bluuebunny/crossref_metadata_2025_split huggingface dataset:
I/P interface modification for stable and efficient perovskite solar cells
Authors: Zhang Jie , Hou Shixin , Li Renjie , Chen Bingbing , Hou Fuhua , Cui Xinghua , Liu Jingjing , Wang Qi , Wang Pengyang , Zhang Dekun , Zhao Ying , Zhang Xiaodan 
Published: May 2020

Abstract
Interface engineering has played an increasingly essential role in the development of perovskite solar cells (PSCs). Herein, we adopted an effective and simple one-step interface passivation method on a FA-based perovskite to fabricate efficient and stable planar PSCs. The surface defects are reduced by the perovskite interface passivation layer incorporated between the hole transport and perovskite absorber layers, and then non-radiative recombination is suppressed while interfacial carrier extraction is enhanced. The passivated planar PSCs demonstrates 20.83% power conversion efficiency (PCE), which is caused by the simultaneous enhancement of the fill factor and open-circuit voltage. In addition, the device also shows great ambient and thermal stability. It retains 94% of its original PCE after 1000 h under ambient air without encapsulation as well as 90% of its initial efficiency after 400 h under continuous heating at 65 °C with encapsulation. This research provides a strategy for the development of efficient and stable PSCs.
Light-emitting diodes based on all-inorganic copper halide perovskite with self-trapped excitons
Authors: Liu Nian , Zhao Xue , Xia Mengling , Niu Guangda , Guo Qingxun , Gao Liang , Tang Jiang 
Published: May 2020

Abstract
Light-emitting diodes based on lead halide perovskite have attracted great attention due to their outstanding performance. However, their application is plagued by the toxicity of Pb and the poor stability. Herein novel copper-based all inorganic perovskite CsCu2I3 with much enhanced stability has been reported with a potential photoluminescence quantum yield (PLQY) over 20% and self-trapped excitons (STE). By taking advantage of its extraordinary thermal stability, we successfully fabricate high-quality CsCu2I3 film through direct vacuum-based deposition (VBD) of CsCu2I3 powder. The resulting film shows almost the same PLQY with the synthesized powder, as well as excellent uniformity and stability. The perovskite light-emitting diodes (Pe-LED) based on the evaporated CsCu2I3 emitting layer achieve a luminescence of 10 cd/m2 and an external quantum efficiency (EQE) of 0.02%. To the best of our knowledge, this is the first CsCu2I3 Pe-LED fabricated by VBD with STE property, which offers a new avenue for lead-free Pe-LED.
Giant efficiency and color purity enhancement in multicolor inorganic perovskite light-emitting diodes via heating-assisted vacuum deposition
Authors: Han Boning , Shan Qingsong , Zhang Fengjuan , Song Jizhong , Zeng Haibo 
Published: May 2020

Abstract
Inorganic perovskites (CsPbX3 (X = I, Br, Cl)) have broad prospection in the field of high-definition displaying due to its excellent optoelectronic characteristics. The vacuum deposition process possesses advantages and competitiveness in the industrialized production. However, the performance of light emitting diodes (LEDs) based on vacuum-deposited is incredibly low. Herein, we proposed a heating-assisted vacuum deposition (HAVD) method to construct inorganic perovskite LEDs (PeLEDs) with enhanced performance. The roughness and crystallinity of perovskite film were improved by regulating the heating treatment of substrates. And the perovskite film exhibited largely rise in luminescence, with decreasing defect density. Consequently, with the optimized temperature, the green PeLEDs exhibited 100-fold improvement of external quantum efficiency (EQE) with the luminance of up to 11 941 cd/m2, and the full width at half-maximum (FWHM) of the electroluminescence (EL) spectra was decreased from 25 to 17 nm. At the same time, the red and blue PeLEDs also exhibited obvious enhancement in EQE and luminance by HAVD method, and both the FWHM of EL spectra dropped below 20 nm, exhibiting excellent high color purity. HAVD strategy has a huge potential to be a new commonly used method for low-cost fabrication of displays and lighting.
Two-dimensional transition metal dichalcogenides for lead halide perovskites-based photodetectors: band alignment investigation for the case of CsPbBr3/MoSe2
Authors: Huang Le , Huo Nengjie , Zheng Zhaoqiang , Dong Huafeng , Li Jingbo 
Published: May 2020

Abstract
The distinguished electronic and optical properties of lead halide perovskites (LHPs) make them good candidates for active layer in optoelectronic devices. Integrating LHPs and two-dimensional (2D) transition metal dichalcogenides (TMDs) provides opportunities for achieving increased performance in heterostructured LHPs/TMDs based optoelectronic devices. The electronic structures of LHPs/TMDs heterostructures, such as the band offsets and interfacial interaction, are of fundamental and technological interest. Here CsPbBr3 and MoSe2 are taken as prototypes of LHPs and 2D TMDs to investigate the band alignment and interfacial coupling between them. Our GGA-PBE and HSE06 calculations reveal an intrinsic type-II band alignment between CsPbBr3 and MoSe2. This type-II band alignment suggests that the performance of CsPbBr3-based photodetectors can be improved by incorporating MoSe2 monolayer. Furthermore, the absence of deep defect states at CsPbBr3/MoSe2 interfaces is also beneficial to the better performance of photodetectors based on CsPbBr3/MoSe2 heterostructure. This work not only offers insights into the improved performance of photodetectors based on LHPs/TMDs heterostructures but it also provides guidelines for designing high-efficiency optoelectronic devices based on LHPs/TMDs heterostructures.
Keep it real: selecting realistic sets of urban green space indicators
Authors: Carmen Raïsa , Jacobs Sander , Leone Michael , Palliwoda Julia , Pinto Luís , Misiune Ieva , Priess Jörg A , Pereira Paulo , Wanner Saskia , Ferreira Carla Sofia , Ferreira António 
Published: May 2020

Abstract
With increasing urbanisation, urban green spaces are expected to be crucial for urban resilience and sustainability, through the delivery of ecological, economic and social benefits. In practice, however, planning, management and evaluation of urban green spaces are rarely structured and evidence-based. This represents a missed opportunity to account for, track and foster the multiple benefits that green spaces are expected to deliver. To gain insight into this gap, this study assesses the availability and uptake of relevant evidence by city governments. Interviews, focus groups and quantitative surveys were applied in four medium-sized European cities: Coimbra (Portugal), Genk (Belgium), Leipzig (Germany), and Vilnius (Lithuania), covering the main governance and climatic gradients in Europe. Using straightforward data exploration and regression, we analyse which ecological, economic and social indicators are typically chosen by cities and why. Together with the city stakeholders, we derived a common set of benefit categories and key performance indicators which can be adapted to diverse local contexts. We conclude that cities tend to make pragmatic decisions when composing their indicator sets, but nevertheless cover multiple urban green space dimensions. Finally, we explore how indicator choice could be optimised towards a complementary and credible indicator set, taking into account a realistically feasible monitoring effort undertaken by the cities.
A note on the Drinfeld associator for genus-zero superstring amplitudes in twisted de Rham theory
Authors: Kaderli André 
Published: May 2020

Abstract
The string corrections of tree-level open-string amplitudes can be described by Selberg integrals satisfying a Knizhnik–Zamolodchikov (KZ) equation. This allows for a recursion of the α′-expansion of tree-level string corrections in the number of external states using the Drinfeld associator.
While the feasibility of this recursion is well-known, we provide a mathematical description in terms of twisted de Rham theory and intersection numbers of twisted forms. In particular, this leads to purely combinatorial expressions for the matrix representation of the Lie algebra generators appearing in the KZ equation in terms of directed graphs. This, in turn, admits efficient algorithms for symbolic and numerical computations using adjacency matrices of directed graphs and is a crucial step towards analogous recursions and algorithms at higher genera.
Research on the Signal Characteristics of Internal Gas Leakage in Safety Valve
Authors: Haodong Ma , Rui He , Dianjing Chen , Haodong Ma 
Published: May 2020

Abstract
Based on the acoustic emission theory, this paper explores the signal characteristics of internal gas leakage in safety valve. In this paper, a simulation test-bed and an acoustic emission signal detection system for internal leakage in safety valve are designed and built. Through theoretical analysis and experimental research, the influence of factors such as inlet pressure of safety valve, size of leakage hole of sealing surface are explored, and the quantitative relationship between the gas volume leakage rate and the average signal level ASL of the characteristic parameters of acoustic emission signal is established.
Analysis of Importance of Engineering Survey in Construction Engineering Quality Management
Authors: Liguo Liu , Caixia Zhang 
Published: May 2020

Abstract
Engineering survey is an important technology applied in the quality management of construction engineering. By conducting engineering survey, it can provide necessary data support and measurement methods for the early exploration, mid-term construction, and later acceptance quality management of construction engineering. In the process of construction quality management, how to apply the engineering measurement technology reasonably becomes an urgent problem to be solved. This article will give an overview of engineering survey, and describe the important role of it, and give some opinions and suggestions.
Real-time Monitoring System of Leakage Current for Electric Submersible Pump
Authors: Song Nan , Wang Min , Dang Bo , Liu Shenghu , Ren Zhiping 
Published: May 2020

Abstract
With the increasing exploitation of marine gas, electric submersible pump technology has attracted more and more attention. Under the influence of the bad underground environment, the insulation performance of the electric submersible pump will gradually deteriorate during its operation, resulting in current leakage, causing phase-to-phase open circuit, fire or electric leakage to ground and other dangerous phenomena, which brings destructive damage to the electric submersible pump equipment. In order to solve this problem, this paper designs a real-time monitoring system of the leakage current for the electric submersible pump based on the principle of current mutual inductance and transducing, and constructs the indoor well condition simulation experiment. The experimental data shows that the system can monitor and display the current leakage of the electric submersible pump in real time to ensure the safe operation of the electric submersible pump.
Research on Multi-points Measurement of a Novel Alternate arrangement dynamometer Model
Authors: Danaish  , Zongjin Ren , Jun Zhang , Akbar Muhammad Ayaz 
Published: May 2020

Abstract
The basis of this research is to design and fabricate a new type of alternating arrangement of three-axis piezoelectric sensors dynamometer for measuring six-component force/torque measurement. The system consists of a long dynamometer with eight tri-axial piezoelectric sensors alternatively distributed. The design theory of the piezoelectric six-axis force dynamometer is established, including a finite element model (FEM: ANSYS analysis) and experimental model (static and dynamic calibrations). Structural design is constructed for analyzing the operating principle and performing the experimental measurements. The multipoints measurement (MP-M) model is fabricated based on the established alternate arrangement pattern and force application of multi-points allocation to apply the force/torque. Therefore, this work describes linearity error, repeatability error and cross-talk error of the constructed model. However, the designed model is not limited only to an alternate arrangement pattern of tri-axial sensors. But in the future, other types of arrangements will be researched and will be experimentally performed.
The Positioning Accuracy and Performance Simulation Analysis of BeiDou-3 in Cote d’Ivoire
Authors: Eugene Krou Sub-Lieutenant Brou , Li Houpu , Song Yue 
Published: May 2020

Abstract
BeiDou Navigation Satellite System will operate world widely in 2020. Therefore, it is very important to master the accuracy and positioning performance of BeiDou-3 in West Africa. The number of visible satellite, the navigation accuracy and Geometric Dilution of Precision (GDOP) of BeiDou-3 (3 GEO-3IGSO-24MEO) are simulated using STK software in Cote d’Ivoire. Using data of five stations in Cote d’Ivoire, the simulation results are compared for BeiDou-3 and GPS. Thus, the results are allowed to possess a database about the positioning performance of BeiDou-3 not only for Cote d’Ivoire but also benefit for surrounding Regions of the Gulf of Guinea.
Development and Current Situation of Radar Performance Parameter Measurement Simulation Training Platform
Authors: Wang Jun , Deng Bin , Li Chuanqi 
Published: May 2020

Abstract
The measurement of radar performance parameters is the basic work of radar support forces, and the development of simulation training platform has a very good role in promoting this work. This paper describes the current situation of radar parameter measurement, introduces the development of equipment simulation training platform, and combs the development process of radar performance parameter measurement simulation training platform. At last, the practical requirements of the simulation training platform for radar performance parameter measurement are put forward, that is, by building the simulation training platform for radar main parameter measurement, to meet the requirements of the new two-level maintenance system for the parameter measurement of military maintenance personnel.
Air-Ground Rotary Scanning Imaging System for Ground Vehicles Based on Passive Infrared Detection
Authors: Lei Bingshan , Hao Weina , Zhu Wenbin , Yan Keding 
Published: May 2020

Abstract
General target detection system is based on active detection method, which is usually of poor concealment and bulky. In order to improve the concealment and dexterity of airborne detection, an airborne infrared scanning imaging system for ground vehicles based on passive infrared detection is proposed. Under the condition of guaranteeing the minimum effective detection interval, a rotary scanning dynamic detection model is established based on the principle of single-point passive infrared detection, and the relationships between the detection distance, the rotating angular velocity, the scanning angle, the relative motion velocity and the size of detection area are obtained. According to the expression of infrared characteristic of ground vehicles, the relationship between the response voltage of radiation signal and the relationships among the detection distance is obtained. Based on the projection distribution of the infrared feature area received by the infrared detector, the signal response expression including the size information of the target is obtained at a certain rotating angular velocity. Finally, through simulation and experiment, the system can effectively acquire the signal intensity and signal response width information in the infrared feature area of ground vehicles between the detection distance of 5.4 m and 33.4 m, which verifies the effectiveness of the system.
Numerical simulation of reflected wave characteristics in oil wells measured by Acoustic method
Authors: Wang Ke , Liu Yanping , Wu Jie , Gao Jianshen 
Published: May 2020

Abstract
In order to analyze and identify the corrosion of the inner interface of the coupling, perforating and casing, or the collapse and depression of the casing, as well as the reflection form of the dynamic liquid level, the COMSOL finite element analysis software was used to carry out numerical simulation research on the above situation, and its response characteristics were obtained through calculation. In this paper, three-dimensional propagation characteristics of acoustic waves in the annulus of the oil jacket were studied using signal sources of different polarities. The results showed that when the polarity of the signal source was positive (negative), the coupling reflection signal was first positive (negative) and then negative (positive), and the perforation reflection signal was first negative and then positive (positive then negative). The waveform of the reflection signal in the case of corrosion or casing collapse was consistent with the waveform of the perforation reflection signal; the reflection signal of the moving surface was of the same polarity as the emission signal source. When the signal source was a positive-negative superimposed source, the conclusion obtained by applying the above-mentioned positive (negative) polarized signal source was based on the polarity of the first peak of the superposed source. The research results can provide strong support for the popularization and improvement of related theories, and correct reference standards for the performance verification of echo processing methods, as well as important theoretical basis for the correct identification of echo positions on the Dynamic fluid interface.
Investigation into position deviation effect on micro newton force sensor
Authors: Xu Li , Wang Shuxiang , Zheng Peiliang , Huang Zhenyu , Luo Xudong 
Published: May 2020

Abstract
The position deviation effect on force sensor with a resolution of micro newton scale was investigated by theory model analysis and numerical simulation method. The finite element method and theoretical model were used to analyse the influence of the electrostatic micro force sensors when the electrode position of the cylindrical capacitor changed. Relationship between the sensor output micro force and the position deviation of the internal electrode in the cylindrical capacitance was obtained. It was found that different position deviation form had different degrees of influence on the sensor’s output result and the regions with little effect by position deviation were existed. For translation along Z-axis, the region was [-4 mm, 14 mm]. For translation along r-axis, the region was [-0.2 mm, 0.2 mm]. And for rotation around r-axis, the region was [-1°, 1°]. The corresponding maximum errors of the micro force output were 1.49%, 2.09% and 2.20%, respectively.
Observing the Polarization Dependent Light Shifts Using an Atom Fountain
Authors: Hu Qingqing , Wang Qian , Luo Yukun , Xu Fufang , Jiang Wei , Wei Rong 
Published: May 2020

Abstract
We theoretically predicted and experimentally demonstrated the sinusoidal shifts of the 87Rb atom Raman transition frequencies as the polarization vectors of the Raman lasers rotate. We also presented the vanish of the differential light shifts for the magnetic sensitive Raman transitions at some elliptically polarized configurations while no vanish for the magnetic insensitive Raman transition. These results are helpful for the evaluation and elimination of the light shifts induced systemic errors in the atomic magnetometer, atomic interferometer, atomic clock and quantum computing.
Research on the Main Problems and Countermeasures in the Construction of University Library Informatization
Authors: Wang Weifeng , Meng Luyang , Wu Lei , Hu Jianfei 
Published: May 2020

Abstract
University library informationization plays an important role in developing reading habits and knowledge literacy of teachers and students in universities. However, most college libraries in China still have problems such as not paying enough attention to informatization construction and low informatization construction. This paper adheres to the problem-oriented, and on the basis of analyzing the problems, puts forward countermeasures and suggestions to improve the level of informationization construction of university libraries.
Research on Cow Gesture Recognition Based on Multi-label Chain GBDT and LR Fusion
Authors: Zhao ZhiQiang , Zhu Zheng , Ye ShunAn 
Published: May 2020

Abstract
In this paper, by wearing a nine-axis motion sensor on the neck of a cow, the three-axis acceleration, three-axis angular velocity and three-axis angular motion data of the cow are collected, and the cow’s sports behavior is divided into six postures: standing, resting, walking, and so on, which are used as secondary marks. After the data is balanced and sampled, the six types of gesture labels are divided into three categories as the first level labels, namely, static, small motion and large motion. Gradient Boosting Decison Tree and logistic regression fusion algorithm are used to learn and predict the first-level label, and the prediction result is used as the new feature to learn and predict the second-level label, so as to achieve the purpose of classification of cow gesture recognition. The experimental results show that the average accuracy of the model is 93.6%, and the AUC value is 96.1%. This study can provide an effective basis for dairy cow on estrus and health monitoring.
Design and Implementation of Unmanned Agricultural Machinery
Authors: Jang Ru , Kasimov Farkhod , Zhang Dong , Kaliyeva Kulyash 
Published: May 2020

Abstract
The unmanned agricultural machinery can greatly improve operating efficiency and can cover a large area of farmland operations with very little manpower, which saves agricultural investment costs. In this paper, the hardware and software design of unmanned agricultural machinery are introduced, the unmanned agricultural machine is developed, the autonomous driving experiments in different paths are carried out, and the accuracy of the operation is tested. The results of the experiments show that the unmanned agricultural machinery has high tracking accuracy and can meet the needs of field operations.
Low-illumination image enhancement algorithm based on multi-feature fusion
Authors: Zhang Xuewei , Sun Xiaojuan , Wang Tianfeng 
Published: May 2020

Abstract
In order to improve the effect of image acquisition under the condition of low illumination, a low illumination image enhancement algorithm based on multi-feature fusion is adopted in this paper. In this algorithm, the illumination information is extracted by bilateral filtering, and the illumination parameters are processed by adaptive gamma correction and limited contrast histogram equalization algorithm. The final illumination parameters are obtained by the feature weighted fusion of the processed parameters and the original illumination parameters. The RGB image is obtained by combining the illumination and reflection parameters, and the enhancement of the image is realized. The experimental results show that the algorithm used in this paper can not only improve the brightness of the image, but also enhance the characteristic parameters of the image, remove the noise, and make the color information of the image fuller and richer