bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of cadmium stress on growth and physiological characteristics of sassafras seedlings
Authors: Zhao Hongyi , Guan Juelan , Liang Qing , Zhang Xueyuan , Hu Hongling , Zhang Jian
Published: May 2021

The effects of cadmium stress on the growth and physiological characteristics of Sassafras tzumu Hemsl. were studied in pot experiments. Five Cd levels were tested [CT(Control Treatment) : 0 mg/kg, Cd5: 5 mg/kg, Cd20: 20 mg/kg, Cd50: 50 mg/kg, and Cd100: 100 mg/kg]. The growth and physiological characteristics of the sassafras seedlings in each level were measured. The results showed that soil Cd had negative influences on sassafras growth and reduced the net growth of plant height and the biomass of leaf, branch and root. Significant reductions were recorded in root biomass by 18.18%(Cd5), 27.35%(Cd20), 27.57%(Cd50) and 28.95%(Cd100). The contents of hydrogen peroxide decreased first then increased while malondialdehyde showed the opposite trend with increasing cadmium concentration. Decreases were found in hydrogen peroxide contents by 10.96%(Cd5), 11.82%(Cd20) and 7.02%(Cd50); increases were found in malondialdehyde contents by 15.47%(Cd5), 16.07%(Cd20) and 7.85%(Cd50), indicating that cadmium stress had a certain effect on the peroxidation of the inner cell membranes in the seedlings that resulted in damage to the cell membrane structure. Superoxide dismutase activity decreased among treatments by 17.05%(Cd5), 10,68%(Cd20), 20.85%(Cd50) and 8.91%(Cd100), while peroxidase activity increased steadily with increasing cadmium concentration; these results suggest that peroxidase is likely the main protective enzyme involved in the reactive oxygen removal system in sassafras seedlings. Upward trends were observed in proline content by 90.76%(Cd5), 74.36%(Cd20), 99.73%(Cd50) and 126.01%(Cd100). The increase in proline content with increasing cadmium concentration indicated that cadmium stress induced proline synthesis to resist osmotic stress in the seedlings. Compared to that in CT, the soluble sugar content declined under the different treatments by 32.84%(Cd5), 5.85%(Cd20), 25.55%(Cd50) and 38.69%(Cd100). Increases were observed in the soluble protein content by 2.34%(Cd5), 21.36%(Cd20), 53.15%(Cd50) and 24.22%(Cd100). At different levels of cadmium stress, the chlorophyll content in the seedlings first increased and then decreased, and it was higher in the Cd5 and Cd20 treatments than that in the CT treatment. These results reflected that cadmium had photosynthesis-promoting effects at low concentrations and photosynthesis-suppressing effects at high concentrations. The photosynthetic gas exchange parameters and photosynthetic light-response parameters showed downward trends with increasing cadmium concentration compared with those in CT; these results reflected the negative effects of cadmium stress on photosynthesis in sassafras seedlings.
Generation and properties of the new asphalt binder model using molecular dynamics (MD)
Authors: Yao Hui , Liu Junfu , Xu Mei , Bick Andreas , Xu Qing , Zhang Jinxi
Published: May 2021

Asphalt binder is the main material for road pavement and building construction. It is a complex mixture composed of a large number of hydrocarbons with different molecular weights. The study of asphalt binders and asphalt concretes from a molecular perspective is an important means to understand the intricate properties of asphalt. Molecular dynamics simulation is based on Newton’s law and predicts the microscopic performance of materials by calculating the intra- and intermolecular interactions. The asphalt binder can be divided into four components: saturates, aromatics, resins, and asphaltenes (SARA). A new molecular model of asphalt was proposed and verified in this study. Eight molecules selected from the literature were used to represent the four components of asphalt. The AMBER Cornell Extension Force Field was applied in this study to model building and the calculation of properties. The density of the asphalt model was calculated and compared with experimental results for validity verifications. The results show that the purposed model can be used to calculate the microscopic properties of the asphalt binder because the density of the model is close to the real value in the field. Besides, the proportions of different molecules in the model were adjusted to predict the relationship between the asphalt binder density and the hydrocarbon ratios and heteroatom contents of the molecular model. Moreover, the glass transition temperature of the asphalt binder model is predicted by the simulation of the heating process. The range of the glass transition temperature is determined by calculating the relationship between specific volume and temperature, and the calculated range is close to the experimental value.
Ultrasonication-mediated nitrogen-doped multiwalled carbon nanotubes involving carboxy methylcellulose composite for solid-state supercapacitor applications
Authors: Basivi Praveen Kumar , Ramesh Sivalingam , Kakani Vijay , Yadav H. M. , Bathula Chinna , Afsar N. , Sivasamy Arumugam , Kim Heung Soo , Pasupuleti Visweswara Rao , Lee Handol
Published: May 2021

In this study, a novel nanohybrid composite containing nitrogen-doped multiwalled carbon nanotubes/carboxymethylcellulose (N-MWCNT/CMC) was synthesized for supercapacitor applications. The synthesized composite materials were subjected to an ultrasonication-mediated solvothermal hydrothermal reaction. The synthesized nanohybrid composite electrode material was characterized using analytical methods to confirm its structure and morphology. The electrochemical properties of the composite electrode were investigated using cyclic voltammetry (CV), galvanic charge–discharge, and electrochemical impedance spectroscopy (EIS) using a 3 M KOH electrolyte. The fabricated composite material exhibited unique electrochemical properties by delivering a maximum specific capacitance of approximately 274 F g−1 at a current density of 2 A g−1. The composite electrode displayed high cycling stability of 96% after 4000 cycles at 2 A g−1, indicating that it is favorable for supercapacitor applications.
Enhanced electrical conductivity and mechanical properties in thermally stable fine-grained copper wire
Authors: Mao Qingzhong , Zhang Yusheng , Guo Yazhou , Zhao Yonghao
Published: May 2021

The rapid development of high-speed rail requires copper contact wire that simultaneously possesses excellent electrical conductivity, thermal stability and mechanical properties. Unfortunately, these are generally mutually exclusive properties. Here, we demonstrate directional optimization of microstructure and overcome the strength-conductivity tradeoff in copper wire. We use rotary swaging to prepare copper wire with a fiber texture and long ultrafine grains aligned along the wire axis. The wire exhibits a high electrical conductivity of 97% of the international annealed copper standard (IACS), a yield strength of over 450 MPa, high impact and wear resistances, and thermal stability of up to 573 K for 1 h. Subsequent annealing enhances the conductivity to 103 % of IACS while maintaining a yield strength above 380 MPa. The long grains provide a channel for free electrons, while the low-angle grain boundaries between ultrafine grains block dislocation slip and crack propagation, and lower the ability for boundary migration.
A method for the growth of uniform silica shells on different size and morphology upconversion nanoparticles
Authors: Ureña-Horno Elena , Kyriazi Maria-Eleni , Kanaras Antonios G.
Published: May 2021

Silica shell growth on lanthanide-doped upconversion nanoparticles.
Protection against proteolysis of a targeting peptide on gold nanostructures
Authors: Biscaglia Francesca , Caligiuri Isabella , Rizzolio Flavio , Ripani Giorgio , Palleschi Antonio , Meneghetti Moreno , Gobbo Marina
Published: May 2021

Targeting peptides are shown to be very stable on the surface of gold nanoparticles and to preserve their binding activity also when exposed to a proteolytic environment.
Macroscopic and microscopic picture of negative capacitance operation in ferroelectric capacitors
Authors: Esseni David , Fontanini Riccardo
Published: May 2021

The negative capacitance operation of ferroelectric capacitors is an interesting and partly elusive topic from a material science perspective, and it is a promising option for the design of nanoscale transistors.
Effects of high-fat diet on the formation of depressive-like behavior in mice
Authors: Yu Haining , Qin Xiuyuan , Yu Zhen , Chen Yan , Tang Lan , Shan Weiguang
Published: May 2021

HFD accelerates lipid metabolism disorders and promotes depressive-like behaviours.
Anisotropic silicon nanowire arrays fabricated by colloidal lithography
Authors: Rey Marcel , Wendisch Fedja Jan , Aaron Goerlitzer Eric Sidney , Julia Tang Jo Sing , Bader Romina Sigrid , Bourret Gilles Remi , Vogel Nicolas
Published: May 2021

We demonstrate the design of silicon nanowire arrays with tunable elliptical cross-sections. Their anisotropic character of the individual pillars affords defined bending or bundling of the arrays.
Correction: Indolo[3,2-b]indole donor-based D–π–A dyes for DSCs: investigating the role of π-spacers towards recombination
Authors: Santhini P. V. , V. Jayadev , Pradhan Sourava C. , Lingamoorthy Sivasankaran , P. R. Nitha , M. V. Chaithanya , Mishra Rakesh K. , K. N. Narayanan Unni , John Jubi , Soman Suraj
Published: May 2021

Correction for ‘Indolo[3,2-b]indole donor-based D–π–A dyes for DSCs: investigating the role of π-spacers towards recombination’ by P. V. Santhini et al., New J. Chem., 2019, 43, 862–873, DOI: 10.1039/C8NJ04561E.
Graphene and water-based elastomer nanocomposites – a review
Authors: Nwosu Christian N. , Iliut Maria , Vijayaraghavan Aravind
Published: May 2021

This review covers the emerging field of graphene reinforced water-based elastomers, which offer enhanced strength, elasticity, electrical and thermal conductivity and other properties for a wide range of application sectors.
Extending photocatalysis to the visible and NIR: the molecular strategy
Authors: Mavridi-Printezi Alexandra , Menichetti Arianna , Guernelli Moreno , Montalti Marco
Published: May 2021

Molecular photosensitizers (PS) allow to exploit visible (Vis) and near-infrared (NIR) light for photocatalytic production of solar fuels, organic synthesis and environmental remediation.
Acidic tumor microenvironment-sensitive liposomes enhance colorectal cancer therapy by acting on both tumor cells and cancer-associated fibroblasts
Authors: Li Chenglei , Li Zhaohuan , Gong Xue , Liu Jianhao , Zheng Tingyue , Wang Fangqing , Wu Jingliang , Zhang Bo
Published: May 2021

IRI&398-s-LPs was destroyed in the TME, leading to rapid release of drugs, thus killing tumor cells and CAFs simultaneously. The combinational strategy by eliminating both “seeds” and “soil” of the tumor is beneficial for enhancing antitumor effect.
Surfactant-mediated morphology evolution and self-assembly of cerium oxide nanocrystals for catalytic and supercapacitor applications
Authors: Hao Xiaodong , Zhang Shuai , Xu Yang , Tang Liangyu , Inoue Kazutoshi , Saito Mitsuhiro , Ma Shufang , Chen Chunlin , Xu Bingshe , Adschiri Tadafumi , Ikuhara Yuichi
Published: May 2021

Surfactant-mediated morphology evolution of CeO2 nanocrystals is fully investigated at the atomic scale and it was found that the exposure of {100} facets largely affects the concentration of Ce3+ and subsequently the OSC performance.
Limonene as a renewable unsaturated hydrocarbon solvent for living anionic polymerization of β-myrcene
Authors: Dev Akhil , Rösler Alexander , Schlaad Helmut
Published: May 2021

The acyclic monoterpene β-myrcene is polymerized by living anionic polymerization at room temperature using the cyclic monoterpene limonene as an unsaturated hydrocarbon solvent.
Submonomer synthesis of peptoids containing trans-inducing N-imino- and N-alkylamino-glycines
Authors: Davern Carolynn M. , Lowe Brandon D. , Rosfi Adam , Ison Elon A. , Proulx Caroline
Published: May 2021

The use of hydrazones as a new type of submonomer in peptoid synthesis is described, giving access to peptoid monomers that are structure-inducing.
Actinide tetra-N-heterocyclic carbene ‘sandwiches’
Authors: DeJesus Joseph F. , Kerr Ryan W. F. , Penchoff Deborah A. , Carroll Xian B. , Peterson Charles C. , Arnold Polly L. , Jenkins David M.
Published: May 2021

Highly-symmetrical, thorium and uranium octakis-carbene ‘sandwich’ complexes have been prepared by ‘sandwiching’ the An(iv) cations between two anionic macrocyclic tetra-NHC ligands, one with sixteen atoms and the other with eighteen atoms.
Effect of the abolition of intersubunit salt bridges on allosteric protein structural dynamics
Authors: Choi Minseo , Kim Jong Goo , Muniyappan Srinivasan , Kim Hanui , Kim Tae Wu , Lee Yunbeom , Lee Sang Jin , Kim Seong Ok , Ihee Hyotcherl
Published: May 2021

The structural and functional roles of salt bridges in the allosteric structural transition of homodimeric hemoglobin are investigated by time-resolved X-ray solution scattering.
Photo-induced ultralong phosphorescence of carbon dots for thermally sensitive dynamic patterning
Authors: Liu Yanfeng , Huang Xin , Niu Zuoji , Wang Dongni , Gou Huilin , Liao Qiaobo , Xi Kai , An Zhongfu , Jia Xudong
Published: May 2021

A flexible CD–polymer composite with a reversibly editable photo-induced URTP long afterglow was rationally designed and successfully applied in dynamic optical patterning with built-in time–temperature indicating functionality.
Bouncing-to-wetting transition of water droplets impacting soft solids
Authors: Mitra Surjyasish , Vo Quoc , Tran Tuan
Published: May 2021

The bouncing-to-wetting transition of water droplets impacting PDMS-coated substrates was investigated. It was found that such transitions are dictated by a dimple inversion phenomenon.
Decentralizing indexing and bootstrapping for online applications
Authors: Schutz Pierre , Gal Stanislas , Chatzopoulos Dimitris , Hui Pan
Published: May 2021

Peer‐to‐peer (P2P) networks utilize centralized entities (trackers) to assist peers in finding and exchanging information. Although modern P2P protocols are now trackerless and their function relies on distributed hash tables (DHTs), centralized entities are still needed to build file indices (indexing) and assist users in joining DHT swarms (bootstrapping). Although the functionality of these centralized entities are limited, every peer in the network is expected to trust them to function as expected (e.g. to correctly index new files). In this work, a new approach for designing and building decentralized online applications is proposed by introducing DIBDApp. The approach combines blockchain, smart contracts and BitTorrent for building up a combined technology that permits to create decentralized applications that do not require any assistance from centralized entities. DIBDApp is a software library composed of Ethereum smart contracts and an API to the BitTorrent protocol that fully decentralizes indexing, bootstrapping and file storing. DIBDApp enables any peer to seamlessly connect to the designed smart contracts via the Web3J protocol. Extensive experimentation on the Rinkeby Ethereum testnet shows that applications built using the DIBDApp library can perform the same operations as in traditional back‐end architectures with a gas cost of a few USD cents.
Application of blockchain in the cluster of unmanned aerial vehicles
Authors: Chen Shiwu , Li Qin , Wang Wei , Yang Yu , Jiang Jun
Published: May 2021

With the considerable exploration of unmanned aerial vehicles in civilian and military fields, the data storage and transmission mechanism of unmanned aerial vehicles exhibit significant security limitations, which cannot meet the strict requirements for data security in civilian and military business scenarios. In recent years, blockchain technology has been tried to be applied to multiple fields. The features of blockchain includes decentralization, immutability, transparency and auditability, make transactions more secure and tamper proof. In view of the many excellent features of blockchain, in this paper, blockchain technology is introduced into the application of cluster of unmanned aerial vehicles, aiming to solve the problems of identity authentication, secure and reliable transmission of data between unmanned aerial vehicles, and access control of the data on the blockchain, thereby to enhance the security of the cluster of unmanned aerial vehicles and to ensure the integrity and security of data.
Long-term pulse period evolution of the ultra-luminous X-ray pulsar NGC 7793 P13
Authors: Fürst F. , Walton D. J. , Heida M. , Bachetti M. , Pinto C. , Middleton M. J. , Brightman M. , Earnshaw H. P. , Barret D. , Fabian A. C. , Kretschmar P. , Pottschmidt K. , Ptak A. , Roberts T. , Stern D. , Webb N. , Wilms J.
Published: May 2021

Ultra-luminous X-ray pulsars (ULXPs) provide a unique opportunity to study persistent super-Eddington accretion. Here we present the results of a long-term monitoring campaign of ULXP NGC 7793 P13, focusing on the pulse period evolution and the determination of the orbital ephemeris. Over our four year monitoring campaign with Swift, XMM-Newton, and NuSTAR, we measured a continuous spin-up with an average value of Ṗ ≈ −3.8 × 10−11 s s−1. We find that the strength of the spin-up is independent of the observed X-ray flux, indicating that despite a drop in observed flux in 2019, accretion onto the source has continued at largely similar rates. The source entered an apparent off-state in early 2020, which might have resulted in a change in the accretion geometry as no pulsations were found in observations in July and August 2020. We used the long-term monitoring to update the orbital ephemeris, as well as the periodicities seen in both the observed optical and UV magnitudes and the X-ray fluxes. We find that the optical and UV period is very stable over the years, with PUV = 63.75−0.12+0.17 d. The best-fit orbital period determined from our X-ray timing results is 64.86 ± 0.19 d, which is almost a day longer than previously implied, and the X-ray flux period is 65.21 ± 0.15 d, which is slightly shorter than previously measured. The physical origin of these different flux periods is currently unknown. We study the hardness ratio of the XMM-Newton and NuSTAR data between 2013−2020 to search for indications of spectral changes. We find that the hardness ratios at high energies are very stable and not directly correlated with the observed flux. At lower energies we observe a small hardening with increased flux, which might indicate increased obscuration through outflows at higher luminosities. Comparing the changes in flux with the observed pulsed fraction, we find that the pulsed fraction is significantly higher at low fluxes. This seems to imply that the accretion geometry already changed before the source entered the deep off-state. We discuss possible scenarios to explain this behavior, which is likely driven by a precessing accretion disk.
Coordinated Recovery Strategy for Multi-infeed HVDC Systems Based on MIESCR
Authors: Xiaobin Li , Shihao Hu , Haoyu Huang
Published: May 2021

A coordinated recovery strategy, based on MIESCR, is proposed for the converters Excessive dynamic reactive power demand and the low speed of power transmission recovery in multi-infeed HVDC system in this paper. Firstly, the article deduces the consistency of two type definition of MIESCR, and uses the respective advantages of the definition to improve the physical meaning of MIESCR; and then it elaborates the role of MIESCR played in in MIDC system voltage and power-angle stability Third, this pages put forward MIESCR as the fundamental to distinguish the strength of AC system, and use the size of MIESCR to arrange the recovery order of DC systems. Furthermore, the parameter of PI controller is used to realize the control of each DC system current. There is a great method to ensure coordinate control of PI controller. The last, a double infeed HVDC system simulation model, based on two actual DC system of China Southern Power Grid, is built on Electromagnetic transient simulation software of PSCAD/EMTDC to confirm the validity of this method proposed in this paper.
Predictive Model for Conducting Electromagnetic Interference by Bidirectional Excitation Controller
Authors: Xucai Shao , Jinghong Zhao , Hansi Chen , Yinping Zhou , Yinhao Mao
Published: May 2021

Bidirectional excitation controller is used in the excitation system of brushed DC motor. There are many monitoring sensors and weak current switches nearby. Therefore, it is necessary to study the conduction interference of the excitation controller. Firstly, based on the working principle of bidirectional excitation controller, the propagation path model and corresponding equivalent circuit of bidirectional excitation controller are established. Then, the parasitic capacitance parameters between the switch tube and the heat sink were extracted by ANSYS Q3D software, and the dynamic model of IGBT was established by using ANSYS Simplorer software. Based on ANSYS software, the prediction model of the equipment conducted electromagnetic interference was obtained. Finally an excitation controller conducting interference test platform was built, and the predicted results were compared with the measured interference results of the experimental platform to verify the accuracy of the prediction model.
Performance test and typical fault analysis of electric emergency power supply vehicle
Authors: Gu Chunhui , Fang Jian , Zhang Zichong , Gong Jianping
Published: May 2021

In the emergency repair of electric power caused by sudden natural disasters, the reliability and stability of emergency power supply vehicles largely determine the speed and efficiency of restoring power supply. Based on the performance test and reliability study of 18 diesel-powered vehicles in Guangzhou Power Supply Company Limited, the typical defects of emergency power supply equipment and the causes of the faults are analyzed. It provides technical support for the technical standards and the maintenance guidance of emergency power supply equipment, and greatly improves the emergency capability of rapid power recovery under extreme natural disasters. It has improved the emergency response capability of rapid re-powering under extreme natural disasters, shortened the repair time, and significantly reduced the loss and impact of extreme natural disasters on the power system and the entire national economy.
Optimization design and development of UHF omnidirectional wideband antenna for PD detection in substation
Authors: Xing Zhen-hua , Wang Zhen , Xu Hang , Xu Miao , Mou Xiao-lin , Wu Lu-xiao , Yang Kun , Liu Zhao
Published: May 2021

In order to meet the requirements of partial discharge (PD) detection of electrical equipment in substation station area, the ultra-high frequency (UHF) antenna with broadband, high gain and horizontal plane (H-plane) omnidirectional is studied and designed as a PD sensor. By analyzing the characteristic impedance and structural characteristics of the biconic antenna, it is determined to be an UHF omnidirectional wideband antenna for detecting PD. The influence of structural parameters such as half-cone angle and vertebral body height on the antenna performance is simulated. At last, a double cone antenna is made and its bandwidth, directional pattern, gain and equivalent height are tested.
Design of the user-side contract power transfer transaction mechanism considering adjustable loads
Authors: Guo Junhong , Liu Yining , Li Ling , Xue Xiaoqiang , Su Jingya , Ouyang Haowen
Published: May 2021

In recent years, to cope with the increasing uncertainty of load side, the adjustability of load side is constantly improved. However, the power deviation of user side hasn’t been well adjusted due to the lack of the channel. This not only makes users face higher risks, but also makes incomplete use of sufficient load side adjustable resources. One of the effective ways to solve the problems above is user-side contract power transfer transaction. In this paper, main forms of adjustable load in major fields are discussed at first, then the user-side contract power transfer transaction mechanism considering adjustable load is proposed, finally the validity of the proposed mechanism is verified by a study case.
On-line Update Method for the Sensitivity Consistency Model of Interconnected Power Grid Based on Electric Power Big Data
Authors: Lian Shuai , Li Bintang , Wang Jianbo , Jiang Rui
Published: May 2021

Real-time fast calculation of the power flow of the interconnected power grid is an important guarantee for the reliable operation of the interconnected power grid. The topology of the interconnected power grid is complex, and the calculation of the power flow of the whole network is large and timeconsuming. The sensitivity equivalent model can effectively simplify the interconnected power grid and shorten the time of the power flow calculation of the whole network. The operating state of the power grid is constantly changing. In order to ensure the accuracy of the power flow calculation results, it is necessary to update the uniform sensitivity equivalent model in real time. Due to factors such as the vertical management system between the interconnected power grids and the principle of commercial confidentiality, it is difficult to share information between interconnected power grids in real time, and the sensitivity equivalent model cannot be updated in real time, resulting in too much error in the calculation results and no reference value. To solve this problem, this paper proposes an online update method for the sensitivity equivalent model of the interconnected power grid based on power big data to solve the problem of excessive power flow calculation errors caused by the untimely update of the equivalent model parameters, and to ensure the operational reliability of the interconnected power grid.
Safety Analysis and System Design of Lithium Iron Phosphate Battery in Substation
Authors: Fang Zhang , Junming Li , Xiaochen Yu , Hainan Su , Xin Yu , Jing Pang , Hongxu Xie
Published: May 2021

This paper discusses the safety protection design of lithium iron phosphate batteries based on the technical characteristics of lithium iron phosphate batteries. Combined with the current background of the application of lithium iron phosphate batteries in substations, the system design of lithium iron phosphate batteries is discussed from many aspects. It focuses on how to ensure its safety in order to improve the application effect of lithium iron phosphate batteries in substations.
Influence of Inverter Controller Parameters on the Small-signal Stability of LCC-HVDC System Based on a Practical Project
Authors: Li Huan , Qin Kang
Published: May 2021

Unreasonable control parameters of the Line Commutated Converter based High Voltage Direct Current (LCC-HVDC) system may induce small-signal instability. This paper studies the impact of inverter controller parameters on steady response of the LCC-HVDC system under weak AC grid condition. Firstly, according to a practical project, the small-signal model of LCC-HVDC system is established based on the switching function. Then, the eigen-analysis method is adopted to study the impact of the controller parameters on the inverter side on the oscillation mode and damping characteristics of the LCC system, and the correctness of results is verified by PSCAD/EMTDC simulation. The conclusion shows that reasonable controller parameters can improve the stability margin of the system.
A Planning Method of Hybrid AC/DC Receiving End Grid with Mutually Exclusive Constraints
Authors: Luo Yi , Zhang Yin , Tang Muyi , Zhou Youbin , Wang Ying , Cai Defu , Liu Haiguang , Li Ding , Wu Yaning , Han Yue
Published: May 2021

With the large-scale application of LCC-HVDC and VSC-HVDC in power systems, the mutually exclusive constraints (MES) appear in the optimal planning of hybrid AC/DC receiving end power grid. The MES increase the scale of the construction set of substations and the transmission lines and decrease the planning efficiency and effectiveness of the conventional method. This paper proposes a novel hybrid AC/DC receiving end grid planning method with MES. Constraint satisfaction problem (CSP) is utilized to model the set of mutually exclusive selected lines, in which mutually exclusive candidate lines are converted to mutually exclusive variables and then introduced into the planning model as constraints. After establishing the hybrid AC/DC receiving end grid planning model with MES, the backtracking search algorithm (BSA) is used to solve the optimal planning. The effectiveness of the proposed hybrid AC/DC power grid planning method with MES is verified by case studies.
Construction Technology of Knowledge Graph and its Application in Power Grid
Authors: Xiaoping Gai , Mengyu Ruan , Hong Zhang , Ping Wu , Ruijun Ren , Feng Gao
Published: May 2021

With the rapid development of energy internet, dispatchers need to learn more knowledge with wider scope and fast update speed. It’s urgent to realize the knowledge electrification, knowledge systematization, knowledge visualization and knowledge sharing of power grid dispatching. Firstly, this paper studies the definition and traits of knowledge graph, deeply analyses the key technologies of knowledge graph construction. Secondly, considering the contents and requirements of power grid dispatching business as well as the internal relationship of basic theoretical knowledge of power grid operation analysis, a method of constructing AC/DC power grid dispatching knowledge property graph is proposed. Finally, a practical example of a regional power grid knowledge graph is built to verify the effectiveness and practicality of the proposed method.
Research on Reduced-Order Modeling of Droop Controlled Inverter Suitable for Analysis of Transient Characteristics
Authors: Yingjie Tan , Min Xu , Zuogang Guo , Jinyong Lei , Zhiyong Yuan , Changcheng Zhou
Published: May 2021

Under the background of a large number of converters connected to the power grid, the converter’s weak overcurrent capability and poor anti-interference ability bring challenges and hidden dangers to the transient safe and stable operation of the power grid. It is urgent to carry out the transient characteristics analysis of the converter. Numerical simulation calculation is an important means to study transient characteristics. However, numerical simulation is time-consuming and poor in generality, which greatly limits the study of transient characteristics of systems with multiple converters. In this paper, the vertical control is the object, and the inverter reduced-order simplified model suitable for different transient stability problems is studied. First, a full-order model of the droop control inverter is established, and the singular perturbation method is used to complete the extraction of system characteristic roots and the analysis of participating factors. Then, according to the droop control of the inverter’s power angle, voltage, and frequency transient response process, accuracy and rapidity are selected as the goals, and a reduced-order simplified model suitable for different transient stability analysis is obtained. The transient characteristic analysis of the numerical simulation of the converter system provides a reduced order reference.
Research on Bi-level Coordinated Optimal Dispatching Strategy for Microgrid Cluster
Authors: langchao He , Lizhen Wu , Wei Chen , Xiaohong Hao
Published: May 2021

The interconnection of multiple microgrids can form a microgrid cluster (MGC). The economic benefit and operation reliability of the whole system can be improved through the energy mutual-aid and coordination control between microgrids. This paper proposes a bi-level coordinated optimal dispatching strategy for microgrid clusters. The upper layer aims to minimize the operating costs of the microgrid cluster system and the power fluctuation of the tie lines. The exchange power and generation power of each sub-microgrid are coordinated and controlled, which are sent to the lower level model as scheduling instructions. The lower layer takes a single microgrid as the research object. By optimizing the output of power generation unit, the operation cost of single microgrid can be minimized. Iterative solution is adopted between the bi-level optimization models. In order to avoid the premature and local convergence of the algorithm in the optimization process, the improved artificial bee colony algorithm (ABC) is used to solve the objective function. Finally, simulation examples verify the effectiveness and feasibility of the proposed strategy.
Application of SRNN-GRU in Photovoltaic power Forecasting
Authors: Liu Shiyan , Hao Xiaoguang , Meng Zhengji , Li Jianfeng , Cui Tongfei , Wei Le
Published: May 2021

Short-term photovoltaic power forecasting is of great significance for maintaining the security and stability of the power grid and coordinating the utilization of resources. As one of the Deep Learning Methods, Recurrent Neural Network (RNN) is widely used in time series prediction but lacks the ability of parallel computing. With good prediction effect, RNN is faced with the problem of long training time. In this paper, Sliced Recurrent Neural Network (SRNN) is applied to PV power prediction to guarantee the ability of parallel computing. The research result shows that compared to other commonly used models, SRNN can greatly speed up the training of Deep Learning Network with over 4 times higher training speed of the application of PV power prediction than that of ordinary RNN structure like LSTM and GRU. The accuracy of SRNN model is also improved by 0.1102 mae, which is significantly ahead of the others, as its parallel structure causes the more efficient parameter update, thus achieving ideal effect in PV prediction.
Short-term wind power prediction based on GPR-BSO model
Authors: Chen Tao , Li Xinjian , Zhang Zhemeng , Yang Tongguang , He Shengtao , Shao Xiwen , Liao Jing
Published: May 2021

Wind power forecasting is a crucial part for the safe and stable operation of wind power integration, which is under the influence of different factors such as wind speed, wind direction, atmospheric pressure. These factors bring randomness and volatility to wind power which makes it less predictable. While, there are very limited studies on describing the uncertainty of wind power. Therefore, to providing additional information on the uncertainty and volatility, a kernel-based on Gaussian Process Regression (GPR) incorporating the hyper-parameters intelligent optimization method is proposed in this paper. Firstly, the hyper-parameters solution of GPR is formulated as a nonlinear optimization with constraints. Then, an intelligent algorithm named Brain-storming optimization (BSO) is adopted to obtain the optimal hyper-parameters of GPR. Furthermore, the performance is examined on short-term wind power data. Most importantly, the GPR incorporating BSO can avoid the hyper-parameters at local optimum.
Multivariate time series prediction of high dimensional data based on deep reinforcement learning
Authors: Ji Xin , Zhang Haifeng , Li Jianfang , Zhao Xiaolong , Li Shouchao , Chen Rundong
Published: May 2021

In order to improve the prediction accuracy of high-dimensional data time series, a high-dimensional data multivariate time series prediction method based on deep reinforcement learning is proposed. The deep reinforcement learning method is used to solve the time delay of each variable and mine the data characteristics. According to the principle of maximum conditional entropy, the embedding dimension of the phase space is expanded, and a multivariate time series model of high-dimensional data is constructed. Thus, the conversion of reconstructed coordinates from low-dimensional to high-dimensional can be kept relatively stable. The strong independence and low redundancy of the final reconstructed phase space construct an effective model input vector for multivariate time series forecasting. Numerical experiments of classical multivariable chaotic time series show that the method proposed in this paper has better forecasting effect, which shows the forecasting effectiveness of this method.
Calculation Method and Application of Inter-Regional and Inter-Provincial Market Trading Space for Promoting the Consumption of Clean Energy
Authors: Tan Hao , Yuan Mingzhu , Wang Lei , Dong Wujun , Bai Ziyang
Published: May 2021

Inter-provincial market trading is putting up with to implement the national energy strategy, increasing clean energy consuming and optimization energy allocation in large-scale. To promote energy consumption, the inter-province power transmission channel’ potential needs to be full excavate to deal with clean energy fluctuation, improving trading frequency and reduce transaction period. This article puts up with an inter-province power market trading space calculation method to calculate the available power transmission ability of inter-provincial transmission channel, discovering transmission channel and releasing transaction space. Besides, for certain transmission channel or supply-demand province’s electricity requirements, the calculation method can explore the trading market space, organizing clean energy evacuation to improve transmission channel utilization and safety checking pass rates, reducing blocking.
Efficacy and Safety of Non-Vitamin K Antagonist Oral Anticoagulants in Pediatric Venous Thromboembolism Treatment and Thromboprophylaxis: A Systematic Review of the Literature
Authors: Branstetter Joshua W. , Kiskaddon Amy L. , King Madeleine A. , Coalter Carli , Grubbs Kimberly M. , Fly Hunter , Male Christoph , Brandão Leonardo , Goldenberg Neil A.
Published: May 2021

Venous thromboembolism (VTE) in children can lead to significant morbidity and mortality. Traditionally, treatment for thrombotic events in pediatric patients has been limited mainly to unfractionated heparin, low-molecular-weight heparin (LMWH), or vitamin K antagonists. Since the first non–vitamin K antagonist oral anticoagulant (NOAC) was approved for adult use, these agents have gained popularity for a variety of indications. This is largely due to their ease of administration, favorable pharmacokinetic and pharmacodynamic profile, decreased food interactions, and decreased need for therapeutic drug monitoring. Treating and preventing VTE with traditional anticoagulants in pediatric patients presents many challenges. This systematic review evaluated the current literature regarding pediatric NOAC trials. Additionally, based on an up-to-date query of clinicaltrials.gov, we detail current ongoing and as-yet unpublished clinical trials, study outcomes, and projected completion dates. Published pediatric NOAC trials have included 1,007 total children to date and have ranged from phase 1 to 4, with “indications” including both thromboembolism prophylaxis and VTE treatment. Three recent phase 3 trials, specifically involving rivaroxaban and dabigatran, have shown the agents to be at least as effective as traditional anticoagulants for acute and/or extended VTE treatment, with low frequency of recurrent thrombosis and clinically significant bleeding rates. Additionally, specially developed and tested pediatric formulations have allowed for accurate and reliable dosing, oral administration, stable pharmacokinetics and pharmacodynamics, and fewer drug or food interactions. Ongoing trials, anticipated for completion in the next few years, will reveal important information with regard to thromboembolism prophylaxis in special pediatric subpopulations and settings.
The Advent of Spinoplastics: Easing the Growing Global Disease Burden of Spinal Injury
Authors: Delancy Matthew M. , Perdanasari Aurelia , Davis Matthew J. , Abu-Ghname Amjed , Kaplan Jordan , Winocour Sebastian J. , Reece Edward M. , Sim Alfred Sutrisno
Published: May 2021

Epidemiologic studies have demonstrated a growing global disease burden of pathologies affecting the vertebral column. Allograft or implant-based reconstruction and fusion surgeries have been the mainstay of treatment. The efficacy of various surgical methods and the reliability of instrumentation or implants to execute these surgeries continue to be debated in the literature. Advances such as the free-tissue transfer have improved postoperative measures; however, they add high operative risk. The advent of spinoplastics introduces a practical surgical model to augment these spinal surgeries using vascularized bone grafts. As this technique becomes more widespread, it can be utilized to ease the growing disease burden that spinal injury places on both patients and the health care system. Ultimately, it will ameliorate strains on health care resources, reduce health care costs, and improve patient outcomes and quality of life.
Vascularized Bone Grafts in Spinal Reconstruction: An Overview of Nomenclature and Indications
Authors: Skochdopole Anna J. , Wagner Ryan D. , Davis Matthew J. , Raj Sarth , Winocour Sebastian J. , Ropper Alexander E. , Xu David S. , Bohl Michael A. , Reece Edward M.
Published: May 2021

Several vascularized bone grafts (VBGs) have been introduced for reconstruction and augmenting fusion of the spine. The expanding use of VBGs in the field of spinoplastic reconstruction, however, has highlighted the need to clarify the nomenclature for bony reconstruction as well as establish the position of VBGs on the bony reconstructive algorithm. In the current literature, the terms “flap” and “graft” are often applied inconsistently when describing vascularized bone transfer. Such inconsistency creates barriers in communication between physicians, confusion in interpreting the existing studies, and difficulty in comparing surgical techniques. VBGs are defined as bone segments transferred on their corresponding muscular attachments without a named major feeding vessel. The bone is directly vascularized by the muscle attachments and unnamed periosteal feeding vessels. VBGs are best positioned as a separate entity in the bony reconstruction algorithm between nonvascularized bone grafts (N-VBGs) and bone flaps. VBGs offer numerous advantages as they supply fully vascularized bone to the recipient site without the microsurgical techniques or pedicle dissection required for raising bone flaps. Multiple VBGs have been introduced in recent years to optimize these benefits for spinoplastic reconstruction.
Extending the in vivo Half-Life of Adalimumab Fab via Sortase A-Mediated Conjugation of Adalimumab Fab with Modified Fatty Acids
Authors: Zhang Qing-Bin , Ruan Si-Da , Wu Yong , Zhang Jin-Hua , Lu Jian-Guang , Feng Jun
Published: May 2021

Adalimumab, a full-length monoclonal antibody, is widely used as an anti-tumor necrosis factor-α (anti-TNF-α) agent. In this article, we aimed to prolong the in vivo half-life of adalimumab antigen-binding fragment (Fab) through Sortase A (SrtA)-mediated conjugation of its Fab with fatty acid (FA). In our study, adalimumab Fab analog was prepared by adding an SrtA recognition sequence (LPETGG) and His6 tag to the heavy chain C-terminal of the Fab via (G4S)3 linker. Four FA motifs with different linkers were designed and synthesized by solid-phase methodology, then conjugated with the Fab analog using SrtA to produce Fab bioconjugates. The successful generation of four Fab bioconjugates (Fab–FA1, Fab–FA2, Fab–FA3, and Fab–FA4) was confirmed by SDS-PAGE (sodium dodecyl sulfate polyacrylamide gel electrophoresis) and mass spectrometry. Then, the bioactivities and half-life of these Fab bioconjugates were examined using TNF-α-/human serum albumin (HSA)-binding enzyme-linked immunosorbent assay, cytotoxicity assay, and pharmacokinetic study, respectively. All Fab bioconjugates exhibited similar TNF-α-neutralizing activities when compared with the Fab analog, even in the presence of albumin, indicating that there were no apparent influences on the functional site of Fab after FA modification. However, different degrees of affinity for HSA were observed among these Fab–FA bioconjugates, with Fab–FA3 exhibiting the maximal affinity. An in vivo study in mice further revealed remarkably improved pharmacokinetics of Fab– FA3 with a 15.2-fold longer plasma half-life (19.86 hours) compared with that of the Fab analog (1.31 hours). In summary, we have developed a novel long-acting adalimumab Fab bioconjugate, Fab–FA3, with more sustained in vivo activity, which can be used for drug development targeting TNF-α-mediated inflammatory diseases.
Loss to Follow-up: A Deceptive Enigma
Authors: Patel Sandeep , Kumar Vishal , Khan Shahnawaz , Salaria Amit
Published: May 2021

Loss to follow-up indicates both patients not reporting and inability to trace them during the required follow-up period or study period. Significant loss to follow-up can affect the validity of a study and thereby the impact of that study. The importance of loss to follow-up has been very scarcely and meagerly highlighted in literature. More than one-fifth loss to follow-up can lead to significant selection bias. Loss to follow-up affects delivery of appropriate patient care. In the cohort studies, follow-up rates of 50 to 80% are accepted by authors, due to lack of any recommendations. The causes of loss to follow-up may vary from patient's age, occupation, chronicity of the disease, etc. Loss to follow-up needs to be reported in all prospective studies, and intention to treat analysis should be applied. This will improve the validity of study, provide reliable results, and reflect the true effect of the intervention used in the study. It also helps to determine the actual survival rates in fatal diseases. The course of a disease can also be monitored, and appropriate intervention can be done at an appropriate point of time to prevent morbidity and mortality. Its overall benefits are better patient care and improved outcomes of the treatment method.
Parent Perception of Child Safety following Admission to a Neonatal Unit
Authors: Arriaga-Redondo María , Sanz-Lopez Ester , Rodríguez-Sánchez de la Blanca Ana , Marsinyach-Ros Itziar , Lambea-Rueda Leticia , Díaz-Redondo Alicia , Sanchez-Luna Manuel
Published: May 2021

Objective Parent partnership is a key aspect of neonatal hospital care. However, there is a lack of information regarding parents' perception of neonatal safety. This study explores parents' opinions on safety during their child's hospitalization to identify points for improvement.

Study Design We used a questionnaire, validated by the Spanish National Healthcare Authorities, on perception of safety with respect to hospital health care.

Results Thirty-seven parents of 20 newborns treated in the neonatal intensive care unit (NICU) and 139 parents of newborns in intermediate care (IC) participated in this study. With regard to overall perception of safety, more than 96% of parents felt “very safe” or “fairly safe.” In the NICU, an area for improvement detected was to ask parents more often their opinion about the care or treatment provided to their child. In IC, three points for improvement were identified from the group of parents whose child was admitted directly to IC: the consistency of the information received, the request for consent for procedures, and the request for an opinion on their child's care and treatment. Only four parents reported that their child suffered an incident. Regarding incident management, parents were not completely satisfied with the information they received.

Conclusion To the best of our knowledge, this is the first study of parent perception of patient safety in a neonatal unit using a validated questionnaire. Our findings suggest that parents can provide valuable information on neonatal safety, which can then be used to identify areas for improvement.

Key Points