bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Development And Process of A Dual-Band UAV Radar Antenna
Authors: Tong Wenqing , Bai Yifeng , Chen Qihai , Huo Shaoxin 
Published: June 2021

Abstract
This In order to meet the design requirements of airborne radar antenna, this article introduces the design and molding process of a dual-band UAV-borne radar compositematerial antenna. Thearticle proposed a kind of antennaunit which composed of skin, foam and microstrip antennas and carbon fiber, and a reflector with composite structure composed of foam, carbon fiber and stiffeners. The antenna and reflector are designed through an integrated process. A series of measures including the weight reduction and functional design of the antenna unit and reflector, the material performance is analyzed and optimized, and the mold design is adopted. It successfully developed a composite antenna with a size of 6000mm × 800mm × 20mm. After environmental test verification and a series of performance tests, the product is in good technical condition and meets the design requirements. This kind of composite material antenna has already been used on a type of drone, the drone has gone through flight test and the performance of the antenna is great. The successful development of this product can be used as reference for similar kind of UAV-borne radar antenna.
Water availability surpasses warmth in controlling global vegetation trends in recent decade: revealed by satellite time series
Authors: Zhang Anzhi , Jia Gensuo , Ustin Susan L 
Published: June 2021

Abstract
A better understanding of the dominant climatic drivers that control vegetation trends across regions and biomes is essential for assessing ecosystem dynamics and land-climate interactions in a warming world. Temperature (TMP) has long been considered as dominant control in global vegetation trends, and growing evidence suggests that water availability plays an increasingly important role in determining trends in vegetation growth over many biomes. However, a detailed spatial-temporal evolution of the vegetation trends and the climatic drivers that effect vegetation trends are not well known. In this study, using a time-varying trend (extracted by the ensemble empirical mode decomposition) of climate and satellite-derived normalized diﬀerence vegetation index (as a proxy for vegetation productivity) from 1981 to 2015, we find that the trends in vegetation greening and terrestrial carbon uptake reversed, beginning in the early 2000s, largely driven by the recent drying trend. The relative importance of climatic controls on vegetation productivity trend is estimated using a principal component analysis procedure, and the results demonstrate a global shift in the dominant driver of vegetation trends from TMP to precipitation, and point to intensified water limitation to vegetation growth as warming continues. The findings provide empirical evidence of the spatial-temporal evolution of different climatic drivers behind trends in vegetation productivity.
Retraction: Land subsidence in Beijing from 2017-2018 revealed by Sentinel-1A TOPS time series interferometry (IOP Conf. Ser.: Earth Environ. Sci.
638 012043)
Authors: Ran Peilian , Li Shaoda , Dai Keren , Yang Xiaoxia 
Published: June 2021

This article has been retracted by the authors, who have admitted a very similar version has already been published [1]. In accordance with the COPE guidelines, IOP Publishing agrees to retract this paper.
The authors agree with the retraction and apologise for the mistake.

[1] Gou J et al 2019, Revealing Land Subsidence in Beijing by Sentinel-1 Time Series InSAR, The 2019 International Conference on Big Data Analytics for Cyber-Physical System in Smart City, AISC 928, pp. 113-119
Retraction published: 15 June 2021
Numerical Assessment of Twin-Propeller Performances
Authors: Lungu A 
Published: June 2021

Abstract
The paper describes a methodology for assessing the hydrodynamic performances of a four blade fixed-pitch propeller working in open water. Both single propeller and twin-propeller arrangements are studied. The numerical solver, which is a part of the Numeca FineTM-Marine package is based on the finite volume method. Closure to turbulence is based on the detached eddy simulation (DES). A double sliding grid technique is used to treat the contra-rotational flow around the propellers. A grid convergence test is carried out to verify the robustness of the numerical treatment. Comparisons with the experimental data for the single propeller are performed twice to validate the ISIS-CFD viscous flow solver for both starboard and portside propellers. Discussions based on the numerical solutions are provided aimed at clarifying the particular issues of the hydrodynamic interference between the two propellers. Finally, a series of remarks are concluding the findings of the present work.
A technical analysis and comparison of tubular and lattice towers for wind turbines
Authors: Barbu M , Darie G , Patrascu R 
Published: June 2021

Abstract
The advancement of wind energy technology brings about an increase in the size and height of the wind turbine towers. As the upscaling of the conventional steel tubular tower is problematic, alternatives are being investigated. In this paper, several configurations were reviewed and the lattice tower was identified as a possible solution. This study analyses and compares the structural performance of the two tower configurations, tubular steel and lattice, of equivalent height, stiffness and mounted rotor, in two sets of tower heights, 120 m and 150 m. The towers are mounted by the baseline 5 MW turbine developed by National Renewable Energy Laboratory (NREL). The results indicate that lattice towers are a suitable alternative to the tubular towers, providing significant material savings for a similar structural behaviour. Comparable bending moments were recorded in the base of the structures. The most demanding operating condition of the wind turbines was identified to be system braking cause by a sudden increase in wind velocity outside of the operating range. The 150 m lattice tower responds with excessive displacement during this abnormal operating condition; this is a potential issue that can cause generator failure if not accounted for in the rotor design.
Elements of influence for solar ventilated building facades: a review
Authors: Sima C , Teodosiu C , Fokone A T , Bejan A S 
Published: June 2021

Abstract
Climate change has become a fundamental concern for scientific researchers, architects and engineers, so it’s required to improve the performance of sectors responsible for city and building infrastructure. Burning fossil fuels to produce electricity and heat is the biggest cause of climate change and emissions, and represents one third of total greenhouse gas emissions. Thus, buildings become responsible for improving the external environment, either by construction phase, rehabilitation process or by maintainability process. This work reviews and evaluates elements of influence for solar ventilated building facades in order to improve this field of research as this solution allows to achieve important energy savings.
In vitro growth of Sempur (Dillenia philippinensis Rolfe) shoots in response to different types of plants growth regulators supplemented on MS medium
Authors: Wulandari D R , Rudiyanto  , Rantau D E , Ermayanti T M , Firdaus H L 
Published: June 2021

AbstractPlant tissue culture of Sempur (Dillenia philippinensisRolfe) has not been widely reported. The previous study showed that BAP added to Murashige & Skoog (MS) basal medium promoted the growth ofD. philippinensisshoot culture. This research aimed to investigate the growth ofD. philippinensisshoot tip cultures on MS medium containing three types of cytokinins namely BAP, Kinetin, and 2-iP compared with Gibberelic acid (GA3). The results showed that the type and concentrations of cytokinins significantly affected all growth parameters observed except the number of roots which was only influenced by cytokinin concentrations alone. However, different levels of GA3did not significantly affect all growth parameters observed. After eight weeks of culture, MS medium containing 1 mg/l 2-iP gave the best response for plant height, (3.68± 0.26 cm). The highest number of leaves (20.33±3.14) and nodes (6.67± 0.21) were found in MS medium containing 0.5 mg/l BAP. While the highest number of roots (1.83±0.17) was found in MS medium without the addition of cytokinins. The range of average values of plant height at different levels of GA3was 3.08-3.74 cm; the number of leaves was 5.1-7.5; the number of nodes was 3.9-5.4 and the number of roots was 1.0-2.8.
Study on Renewable Energy System based on Mars Resources
Authors: Feng L , Shu W X , Xie F , Wen C , Bai J Y , Wan C A , Yu H M 
Published: June 2021

Abstract
This project discussed the technical feasibility and comprehensive utilization of resources and energy on Mars, which may have applications in the Mars exploration. Renewable fuel cell system could convert solar energy into chemical energy, electric energy and heat energy with the medium of recycled water, hydrogen and oxygen. In this project, a renewable energy system was designed based on fuel cell and water electrolyzer. Thereafter, the performance of the regenerative fuel cell was tested. The result shows that the power generation efficiency of the regenerative fuel cell was 65.41%, and the electrolysis efficiency was 90.2%. Meanwhile, the purity of hydrogen and oxygen were over 99.99% and the conductivity of water was lower than 5.0μS/cm.
Research on Hot Water System of PVT Coupled Heat Pump High-speed Service Area Based on TRNSYS
Authors: Feng Ran , Xu Jinghua , Guan Xia , Gao Qingfei , Li Xianming , Shan Baoqi , Yin Zizhuang 
Published: June 2021

Abstract
The high-speed service area is located outside of the urban energy system. If there is no efficient energy saving technology, it will lead to a large amount of energy consumption. As an important ancillary facility along the expressway, the service area has a large demand for hot water due to the high density of human flow. Renewable energy should be fully utilized to make domestic hot water. In this paper, a water-cooled photo-voltaic thermal (PV/T) coupled heat pump hot water system model is proposed. The TRNSYS model for the system operation is built, and an operating experimental platform is set up to verify the model experimentally. The comprehensive performance of typical days in winter and summer was evaluated, and it was found that the average COP of the system was as high as 7.9 and 8.1 respectively. The photoelectric conversion efficiency is as high as 17.5% and 19.5%, respectively. This system has good technical adaptability in the high-speed service area, providing certain guidance for building the green and ecological high-speed service area.
Multi-energy System Planning Based on Cascade Hydro-Photovoltaic-Pumped Storage Hybrid Generation System
Authors: Zhou Nan , Xie Da 
Published: June 2021

Abstract
Yalong River in Sichuan, China is a typical cascade hydro-photovoltaic-pumped storage (CHPPS) correlation system. CHPPS correlation system can achieve the objectives of multi-energy complementarities, renewable energy consumption and power supply structure optimization. This paper proposes a novel planning of cascade hydro-photovoltaic hybrid generation with pumped storage generations (PG). Firstly, the concept of comprehensive model of location and capacity for multi-energy system is proposed. With the form of equality constraint, correlation model reflects the space-time complementarities of hydropower (HY) and photovoltaic power (PV). Secondly, the correlation model is derived in detail with the specific form provided. Then, a multi-objective planning model is established with power flow and reliability constraints. Thereafter, a novel solution method that combines the fast non-dominated genetic algorithm (NSGA-II) is developed. An example using the CHPPS based on IEEE 33-node distribution system is demonstrated in this paper. Simulation results show that the proposed model considering the correlation model possesses reasonable investments, good income and excellent water-light complementary ability.
Study on the flexibility enhancement of China’s power system with renewable energy
Authors: Jiao Jian 
Published: June 2021

Abstract
At present, China’s renewable energy utilization scale has ranked first in the world. By the end of 2019, China’s cumulative installed capacity of solar power had reached 204.3 million kW, and that of wind power had reached 210 million kW. Some parts of China already have a high proportion of renewable energy power systems. However, the lack of flexibility in China’s power system has become a constraint to the development of renewable energy. This paper analyzes the current situation of the flexibility of China’s power system and the problems facing the development of high proportion of renewable energy. It is proposed that the flexibility of China’s power system should be improved by retrofitting the existing coal power system, controlling the scale of newly installed coal power plant, establishing the demand side resource utilization system, planning the energy storage application of the power system, and implementing the reform of the power market.
Optimal Operation for Integrated Electricity and Natural Gas Systems Considering Dynamic Gas Linepack
Authors: Han Huachun , Li Qiang , Wu Shengjun 
Published: June 2021

Abstract
With the increasing penetration of gas-fired turbines, the efficient and safe operation of power systems depends on the sufficient supply of natural gas. Hence, we proposed a coordinated optimal operation model of integrated electricity and natural gas systems (IENs). The gas linepack is considered by applying dynamic flow models. The non-convex Weymouth equality is converted to a second-order cone inequality constraint and a concave constraint that can be linearized by Taylor expansion. The initial operation point is obtained by optimizing the steady flow model. We proposed an algorithm based on the sequential strategy to solve this mixed-integer second order cone programming (MISOCP). The case study demonstrates that the proposed method can solve the MISOCP effectively and the operation cost can be reduced by taking full use of the gas linepack that is calculated by the dynamic gas flow model.
Performance optimization of high-temperature heat pump system for staged heating under large temperature span
Authors: Hao Zhang , Yanting Zhang , Lin Wang , Jingyu Xu , Lumeng Huang , Zheng Huang , Guangzhi Zhang 
Published: June 2021

Abstract
With the rise in the widespread application of high-temperature heat pump (HTHP) systems, the system temperature across the large volume, high condensing temperature, and sink unbalanced proportion of heat supply, and other characteristics of the HTHP system need to be optimized as the primary solution. To improve the thermodynamic performance of the system at high temperatures across the process, the effects of the intermediate cooling structure circulation mode and hierarchical heating on the HTHP system were analyzed in this work. Furthermore, the HTHP system was optimized by adjusting the appropriate diversion coefficients in order to improve its coefficient of performance (COP). The optimum value of COP and the corresponding coefficients of diversion for the different process requirements were calculated using R245fa as the refrigerant and perturbing the coefficients of diversion in combination with a simulated annealing algorithm. When the condensing temperature was between 120–140 °C, the COP of the optimized system was observed to be 15.93–20.48% higher than that of the traditional two-stage compression system, and the system was found to exhibit a significant unit heat production and refrigeration capacity.
A Park-type energy local area network planning method considering multi-energy co-optimization
Authors: Wang Chenlei , Chen Dong , Chen Aikang , Xie Da 
Published: June 2021

Abstract
Energy Internet, which is regarded as the new generation energy utilization system, is an ideal solution to achieve sustainable development. In this paper, we propose a park-type Energy Local Area Network (ELAN) planning method for the planning and operation control of the ELAN. Firstly, we classify the park from its industrial structure and analyse the positioning of the park in terms of energy, environment, and load factors. Then, the physical planning architecture of the park-type ELAN is built. Subsequently, a planning method of park-type ELAN is proposed, which can incorporate the optimization problem of multi-energy cooperative scheduling into the planning model. Finally, the effectiveness of the proposed method is verified by performing calculations with a solid waste treatment park system.
Research on electric heating integrated system based on multi-factor game equilibrium
Authors: Qiao Ke , Wu Xinling , Zhan Tao , Huang Furong , Jiang Xi 
Published: June 2021

Abstract
Taking the electric heating joint market as the research object, based on the standard Nash game model framework, a two-stage game model consisting of consumers, energy suppliers and electric heating joint trading center is established. It reveals the electric heating joint trading center and the consumer game mechanism, analyzes the game process, and proposes the overall structure of the game in the electric heating joint market, uses a distributed algorithm to solve the model, and establishes the optimal strategy for the interests of both parties. Finally, the model was simulated and verified, and the conclusion showed that the peak-to-average ratio decreased to 1.42 by using the method in this paper, which is lower than the value of 1.51 in the traditional method. The fluctuation range of electricity price is between 9.43∼18.56 ￠ / kWh, and its highest and lowest values are both smaller than the peak-valley price in the time-of-use tariff strategy.
Analysis on Several Blackouts Caused by Extreme Weather and its Enlightenment
Authors: Wang Ying , Wu Jiechen , Yi Haiqiong 
Published: June 2021

Abstract
In recent years, blackouts caused by extreme weather show a trend of frequent occurrence. This paper analyses the external causes of blackouts, summarizes the evolution process of blackouts, discusses the internal causes of blackouts in power system, analyses the challenges faced by power system under the superposition of extreme weather and renewable energy, and finally puts forward some suggestions for the planning of high proportion renewable energy power system.
Structural calculation analysis and design of a Towering concrete building
Authors: Ren Haibo 
Published: June 2021

Abstract
This Towering building is a concrete tower with a height of 199. 10m and an octagonal plane, with a complex structure. The structure is calculated as a whole through the programs of two different mechanical models, the calculation results are relatively close, and the control indicators meet the requirements of relevant specifications and regulations. This article introduces and analyzes the structural system, structural calculation and analysis methods, seismic performance objectives, and overall calculation results of the project, and details the design of the steel tower.
Research on the Influence of Balance Hole on the Performance of Ocean energy gas-liquid multiphase pump
Authors: Xie Hang , Luo Xingqi , Li Chenhao , Yan Sina , Zhu Guojun 
Published: June 2021

Abstract
In this paper, the Euler-Euler heterogeneous flow model is used to simulate the models of centrifugal deep-sea multiphase pump before and after the balance hole is opened under different inlet air ratios. The effect of the balance hole on the external characteristics of the pump is illustrated by comparing the static pressure distribution on the blade surface before and after the opening and the hydraulic loss in the impeller. The research results show that when the inlet air content is less than 5%, the external characteristics of the multipahse pump are reduced, and when the inlet air content is greater than 5%, the balance hole has an improved effect on the external characteristics of the mixed pump. At this time, the static pressure on the blade surface is increased compared with the original model, and the flow loss on the impeller is significantly reduced.
Study on the influence of tip clearance of tidal tubular turbine on pressure pulsation of draft tube
Authors: Wu Yuyang , Li Chenhao , Wang Xiaohang , Zhu Guojun 
Published: June 2021

Abstract
With the development of clean and renewable energy, especially tidal energy, people pay more and more attention to the performance optimization of tubular turbine. Tip clearance of a tubular turbine affects the flow field at the draft tube inlet, and then affects the overall performance of the turbine. In this paper, a full-passage model is established for a bulb tubular turbine. When the tip clearance is 2mm, the variation of pressure pulsation in the different sections of draft tube and the wall surface in different working conditions are monitored. And the effect of tip clearance on the pressure pulsation in the diffusion section is analyzed. The results show that the pressure pulsation is significantly enhanced near the inlet wall of draft tube under the effect of clearance leakage flow. The main frequency amplitude of pressure pulsation on the draft tube wall decreases along the flow direction, indicating that the effect of tip clearance leakage flow on the draft tube wall decreases gradually. The amplitude of pressure pulsation under deviation condition is much larger than the optimal condition, indicating that the effect of clearance leakage vortex on the wall of diffusion section is stronger under the deviation condition. The research results provide reference for the draft tube design of the tubular turbine and the safe and stable operation of the unit.
Modelling of Reverse Logistics Network Design for Waste Refrigerators
Authors: Wang Bin , Hao Hao , Li Hehuang 
Published: June 2021

Abstract
Recycling of waste refrigerators plays an important role in the current reverse logistics research. In this paper, the integer programming model is applied to establish the optimization model of recycling network of waste refrigerators. The model considers whether the recycling center, re-manufacturing center and other nodes are set up or not, and the distribution plan between logistics nodes. The objective function is to minimize the total cost of logistics which includes the fixed cost of facility establishment and the variable cost including cost of processing products at the logistics node as well as vehicle use. Constraints consider the balance of goods in and out logistics nodes and the capacity limit to facilities and vehicles. The model in this paper is verified with actual enterprise cases, which proves the effectiveness of the model in this paper. Applying the model in this paper can effectively improve the operating efficiency of waste refrigerator logistics enterprises.