The challenges of COVID-19 control policies for sustainable development of business: Evidence from service industries

Such large-scale disruptions as the pandemic increase the uncertainty and risk related to business. Therefore, the business continuity management (BCM) has become an essential technical solution for enterprise emergency response. Since the beginning of 2020, the COVID-19 has spread worldwide at an alarming rate causing many threats to sustainable development of the business sector. The decline in consumer demand has hugely impacted service industries, such as wholesale and retail sales, tourism. Enterprise production and operations have faced severe challenges. In this study, we develop a risk factor analysis of BCM under the presence of COVID-19 in China. Based on a statistical survey of 940 enterprises in Hangzhou City, China, this study employs ordinal logistic regression to explore the hindering effect of risk factors introduced by the epidemic on business performance. Then, the interpretive structure model (ISM) is applied to analyze the hierarchical structure of the factors under examination. The key factors influencing the enterprise production and operation during COVID-19 outbreak significantly differ across the sub-sectors of the service industry. Therefore, this paper assesses the resilience of the productive technologies and business models of different industries amid the pandemic. This paper proposes epidemic prevention and control strategy focusing on investment and government regulation to ensure sustainable business development.     

Effects of CuO nano powder on performance improvement and entropy production of double-pipe heat exchanger with innovative perforated turbulators

The objective of the present numerical study is to investigate the heat transfer enhancement, entropy generation, and thermal performance of turbulent nanofluids inside double-pipe heat exchangers equipped with novel perforated cylindrical turbulators. Effects of inflow velocity, CuO nanoparticles volume fraction and perforated index are evaluated on the Nusselt number, friction loss, thermal performance factor (η), and viscous irreversibilities of the double-pipe heat exchangers. The newly proposed perforated turbulators with CuO nanopowder with ϕ = 1.5% provide the thermal performance of η = 1.931, which is considerably higher than the other previous studies. The results show that raising PI reduces the turbulent kinetic energy, especially in outer regions of the cylindrical turbulator. The jet formation near the walls and the perforations is the primary physical reason for this. The viscous entropy generation is increased up to 153.0% by increasing the Re number from 6,000 to 17,000 for PI = 8% and DR = 0.7. Thermal boundary layer disruption is the primary physical reason for heat transfer enhancement.     

Policy effectiveness on emissions and cost reduction for hydrogen supply chains: The case for British Columbia

Hydrogen-specific policies are required to accelerate the adoption of low-carbon hydrogen. In this study, a range of economic instruments and regulations were incorporated explicitly to optimize a hydrogen supply chain. The effectivenes of policies aiming to enhance the financial viability of low-carbon hydrogen production was quantified. A spatially explicit, multi-period cost optimization model was developed for light duty hydrogen hydrogen vehicle deployment in British Columbia under three demand scenarios. Subsidies and regulations were coupled to current provincial policies (a carbon tax and a low carbon fuel standard). The results indicated that production tax credits and electricity incentives were up to 24 times more effective in facilitating low-carbon hydrogen production compared to capital subsidies, bans on steam methane reforming or the adoption of higher carbon taxes. The strategic deployment of policies over time was found to be more effective than cumulative subsidies.     

聚乙烯生产工艺技术探析

乙烯经过聚合反应之后,就会直接获取聚乙烯产品,其能够创造显著的经济效益。针对聚乙烯生产工艺技术措施进行分析与研究,才能够选择最优化的生产工艺,能够获取最佳的聚乙烯产品,从而达到市场所需。所以,基于聚乙烯生产工艺技术进行分析,希望能够对其有一个全面的认识。     

Short-Term Relay Quality Prediction Algorithm Based on Long and Short-Term Memory

The fraction defective of semi-finished products is predicted to optimize the process of relay production lines, by which production quality and productivity are increased, and the costs are decreased. The process parameters of relay production lines are studied based on the long-and-short-term memory network. Then, the Keras deep learning framework is utilized to build up a short-term relay quality prediction algorithm for the semi-finished product. A simulation model is used to study prediction algorithm. The simulation results show that the average prediction absolute error of the fraction is less than 5%. This work displays great application potential in the relay production lines.     

Effects of atmospheric exposure on chlorophyll a,biomass and productivity of the epilithon of a tailwater river

Field experiments were conducted to determine the effects of atmospheric exposure on the chlorophyll a content, biomass and gross primary productivity (GPP) of littoral epilithon in the Colorado River below Glen Canyon Dam, Arizona. The chlorophyll a content of the epilithon was much more sensitive to exposure than the biomass. The epilithon was rapidly bleached during summer daytime exposures, but algal filaments remained attached for several weeks after reinundation. The percentage of initial chlorophyll a remaining after one day of exposure was not different from the percentage remaining after two days of exposure. However, significant reductions in chlorophyll a content were detected for daytime exposures as short as six hours. Overall, there were close inverse relationships (r² ≥ 0–73) between the time exposed or cumulative solar radiation (400–700 nm) and the percentage of initial chlorophyll a remaining after reinundation. The GPP of Cladophora glomerata-dommaled epilithon from the permanently inundated channel was 10 times higher than the GPP of epilithon from the zone of daily water level fluctuation. Experimental atmospheric exposure of the epilithon from each zone reduced the GPP, but not the assimilation ratio (GPP per unit of chlorophyll a) of the epilithon. The Glen Canyon epilithon has low resistance to exposure disturbances, and recolonization is slow under hydropower peaking flow regimes. Cladophora glomerata has an important structural role in Glen Canyon, the disruption of which is likely to precipitate effects at higher trophic levels.     

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在油气藏工程研究中，ｔ模型是一个有用的预测模型。文章首次提出ｔ模型参数ｎ的变化范围，提出预测油，气田可采储量，产量和累积产量的方法，为油气田开发管理决策提供了依据。     

Comparison of Economics of Various Ozone Generation Systems

The specific production costs of ozone are presented for a capacity range of 1 to 1,000 kg/h ozone for various plant configurations and air or oxygen as feed gas, and for air preparation, liquid oxygen delivered to site, oxygen produced on–site and/or oxygen recycle systems. The influence of operating parameters such as ozone concentration or on–stream time are studied. Ozone is often considered to be “expensive”. It is difficult to pinpoint the rationale behind this statement. It could be caused by the difficulty to compare a chemical (ozone) which is produced on–site and requires a plant investment, with chemicals (such as chlorine) which are bought as such and delivered to the plant. It is certainly influenced by the fact that the economy of utilizing ozone s i not easily quantified. This paper presents an attempt to quantify the economics of ozone production for a wide range of production capacities, ranging from 1 to 1,000 kg/h. Different operating conditions are compared as well as different plant concepts. In order t o assure a meaningful comparison, certain parameters are common for all cases.     

1，4－丁二醇的生产与应用

本文介绍了世界１，４－丁二醇的现状、生产方法和下游产品的生产。     

张家港润忠公司90t竖炉电弧炉

介绍了亚洲第１台竖炉一张家港润忠公司９０Ｔ单竖炉电弧炉生产简况，并对竖炉不设渣罐的出渣方式及电炉横向纵向布置提出了个人看法。