bluuebunny/crossref_metadata_2025 huggingface dataset:
Sub- and supercritical water in the processes of conversion of Domanik rock organic matter
Authors: Nasyrova Z.R. , Kayukova G.P. , Chemodanov A.E. , Vakhin A.V.
Published: June 2021

Studies on the conversion of organic matter of high-carbon Domanik (siliceous-clay carbonate) rock of the Romashkinskoye deposit with a mineral content Corg of 7.07% in sub- and supercritical water have been carried out. It was shown that subcritical water at a temperature of 320°С and 17.0 MPa leads to a partial decomposition of the kerogenic structure, increasing the yield of bitumen from 3.12 to 3.98%, and a more complete recovery of asphaltenes and heavy C22-C30 n-alkanes from the rock sample. Supercritical water at temperatures of 374 and 420°C and pressures above 24.4 MPa leads to intensive formation of hydrocarbon and inorganic gases in the processes of kerogen decomposition, destruction of aliphatic substituents from condensed heteroatomic structures of resins and asphaltenes, and the carbonate component of Domanik rock. Degradation of the organic matter of the Domanik rock is also accompanied by the formation of saturated hydrocarbons with an increased content of light C12-C21 n-alkanes, and carbonaceous substances, such as carbene-carboids. Changes in the structure of asphaltenes and their paramagnetic properties were determined by the EPR method. The influence of sub- and supercritical water on phase changes in the composition of rock minerals, as well as on the yield and composition of formed gases, was revealed.
Physical modeling of the Bazhenov formation in combination with CSEM and seismic methods
Authors: Ananyev V.V. , Grigoryev G.S. , Gorelik G.D.
Published: June 2021

To predict the properties of the Bazhenov formation and to identify the areas in which oil deposits are localized the use of electrical prospecting methods is promising. The main goal of the current research is to evaluate the effectiveness of using Controlled Source Electro Magnetics (CSEM) exploration for the area forecast of the properties of the Bazhenov formation. The main objectives of physical modeling in this research are: Creation of an isotropic physical model corresponding to the electrical and elastic parameters of the section of the studied area, and performing 3D modeling on it with survey parameters that reproduce real seismic and CSEM surveys To convince that the contrast of the elastic properties and the ratio of the resistivity of the target interval of the Bazhenov formation and overlying rocks in the created physical model corresponds to the real petrophysical characteristics of the section of the studied area; Obtaining initial data for testing algorithms for synchronous inversion of seismic + electric and testing various approaches to processing and interpretation of CSEM and 3D seismic data.
Petrological features of picrobasaltic melts on Lanzarote, Canary Islands
Authors: Canhimbue L.S. , Mezhelovskaya S.V. , Erofeeva K.G.
Published: June 2021

The paper discusses issues related to the petrology of picrobasaltic melts forming lava flows on Lanzarote, Canary Islands. During ascientific and educational expedition on the aforementioned island, lava flows of picro basalt of the third phase of the 1731–1732 eruption were studied and tested. Preference was given to the well-preserved streams in the west and south of the island thatare accessible for direct study. Volcanogenic-sedimentary associations were identified in the studied outcropsand described, the structural and textural features of the flows were characterized, and samples with mantle rock xenoliths were taken for petrological reconstructions. New geochemical data onrocks and minerals are presented. It was established that the temperature of the initial melt was 1100–1180°C. Large harzburgitephenocrysts in picro basalt are xenocrysts formed as a result of melting and disintegration of mantle xenoliths.
The hydrocarbon compounds sources in surface sediments of the Laptev Sea shelf
Authors: Oberemok I.A. , Gershelis E.V.
Published: June 2021

Rapid warming of the Arctic provokes large-scale degradation of permafrost on land terrestrial and in submarines. A vast amount of remobilized organic matter (OM) is involved in the modern biogeochemical cycle. Understanding of the fate of terrestrial OM moving from the land to the Arctic shelf is essential for predicting the potential feedback of Arctic ecosystems. In our research, an attempt was made to characterize the modern OM stored in the surface sediments of the Laptev Sea to estimate its composition variability and to identify the OM sources along with the “coastline - outer shelf” profile. Here we discuss the OM features revealed by Rock-Eval pyrolysis (RE) and the distribution of n-alkanes in combination with sediment grain-size analysis. The GC/MS records are directly comparable with RE data tracing the terrestrial OM along with the entire studied profile. However, we observe both a significant decline of terrestrial input and the rise of hydrobiont in the outer shelf zone. We assume that different OM sources may produce different ranges of RE values.
Justification of the line of action for reclamation of lands disturbed by opencast mining
Authors: Smirnov Y.D. , Suchkov D.V. , Goryunova T.V.
Published: June 2021

The article is devoted to the substantiation of the line of action for reclamationof disturbed lands. The object of reclamation is a land plot (Russia, Leningrad Region), disturbed as a result of unauthorized open-pit mining operations for the extraction of limestone. In order to obtain the information necessary to justify the reclamation project, the following works were carried out: reconnaissance and route observations, topographic, geological, and environmental surveys of the land. Based on the results of the generalized study data of the environmental and economic justification, a line of action for agricultural reclamation was chosen. In addition, an assessment of the estimated cost of the event was carried out and a list of necessary works was proposed within the framework of the technical and biological stages of reclamation.
Steganography in Frames of Graphical Animation
Authors: Balagyozyan L.A. , Hakobyan R.G.
Published: June 2021

Information exchanged between two parties is often targeted by a third party. Steganography in images is often used for handling threats, such as, in this case, an attacker suspecting the existence of confidential information. But even in this case, if a pattern is used, e.g., hiding the information in successive or every third pixel, the attacker might discover the pattern, and the following revelation of the secret information will cause no difficulties. To avoid such vulnerabilities, the information is hidden in the frames of graphical animation. In the frames, the positions of the pixels selected to store confidential information in the given work are determined by the values of a mathematical function. These actions will ensure the high secrecy of information.
Effects of straw’s comprehensive utilization-technology on agricultural carbon emission in Jiangsu Province
Authors: Qin Xue , Yan Jun , Zhu G.Y.
Published: June 2021

Straw resources are abundant in Jiangsu province, the utilization and burning of straw is an important problem in agriculture carbon emission reduction. In order to analyze the effect of straw’s comprehensive utilization technology on agricultural carbon emission, the STIRPAT model is introduced, which takes straw utilization technology as the core explanatory variable while other influencing factors as control variables, and the ridge regression is adopted to conduct an empirical analysis on the influencing factors of agricultural carbon emission in Jiangsu province from 2008 to 2018. The results demonstrate that for every 1% increasing of straw’s comprehensive utilization technology, agriculture carbon emission will be reduced by 0.17%; the labor force is the biggest driver of agriculture carbon emissions; agriculture economic development, energy consumption takes a certain inhibitory effect on agriculture carbon emissions, but not very great.
Environmental flow assessment in the Lower Yellow River using habitat simulation and hydrological reference system
Authors: Shang Wenxiu , Yan Dengming , Peng Shaoming
Published: June 2021

The accuracy of the habitat simulation method is often questioned due to limited simulated elements and indicator species. This study established an environmental flow assessment method by coupling fish habitat simulation with hydrological reference system. The environmental flow obtained through the habitat simulation method was corrected by the statistical characteristics of natural flow regime. The environmental flow of the Huayuankou section in the Lower Yellow River was assessed. The results show that the environmental flow demand of the Huayuankou section is 7.9 - 15.4 billion m3/y without consideration of sediment transport. An environmental baseflow of 220 - 400 m3/s is required throughout the year. One to two high flow pulses are needed in the rising-water season to trigger spawning, followed by flow events of 350 - 500 m3/s with more than 1 week duration to create the spawning grounds.
Research Status of Defrosting Technology of Air Source Heat Pump
Authors: Kun Cheng , Bingzhan Liu , Guangpeng Li
Published: June 2021

Air source heat pump has the characteristics of high efficiency, energy saving, green and pollution-free, and has been widely used in building energy saving projects. However, the frosting phenomenon of the air source heat pump evaporator during the heating operation in cold areas in winter will reduce the heat production of the system, affect the comfort experience, and even cause the system down or irreversible damage to the heat pump system when the frosting is serious. This paper summarizes the research of domestic and foreign scholars on air source heat pump defrosting, analyzes the existing problems of defrosting technology, and finally looks forward to the future development trend of air source heat pump defrosting research.
Phytoplankton Community Investigation and Water Quality Assessment of M River in winter in Shijiazhuang City
Authors: Zhang Ziqi , Yang Lei , Han Dongxu , Shen Hongyan
Published: June 2021

An investigation of phytoplankton community and water quality for M River was conducted in December 2019.The results showed that 38 species of phytoplankton belonging to 6 phyla and 26 genera were collected. Among them, Bacillariophyta is the richest species, which accounted for 34.21%, followed by Cyanophyta with 26.32% and Chlorophyta with 28.95%. The density of phytoplankton was 63.0*106 inds/L which indicated as eutrophic water body. The highest density was Bacillariophyta, accounting for 51.03%. The Shannon-Wiener diversity index (H’) varied from 1.34 to 2.24, the Margalef Species diversity index (d) varied from 2.71 to 3.85, and the Pielou evenness index (J) varied from 0.38 to 0.67. According to the integrative analysis results of H’, d and J, M River water quality belongs to oligo-polluted, but individual sites belong to meso-polluted.
Wind-induced vibration piezoelectric energy collection in ventilation tunnels
Authors: Zhou Daiyong , Lin Yin , Ren Gaojian , Shao Yan
Published: June 2021

Ventilation tunnel wind-induced vibration piezoelectric energy collection MFC as vibration energy in the ventilation tunnel and stores it in the energy storage device to provide the electrical energy required by the wireless sensor in the tunnel. According to the piezoelectric effect of piezoelectric materials, the instantaneous accumulated positive and negative charges generated at both ends of the piezoelectric vibrator at the instantaneous wind speed and wind vibration in the tunnel are collected. By establishing a piezoelectric energy collection model, the irregular transient charges are captured and stored as Available direct current. The piezoelectric energy harvesting model uses wind speed rotation as the traction force to drive the piezoelectric vibrator to vibrate, thereby converting wind energy into instantaneous electrical energy, and using the electrical energy harvesting device to store the electrical energy in the energy storage device. Experiments verify that when the wind-induced vibration piezoelectric energy collection model of the ventilation tunnel is at a wind speed of 8m/s, the maximum output voltage of the energy storage device is 42.2V, which can meet the power supply requirements of wireless sensors in the ventilation tunnel.
Noise Prediction of Centrifugal Fan Based on Improved Nenral Network
Authors: Long Bo , Jiang Shuxia , Zhang Changwei , Liu Wen
Published: June 2021

In order to solve the problems that the prediction accuracy of the traditional centrifugal fan is low and the cost is high, a noise prediction model for centrifugal fan based on improved particle swarm optimization (IPSO) optimized BP neural network was presented. The initial weights and thresholds of BP neural network were optimized by using IPSO. The 17 parameters were collected by the liancheng company and be used to establish the regression equation to obtain the standard regression coefficient. The importance of the fan parameters was ranked and four key characteristic parameters were determined as input values by the optimization algorithm to build the IPSO-BP centrifugal fan noise prediction model. After comparative study, IPSO-BP model has better prediction effect than PSO-BP model and BP model, and the prediction error is only 0. 97%. The research shows that IPSO-BP model can effectively shorten the fan design period and save the design cost.
Analysis of Wind Power Grid Connection Based on MATLAB
Authors: Mao Yuyang , Wang Xiaolong , Wang Zhiqiang
Published: June 2021

As the proportion of new energy sources such as wind power and photovoltaics in the power system continues to increase, their volatility and intermittentness have also brought new challenges to the stable operation of the power grid. The impact of the decline in power quality caused by a large number of wind power grids has become increasingly significant. This article analyzes and summarizes the development, status quo of wind power and the current problems of a large number of wind power grid connections. First, it briefly describes the history of wind power and the current development of wind power, and uses MATLAB to establish models of variable speed wind turbines connected to the grid. The models are used to analyze the output characteristics of wind turbines under normal operating conditions and faulty operating conditions. Finally, the impact of a large number of wind power grids on the power system is studied.
Influence of reheat pressure on reheat cycle economy
Authors: Wang Yarong , Wang Peirong
Published: June 2021

After steam expands to a certain intermediate pressure in steam turbine, it is led out of steam turbine and sent to reheater of boiler. The steam is heated to the initial temperature by constant pressure in the reheater. After that, the steam is introduced into the steam turbine and continues to expand to the exhaust steam pressure. The steam after work enters the condenser for cooling and heat release. Such a steam power cycle is a reheat cycle. The purpose of reheat cycle is to solve the contradiction that the dryness of exhaust steam decreases after the application of high parameters in steam power cycle. Through theoretical study and qualitative analysis, we know that the correct selection of reheat pressure can not only improve the steam turbine exhaust dryness, but also improve the thermal efficiency of the cycle. Reheat pressure is very important to the economy of reheat cycle and the safe operation of equipment. The correct choice of reheat pressure will affect the economy of the whole cycle.
Coral sand from hydraulic reclamation for the remediation of acid sulfate soil
Authors: Zeng Jiachen , Hao Yuchi , Sun Wenbo , Wei De , Tao Runli , Shi Baolin , Zheng Jianfei , Zhang Zhen
Published: June 2021

For the first time, Coral sand, as the main geotechnical material in reclamation, has the characteristics of loose and porous structure, relatively small volume and mass, easy to break and high compression, and high calcium carbonate, which may be a natural material to control acid release of acid soil. In this paper, by studying the neutralization effect of coral sand under different sand ratio, particle size and adding methods, the optimal dosage and particle size of coral sand and the adding sequence were determined under typical acid soil conditions; The neutralization performance of different neutralizing materials was compared through internal structure characterization, and the structural advantages of coral sand were explored. The results show that the specific surface area of coral sand was 1.2361m2g-1, second only to calcite and shell powder. The particles were evenly distributed and can fully react with sulfuric acid to produce CaSO4 precipitation. When the addition of coral sand was 9% (Ca: S = 18:5), the PASS can be neutralized to pH > 6.5. The PASS neutralization ability of coral sand was related to particle size. The overall trend was that the smaller the particle size, the stronger the neutralization ability. The best effect was at 0.15mm, when the particle size exceeded 0.27mm, the neutralization ability began to decline.
Advances on the application of biochar in radioactive wastewater treatment
Authors: Zizhen Bao , Dong Liang , Honghui Li , Yuchen Liu , Anxi Cui
Published: June 2021

The domestic and foreign scholars found that biochar prepared from waste crops, animal manure, and tissues has a good adsorption effect on radioactive pollutants. Biochar is an ideal material for the adsorbent. This article summarizes the preparation methods and modification methods of biochar, and the adsorption characteristics of biochar to heavy metals and radioactive elements. This article also points out the problems and development trends in the current research of biochar.
Application and analysis of carbon dioxide refrigeration system with ejector in commercial super cold cabinet
Authors: Guangpeng Li , Yingli Zhou , Qi Wang
Published: June 2021

In this paper, the transcritical CO2 refrigeration system with ejector is applied to a commercial ultra-cold cabinet. The influence of the key operating parameters of the ejector on the system performance is analyzed, and the measurement method of the experimental parameters is proposed. The results show that the ejector can eject the low pressure refrigerant into the reservoir by using the energy of the large pressure difference throttle, and the COP of the system can be increased by 9%-19%. This paper provides a theoretical basis for the design, development and optimization of CO2 refrigeration and air conditioning system with ejector.
Effect of current on biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) for nitrate removal from wastewater
Authors: Liu Hengyuan , Zhang Chenhe
Published: June 2021

The biofilm-electrode reactor coupled with sulfur autotrophic denitrification process (BER-SAD) was used to remove nitrate in groundwater, and the effect of current intensity on the denitrification characteristics of the coupled process was explored. Current intensity had a great influence on the denitrification effect of the coupled process, the maximum nitrate removal efficiency of 99.9% and lowest nitrite production were gained under the optimum current density of 100 mA. Moreover, the accumulation concentration of SO42- increased gradually with the increase of current intensity. With the increase of current intensity, the proportion of hydrogen autotrophic denitrification decreased, while the proportion of sulfur autotrophic denitrification increased.
Sanitary wares (Wash-basin) product industry situation and quality analysis
Authors: Yin Wen , Wang Kaifang
Published: June 2021

Sanitary ceramic products refer to glazed ceramic products used for sanitary installations. Sanitary wares products are divided into ceramic Sanitary wares and ceramic Sanitary wares according to different materials. According to use divide for implement kind, basin kind. The urinal type includes sit urinal, squat urinal, urinal; The basin category includes the Wash-basiner, washing tank, mop pool and so on. Among them, the Wash-basiner refers to the glazed ceramic products used for washing face and hands. It is a necessary sanitary equipment in family or public places and has become an essential sanitary appliance in people’s life.
Potential Molecular Mechanism of Rubi Fructus in the Treatment of T2DM Based on Multidimensional Biological Network
Authors: Huang Wenjing , Hong Jiana , Chen Wenlu , Li Bingbing , Li Shasha , Chen Guoliang , Xiao Xue
Published: June 2021

Objective: To explore the potential targets and underlying mechanism of Rubi Fructus in the treatment of type 2 diabetes mellitus. Methods: Potential active components of Rubi Fructus were proposed by literature search and as well followed the Lipinski’s Rule of Five. The therapeutic targets of potential active components and T2DM-related genes were selected through Swiss target prediction and Gene Cards. The network of potential active components and T2DM-related targets were constructed by Cytoscape 3.7.2, and STRING analysis was performed to reveal the interaction among target proteins and to build the network of protein-protein interaction. Both Gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) enrichment analysis of core targets were performed using David database. Results: Totally, 68 potential active components of Rubi Fructus and 196 T2DM-related targets were found. Among them, 39 key targets were obtained by network analysis, which were primarily enriched on PI3K-Akt, HIF-1, TNF, Toll-like receptor, and Focal adhesion signaling pathways. Conclusion: For the treatment of T2DM, the active compounts of Rubi Fructus can regulate the expression of proinflammatory and oxidative stress mediators and improving insulin resistance through multiple components, targets, and pathways, which offers a scientific support to further Rubi Fructus studies and to the research on T2DM treatment.
Innovative immunotherapy targeting at PD-1/PD-L1 signaling pathway: mechanism, efficacy and safety analysis of monotherapy and combination therapies in non-small cell lung cancer (NSCLC) treatment
Authors: Song Zhixuan , Lin Yimiao
Published: June 2021

Lung cancer remains a leading cause of cancer-related mortality worldwide with a poor prognosis. Conventional therapies are most commonly used in all kinds of treatment because of their relatively high efficacy in killing tumor cells at first. However, as treatment time increases, this efficacy would gradually decrease, along with unavoidable and growing resistance and multiple and serious side effects. At this point, immunotherapy, including anti-PD-1 and anti-PD-L1 antibodies, renders an innovative and more effective way to take advantage of our own immune response to kill cancer cells. It is confirmed to have greater efficacy and safety of immunotherapy over conventional therapies in various cancer treatments, including non-small cell cancer. Combining conventional therapies can also lead to synergistic effects in controlling and killing cancer cells. The purpose of this summary is to verify the efficacy and safety of immune checkpoint inhibitor monotherapy and the synergistic effects of combination therapy with chemotherapy and radiotherapy. This review will introduce the mechanism, efficacy, and safety of immune checkpoint inhibitor monotherapy and combination therapies with chemotherapy and radiotherapy via a summary and interpretation of related preclinical and clinical trials.
Fouling microorganisms in the reservoirs of the groundwater treatment system
Authors: Litvinenko Zoia , Kondratyeva Liubov , Golubeva Evgenia
Published: June 2021

The work discusses the features of the structure of fouling (biofilms) formed in the water treatment system of the iron-bearing groundwater of the Tungusskii deposit (Far East, Russia). The main factors affecting the composition of biofilms are trace amounts of organic substances, oxygen, different phylogenetic composition of microbial communities and their ability to form a polysaccharide matrix. The formation of structured communities in biofouling of the water treatment system can have a negative impact on the organoleptic characteristics of drinking water due to the formation of complex trophic connections.
Study on strata behavior law of weak cohesive roof in deep buried fully mechanized top coal caving face
Authors: Ren Qihan
Published: June 2021

In view of the severe ground pressure behavior and spontaneous combustion risk of goaf in fully mechanized top coal caving face with deep buried weak cohesive roof and thick coal seam prone to spontaneous combustion, combined with theoretical analysis of mining overburden structure and field engineering practice, the structural characteristics of overburden rock and strata pressure behavior law are studied. The results show that: the deep buried thick coal seam fully mechanized top coal caving stope also has the phenomenon of surface step subsidence. Compared with the shallow coal seam, the surface subsidence is relatively slow, and the weak adhesion of the roof leads to the short periodic weighting step distance of the stope, and the average step distance is 9.9m. The measured peak value of advance abutment pressure is 7~10.5m in front of coal wall. According to the mine pressure control and fire prevention demand of goaf, the reasonable advancing speed is 4~5m/d.
Failure analysis for tube bundle of methanol condensation recovery heat exchanger
Authors: Chengjun Jiang , Wei Wang , xiaolong Xue , gaoping Fan , Xin Wang
Published: June 2021

The S30408 tube bundle of methanol condensation recovery heat exchanger in a chemical company was found leaked during use. The cause of tube bundle leakage was analyzed by means of macroscopic inspection, chemical composition analysis, metallographic analysis, hardness test and leakage fracture analysis. The results show that formic acid and chloride condensate are formed by the exhaust gas in the shell side near the outlet of the shell side, which results in the spot corrosion and stress corrosion cracking of the tubes. Surface coating or replaced material is recommended to prevent such failure.
Application of fine structure interpretation and reservoir prediction technology in Beier Sag
Authors: Zhang Bin
Published: June 2021

After years of exploration in Beier Sag, the exploration is becoming more and more difficult. Beier Sag is characterized by many faults and complex structures. For a long time, the exploration and development effect of many fault blocks is not good due to unclear structure and poor reservoir prediction effect. Therefore, through the close combination of Geology and earthquake, we need to use the fine structure interpretation technology to interpret the seismic data carefully, and on this basis, we need to carry out the fine characterization of favorable reservoirs through the appropriate reservoir prediction technology. The fusion frequency inversion technology is based on improving the resolution through different inversion methods, combining with dominant frequency fusion, applying simulated annealing inversion and geostatistics (SMI) inversion to calculate separately, then fusing the inversion results of dominant frequency, and interpreting the fusion results, and finally accurately predicting the reservoir distribution in the fan body, favorable exploration targets should be implemented.
Numerical simulation of NO emission reduction in coke oven regenerator with synergistic SNCR/SCR process
Authors: Zhao Yujie , Feng Junxiao
Published: June 2021

According to the temperature gradient distribution characteristics of the regenerator of the coke oven, a method of synergistic the SNCR/SCR process inside the regenerator to achieve NO emission reduction was proposed in this work. Based on the verification of SNCR and SCR models, the NH3/NO concentration field and the spatial distribution characteristics of NO in the process of SNCR, SCR, and SNCR+SCR were studied. The conclusion shows that the synergistic SNCR and SCR processes had achieved NO reduction by 64.3% and 37.1%, respectively. However, the increase in reaction temperature caused by the change of injection position resulted in a 0.4% decrease in SNCR+SCR compared to SNCR. It was also found that temperature dramatically influences the SNCR process and the reductant injection position. Limited by the structure of the regenerator and the catalyst coating area, the SCR process exhibited a low NO reduction ability. The SNCR+SCR process should focus on improving the efficiency of the SCR process.
Research progress of carbon based nanoenzyme and composites in antibacterial field
Authors: Zhao ChuanXin , Gu QiaMin , Chen GaoYun , Yu MengBin , Liu Min
Published: June 2021

Due to the abuse of antibiotics, more and more bacteria are resistant to antibiotics. Non antibiotic nano antibacterial materials emerge as the times require. Carbon based nano enzyme is an efficient and environmentally friendly antibacterial material with certain antibacterial effect. It has simple structure and good compatibility. It can be combined with a variety of antibacterial substances to form composite antibacterial materials, expand the scope of antibacterial and improve the antibacterial ability. This paper summarizes the research progress of three kinds of carbon based nanoenzymes including carbon nanotubes, graphene, carbon quantum dots and their composites in the field of antibacterial.
Comparison of Grounding Grid Parameters Between Copper and Galvanized Flat Steel
Authors: Yu Yue , Li Yanjun , Wang Dehong , Du Rongtian , Jiao Chongqing , Sun Jiwei
Published: June 2021

In the intelligent substation, the shell of the secondary equipment is connected to the ground grid locally. When the short circuit fault current is injected into the grounding grid to cause the ground potential rise, the potential difference between the two points of the grounding grid will affect the normal operation of the secondary equipment. In this paper, aiming at the grounding grid of a 220kV substation, the grounding impedance, ground potential rise and ground potential difference between galvanized flat steel and copper grounding grid are calculated by using CDEGS software. The results show that the copper ground grid has a significant effect on reducing the potential difference of the ground grid.
Study on detoxification property of alkaline-modified MoO42--H2O2 decontaminants against PhSMe under subzero environment
Authors: Wei Shaohua , Zhang Hongpeng , Zhu Haiyan , Wang Lianyuan , Liang Jing , Cheng Zhenxing
Published: June 2021

The decontaminant activated by MoO42- (MoO42--H2O2) suitable for subzero environment shows strong oxidizing ability and weak nucleophilicity due to its acid. In this paper, in order to improve nucleophilicity and retain oxidation of MoO42--H2O2 as far as possible, NH3 and NaOH were used as alkaline modifiers, and PhSMe was used as a simulant of HD to study the oxidation rate and products of sulfides by alkaline-modified MoO42--H2O2 below zero. Results showed that the reaction rate constants decreased with the increase of pH in both NH3 and NaOH modified MoO42--H2O2 at -20°C, and the relative ratio of sulfone to sulfoxide increased especially at pH>9. The reaction activation energy Ea of PhSMe oxidation in the alkaline-modified MoO42--H2O2 decontaminants was lower than that in the MoO42--H2O2 decontaminant, which indicated that the sensitivity of the oxidation reaction rate to temperature in MoO42--H2O2 was reduced after modification.
Optimization of Multi-zone Cooling System of Complex Pipe Network Based on Particle Swarm and Genetic Algorithm
Authors: Xingsheng Lao , Xiaohu Yang , Bangming Li
Published: June 2021

The cooling pipe network system of the power plant has the characteristics of multiple users, multiple working conditions, and complex topological structure. The division of water supply to the pipe network can simplify the topological structure of the pipe network, facilitate flow regulation, and adapt to the requirements of multiple working conditions. District water supply can be divided into districts according to flow, pressure and structure. The user allocation of pipe network water supply system is a typical combined optimization problem. When the system is relatively complex and the number of users is huge, conventional enumeration methods, dynamic programming and other methods are often unable to solve such problems. The combined algorithm of particle swarm algorithm and genetic algorithm can obtain approximate solutions to such problems. By using a combination of particle swarm algorithm and genetic algorithm to analyze and determine the distribution of pipe network user traffic, it is possible to avoid the waste of energy in the distribution of pipe network users based on experience. The combined algorithm proposed in this paper has high stability, can change the number of partitions to adjust user allocation according to actual needs, and has strong versatility. For the case described in this article, when the number of partitions is 2, compared to the cases where the number of partitions is 3 and 4, the flow rate and pressure drop of each partition are not much different, which can better meet the reliability and maintainability requirements
Multi-objective performance optimization of ammonia decomposition thermal storage reactor
Authors: Xie Tianchao , Xia Shaojun , Wang Chao
Published: June 2021

Heat storage technology plays an essential role in the stable operation of solar thermal power generation. In this paper, a one-dimensional model of a tubular filled bed heat absorption reactor for ammonia decomposition is established by applying finite time thermodynamics. Taking the inlet temperature, the outside diameter and the length of the reactor as optimization variables, the multi-objective particle swarm optimization is used to perform multi-objective optimization considering the maximum heat absorption rate and the minimum total entropy generation rate, and the Pareto Fronts are determined under different reactor outer wall temperatures. Finally, three optimized reactors’ design parameters and performance indicators are obtained by LINMAP, TOPSIS and Shannon Entropy decision methods, and the cross-sectional comparisonof the optimal reactors at different outer wall temperatures. Compared to the reference reactor, the three optimized reactors improve heat absorption rate by 58%-143%, while the total entropy generate rate is reduced by 26.4%-38.8%. The obtained results have some guidance for optimal designs of ammonia decomposition reactor in real engineering.
Safe Eating of Fermented Corn and Coconut Food: Mechanism, Clinical Manifestations and Inhibition of Food Poisoning Involved in Bongkrekic Acid
Authors: Huang Qingyu , Wu Zhentian
Published: June 2021

Bongkrekic acid (BA) is a colorless and tasteless toxic. It exists in some fermented food and can be easily taken in by accident. Currently, no proper treatment has not been developed to treat this toxin in human body, therefore the death rate is very high. Mechanism of BA has been well studied these years and found that BA inhibit ATP synthesis, which lead to severe clinical symptoms, such as limb soreness, weakness and liver damage. In this paper, we mainly focus on the mechanism of BA in our human body, its related cases and the inhibition of BA in the food. This review can provide basic information for the future development of the treatment of BA in human body.
Technik und klinische Bedeutung des kardialen Mappings – was der Radiologe wissen sollte
Authors: Pennig Lenhard , Luetkens Julian , Nähle Claas Philip
Published: June 2021

In den letzten Jahren sind die Mapping-Techniken der kardialen MRT vermehrt in das Interesse von Forschung und klinischer Praxis gerückt. Damit kann der Radiologe magnetische (T1-, T2- und T2*-Zeiten) und histologische (Extrazellulärvolumen-Fraktion) Parameter des Myokards quantifizieren und vor allem diffuse akute und chronische Erkrankungen des Myokards besser nachweisen als mit den Standardsequenzen.
Aminothiaindanone as an Accessible Scaffold for a Three-Point Chemical Diversity
Authors: Dallemagne Patrick , Zipfel Pauline , Lalut Julien , Sopková-de Oliveira Santos Jana , Rochais Christophe
Published: June 2021

Aminothiaindanone heterocycle appears to be a scaffold of interest in medicinal chemistry. To increase the chemical diversity in this series, the introduction of three-point chemical diversity on the cyclopenta[b]thiophen-4-one scaffold was explored. About thirty newly functionalized thiophene-containing bicycles were obtained using various chemical reactions, paving the way for novel possibilities in medicinal chemistry projects.
Homologation of Alkyl Acetates, Alkyl Ethers, Acetals, and Ketals by Formal Insertion of Diazo Compounds into a Carbon–Carbon Bond
Authors: Nishimoto Yoshihiro , Yasuda Makoto , Wang Fei , Yi Junyi
Published: June 2021

Homologation of alkyl acetates, alkyl ethers, acetals, and ketals was accomplished via formal insertion of diazo esters into carbon–carbon σ-bonds. The combined Lewis acid InI3 with Me3SiBr catalyzed the homologation of alkyl acetates and alkyl ethers. That of acetals and ketals was catalyzed solely by the use of InBr3. The key point of the homologation mechanism is that the indium-based Lewis acids have the appropriate amount of Lewis acidity to achieve both the abstraction and release of leaving groups. The abstraction of a leaving group by an indium-based Lewis acid and the electrophilic addition of carbocation or oxonium intermediates to diazo esters followed by the rearrangement of carbon substituents provide the corresponding cation intermediates. Finally, the leaving group that is captured by the Lewis acid bonds with cation intermediates to furnish the homologated products.
The Impact of COVID-19 Disease on Urology Practice
Authors: Moussa Mohamad , Chakra Mohamed Abou , Papatsoris Athanasios G. , Dellis Athanasios
Published: June 2021

The diagnosis and timely treatment of cancer patients should not be compromised during an infectious disease pandemic. The pandemic of coronavirus disease 2019 (COVID-19) has serious implications on urology practice and raises particular questions for urologists about the management of different conditions. It was recommended to cancel most of the elective urological surgeries. Urological cancers surgeries that should be prioritized are radical cystectomy for selective tumors, orchiectomy for suspected testicular tumors, nephrectomy for c T3 + , nephroureterectomy for high-grade disease, and radical adrenalectomy for tumors >6 cm or adrenal carcinoma. Most prostatectomies can be delayed without compromising the survival rate of patients. Urological emergencies should be treated adequately even during this pandemic. There is a potential risk of coronavirus diffusion during minimally invasive procedures performed. It is crucial to use specific precautions when urologists performed those type of surgeries. It was also recommended to suspend the kidney transplantation program during the COVID-19 pandemic except for specific cases. In this review, we discussed the triage of urological surgeries, the risk of minimally invasive urological procedure, the kidney transplantation challenges, the systemic therapies, intravesical instillation of Bacillus Calmette-Guérin (BCG), endourology, teleconferencing, and telemedicine application in urology during the COVID-19 pandemic.
Central Venoplasty in Patients with Cardiac Implantable Electronic Devices
Authors: Aljarie Mohammed , Alahmari Mohammed , Arabi Mohammad
Published: June 2021

Objective The aim of this study was to assess the safety and effectiveness of the central venous angioplasty in patients with central venous occlusion and cardiac implantable electronic device (CIED) without lead extraction.

Materials and Methods A retrospective study was used to evaluate the effectiveness of 37 central venous angioplasty procedure for 15 patients with CIED without lead extraction.

Results Technical success was achieved in 97% (n = 36/37) and clinical success was achieved in 89% (33/37) of the procedures. One procedure failed recanalization of chronic total occlusion of the left subclavian vein, and the patient required fistula embolization due to severe arm swelling. Another procedure failed initially to recanalize long-segment occlusion involving the right subclavian vein/brachiocephalic vein and superior vena cava in a patient with a history of Hickman line and left-sided CIED. This was successfully recanalized and angioplastied on a subsequent session. No lead fracture or dislodgment was documented in any procedure. No procedure-related complication was documented within 2 weeks after the angioplasty. Six-month primary patency was achieved in 62% (23/37) of the procedures. Ten patients (66%) required an average of 1.4 reinterventions (range: 1–4 interventions) during the follow-up time with mean time to reintervention of 318 days (5–1,380 days). Two patients required early reinterventions within 10 days due to catheter dysfunction.

Conclusion Findings of this study support the existing evidence on the safety and effectiveness of balloon angioplasty without lead extraction.
Optimization of the performance of a voltage measuring station using genetic algorithm
Authors: Nooruddin Mehbub A. K. , Roy Subhasish , Bhandary Nilotpal
Published: June 2021

This article describes the use of the genetic algorithm (GA) for the optimization of the performance of a voltage measuring station. This procedure can be used for the instruments for which regular and systematic calibration is required for better performance. Here, a GA-based correction module has been used to internally store a few previous measured-value and measured-time pairs and to use these values to correct the current readings. Sanity-checking runs against zero and standard voltages from time to time and auto-calibrates itself. The genetic algorithm libraries have been developed along with the correction module. This system can also be considered as a test bed for the study of self-calibration algorithms.
An extended scaling for the ignition threshold through statistical modeling
Authors: Yang Chen , Zhang Cunbo , Gao Congzhang , Xu Xuefeng , Yu Chengxin , Wang Shuaichuang , Fan Zhengfeng , Liu Jie
Published: June 2021

In laser-driven fusion, determining the ignition margin is an important prerequisite for evaluating the ignition robustness of a target design. The ignition threshold factor (ITF), defined as the shell kinetic energy at the time of maximum implosion velocity divided by the minimum ignition energy of the capsule, is widely adopted as a specific metric of the ignition margin. In this paper, in contrast to previous definitions of ITF, an additional quantity, i.e., the shell aspect ratio (Ar) at the maximum implosion velocity time, is found to have an important influence on the ignition margin. With including the quantity of Ar, we have obtained an extended ITF through the statistical modeling of following two steps with the help of a free available MULTI-IFE code and the PyMC3 Bayesian inference package: first, the sensitivity of the ignition cliff on implosion physical quantities at the maximum implosion velocity time is evaluated and the importance of Ar is revealed; second, an extended ITF that is proportional to Arα(α≈−1.6) is obtained. Our simulations on fusion yields identify a definitive ignition cliff when the extended ITF equals unity. We then conclude that the shell aspect ratio Ar is an important quantity in our extended ITF expression that will be helpful for evaluating and optimizing the ignition target designs and practical implosion experiments.
Hyperdynamics simulations with ab initio forces
Authors: Gu Hong-Yang , Gao Weiguo , Gong Xin-Gao
Published: June 2021

By applying the locally optimal rotation method to deal with the lowest eigenvalue of a Hessian matrix, we have efficiently incorporated the hyperdynamics method into the ab initio scheme. In the present method, we only need to calculate the first derivative of the potential and several more force calls in each molecular dynamics (MD) step, which makes hyperdynamics simulation applicable in ab initio MD simulations. With this implementation, we are able to simulate defect diffusion in silicon with boost factors up to 105. We utilized both direct MD and the hyperdynamics method to investigate diffusion of lithium atoms and silicon vacancies in silicon. We identified the complex diffusion process. The obtained diffusion coefficients of Li atoms and Si vacancies are in good agreement with the direct MD results.
All-optical switch based on novel physics effects
Authors: Qi Huixin , Wang Xiaoxiao , Hu Xiaoyong , Du Zhuochen , Yang Jiayu , Yu Zixuan , Ding Shaoqi , Chu Saisai , Gong Qihuang
Published: June 2021

All-optical switches are among the most important parts of integrated photonics. Ultrahigh speed and ultralow energy consumption are two necessary indexes of all-optical switches. Traditionally, all-optical switches are based on concepts such as micro-ring resonators, surface plasmon polaritons, photonic crystals, and metamaterials. However, such platforms cannot satisfy the demand for high performance of all-optical switches. To overcome the limited response time and energy consumption, recent studies have introduced new applications of such physics as parity–time symmetry, exceptional points, topological insulators, and bound states in a continuum. Such physical concepts not only provide promising research avenues for the all-optical switch but also broaden the design channel. This is expected to achieve ultracompact, ultrafast, and high-capacity all-optical information processing.
Probabilistic effects of porosity and chemical kinetics on the shock initiation of an octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) based explosive
Authors: Miller Christopher M. , Springer H. Keo
Published: June 2021

We investigate the effects of porosity and chemical reactivity on the shock initiation of an HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine)-based polymer bonded explosive due to thin flyer impact using two-dimensional mesoscale simulations. Microstructural samples are computationally generated, and the calculated shock response is compared to experiments. The sample dimensions are 0.1 × 1.05 mm2, and each sample accounts for grain scale heterogeneities, including randomized grain morphology and pore spacing. Simulations are performed using the Lawrence Livermore National Laboratory (LLNL) arbitrary Lagrangian–Eulerian multi-physics code ALE3D. Chemistry and equation of states are handled with LLNL's thermochemical code Cheetah. We employ a modified Arrhenius-based chemical kinetics model that scales the temperature exponent fitting parameter with flyer shock conditions. This new model is calibrated to the mean response of experimental shock initiation thresholds for three separate Kapton flyer thicknesses. A simplified shock initiation criterion is proposed, which classifies the macroscale initiation response based on cross-sectional temperature profiles of the shocked sample. This criterion is used to further investigate the probabilistic response of the sample to variations in the mean porosity and chemical kinetics rate, and we find an inverse correlation between the shock pressure and the confidence interval of the experimental threshold velocity. The methodology presented in this work for quantifying the probabilistic nature of shock initiation is material agnostic. These mesoscale studies may be used to inform continuum scale models and expedite the development of future, tailored energetic formulations.