in the experimental research. PMV-PDD was calculated to analyse its indoor thermal comfort by a program. The results show that the indoor thermal comfort of the room without a heat source was always not satisfied. Furthermore, the average indoor PMV of the room with coal-fired heating was -1.6 and that with solar heating was -0.5. At the same time, the room with solar energy heating can control the fluctuation margin of indoor temperature within a certain range, especially to the temperature fluctuations during the working time. Therefore, the technology of solar heating was certified as a suitable method to maintain indoor comfort in Xinjiang.
Optimal planning of multiple energy flows for microgrid with renewable energy sources
Authors: Wang Xi , Zhang Quanming , Ren Zhichao , Chen Lipin , Li Huaqiang , Yan Mengyang
Published: April 2020

With the gradual depletion of fossil energy and the increasingly serious environmental pollution problems, the combined cooling heating and power (CCHP) microgrid with renewable energy sources which with high energy efficiency, less pollution emissions and flexible operation control have become research hotspots. In this paper, the optimal planning of CCHP microgrid with renewable energy sources is studied, and the mathematical model of optimal configuration of the system is established with the minimum total cost as the objective function, then the separated production (SP) system is used as a reference to compare the optimal configuration results of the CCHP microgrid system under the two modes of following the thermal load (FTL) and following the electric load (FEL). After that, the optimization configuration results of the two schemes of whether the CCHP microgrid system is equipped with the thermal storage tank (TST) in the same operating mode are compared. The simulation result shows that the system with TST under the FEL mode is more economical, energy-saving and environmentally friendly. Finally, the effects of natural gas price and electricity price on the optimal configuration results of the system in two operating modes are studied.
Fault diagnosis of PV array using adaptive network based fuzzy inference system
Authors: Gan Yutao , Chen Zhicong , Wu Lijun , Cheng Shuying , Lin Peijie
Published: April 2020

A new online intelligent fault diagnosis method is proposed for PV arrays in this paper to improve the reliability and efficiency of PV systems. Firstly, a new seven-dimensional fault feature vector is extracted from the raw data of dynamic operating points of PV arrays including operating voltage, current, irradiance and temperature. Secondly, an optimized adaptive network based fuzzy inference system (ANFIS) is proposed as the fault diagnosis model. Lastly, the feasibility and superiority of the proposed ANFIS based fault diagnosis model are tested by both Simulink based simulation and real fault experiments on a laboratory PV system. Experimental results validate that the proposed ANFIS based method achieves a high performance and is superior to conventional back-propagation neural network (BPNN) based methods. The overall accuracy of the ANFIS based fault diagnosis model on the simulation and experimental dataset is 99.9% and over 97% respectively.
Forecasting the installed wind capacity using a new information priority accumulated nonlinear grey Bernoulli model
Authors: Xiang Xiwang , Liu Liang , Cao Jiahao , Zhang Peng
Published: April 2020

Wind energy is an important renewable and clean energy, and the accurate realization of the prediction of the installed wind capacity is urgent and should not be delayed. This paper proposes a novel new information priority accumulated nonlinear grey Bernoulli model and applies it to forecast the installed wind capacity in Europe and South America. The nonlinear parameters of the proposed model are optimized by the Grasshopper Optimization Algorithm. In the application case, the model our proposed has a more satisfactory predictive performance by comparing it with other three classical models.
Study on electromagnetic environment of ±800 kV UHV DC and 1000 kV UHV AC parallel transmission lines
Authors: Wang Guangzhou , Yao Degui , Zhang Songyang , Wang Donghui , Wang Leilei , Guo Xing , Yang Fan
Published: April 2020

Aiming at the typical AC/DC parallel transmission lines which have been put into operation in China, the electromagnetic environment of parallel transmission lines is monitored and the interaction between AC and DC electromagnetic environment is analyzed. Monitoring results show that: The electromagnetic environment of UHV AC/DC parallel transmission lines meets the corresponding national standard limits. UHV DC transmission line has little influence on power frequency electromagnetic field, which is mainly affected by distance and wire height to ground. UHV AC transmission line may have a certain impact on DC composite field strength, and wind speed will have a greater impact on DC composite field strength.
Power unit load system modelling research based on BP neural network
Authors: Si Ruicai , Wang Songhan , Liu Xiwen , Li Jia , Zhou Chi , Li Baoju
Published: April 2020

A thermal power unit is a very complex non-linear multi-variable control object. It has the characteristics of strong coupling, large inertia, large delay and time-varying parameters. The traditional mathematical model is difficult to describe the non-linear characteristics among the parameters of the unit, and it is difficult to meet the control requirements of unit load, main steam pressure and so on. Based on the more advanced BP neural network modeling method, the mathematical model of the operation of 600MW thermal power unit under low, medium and high load is established by using the actual operation data on site. The method used is novel, and the simulation analysis shows that the model also has a strong engineering practice.
Technology and mode of the virtual thermal power plant in the clean heating field
Authors: Zhao Dongyuan , Zi Zhenning , He Yongjun , Chen Yufei
Published: April 2020

China has the largest installed capacity of wind and solar power in the world, but winter heating in the northern region still relies mainly on coal combustion, and the current comprehensive heating scheme is still far from achieving climate change and environmental protection goals. Firstly, this paper analyses the significance of clean heating in china at the present stage, and the problems in the implementation of clean heating plan, and puts forward a virtual thermal power plant scheme based on Energy Internet. By comparing the advantages and disadvantages of the new scheme with the traditional clean energy heating scheme, it is concluded that the new scheme can not only absorb a large number of clean energy such as wind power, but also help to solve the problems of abandoned wind and solar power. In addition, it also has good economic benefits. Through the wide implementation of this scheme, the Energy Internet will lead the change of clean heating technology.
Constant power start-up control strategy for modular multilevel converter
Authors: Liu Wentao , Li Ke-Jun , Liu Zhijie , Zhang Jin , Cui Mei
Published: April 2020

HVDC system based on modular multilevel converter(MMC) usually adopts fixed DC bus voltage to realize the start-up control of converter, which will have a great impact on AC network during charging process. This paper presents a constant power start-up control strategy based on MMC arm current control, which can effectively control active power, reactive power, output current and submodule(SM) capacitor voltage. Based on the existing two-stage start-up control mode, according to the output characteristics of arm voltage in controlled charging process, the circuit topology of DC side open circuit of converter is proposed, and the mathematical model is established. Based on the derived instantaneous arm power calculation method and the average sliding filter of SM capacitor voltage, the double closed-loop fast response controller of fixed AC power in controlled precharging stage is given. The safety of the power electronic equipment in the converter is effectively guaranteed and the impact of converter on ac power grid is greatly reduced. Finally, simulation models of conventional start-up method and proposed start-up method are built on MATLAB/Simulink platform to verify the validity and correctness of the proposed start-up control strategy.
Application research on high efficiency desulfurization technology of reducing calcium-sulfur ratio in circulating fluidized bed boiler
Authors: Xie Guowei
Published: April 2020

Based on current status of desulfurization calcium-sulfur ratio on active 150MW CFB boiler running poor economically, the actual influencing factors of the low desulfurization efficiency are studied combined with the desulfurization mechanism. In a typical load of 150MW CFB boiler, the degree of key factors influence on calcium-sulfur ratio is analyzed. On this basis, high efficiency technologies for improving the desulfurization efficiency and reducing calcium-sulfur ratio are proposed one by one for the influencing factors, and the application of technology is implemented on 150MW CFB boiler. The experiment is arranged to test desulfurization calcium-sulfur ratio of the boiler furnace before and after the implementation of the technology. The results show that the comprehensive operating calcium-sulfur ratio of the unit is reduced by 70% after the the application, and the technology has a good effect on significantly reducing calcium-sulfur ratio.
An investigation of haloacetic acid occurrence in indoor and outdoor swimming pools in Beijing China
Authors: Yao Shan
Published: April 2020

Swimming is one of the most popular amusement activities. In order to keep the swimmers from microbiological, the water need to be constantly disinfected. In this study, several indoor and outdoor swimming pools water and drinking water were investigated, it has found that swimming pool water has much higher HAA concentration and toxicity than the drinking water. DCAA and TCAA are the most abundant species in the indoor and outdoor swimming pool water. In the outdoor swimming pool water, TCAA concentration was higher than DCAA, while [DCAA]/[TCAA] was higher in the indoor swimming pool water.
Water management in hydraulic fracturing technology
Authors: Li Xuening , Liu Guoliang , Zhang Fusheng , Guan Baoshan , Sun Jianghe
Published: April 2020

Shale gas is a clean and efficient unconventional natural gas energy, which has gradually become a new hotspot in global oil and gas exploration and development. Hydraulic fracturing technology is one of the core technologies in shale gas production, which consumes a lot of water resources and produces a lot of polluted flowback fluid. How to effectively deal with the treatment of flowback fluid is a crucial issue. By analyzing the characteristics of fracturing flowback fluid, this paper lists the treatment technologies of fracturing flowback fluid, which can relieve the worries of shale gas exploitation and wide application.
Screening and characterization of high performance synthetic-based drilling fluids degrading bacteria
Authors: Zhang Qiaobo , liu Die , Liu Yihao , Liu Hanjun , Huang Min , Chen Lirong , Chen Qiang
Published: April 2020

In this paper, eight degrading bacteria using waste high performance synthetic-based fluids (WHPSF) as sole carbon source were isolated. Genetic analysis showed that these strains belonged to 8 species, and distributed in 3 genera. Of them, genus Bacillus was the predominated one with 6 strains. Based on the COD removal rate, 3 effective strains, i.e. SQ17, SQ8-1 and SQ6-1, were screened; and SQ6-1 had the highest COD degradation rate (40.26%). Growth characteristic analysis indicated that SQ8-1 and SQ6-1 could grow at initial pH value from 4.0 to 10.0, and grow at 10 °C to 40 °C. Moreover, these bacterial strains had strong ability to degrade WHPSF, and both the bacteria amount and COD removal rate increased along with treating time. The results suggested that these bacteria could degrade WHPSF properly, and had good application potential.
Application of fuzzy comprehensive evaluation method using entropy weight in groundwater quality evaluation: A case study on Xianyang, China
Authors: Zhang Qiying , Xu Panpan , Qian Hui
Published: April 2020

Groundwater, especially unconfined water, is easy to be polluted in Xianyang of Guanzhong Basin. Therefore, the evaluation of groundwater quality is of great significance for the safety of drinking and control of pollution. In order to find out the water quality, 14 water quality assessment indicators were selected for 16 points. And the fuzzy comprehensive evaluation method based on entropy weight is used to evaluate the groundwater quality. The results show that the water quality level determined by the weighted average principle is better than that by the maximum membership principle. Nearly 75% of the water quality ranks are Class IV and Class V, and evaluation of water not exceed groundwater Class III water standard is solely approximately 25%. Moreover, the water quality in upstream of groundwater flow field is better than that in downstream. The main indicators of groundwater pollution are fluoride from the impact of geological environment and human activities and hexavalent chromium contained in wastewater discharged from industrial development in Xianyang city.
Effect of nitrogen and phosphorus removal by two species of Chlorella in allelochemical EMA condition
Authors: Zheng Yi , Chu Qiang , Ji Fangzhi , Peng Shitao , Liu Xianbin
Published: April 2020

In order to examine the effect of allelochemical EMA on the absorption of nitrogen and phosphorus by Chlorella vulgaris and Chlorella pyrenoidosa in eutrophic water, Algae were constantly cultured by BG-11 medium with different concentration of allelochemical. The experimental results showed that lower concentrations (0.1mg/L) of EMA have a growth-promoting effect on Chlorella. vulgaris, but no obvious effect with higher concentrations. However, EMA has a significant inhibitory effect on Chlorella. pyrenoidosa. EMA can also promote the absorption of ammonia nitrogen by two algae. After nine days experiment, The highest ammonia nitrogen removal efficiency occurred in the 1.1 mg/L concentration of EMA, Chlorella vulgaris and Chlorella Pyrenoidosa removal efficiency were 71.89% and 79.06% respectively. High concentration of EMA can inhibit the absorption and utilization of total nitrogen and total phosphorus by two algae. The best removal efficiency of TN were 45.44% (0.1mg/L EMA) and 58.80% (0.1mg/L EMA) respectively. The best removal efficiency of TP were 95.06% (0 mg/L EMA) and 99.70% (0.3mg/L EMA) respectively.
Study on water resource carrying capacity of Xi’an based on AHP-fuzzy synthetic evaluation model
Authors: Feng Wenwen , Xu Panpan , Qian Hui
Published: April 2020

Based on the statistical data of water resource in Xi’an from 2005 to 2017, a fuzzy comprehensive evaluation model based on Analytic Hierarchy Process (AHP) was used to analyse the status and influencing factors of water resource carrying capacity in Xi’an for the past 13 years. The results show that the water resource carrying capacity of Xi’an in 2005∼2017 has been declining, and the water supply capacity has also shown a downward trend with a decrease of -0.0023/a. Nevertheless, the economic development and urban spatial assessment index have shown a rapid upward trend. In 2017, the annual total water supply of the city increased, leading to the continuous improvement of the environmental status of water resource in Xi’an. However, compared with the urban population growth rate of 9%, GDP growth rate of 19%, and urban consumption rate of 21%, the water resource carrying capacity will continue to decline in the short term and cannot be effectively improved. The main reason for the continuous decline of water resource carrying capacity in Xi’an is the shortage of water resource, and the daily water consumption per capita is increasing. Under the current water resource situation, it is difficult to effectively support the rapid development of urban economy and urbanization. Developing and enhancing citizens’ awareness for water conservation and improvement is necessary to support sustainable urbanization in Xi’an City.
Prediction model of air pollutant concentration based on deep neural network: A case study of Fushun, Liaoning Province
Authors: Lei Fei , Gu Deyu , Wang Xueli
Published: April 2020

With the rapid development of the economy, the sources of air pollution are increasing, and the problem of air pollution is becoming more and more serious. Air quality prediction is a very effective means of predicting air pollution in the future, which helps the government regulatory authorities to provide early warning and protect people’s physical and mental health. In this paper, a prediction model of air pollutant concentration based on deep neural network is proposed. With the concentration of PM2.5 as the prediction target, the neural network chooses bidirectional Long Short-Term Memory (LSTM) and fully connected neural network. First, historical meteorological data and the PM2.5 density from 2016 to 2017 were used as training data in this paper, which were obtained from website. Then, after pre-processing the input data, the data is transmitted to the network and trained multiple times to obtain network parameters that make the prediction effect better. Next, the network model is applied to the test set, and the test results are compared with the actual values to measure the prediction effect. Finally, by comparing with other prediction models, the results show that the proposed model performs better and has higher accuracy.
Estimation of agricultural greenhouse gas emissions from 1987 to 2015 in Fujian Province, China
Authors: Gan Hui , Liu Jia , Huang Wuhong , Yang Yanyan , Jiang Yuwei , Cai Yanan
Published: April 2020

Based on the data of agricultural activities of Fujian Province, the agricultural greenhouse gases emissions of Fujian Province during 1987-2015 were estimated and the uncertainties were analysed. The following conclusions were drawn. Firstly, the greenhouse gas emissions increased continuously during 1987-1992 while they decreased greatly in fluctuation during 1993-2015. Secondly, agricultural land was the largest emission source of the agricultural greenhouse gas emissions, followed by rice planting, and animal excrement and intestinal fermentation. Thirdly, the agricultural economic level had a far greater impact than the input of agricultural production materials.
Mapping the probability of exceeding environmental quality standards for Cd and Pb concentrations in soil of northern Tarim Basin using Bayesian geostatistical model
Authors: Wu Weimo , Wu Jiaping , Wang Jiaqiang , Cao Qi
Published: April 2020

Cadmium and Pb are important hazardous trace metals in the biosphere, and they are considered to pose a great threat to environmental health. The probability map exceeding the environmental quality standard (EQS) can be used to measure the uncertainty of the spatial distribution of soil Cd and Pb and provides useful information for decision-making for environmental management. Many researchers have focused on Cd and Pb environmental problems in agricultural soils, and there are few studies that have investigated the Cd and Pb contents exceeding EQS in natural soils of the arid desert areas of northwest China. We collected 150 samples at 0-0.05 m and 0.05-0.1 m depths in the natural solonchak soil of northern Tarim Basin, Xinjiang Province. The average concentrations of Cd and Pb were 0.45 mg/kg and 42.13 mg/kg at 0-0.05 m, and 0.29 mg/kg and 16.88 mg/kg at 0.05-0.1 m, respectively. The soil Cd and Pb concentrations were increased in comparison with the environmental background values. In addition, the soil Cd and Pb concentrations at 0-0.05 m were significantly higher than those at 0.05-0.1 m. We used the Bayesian geostatistical model to predict the spatial distribution of Cd and Pb concentrations and to map the probability of soil Cd and Pb exceeding the EQS. These probability maps are expected to be helpful for soil environmental protection of northern Tarim Basin.
The extension of continuous carbon emission monitoring system in China’s thermal power plants under the carbon market
Authors: Sun Shuanzhu , Zhou Chunlei , Wang Ming , Jiang Kai , Mujeeb Asad , Wang Peng
Published: April 2020

China is facing severe climate pollution, thus the CO2 emissions of thermal power plants which consume a lot of fossil energy, need to be strictly monitored. At the same time, the thermal power plants and the government will face brand new environment, where the exactly appropriate monitoring approach of CO2 emission remains ambiguous. This study aims to distinguish monitoring approaches between Continuous Emission Monitoring System (CEMS) and factor-based approach on the basis of the operation features of China’s thermal power plants, analyzing the extension of CEMS. We review the major reducing greenhouse gas initiative in China—carbon market, and different emission monitoring approaches at first. We present the prospects of extension in CEMS’s technical features by analyzing an example of two generations using coal and gas, respectively, finding that CEMS is more accurate and dynamic. This study also presents the challenges by analyzing the refinement of factor-based monitoring approach. However, In contrast to many previous studies, we consider different influence in prospect and challenge from the market itself, the application experience and equipment installation basis. We finally draw an important conclusion that the factor-based monitoring approach is more suitable for China’s thermal power plants currently, but CEMS is more promising.
Decomposition analysis: Carbon emissions in China’s transportation sector
Authors: Yan Xiao , Zhang Zhongyun , Wei Zhehuan , Huang Xiaofei , Peng Peng
Published: April 2020

In order to deal with global warming and control carbon emissions, it is of great importance to identify the factors and their impact on the growth of carbon emission in the transportation sector. In this paper, the situation of carbon emissions in China’s transportation sector during 1996-2013 has been discussed and the decomposition analysis has been carried out by using the generalized Fisher index (GFI) method. It is found that: (i) Economic growth, energy intensity, population size and transportation intensity have positive effect on the growth of carbon emissions. (ii) Output value of per unit traffic turnover and energy structure have negative effects, among them, the former is the primary factor and the latter has an unobvious inhibition effect. We put forward suggestions to develop low-carbon transportation in China including to encourage people to adopt new energy vehicles in the passenger transport area, to utilize new energy vehicles in road freight and new energy ships in water freight, to encourage public and shared transportation, and promote the infrastructure construction of national multimodal transport.
Determination of 7 nitrobenzene compounds in soil, glass, and cotton cloth by ultrahigh performance liquid chromatography
Authors: Gu Haixin , Bao Renlie , Yuan Yanhua , Zhang Xuan , Luo Yiwen , Kong Cong
Published: April 2020

An ultrahigh performance liquid chromatographic (UHPLC) method has been developed for detection of 7 nitrobenzene compounds (nitrobenzene, 2-nitrotoluene, 1, 3, 5-trinitrotoluene, 3-nitrotoluene, 3, 4-dinitrotoluene, 2, 6-dinitrotoluene, 2, 4, 6-trinitrotoluene) in soil, glass and cotton cloth. Analytes were extracted twice by acetonitrile. 200 μL of the extract solution was pipetted to a tube with 800 μL water. After filtration by a nylon membrane, the analytes were determined by UHPLC with a phenyl modified column. The linear correlation coefficients of more than 0.99 were achieved. The detection range was examined from 0.05 to 5.0 mg/L. In this method, the limit of detection (LOD) of 0.5 mg/kg was obtained. Recoveries in spiked samples were more than 87.8%, and the relative standard deviations were less than 8.5%. This method is simple, and of good recovery, allowing the detection of nitrobenzene compounds in soil, glass and cotton cloth.
Evaluation research and development suggestion on the low-carbon transformation of regional industry: Take Quangang District as an example
Authors: Gan Hui , Jiang Yuwei , Qi Huimin , Huang Wuhong , Cai Yanan
Published: April 2020

Quangang is an emerging petrochemical base in Fujian Province. This paper evaluated the low-carbon transformation of Quangang industry, and put forward suggestions. The statistic data of Quangang from 2007 to 2015 were collected. Through the frequency statistical analysis and framework analysis of the indicators in 78 related references, combined with the actual situation of the development of the industry in Quangang, 14 indicators were selected as the evaluation index system of low-carbon transformation for Quangang industry. The data was processed, analyzed and evaluated mainly using the CRITIC method. In 2007-2015, the total evaluation scores of the industrial sectors of Quangang showed a fluctuated upward trend. Among them, the total evaluation scores from 2007 to 2008 showed an upward trend, and it fell back from 2008 to 2010, then the scores increased greatly from 2010 to 2012 and decreased slightly from 2012 to 2015, and the peak of 0.420 appeared in 2012. The following suggestions were put forward: among the advantage industrial sectors, the key development ones would be Processing of Petroleum, Coking, Processing of Nucleus Fuels (9), Production and Distribution of Electricity and Heating Power (24), Manufacture of Foods (2), Production and Distribution of Gas (26), Printing and Recording Media Reproduction Industry (10); among the disadvantaged industrial sectors, the key adjustment ones for the low-carbon industrial transformation would be Manufacture of Rubber products (13), Manufacture of Pressing of Ferrous Metals (16), Production and Distribution of Water (25), Manufacture of Paper and Paper Products (7), Manufacture of Pressing of Non-ferrous Metals (17), Manufacture of Chemical Raw Materials and Chemical Products (10).
Research on real-time pricing strategy for load serving entity based on simultaneous perturbation stochastic approximation
Authors: Lu Xing , Zhang Hongzhi , Zhang Dongyi
Published: April 2020

As one of the main participant in the electricity market, load serving entities (LSE) purchase electricity in the wholesale market, and provide different types of electricity package to users in the retail market. LSE’s profit mainly comes from the difference between the cost of purchasing electricity and the benefit of selling electricity. To reduce the cost, LSE can optimize electricity consumption characteristics of various types of users through real-time price adjustment, which can help to improve the shape of electricity purchase curve and implement demand side response. In this paper, a real-time pricing strategy based on synchronous perturbation stochastic approximation algorithm (SPSA) is proposed. This method considers the difference between diverse users synthetically. Depending on the historical electricity consumption and historical price data, the user side response function is constructed, and the real-time electricity price is formulated with the objective of minimizing load curve’s peak-valley difference. Finally, the effectiveness and advantages of the proposed method are verified by comparing the load curve and the power purchase cost before and after the price adjustment.
Exploration on development mode of rural electrification in Shandong Province
Authors: Liu Weidong , Li Min , Xu Shuangqing , Zhao Guan , Huang Wenrui , Sun Yazhong , Liu Xuejiang , Wang Lei , Zhang Tao , Yan Xing , Ma Junhua
Published: April 2020

Rural electrification construction is an important foundation for promoting the rural revitalization strategy. On the basis of field investigation on the current situation of rural electrification development in 8 cities of Shandong Province, theoretical analysis is made on the methods of work development, and a development mode suitable for rural electrification construction in Shandong Province is explored. Government and company cooperation in full aspects is the key to success of rural electrification. Suitable operation mode with support system can help the expectation turn to reality by resolving the technical and financial problem.
Research on energy transaction mode of regional microgrid cluster and distribution network considering wind power uncertainty
Authors: Chen Lipin , Chen Bo , Cheng Chao , Xu Hao , Chen Shi , Jia Chuyun , Tan Siwei
Published: April 2020

In order to reduce the unnecessary energy interaction between the microgrid and the distribution network, while promoting the local accommodation of wind power, this paper presents an energy transaction mode of regional microgrid cluster and distribution network. Firstly, the mode integrates the load demand and wind power output in the area based on regional multi-microgrid operator. And then, the transaction mode uses the load transfer rate to describe the user response of time of use (TOU) price. Meanwhile, the mode also establishes a model for the TOU price of regional microgrid cluster system considering the uncertainty of wind power. Finally, an NSGA-II algorithm is used to solve the multi-objective optimization problem in the model. Based on the experimental results, the transaction mode achieves cost reduction of microgrid cluster, while reducing unnecessary interaction between the regional microgrid cluster system and the distribution network.
The outdoor thermal comfort of urban square: A field study in a cold season in Chongqing
Authors: Huang Haijing , Peng Mingxi
Published: April 2020

With the development of urban development and various outdoor activities, the outdoor activities time of residents continue to grow, and the good outdoor environment have an important impact on the physical and mental health of residents. For the winter outdoor thermal comfort problem with less attention, taking the Chongqing Three Gorges Square in the hot summer and cold winter area as an example, a winter thermal environment measurement and thermal comfort questionnaire were conducted. The Rayman software is used to calculate the PET (physiological equivalent temperature) value as thermal comfort evaluation parameters, establish a functional relationship between TCV (thermal comfort voting value), TSV (thermal sensation voting value) and PET. The winter thermal comfort range of different outdoor environmental spaces were obtained, and propose a suitable winter thermal comfort evaluation model for hot summer and cold winter area. The research results can provide basic data reference for the improvement of outdoor thermal comfort research in hot summer and cold winter areas.
Tension and Rivalry: The ‘Belt and Road’ Initiative, Global Governance, and International Law
Authors: Chen Jianfu
Published: April 2020

This article attempts to establish a context in which the controversies of the Belt and Road Initiative (BRI) and its practice can be better understood. It is argued that, earlier, the background to the birth of the BRI had effectively determined the initial perception of the initiative as a geopolitical move and that this perception has increasingly led to a view that the initiative is a Chinese geo-economic strategy. While there is no universally agreed meaning of the notion ‘geo-economics’, this notion, more often than not, conjures images of winners and losers in geopolitical manoeuvring. As such, China needs to convince the world that the BRI is indeed a ‘win-win’ scenario in international cooperation. To do so, China needs to engage much more closely with international law and talk less about China’s own model of global governance.
Differential Graded Lie Algebras and Leibniz Algebra Cohomology
Authors: Mostovoy Jacob
Published: April 2020

In this note, we interpret Leibniz algebras as differential graded (DG) Lie algebras. Namely, we consider two fully faithful functors from the category of Leibniz algebras to that of DG Lie algebras and show that they naturally give rise to the Leibniz cohomology and the Chevalley–Eilenberg cohomology. As an application, we prove a conjecture stated by Pirashvili in [ 9].
Trade in electricity under WTO and EAEU Law: compatibility of two legal regimes†
Authors: Boklan Daria , Belova Olga
Published: April 2020

Accession of Russia and Kazakhstan to the World Trade Organization (WTO) constitutes a landmark event in the history of this organization, especially in relation to trade in energy, in general, and trade in electricity, in particular. As a result, the role of the WTO in regulating trade in electricity has increasingly grown. However, the Treaty on the Eurasian Economic Union, a treaty that binds both Russia and Kazakhstan, necessitates additional regulation for trade in electricity, concurrent with law of the WTO. Recently, this treaty was amended by the Protocol on Common Electricity Market on 1 July 2019. As a result, compatibility issues between the rules of the WTO and the Eurasian Economic Union arise. This article concludes that the law of the WTO can be relevant to trade in electricity between Member States of the Eurasian Economic Union and third countries because of the specific place of the rules of the WTO under the Eurasian Economic Union legal order.
Preparing Social Workers to Confront Social Injustice and Oppression: Evaluating the Role of Social Work Education
Authors: Goode Rachel W. , Cowell Mariah , McMillan Dielle , Van Deinse Tonya , Cooper-Lewter Courtney
Published: April 2020

Since the presidential election of 2016, bias-related incidents, hate-filled rhetoric, and extremist violence have been increasing in the United States. Because social workers are often working with individuals and communities affected by these incidents, practitioners may have increasing responsibility to confront social injustice and oppression. However, limited evidence on the preparedness of social workers to assume this responsibility, particularly among those who are still students, exists. To address this gap, this study used focus group and survey data from the Diversity and Oppression Scale to explore the preparedness of MSW students (N = 22) to confront oppression. Six themes were identified as integral to student experiences in their programs: (1) social worker responsibility to confront oppression, (2) use of dominant group discourse on oppression, (3) variation in faculty preparation and comfort, (4) a focus on knowledge of oppression versus skills and process, (5) role of personal responsibility and experience in student preparation, and (6) strategies to increase student preparedness to confront oppression. Factors identified to enhance students’ level of preparedness include faculty opportunities for development, changes to the explicit and implicit curriculum, and creating a formalized way to integrate topics on oppression and diversity into all facets of the curriculum.
Correlations Between the USMLE Step Examinations, American College of Physicians In-Training Examination, and ABIM Internal Medicine Certification Examination
Authors: McDonald Furman S. , Jurich Daniel , Duhigg Lauren M. , Paniagua Miguel , Chick Davoren , Wells Margaret , Williams Amber , Alguire Patrick
Published: April 2020

Purpose

To assess the correlations between United States Medical Licensing Examination (USMLE) performance, American College of Physicians Internal Medicine In-Training Examination (IM-ITE) performance, American Board of Internal Medicine Internal Medicine Certification Exam (IM-CE) performance, and other medical knowledge and demographic variables.

Method

The study included 9,676 postgraduate year (PGY)-1, 11,424 PGY-2, and 10,239 PGY-3 internal medicine (IM) residents from any Accreditation Council for Graduate Medical Education–accredited IM residency program who took the IM-ITE (2014 or 2015) and the IM-CE (2015–2018). USMLE scores, IM-ITE percent correct scores, and IM-CE scores were analyzed using multiple linear regression, and IM-CE pass/fail status was analyzed using multiple logistic regression, controlling for USMLE Step 1, Step 2 Clinical Knowledge, and Step 3 scores; averaged medical knowledge milestones; age at IM-ITE; gender; and medical school location (United States or Canada vs international).

Results

All variables were significant predictors of passing the IM-CE with IM-ITE scores having the strongest association and USMLE Step scores being the next strongest predictors. Prediction curves for the probability of passing the IM-CE based solely on IM-ITE score for each PGY show that residents must score higher on the IM-ITE with each subsequent administration to maintain the same estimated probability of passing the IM-CE.

Conclusions

The findings from this study should support residents and program directors in their efforts to more precisely identify and evaluate knowledge gaps for both personal learning and program improvement. While no individual USMLE Step score was as strongly predictive of IM-CE score as IM-ITE score, the combined relative contribution of all 3 USMLE Step scores was of a magnitude similar to that of IM-ITE score.
Comprehensive Clinicopathologic Analyses of Acquired Cystic Disease–associated Renal Cell Carcinoma With Focus on Adverse Prognostic Factors and Metastatic Lesions
Authors: Kojima Fumiyoshi , Gandhi Jatin S. , Matsuzaki Ibu , Iba Akinori , Collier Scott , Yoshikawa Takanori , Kinoshita Yuichi , Warigaya Kenji , Fujimoto Masakazu , Kuroda Naoto , Morii Eiichi , Hara Isao , Murata Shin-ichi , Amin Mahul B.
Published: April 2020

Acquired cystic disease of kidney–associated renal cell carcinoma (ACD-RCC) is a distinct subtype of renal cell carcinoma with unique morphologic and clinicopathologic features. Generally, ACD-RCC is regarded as an indolent tumor; however, prognostic and outcomes data have been conflicted by the limited and relatively low number of cases with patient follow-up or adverse events. In this study, we focused on the histology of metastatic lesions and identifying prognostic factors associated with metastatic progression. From 32 cases in the cohort, 9 patients had metastasis [ACD-RCC (M+)] and 23 patients were without metastasis [ACD-RCC (M−)]. The median age of patients was 52 years; right side, n=10; left side, n=18; bilateral, n=4; median tumor size=2.6 cm; median hemodialysis duration=17 y; and the median duration of follow-up was 50 mo. Immunohistochemistry showed ACD-RCC to be racemase positive and CK7 negative to focally positive within tumor cells, with consistent positivity for renal histogenesis-associated markers (PAX8 and RCC antigen); S100A1 was a less reliable marker at metastatic sites. All metastatic ACD-RCC except 2 cases involved lymph nodes (para-aortic, renal hilar, subclavicular). Overall, 6/9 (67%) had visceral metastasis to sites including lung (n=3), liver (n=3), bone (n=5), stomach (n=1), and brain (n=1). In total, 5/9 (56%) metastatic tumors had distinctive cystic growth pattern at the metastatic site; intriguingly metastatic tumors had intrametastatic oxalate crystal deposition, a pathognomonic feature associated with primary tumors. Four of nine (44%) patients with ACD-RCC (M+) had fatal outcomes due to metastatic disease. Clinically significant adverse prognostic features associated with metastasis [median follow-up 47 mo, ACD-RCC (M+) vs. ACD-RCC (M−), 50 mo] included: duration of hemodialysis (≥20 vs. <20 y, P=0.0085) and tumor necrosis (P=0.049). Because of sufficient overlap between these parameters, the study was not able to identify parameters that would be reliable in further management strategies, in clinical settings. Our data indicate that ACD-RCC is a tumor which has distinct metastatic potential with nodal and visceral tropism and proclivity for cystic morphology at metastatic sites; this is the first report of the presence of oxalate crystals in metastatic tumors. Our data suggest that ACD-RCC patients with prolonged hemodialysis and tumoral coagulative necrosis require additional surveillance in view of the association of these parameters with metastatic progression.