bluuebunny/crossref_metadata_2025 huggingface dataset:
Multifunctional phononic meta-material actuated by the phase transition in water
Authors: Jin Yuqi , Yang Teng , Dahotre Narendra B , Neogi Arup
Published: April 2023

The functionality of thermally active phononic crystals (PnC) and metamaterials can be greatly enhanced by utilizing the temperature-dependent physical characteristics of heat-sensitive materials within the periodic structure. The phase transformation between water and ice occurs within a narrow range of temperatures that can lead to significant changes in its acoustic transmission due to the modification of the elastic properties of periodic phononic structures in an aqueous medium. A phononic crystal with acrylic scatterers in water is designed to function as an acoustic filter, beam splitter, or lensing based on the device’s temperature due to changes in the phase of the ambient medium. The transition from room temperature to freezing point reduces the contrast in acoustic properties between the ice-lattice and the scatterer materials (acrylic) and switches off the metamaterial of the water-based PnC. The numerically simulated equi-frequency contours and wave propagation characteristics demonstrate the switchable meta-material to the periodic phononic structure’s normal behavior due to the phase transition of water. Effects such as Van Hove’s singularity and filamentation-like effects in an acoustic meta-material system can be thermally tuned.
First principles study on phosphorus or boron doping in si nanocrystals with various sizes embedded in SiO2 matrix
Authors: Han Junnan , Li Dongke , Sun Teng , Chen Jiaming , Wang Yuhao , Pi Xiaodong , Li Wei , Xu Ling , Xu Jun , Chen Kunji
Published: April 2023

Doping in Si nanocrystals (Si NCs) is an interesting topic since the doping behaviors in the nanoscale are quite complicated compared with the case in bulk Si. In our present work, we use the first-principles calculation to study Phosphorus (P) or Boron (B) doping in Si NCs with the size of 2–8 nm embedded in SiO2 matrix by taking into account the existence of dangling bonds on the interfacial region. It is found that both P and B impurities tend to stay at the interfacial region to passivate the dangling bonds when the dot size is as small as 2 nm. However, P impurities exhibit the possibility to occupy the inner sites of Si NCs while B impurities are more difficult to be introduced into Si NCs due to the large formation energy. Our detailed study suggests that P or B impurities preferentially stay at the intermediate sites between Si and oxygen to form stable bonding configurations. With increasing the dot size from 2 nm to 8 nm, both P and B impurities can enter into the Si NCs more easily due to the relaxation of stress in the larger-sized Si NCs. Our theoretical results are in good agreement with the experimental observations.
Spectral pulsations of evolving soliton molecules in an anomalous dispersion fiber laser
Authors: Lu Mengxiang , Wang Xude , Li Kaixin , Geng Xu , Fan Yuhan , Fu Mingzhu , Li Suwen
Published: April 2023

We investigate in detail the spectral pulsation of evolving soliton molecules in an anomalous dispersion fiber laser by utilizing the dispersive Fourier transform technique. The spectral pulsations of an evolving soliton molecule with different properties were achieved in our experiments, such as single-period and double-period pulsation. This type pulsation is characterized by the fact that the soliton molecules periodically experience oscillation in spectral profile and peak power due to the periodic vibration evolution of the internal pulses. However, the continuous weak energy exchange between the two solitons inside the soliton molecules results in an almost invariable pulse energy. In addition, analytical fitting models are given to further reveal the spectral pulsation phenomenon of the evolving soliton molecules. These experimental findings can shed some light on the dynamics of soliton molecules in fiber lasers.
The Edge Sensor of Segmented Mirror Based on Fringes of Equal Thickness
Authors: Zhang Xi , Zuo Heng , Zhang Yong , Li Ye-Ping
Published: April 2023

Co-phase and co-focus detection is one of the key technologies for large-aperture segmented mirror telescopes. In this paper, a new edge sensor based on fringes of equal thickness is developed, which can detect each segment’s relative piston, tilt, and tip errors from the interferograms. Based on the co-focus demand for many ground-based seeing limited segmented mirror telescopes, an edge sensor prototype based on such a principle is built and applied in the indoor segmented mirror experiment system in the lab. According to the co-focus requirement of the Large Sky Area Multi-Object Fiber Spectroscopic Telescope, many simulations and experiments are carried out for co-focus error detection of the segmented mirror system. Experiment results show that the co-focus accuracy is better than 0.″02 rms, which can meet the co-focus requirements of most large or extremely large segmented mirror astronomical telescopes.
Absolute frequency measurements with a robust, transportable 40Ca+ optical clock
Authors: Zhang Huaqing , Huang Yao , Zhang Baolin , Hao Yanmei , Zeng Mengyan , Chen Qunfeng , Wang Yuzhuo , Cao Shiying , Lin Yige , Fang Zhanjun , Guan Hua , Gao Kelin
Published: April 2023

We constructed a transportable 40Ca+ optical clock (with an estimated minimum systematic shift uncertainty of

1.3
×

10

−
17

 

and a stability of

5
×

10

−
15

/

τ

) that can operate outside the laboratory. We transported it from the Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Wuhan to the National Institute of Metrology, Beijing. The absolute frequency of the 729 nm clock transition was measured for up to 35 d by tracing its frequency to the second of International System of Units. Some improvements were implemented in the measurement process, such as the increased effective up-time of 91.3% of the 40Ca+ optical clock over a 35-day-period, the reduced statistical uncertainty of the comparison between the optical clock and hydrogen maser, and the use of longer measurement times to reduce the uncertainty of the frequency traceability link. The absolute frequency measurement of the 40Ca+ optical clock yielded a value of 411 042 129 776 400.26 (13) Hz with an uncertainty of

3.2
×

10

−
16

, which is reduced by a factor of 1.7 compared with our previous results. As a result of the increase in the operating rate of the optical clock, the accuracy of 35 d of absolute frequency measurement can be comparable to the best results of different institutions in the world based on different optical frequency measurements.
Preface
Authors: Tang Wenzhe
Published: April 2023

EEEP (International Conference on Energy Engineering and Environmental Protection) is an annually held conference for all researchers home and abroad since 2016, aiming to provide a good platform for scholars and researchers in the field of energy and environmental protection to discuss the latest developments and achievements, work out good solutions, and make contributions.

The Seventh International Conference on Energy Engineering and Environmental Protection (EEEP2022) was planned to be held in Zhuhai, China on November 19-21, 2022. For public health consideration during epidemic, the event had to be changed from onsite to online during November 19-20, 2022 for academic exchanges & discussions.

There were over 50 participants from 5 different countries and regions, including China, Australia, Italy, Korea and Indonesia, attending EEEP2022. Conference program was divided into 3 sessions: keynote speeches, oral presentations and poster presentations. We greatly appreciate Prof. Wenzhe Tang from Tsinghua University, who presided over the conference, and all participants for attending and sharing!

We are honored to invite 5 experts to give the impressive keynote speeches: A/Professor Farhad Shahnia from Murdoch University, Australia; Prof. Fushuan Wen from Zhejiang University, China; Prof. Wenzhe Tang from Tsinghua University, China; Asso. Prof. Gangtao Liang from Dalian University of Technology, China and Prof. Benedetto Nastasi from Sapienza University of Rome, Italy.

Following the keynote speakers, 6 scholars made oral presentations respectively in the afternoon. And 9 poster presentations came after it. Reporters shared their latest research findings and audiences were actively involved in discussions.

We would like to express our gratitude to the reviewers of these manuscripts, who provided their time and expertise to review papers and facilitate the smooth running of EEEP. We are extremely grateful for organizers, technical program committee and editors and extend our most sincere thanks to all the authors for their excellent contribution and work and participants for their active attending. Our sincere thanks also go to the IOP Publishing editors and managers for their helpful cooperation during the preparation of the proceedings.

On behalf of the Organizing Committee of EEEP 2022.

List of Technical Program Committee is available in this pdf.
Analysis of China’s power system transformation
Authors: Liu Yun , Duan Caili
Published: April 2023

China is the largest CO2 emitter, and thermal power units are the main source of CO2 emissions. The low-carbon transformation of thermal power units is the key to carbon emission reduction. China is rich in wind and solar energy resources; wind power and photovoltaic power generation technologies are mature and have good economic prospects. Significantly increasing the proportion of installed wind power and photovoltaic power is the main idea of the power system low-carbon transformation. Biomass fuel blending is the only solution for thermal power units to reduce carbon emissions. Drawing on the large proportion of biomass blending technology in large foreign coal power units, the low-carbon transformation of thermal power units will be completed, and eventually, together with wind power and photovoltaic power generation, China’s renewable energy-based low-carbon power system will be formed. The process of low-carbon transformation of the power system reduces the use of fossil energy, reduces external energy dependence, and improves national energy security. The low-carbon transformation of the power system should be steadily promoted to prevent large adverse impacts on society and the economy.
The reliability analysis of pressurized water reactor safety injection system based on GO-FLOW
Authors: Zhang Dongliang , Wang Ji , You Wenhao
Published: April 2023

The safety injection system (RIS)is a large and complex fluid system in a nuclear power plant. Its central role is to ensure the safety of the core in the event of a breach event in the first circuit of the nuclear power plant. In order to investigate the timing of the safe injection system at the time of a Small-Break Loss-Of-Coolant Accident (SBLOCA), this paper uses the GO-FLOW method to model seven time points in the three operational phases of the safe injection system. The calculation is completed in conjunction with the failure rate of each component to give the reliability of the RIS at each point in time at SBLOCA. The final analysis yielded low reliability at the beginning of the direct cold section injection phase, which is of great reference for subsequent equipment maintenance and the safe operation of nuclear power.
Current situation and trend analysis of rural electrification in China
Authors: Tang Wei , Feng Gang , Tan Qingkun , Xu Zhao , Feng Kaihui , Lu Xingguo
Published: April 2023

Energy is the foundation of economic and social development. With the implementation of the rural revitalization strategy, the primary, secondary and tertiary industries in rural areas have achieved integrated development, and the living environment has been increasingly improved, promoting the clean and electrified development of rural energy consumption. The development of rural electrification involves many aspects and is related to the future of rural. Based on agricultural production and rural life, this paper analyzes the current situation of rural electrification from energy consumption, electrification growth rate, electricity load characteristics and regional variations. Through building a forecasting model of rural production and living energy demand, this paper forecasts the level of rural energy consumption, analyze the development trend of rural electrification, and put forward relevant conclusions and suggestions.
Thermal economy analysis of flue gas waste heat utilization system of 1000MW secondary reheat unit
Authors: Li Shuai , Lu Xizhen , Zhang Mingzhao , Yao Xuejun , Li Guipeng
Published: April 2023

Deep utilization of flue gas waste heat is an important means to ameliorate the power generation productivity of coal-fired units. Aiming at the waste heat cascade utilization system which is composed of “air preheater bypass + two-stage low-temperature coal economizer + thermal primary air temperature regulating device” proposed in a certain project, using the energy balance method and the equivalent enthalpy drop method, the mathematical model of the impact of waste heat utilization devices at all levels on the unit economy is established from the boiler efficiency and steam engine heat rate. Combined with the rated operation data of the unit, the thermal economy of the system is analyzed. The results show that the bypass of the air preheater and the temperature regulating device of the hot primary air can effectively improve the utilization efficiency of the waste heat of the flue gas at the tail of the boiler, the coal consumption of power supply can be reduced by 3.47 g/kWh under rated working conditions.
Research on digital energy carbon management platform and services for energy-using companies under the “3060” target
Authors: Shen Wentao , Zhang Yupeng , Zhang Xuan , Xia Dan , Zhao Junyong , Xiong Zhiyong , Liang Li
Published: April 2023

This study focuses on serving governments, enterprises and individuals related to digital energy carbon management. The National Grid provides digital carbon management services to electricity-using enterprises, solving the problems of high cost, difficulty and long lead time in managing carbon assets of electricity-using enterprises. We have innovated daily real-time carbon emission management services, carbon emission reduction services, carbon decision-making services, value-added carbon asset services and carbon trading services. Xinjiang Autonomous Region is a water-scarce and arid region which water resources are particularly important, so we choose the wastewater treatment industry in Xinjiang as a case study. The daily electricity consumption of Xinjiang Wastewater Treatment Plant A is 4063.75 kWh and the daily electricity consumption carbon emissions are 2.36 tonnes CO2eq, which is estimated to be about 2.78 tonnes CO2eq per day. the daily carbon emissions of the daily electricity consumption Wi of Xinjiang Wastewater Treatment Plant B is 3469.22 kWh and the daily electricity consumption carbon emission is 2.02 tonnes CO2eq, which is estimated to be 2.38 tonnes CO2eq. The carbon account value-added service provides carbon market users with transaction-assisted decision-making services, realizes accurate and efficient services, and helps society achieve the “3060” strategic goal of low-carbon green transformation.
Peculiarities of thermal calculation of cross-flow plate air recuperators
Authors: Vdovichev A.A.
Published: April 2023

Application of modern energy-saving technologies is the most important task in development of construction industry. In the conditions of exhausting decrease of energy consumption of public, administrative buildings due to reduction of transmission heat losses the implementation of mechanical ventilation with recuperation of exhaust air heat becomes a rational way to increase energy efficiency. One of the key problems in the study of plate-type air recuperators is to find the temperature efficiency of the device. The value of this characteristic is influenced by such parameters as the area of the branched heat exchange surface, initial temperatures of heat carriers, volume flow rates, flow rate ratio, type of fins, etc. The purpose of the study is to compare coefficients of thermal efficiency of outside air as a function of Reynolds number obtained by engineering calculation, mathematical modelling and manufacturer’s data for the recuperator ISIS Recover HR-A-05-V-G4-E-1-60. The article substantiates the calculation method using the existing algebraic dependence describing heat transfer in the cross-flow scheme of coolant motion on the basis of new results. An empirical dependence is obtained, which adequately describes the results of numerical simulation using the ANSYS Fluent solver and engineering calculation.
Energy education policy analysis of China: A perspective of multiple streams theory
Authors: He Qiuyue
Published: April 2023

Since the 1970s, energy education (EE) has become one of the effective ways to solve the energy crisis in developed countries. China’s increasingly severe energy issue requires China to strengthen energy conservation while establishing a conservation-oriented society and to draw on international experience in solving energy questions by vigorously developing EE. The development of EE in China commences late. Although some achievements have been made, there is a lack of legislative protection and platform support in further promoting EE. This paper analyzes China’s EE policy using the multiple streams theory, examines the reality of problematic policy and political streams of China’s EE policy, discusses the issue of addressing the three main streams in China’s EE development, summarizes the necessary conditions fbr opening the EE policy window, and puts forward suggestions fbr erecting China’s EE system.
Acetylene functionalized covalent triazine frameworks with AuPd nanoparticles as photocatalysts for hydrogen evolution from formic acid
Authors: Wang Lu , Zhao Yue , Liu Linghao , Zheng Ziyi , Liu Zijun , Zhang Fuhao , Wang Lin , Fan Zhuangjun
Published: April 2023

Photocatalytic dehydrogenation of formic acid (FA) at room temperature is a promising way to meet the increasing demand for hydrogen energy. In this work, we loaded nanoparticles of plasmonic AuPd alloys on the acetylene functionalized covalent triazine frameworks (CTFs) for the design of Mott-Schottky catalysts (AuPd/CTFs) with further application to photocatalytic hydrogen production from FA. Experimental data showed that the introduction of acetylene (-C≡C-) unit and AuPd alloy into the CTF could significantly enhance the performance of hydrogen evolution. The results of photoelectrochemical tests showed that the introduction of carbon-carbon triple bonds and AuPd alloy could adjust the electronic structure of CTF and inhibit charge recombination. Thus, benefiting from these positive effects, the FA photocatalytic decomposition by the obtained AuPd-CTF-EDDBN photocatalyst yielded H2 at a good rate of 10600 μmol·gcat
−1·h−1.
An analysis of new electrification potential of final energy consumption in southern China under the goal of carbon peaking and carbon neutrality
Authors: Wang Jiayang , Wang Ke , Zhuo Yingjun , Xie Pingping
Published: April 2023

Under the constraint of peak carbon dioxide emissions before 2030 and carbon neutrality before 2060, the current status of the economy, social demography, energy consumption, industrial structure, energy intensity and power consumption in southern China is analyzed, the scenario analysis method is built, three policy scenarios affecting electrification under the constraint of the goal of carbon peaking and carbon neutrality are designed for the analysis of the future power demand in southern China, and the implementation path of new electrification that can achieve the goal of carbon peaking and carbon neutrality is proposed.
Day-ahead scheduling of the electrothermal integrated system considering multiple thermal inertia
Authors: Dai Mengdi , Ke Deping , Cui Yibo , Ling Zaixun , Zheng Jingwen
Published: April 2023

For the problem of optimal scheduling of integrated energy systems involving wind power consumption, by mining multiple thermal inertia, a stochastic optimal scheduling strategy with consideration of mixed uncertainties is proposed. Firstly, the network thermal inertia is explored by considering the dynamic characteristics and thermal storage of heat network. Then the heat load flexibility constraint is introduced to model the thermal inertia of buildings. Finally heat pumps and heat storage are used as time-shiftable loads or sources, which are jointly modelled with CHP units to solve the peak-valley mismatch of electric and heat loads, and on this basis, the model is established. In this paper, the Barry Island’s case which is composed of 33-node thermal network coupled with 9-node grid system is used as an example for analysis, and results show that by exploring the multiple thermal inertia, both the complementarity and the flexible dispatch between multiple heterogeneous energy sources in integrated energy system can be realized.
Refrigerant overheating in the compression circuit air heat pump
Authors: Fedosov Sergey , Fedoseev Vadim , Zayceva Irina , Voronov Vladimir
Published: April 2023

The authors considered the processes of phase transformation of the working fluid in the compression unit of the freon circuit in the section “thermal expansion valve (TEV) - evaporator - compressor”. By adjusting the expansion valve under the conditions of the bubble mode of boiling of the refrigerant, the evaporation process takes place, accompanied by the achievement of a certain excess of steam temperature. Determination of rheological parameters (droplet size, vapor viscosity, refrigerant droplet vaporization rate) is necessary so that when moving from the throttle valve (TEV) to the compressor inlet, they have time to go into the vapor phase or return to the mass of boiling liquid. The article presents the results of an analytical calculation of the parameters of the kinetics of evaporation of Freon droplets as they move in a steam flow. The results of such an analysis make it possible to formulate requirements for the optimal droplet size in the created vapor-liquid mixture in order to ensure their maximum evaporation and the required thermal efficiency of the AHP as a whole. The established patterns of evaporation of refrigerant droplets can be used to select the design and operation of the AHP.
Speed-and-pressure combined control for the CPHPTO of an inverse pendulum wave energy converter
Authors: Yue Xuhui , Liu Jiaying , Ma Shihao , Liu Guanchen , Ming Guangqiang , Chen Qijuan
Published: April 2023

Constant pressure hydraulic power take-off (CPHPTO) utilizes a high-pressure accumulator to weaken its oil pressure fluctuations. However, CPHPTO operating point still changes violently under the circumstance of the changeable irregular waves as well as the limited volume of the high-pressure accumulator. This causes CPHPTO to work away from the designed operating point and even to run in the inefficient and unstable region. This paper proposes a speed-and-pressure combined control (SPCC) strategy, which keeps system speed/pressure around the designed value via the vector control of a PMSG or the displacement tuning of a hydraulic motor, for the efficient and stable operation of a CPHPTO. A SPCC strategy for the CPHPTO embedded in a novel inverse pendulum wave energy converter (NIPWEC) is designed in detail. Furthermore, the overall wave-to-wire dynamic model is simulated in irregular waves to research the effect of SPCC. Results show that both the SPCC with an oil pressure open-loop regulator (OPOLR) and the SPCC with an oil pressure closed-loop regulator (OPCLR) can effectively stabilize the system speed/pressure. Besides, SPCC, especially the SPCC with OPCLR, can effectively improve both the efficiency and stability of CPHPTO. Moreover, system-speed control is more significant than system-pressure control in terms of improving CPHPTO efficiency.
Multilayer composite nanofibrous film accelerates the Li+ diffusion for quasi-solid-state lithium-ion batteries
Authors: Yan Yingchun , Liu Zheng , Yang Xinhou , Fan Zhuangjun
Published: April 2023

The rational design of dense and flexible solid-state electrolytes (SSEs) with interface compatibility is still challenging. Here, we report a three-layer dense 3D nanofibrous matrix (PCOF) by constructing a nanofiber framework combining polyacrylonitrile (PAN) and fast Li-ion conductor covalent organic frameworks (COFs) by electrospinning method. PCOF film can maintain an extraordinary electrolyte/electrode interface and an interconnected ion-conduction pathway, accelerating Li+ diffusion. The PCOF quasi-solid-state electrolyte (QSSE) has high oxidative stability (4.70 V, versus Li+/Li) and ion conductivity of 2.94×10−4 S cm−1 at room temperature. Lithium-ion battery based on PCOF QSSE with LiFPO4 (LFP) cathode exhibits outstanding rate characteristics and cycling stability. This multi-layer composite strategy will start a new area of QSSEs lithium-ion electrolytic devices, and simultaneously accelerate the design of electrolytes featuring a wide range of properties.
Evaluation study on the coordination of marine resources, the environment and social economy: take Taizhou Bay as an example
Authors: Yan Jishun , Wang Peng , Yue Xihe , Chen Chong , Zhang Can , Wang Xiaoyu
Published: April 2023

The sea is an important aspect of development in bay areas. Coordinated development of the marine resource environment and social economy is an inevitable requirement for high-quality development of the marine economy. This paper builds an index to evaluate the coordination of marine resources, environment and social economy in bay areas from four aspects: resource and environmental effects, resource utilization compliance, socio-economic development conditions, and technological investment and development status. The model is implemented for Taizhou Bay. The results show that the overall level of coordination between its marine resource environment and social economy is poor, under 0.4. The main reasons for this situation are the decline in environmental quality of bay resources, and insufficient technological investment and development. In view of the problem of uncoordinated regional development, this paper puts forward two suggestions to provide technical support for the high-quality development of Taizhou Bay: implementation of land and sea resource control, and increased investment in environmental repair technology in the bay.
Spatial and temporal changes of runoff in the Yellow River in recent 15 years
Authors: Li Weiqing , Liu Yixin , Qian Hui , Zhang Yuting , Xu Panpan
Published: April 2023

In this study, the runoff data from 12 representative stations in the Yellow River from 2005 to 2020 is utilized, and the Mann-Kendall trend test is used to examine the changes in the observed runoff of the Yellow River. The results show that the annual runoff has grown in the upper reaches and has gradually reduced along the river flow direction. It is because the runoff is mainly affected by precipitation and human activities. In addition, the runoff mutation of each hydrological station is not consistent. This may be caused by many factors, resulting in the complexity of annual runoff changes. The findings can reveal runoff sequence variation of the Yellow River and provide a theoretical basis for river management.
Correlation analysis between noise reduction function and biological structure of Acer truncatum crown
Authors: Chen Fang , Wang Mingyue , Chen Ruimin , Li Zhandong
Published: April 2023

Taking Acer truncatum as the research object, this paper discusses the influence of structural changes on the noise reduction effect, and quantitatively measures and analyzes the biological structural characteristics and noise reduction effect. The conclusions are as follows: 1) structural changes, especially the changes of branches and leaves, have a significant impact on the noise reduction effect of the crown. The noise reduction effect of the complete crown is the best. With the thinning of branches and leaves, the noise reduction ability of the crown gradually decreases. The noise reduction ability of the complete crown >2/3 crown >1/4 crown >0 crown. 2) All the 17 biological structures have a very significant impact on the noise reduction effect of the crown. The light transmittance, porosity and branch density of the crown are the key structures that affect the noise reduction effect of the crown of Acer truncatum. The light transmittance and porosity of the facade are negatively correlated with the noise reduction effect, and the branch density is positively correlated with the noise reduction effect. The smaller the gap between branches and leaves in the crown and the denser the branches, the better the noise reduction effect of the crown.
Effect of substrate on two anammox packing filler systems
Authors: Wang Weiqiang , Xiong Deqi , Su Yang , Zhu Jinghai , Fu Jinxiang
Published: April 2023

The article investigated the effect of substrate ratio and shock load resistance on the nitrogen removal efficiency of curtain packing anammox filler and bundle packing anammox filler. The results had shown that the nitrogen removal performance was recommendable when the NH4
+-N: NO2
−-N was set as 1:1.20, regardless of the curtain packing filler or the bundle packing filler. After the total nitrogen concentration was directly increased from 770 mg/L to 1320 mg/L for 12 h. From the perspective of the steady of nitrogen removal performance, the bundle packing filler was better than curtain packing filler, and the effluent TN concentration was beyond 70 mg/L. Subsequently, within 1 day when the influent TN concentration increased to 770 mg/L, both filler systems quickly recovered. The structure of the bundle packing was beneficial to the fixed, cultured, and aggregation of anammox bacteria made it a better filler type. The high-throughput results showed that the dominant bacteria in the two packing fillers was Candidatus Kuenenia, which accounted for 15.16% and 22.85% in the curtain packing filler and the bundle packing filler system respectively.
Sediment characteristics and sedimentary environment analysis of a sandbar-lagoon system developed at the estuary of Fudu River, China
Authors: Zhang Pan , Zhang Lianjie , Yan Jishun , Zhao Bo , Lin Xia , Li Shuxian
Published: April 2023

Developed at the estuary of Fudu River, the sandbar-lagoon system there occupies the longest sandy coastline of east coast of Liaodong Bay, China. Over the past several decades, substantial changes are believed to have occurred over the system regarding its sedimentary characteristics and dynamic environment, partly due to the anthropogenic influences. However, few studies have been reported to investigate such evolution. To fill this gap, grain size analysis was conducted with 52 sediment samples to reveal the sediment distribution patterns. In addition, the sedimentary environment and sediment transport trend were studied using the Pejrup M triangular diagram and Gao-Collins grain size trend analysis method. Our results show that the surface sediments are mainly sandy with coarser sediment found over the northern part of the sandbar whereas fine-grained sediments are mainly in the lagoon area. The sedimentary dynamics environment can be divided into the northern area of sandbar and the lagoon area. The relatively larger grain size, low sorting coefficient and positive skewness in the northern part of sandbar indicates a strong and stable hydrodynamic environment dominated by waves and currents. Meanwhile, the small mean size, high sorting coefficient and negative skewness in the lagoon area implies a weak hydrodynamic environment due to significant reduction of hydrodynamic strength. In the lagoon area, the sediments are transported mainly from coastal ocean to the interior of lagoon in suspension. Our study provide basin understanding of the controlling dynamics on sandbar evolution, and can provide guidelines for the preservation of the sandbar-lagoon system.
Experimental study of the effect of CO2 on rock seepage characteristics
Authors: Guo Xing , Sun Xiao , Liu Yiting , Mu Jingfu , Qiao Hongjun , Wan Xin
Published: April 2023

The influence of different phase states of CO2 on the seepage characteristics of different rocks is one of the most important factors to enhance shale gas exploitation, such as CO2 fracturing and displacement, and achieve CO2 geological storage. Rock soaking experiments with different CO2 phase states were carried out to compare and analyze the influence of permeability, contact angle, starting pressure gradient and other seepage characteristic parameters of sandstone and shale before and after soaking. Research shows: After soaking in liquid and supercritical CO2, the permeability and contact angle of sandstone and shale increase in varying degrees, and the starting pressure gradient decreases in varying degrees. After soaking in liquid CO2, the permeability of sandstone and shale increased by 1.71% and 12.88% respectively, the contact angle increased by 3.23% and 7.47% respectively, and the starting pressure gradient decreased by 3.02% and 5.88% respectively. After supercritical CO2 immersion, the permeability of sandstone and shale increased by 37.37% and 48.82% respectively, the contact angle increased by 19.27% and 36.80% respectively, and the starting pressure gradient decreased by 35.39% and 39.34% respectively. Compared with sandstone, the seepage characteristics of shale after soaking in liquid and supercritical CO2 have greater changes; Compared with liquid CO2, the seepage characteristics of sandstone and shale change more after supercritical CO2 soaking. With the increase of supercritical CO2 soaking time, the contact angle of sandstone slightly increases, while that of shale obviously increases. Compared with liquid CO2, the change of seepage curves of sandstone and shale after supercritical CO2 soaking is more different.
Applicability analysis of different evaluation methods in groundwater quality evaluation: A case of Xi’an city
Authors: Li Siqi , Shi Xiaoxin , Qian Hui , Xu Panpan
Published: April 2023

In order to find a suitable method for the evaluation of groundwater quality in Xi’an, the principles of single factor evaluation method, fuzzy comprehensive evaluation method and modified fuzzy comprehensive evaluation method are briefly described. Three methods are applied to the comparative analysis of water quality evaluation of 34 phreatic water samples in Xi’an. The results show that: (1) The results of fuzzy comprehensive evaluation method are more optimistic than those of single factor evaluation method. (2) The single factor evaluation method is simple in calculation and can directly reflect the degree of pollutants exceeding the standard in water, but the evaluation results are too one-sided to reflect the actual situation of water quality; The fuzzy comprehensive evaluation method and the modified fuzzy comprehensive evaluation method more comprehensively consider the comprehensive impact of evaluation factors on water quality, and their results are more objective than the single factor evaluation method. (3) The modified fuzzy comprehensive evaluation method improves the accuracy of the membership matrix by changing the critical value of Class V water. The weighted average calculation method avoids the error caused by the square term of concentration, so that the evaluation results will not be distorted. It is a very effective evaluation method, which should be promoted.
Formaldehyde degradation of waterborne paints over S- and C-doped titanium dioxide under visible light
Authors: Yao Kang , Meng Weijun , Huang Qiaorong , Wang Wukang , Che Xihong , Fang Hong , Duan Ran
Published: April 2023

Fabrication technique of S- and C-doped TiO2 nano-particle via solvo-thermal treatments was introduced, and its appearance and crystal property were studied using transmission electron microscopy, energy-dispersive X-ray and powder X-ray diffraction. All of these characterisations gave a reasonable explanation to satisfactory doping of S and C in the anatase. The photo-catalytic oxidation was conducted in environmental chambers, together with UV-VIS spectra. The catalytically active S- and C-doped anatase was assessed via surveying the formaldehyde degradation of waterborne paints, and a removal efficiency of 93.9% in 85 min illustrated an enhanced visible-light activity.
Synergistic degradation of malachite green by water surface plasma combined with Fe2+/PMS
Authors: Hua Weijie , Kang Yong , Liu Shuai
Published: April 2023

Water surface plasma (WSP) discharge technology coupling with Fe2+and peroxymonosulfate (PMS) was investigated for the degradation of malachite green (MG) dye wastewater. The effects of Fe2+dosage, PMS dosage, input voltage and solution initial conductivity on the degradation of MG were investigated. When the Fe2+dosage was 125 μM, PMS dosage was 0.5 mM and input voltage was 16 kV, the degradation performance and reaction rate of MG reached 96.3% and 0.219 min−1within the discharge time of 15 min. When increasing the initial conductivity from 31.1 μS/cm to 1000 μS/cm, degradation efficiency of MG decreased from 97.9% to 94.1% with the decrease of only 3.8% and degradation rate declined by only 0.074 min−1.
Comparative study of fire characteristics of aged and unaged pinewood
Authors: Huang Jiaxin , Song Lei , Wang Jian
Published: April 2023

Wood has become a promising and more eco-friendly option for modern structures. This work aims to comparatively investigate the combustion characteristics of the aged and unaged wood samples. The tests were conducted by cone calorimeter under the heat fluxes ranging from 35-55 kW/m2. Critical parameters including ignition time, heat release rate and concentration ratio of CO/CO2 were measured and analyzed.
Influence of space electromagnetic radiation on physical characteristics of atmospheric suspended micro particles
Authors: Han Binbin , Ming Zhengfeng , Zhao Yuhu , Wen Tao , Xie Meilin
Published: April 2023

In recent years, researchers from various countries have found that atmospheric microparticle pollution occurring around the world has seriously endangered human health and the earth’s ecological environment. In order to solve the problem of atmospheric micro-particle pollution, researchers have carried out multi-faceted analysis on its source, composition and causes of pollution. However, few people combine the complex electromagnetic environment in space with the problem of micro-particle pollution in recent years. In this study, it is found that atmospheric suspended microparticles have weak magnetism and carry charge, so it is preliminarily explored whether space electromagnetic radiation has an effect on microparticles. Based on this background, this study used simulation modeling and experimental verification methods. The results show that the physical properties of atmospheric suspended microparticles will be significantly changed by electromagnetic radiation.
Study on the response relationship between land use and eco-environmental quality - a case study of Jing-Jin-Ji urban agglomeration
Authors: Ji Jianwan , Jiang Linlin , Sheng Tian , Chen Yi , Zhang Rui
Published: April 2023

In view of the complexity of traditional eco-environmental quality evaluation index system and the time-consuming calculation, this paper used remote sensing ecological index (RSEI), combined with MODIS products and GEE platform, to quantitatively evaluate the eco-environmental quality and land use in Jing-Jin-Ji from 2010 to 2020, and analysed the response relationship between eco-environmental quality and ecological land. The results showed that: 1) The eco-environmental quality in Jing-Jin-Ji showed a “V” shaped change trend in the past ten years, with its average value first decreased from 0.51 to 0.46, and then increased to 0.48; 2) The dynamic degree of arable and grass land in Jing-Jin-Ji was negative, while forest land was positive. The average annual increment of construction land was the highest (638.72 km2•y−1); 3) There existed good consistency between the average RSEI value and the change trend of ecological land in Jing-Jin-Ji, but the change rate was not synchronous, which showed that the increased rate of ecological land was higher than the decreased rate, while the increased rate of the average RSEI value was significantly lower than the decreased rate, reflecting that the recovery rate of eco-environmental quality was lower than the degradation rate.
Equations for a K3 Lehmer map
Authors: Brandhorst Simon , Elkies Noam
Published: April 2023

C. T. McMullen proved the existence of a K3 surface with an automorphism of entropy given by the logarithm of Lehmer’s number, which is the minimum possible among automorphisms of complex surfaces. We reconstruct equations for the surface and its automorphism from the Hodge theoretic model provided by McMullen. The approach is computer aided and relies on finite non-symplectic automorphisms,

p
p

-adic lifting, elliptic fibrations and the Kneser neighbor method for

Z

\mathbb {Z}

-lattices. It can be applied to reconstruct any automorphism of an elliptic K3 surface from its action on the Neron-Severi lattice.
Parabolic induction for Springer fibres
Authors: Saunders Neil , Topley Lewis
Published: April 2023

Let

G
G

be a reductive group satisfying the standard hypotheses, with Lie algebra

g

\mathfrak {g}

. For each nilpotent orbit

O

0

\mathcal {O}_0

in a Levi subalgebra

g

0

\mathfrak {g}_0

we can consider the induced orbit

O

\mathcal {O}

defined by Lusztig and Spaltenstein. We observe that there is a natural closed morphism of relative dimension zero from the Springer fibre over a point of

O

0

\mathcal {O}_0

to the Springer fibre over

O

\mathcal {O}

, which induces an injection on the level of irreducible components. When

G
=
G

L
N

G = GL_N

the components of Springer fibres were classified by Spaltenstein using standard tableaux. Our main result explains how the Lusztig–Spaltenstein map of Springer fibres can be described combinatorially, using a new associative composition rule for standard tableaux which we call stacking.
A review of recent applications of the relative entropy method to discontinuous solutions of conservation laws
Authors: Vasseur Alexis
Published: April 2023

Dafermos [Arch. Rational Mech. Anal. 70 (1979), pp. 167–179] proved the weak/strong principle for conservation laws. It states that Lipschitz solutions to conservation laws endowed with convex entropies are unique and stable among weak solutions. The method, based on relative entropy, was extended by Di Perna [Indiana Univ. Math. J. 28 (1979), pp. 137–188] to show the uniqueness of shocks among weak solutions with strong traces. This theory has been recently revisited with the notion of weighted contractions up to shifts. We review in this paper recent applications of this method, including the weak/BV principle and the stability of discontinuous solutions among inviscid double limits of Navier-Stokes systems.
Beyond the kidney biopsy: genomic approach to undetermined kidney diseases
Authors: Robert Thomas , Raymond Laure , Dancer Marine , Torrents Julia , Jourde-Chiche Noémie , Burtey Stéphane , Béroud Christophe , Mesnard Laurent
Published: April 2023

Background

According to data from large national registries, almost 20%–25% of patients with end-stage kidney disease have an undetermined kidney disease (UKD). Recent data have shown that monogenic disease-causing variants are under-diagnosed. We performed exome sequencing (ES) on UKD patients in our center to improve the diagnosis rate.

Methods

ES was proposed in routine practice for patients with UKD including kidney biopsy from January 2019 to December 2021. Mutations were detected using a targeted bioinformatic customized kidney gene panel (675 genes). The pathogenicity was assessed using American College of Medical Genetics guidelines.

Results

We included 230 adult patients, median age 47.5 years. Consanguinity was reported by 25 patients. A family history of kidney disease was documented in 115 patients (50%). Kidney biopsies were either inconclusive in 69 patients (30.1%) or impossible in 71 (30.9%). We detected 28 monogenic renal disorders in 75 (32.6%) patients. Collagenopathies was the most common genetic kidney diagnosis (46.7%), with COL4A3 and COL4A4 accounting for 80% of these diagnoses. Tubulopathies (16%) and ciliopathies (14.7%) yielded, respectively, the second and third genetic kidney diagnosis category and UMOD-associated nephropathy as the main genetic findings for tubulopathies (7/11). Ten of the 22 patients having ES “first” eventually received a positive diagnosis, thereby avoiding 11 biopsies. Among the 44 patients with glomerular, tubulo-interstitial or vascular nephropathy, 13 (29.5%) were phenocopies. The diagnostic yield of ES was higher in female patients (P = .02) and in patients with a family history of kidney disease (P < .0001), reaching 56.8% when the patient had both first- and second-degree family history of renal disease.

Conclusion

Genetic diagnosis has provided new clinical insights by clarifying or reclassifying kidney disease etiology in over a third of UKD patients. Exome “first” may have a significant positive diagnostic yield, thus avoiding invasive kidney biopsy; moreover, the diagnostic yield remains elevated even when biopsy is impossible or inconclusive. ES provides a clinical benefit for routine nephrological healthcare in patients with UKD.
A case report of pulmonary artery intimal sarcoma negative for 18F-FDG mimicking pulmonary thromboembolism
Authors: Koike Takuma , Iwata Hiroshi , Hirose Kuniaki , Minamino Tohru
Published: April 2023

Background

Pulmonary artery sarcoma is a rare malignant neoplasm arising from intimal mesenchymal cells in the pulmonary artery wall and is often difficult to differentiate from pulmonary embolism, however, 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) can be useful for a differential diagnosis. Here, we present a rare case of pulmonary sarcoma undetectable by PET.

Case summary

A 77-year-old woman who had worsening dyspnoea on effort for a month and progressive chest discomfort with nocturnal cough for a week presented to our hospital. Contrast-enhanced computed tomography (CT) demonstrated a massive filling defect in the left pulmonary artery (PA). Two major differential diagnoses were considered; pulmonary thromboembolism and tumour-like lesions. Positron emission tomography-computed tomography (PET-CT) revealed that there was no abnormal accumulation of 18F-FDG in the mass. However, even after effective anti-thrombotic treatment for 3 weeks, a follow-up CT showed no reduction at all in the size of the lesion in the pulmonary artery. Therefore, surgery for diagnostic therapeutic purposes was performed.

Discussion

The present case is informative because it supports the idea that being aware of PA angiosarcoma as a potential differential diagnosis of pulmonary thromboembolism is essential, particularly in cases of no evident peripheral venous thrombosis and a negative D-dimer test, even if neither heterogenous contrast enhancement in CT and magnetic resonance imaging nor accumulation of 18-FDG in PET-CT is evident.