bluuebunny/crossref_metadata_2025 huggingface dataset:
Catalytic asymmetric propargyl- and allylboration of hydrazonoesters: a metal-free approach to sterically encumbered chiral α-amino acid derivatives
Authors: Jonker Sybrand J. T. , Diner Colin , Schulz Göran , Iwamoto Hiroaki , Eriksson Lars , Szabó Kálmán J.
Published: October 2018

Metal-free asymmetric catalysis for the synthesis of sterically encumbered amino-acids was developed using allyl- and allenylboronic acid reagents.
Mechanochemistryvs.solution growth: striking differences in bench stability of a cimetidine salt based on a synthetic method
Authors: Ayoub Ghada , Štrukil Vjekoslav , Fábián László , Mottillo Cristina , Bao Huizhi , Murata Yasujiro , Moores Audrey , Margetić Davor , Eckert-Maksić Mirjana , Friščić Tomislav
Published: October 2018

A mechanochemically prepared solvated salt of an archetypal blockbuster drug exhibits significantly different bench stability to analogous material made in solution.
Correction: Effects of crystalline growth on structural and luminescence properties of Ca(10−3x)Eu2x(PO4)6F2 nanoparticles fabricated by using a microwave driven hydrothermal process
Authors: Zawisza Katarzyna , Sobierajska Paulina , Renaudin Guillaume , Nedelec Jean-Marie , Wiglusz Rafal J.
Published: October 2018

Correction for ‘Effects of crystalline growth on structural and luminescence properties of Ca(10−3x)Eu2x(PO4)6F2 nanoparticles fabricated by using a microwave driven hydrothermal process’ by Katarzyna Zawisza et al., CrystEngComm, 2017, 19, 6936–6949.
Structural characterization of nucleotide 5′-triphosphates by infrared ion spectroscopy and theoretical studies
Authors: van Outersterp Rianne E. , Martens Jonathan , Berden Giel , Steill Jeffrey D. , Oomens Jos , Rijs Anouk M.
Published: October 2018

Gas-phase IR spectroscopic studies and supporting theoretical studies have been performed on adenosine 5′-triphosphate, cytosine 5′-triphosphate and guanosine 5′-triphosphate to elucidate the structural properties of the NTPs by focusing on the influence of the nucleobase and the extent of deprotonation.
Ab initio molecular dynamics study of solvated electrons in methanol clusters
Authors: Mones Letif , Pohl Gábor , Turi László
Published: October 2018

Stable surface excess electronic states in small methanol cluster anions were identified and characterized in ab initio molecular dynamics simulations.
How a linear triazene photoisomerizes in a volume-conserving fashion
Authors: Marefat Khah Alireza , Grimmelsmann Lena , Knorr Johannes , Nuernberger Patrick , Hättig Christof
Published: October 2018

Ultrafast photoisomerization mechanism of berenil revealed by transient absorption spectroscopy and ADC(2) quantum chemical calculation of reaction coordinates and spectra.
Large magnetic anisotropy and its strain modulation in two-dimensional intrinsic ferromagnetic monolayer RuO2 and OsO2
Authors: Wang Yanjie , Li Fangfang , Zheng Huiling , Han Xiufeng , Yan Yu
Published: October 2018

The magnetic anisotropy energy (MAE) of monolayer 1T-RuO2 and 1T-OsO2 under −4%, −2%, 0%, 2% strains.
Deciphering the helicity switching mechanism: a case study of the rigid three-tiered stacked architecture
Authors: Liu Peng , Liu Yingzhe , Bian Xihui , Tan Xiaoyao
Published: October 2018

The helicity switching mechanism of a rigid three-tiered stacked architecture is elucidated at the atomic level.
New phenyl–nickel complexes of bulky 2-iminopyrrolyl chelates: synthesis, characterisation and application as aluminium-free catalysts for the production of hyperbranched polyethylene
Authors: Figueira Cláudia A. , Lopes Patrícia S. , Gomes Clara S. B. , Gomes Joselaine C. S. , Lemos Francisco , Gomes Pedro T.
Published: October 2018

New mono(5-aryl-2-(N-arylformimino)pyrrolyl) Ni(ii) complexes were synthesised and tested as aluminium-free catalysts for the polymerisation of ethylene, yielding hyperbranched oligo-/polyethylenes.
In vitro and in vivo antiproliferative activity of organo-nickel SCS-pincer complexes on estrogen responsive MCF7 and MC4L2 breast cancer cells. Effects of amine fragment substitutions on BSA binding and cytotoxicity
Authors: Hosseini-Kharat Mahboubeh , Zargarian Davit , Alizadeh Ali Mohammad , Karami Kazem , Saeidifar Maryam , Khalighfard Solmaz , Dubrulle Laurent , Zakariazadeh Mostafa , Cloutier Jean-Philippe , Sohrabijam Zahra
Published: October 2018

A family of organonickel complexes has been prepared, fully characterized, and tested for their antiproliferative activity against estrogen-responsive human breast cancer cells (MCF7).
Electronic density distribution of Mn–N bonds by a tuning effect through partial replacement of Mn by Co or Ni in a sodium-rich hexacyanoferrate and its influence on the stability as a cathode for Na-ion batteries
Authors: Oliver-Tolentino M. , González M. M. , Osiry H. , Ramos-Sánchez G. , González I.
Published: October 2018

This study evaluates the effect of equimolar substitution of manganese by cobalt or nickel in hexacyanoferrate open frameworks as electrode for Na-ion batteries.
3D hierarchical Co3O4@Co3S4 nanoarrays as anode and cathode materials for oxygen evolution reaction and hydrogen evolution reaction
Authors: Du Xiaoqiang , Su Hui , Zhang Xiaoshuang
Published: October 2018

Using Co3O4@Co3S4-24 h as a bifunctional water splitting catalyst, an overpotential of ∼300 mV is obtained at a very low cell voltage of 1.53 V with a current density of 10 mA cm−2 in 1.0 M KOH.
Synaptic dynamics in complex self-assembled nanoparticle networks
Authors: Bose S. K. , Shirai S. , Mallinson J. B. , Brown S. A.
Published: October 2018

We report a detailed study of neuromorphic switching behaviour in inherently complex percolating networks of self-assembled metal nanoparticles.
Monitoring plasmonic hot-carrier chemical reactions at the single particle level
Authors: Simoncelli Sabrina , Pensa Evangelina L. , Brick Thomas , Gargiulo Julian , Lauri Alberto , Cambiasso Javier , Li Yi , Maier Stefan A. , Cortés Emiliano
Published: October 2018

Nanoscopic inspection of reactivity in single plasmonic photocatalysts.
Strawberries decrease circulating levels of tumor necrosis factor and lipid peroxides in obese adults with knee osteoarthritis
Authors: Basu Arpita , Kurien Biji T. , Tran Huyen , Byrd Bre'Ana , Maher Joey , Schell Jace , Masek Emily , Barrett James R. , Lyons Timothy J. , Betts Nancy M. , Hal Scofield R.
Published: October 2018

Objective: Knee osteoarthritis (OA) is increasingly prevalent in obese people, who often have high cardio-metabolic risk factors. We examined effects of strawberries on knee OA.
Anti-inflammatory effects of cinnamon extract and identification of active compounds influencing the TLR2 and TLR4 signaling pathways
Authors: Schink Anne , Naumoska Katerina , Kitanovski Zoran , Kampf Christopher Johannes , Fröhlich-Nowoisky Janine , Thines Eckhard , Pöschl Ulrich , Schuppan Detlef , Lucas Kurt
Published: October 2018

Cinnamon extract and its active compounds attenuate TLR2-/TLR4-mediated inflammatory processes.
Nanoarchitectonics through supramolecular gelation: formation and switching of diverse nanostructures
Authors: Sang Yutao , Liu Minghua
Published: October 2018

The formation and switching in gel systems provide supramolecular gelation many possibilities to obtain diverse nanoarchitectures.
Synthesis of high-quality black phosphorus sponges for all-solid-state supercapacitors
Authors: Wen Min , Liu Danni , Kang Yihong , Wang Jiahong , Huang Hao , Li Jia , Chu Paul K. , Yu Xue-Feng
Published: October 2018

Black phosphorus sponges comprising ultrathin, large and unoxidized nanosheets are prepared and used for an all-solid-state supercapacitor.
Retraction: Cd induces G2/M cell cycle arrest by up-regulating miR-133b via directly targeting PPP2R2D in L02 hepatocytes
Authors: Zhang Yujing , Xiao Fang , Zhong Caigao , Zeng Ming , Zou Lianhong
Published: October 2018

Retraction of ‘Cd induces G2/M cell cycle arrest by up-regulating miR-133b via directly targeting PPP2R2D in L02 hepatocytes’ by Yujing Zhang et al., Metallomics, 2018, 10, 1510–1523.
Au quantum dots engineered room temperature crystallization and magnetic anisotropy in CoFe2O4 thin films
Authors: Shirsath Sagar E. , Liu Xiaoxi , Assadi M. H. N. , Younis Adnan , Yasukawa Yukiko , Karan Sumanta Kumar , Zhang Ji , Kim Jeonghun , Wang Danyang , Morisako Akimitsu , Yamauchi Yusuke , Li Sean
Published: October 2018

For the first time, this work presents a novel room temperature time-effective concept to manipulate the crystallization kinetics and magnetic responses of thin films grown on amorphous substrates.
A new multi-analyte fluorogenic sensor for efficient detection of Al3+and Zn2+ions based on ESIPT and CHEF features
Authors: Patra Lakshman , Das Sangita , Gharami Saswati , Aich Krishnendu , Mondal Tapan Kumar
Published: October 2018

The synthesized ESIPT based fluorogenic chemosensor, H2L, selectively detects Zn2+and Al3+in a MeOH–H2O (4/1, v/v, pH = 7.2) medium.
An effective one-pot method for preparing covalently bonded nanocomposite soft magnetic beadlike microgels and their evaluation as an adsorbent for the removal of toxic heavy metals from aqueous solution
Authors: Jiang Li-Ping , Shi Hai-Xiong , Chai Feng-Ying
Published: October 2018

A simplified “water-in-oil” “one-pot” production process for preparing a covalently bonded nanocomposite soft magnetic beadlike adsorbent is developed.
Synthesis, characterization and first application of covalently immobilized nickel-porphyrin on graphene oxide for Suzuki cross-coupling reaction
Authors: Keyhaniyan Mahdi , Shiri Ali , Eshghi Hossein , Khojastehnezhad Amir
Published: October 2018

In this study, nickel(ii)-coordinated 5,10,15,20-tetrakis(aminophenyl)porphyrin (NiTAPP) as a macrocyclic complex was covalently grafted to the edge of graphene oxide (GO) and applied as nanocatalyst in Suzuki cross-coupling reaction.
Side chain modification on PDI-spirobifluorene-based molecular acceptors and its impact on organic solar cell performances
Authors: Bolognesi Margherita , Gedefaw Desta , Cavazzini Marco , Catellani Marinella , Andersson Mats R. , Muccini Michele , Kozma Erika , Seri Mirko
Published: October 2018

N-Substitution in perylene diimide (PDI) n-type semiconductors is critical for their performance in organic bulk heterojunction solar cells.
A silicon nitride waveguide-integrated chemical vapor deposited graphene photodetector with 38 GHz bandwidth
Authors: Gao Yun , Tsang Hon Ki , Shu Chester
Published: October 2018

We demonstrate a high-speed chemical vapor deposited graphene-on-silicon nitride waveguide photodetector.
Shaping iron oxide nanocrystals for magnetic separation applications
Authors: Testa-Anta Martín , Liébana-Viñas Sara , Rivas-Murias Beatriz , Rodríguez González Benito , Farle Michael , Salgueiriño Verónica
Published: October 2018

The large magnetophoretic mobility stemming from the large magnetic susceptibility and the very small coercivity of octapod-shaped iron oxide nanoparticles improve their capability for magnetic separation.
Synergic effects of upconversion nanoparticles NaYbF4:Ho3+ and ZrO2 enhanced the efficiency in hole-conductor-free perovskite solar cells
Authors: Li Yanyan , Zhao Li , Xiao Meng , Huang Yimin , Dong Binghai , Xu Zuxun , Wan Li , Li Wenlu , Wang Shimin
Published: October 2018

This design enabled the dual-functional effects, that is, the harvesting of NIR light and its conversion to visible light and the reduction of the electron–hole recombination rate.
Correction: Polyoxometalate-coupled MXene nanohybrid via poly(ionic liquid) linkers and its electrode for enhanced supercapacitive performance
Authors: Chen Shu , Xiang Yuanfang , Katherine Banks M. , Peng Chang , Xu Weijian , Wu Ruoxi
Published: October 2018

Correction for ‘Polyoxometalate-coupled MXene nanohybrid via poly(ionic liquid) linkers and its electrode for enhanced supercapacitive performance’ by Shu Chen et al., Nanoscale, 2018, DOI: 10.1039/c8nr05760e.
A facile tandem decyanation/cyanation reaction of α-iminonitriles toward cyano-substituted amides
Authors: Chen Zhengwang , Liang Pei , Liu Botao , Luo Haiqing , Zheng Jing , Wen Xiaowei , Liu Tanggao , Ye Min
Published: October 2018

An efficient method for cyano-substituted amides via a tandem decyanation/cyanation reaction of α-iminonitriles.
The challenge of using isopropylamine as an amine donor in transaminase catalysed reactions
Authors: Kelefiotis-Stratidakis Panagiotis , Tyrikos-Ergas Theodore , Pavlidis Ioannis V.
Published: October 2018

Factors that affect the efficiency of amine transaminase catalyzed reactions using isopropylamine as an amine donor.
Catalytic dehydrogenative aromatization of cyclohexanones and cyclohexenones
Authors: Liu Xueli , Chen Jun , Ma Tianlin
Published: October 2018

Prompted by the scant attention paid by published literature reviews to the comprehensive catalytic dehydrogenative aromatization of cyclohexa(e)nones, this review describes recent methods developed to-date involving transition-metal-catalyzed oxidative aromatization and metal-free strategies for the transformation of cyclohexa(e)nones to substituted phenols.
Cobalt-catalyzed regioselective syntheses of indeno[2,1-c]pyridines from nitriles and diynes bearing propargyl fragments
Authors: Xu Murong , Zheng Zhong , Wang Mengdan , Kong Lingkai , Ao Yujuan , Li Yanzhong
Published: October 2018

Indeno[2,1-c]pyridines were synthesized via the cobalt-catalyzed cycloaddition reaction of nitriles with diynes bearing TBS protected propargylic alcohol fragments under mild conditions with highly functional compatibility and exclusive regio-selectivity.
Cyclopropanation of alkenes with metallocarbenes generated from monocarbonyl iodonium ylides
Authors: Chidley Tristan , Murphy Graham K.
Published: October 2018

Wittig-type reactivity between iodosoarenes and phosphoranes leads to monocarbonyl iodonium ylides, which readily serve as metallocarbene precursors.
Facile synthesis of cylindrical molecular brushes via Lewis pair-mediated polymerization
Authors: Chen Shanshan , Hou Liman , Wang Qiliao , Dong Dewen , Zhang Ning
Published: October 2018

A general strategy for creating molecular brushes via Lewis pair-mediated polymerization is described.
Correction: Reticular control of interpenetration in a complex metal–organic framework
Authors: Nguyen Trang T. M. , Le Hung M. , Kawazoe Yoshiyuki , Nguyen Ha L.
Published: October 2018

Correction for ‘Reticular control of interpenetration in a complex metal–organic framework’ by Trang T. M. Nguyen et al., Mater. Chem. Front., 2018, DOI: 10.1039/c8qm00368h.
Biomimetic syntheses of C23 terpenoids: structural revision of salyunnanin A and confirmation of hassanane
Authors: Zhang Xun , Li Zhongle , Yong Huaya , Xie Zhixiang
Published: October 2018

Salyunnanin A and hassanane, two C23 terpenoids, were achieved from (+)-carnosic acid in 6 and 5 steps, respectively.
Reusable Fe2O3-nanoparticle catalysed efficient and selective hydroboration of carbonyl compounds
Authors: Shegavi Mahadev L. , Baishya Ashim , Geetharani K. , Bose Shubhankar Kumar
Published: October 2018

We present readily accessible Fe2O3 nanoparticles as an efficient catalyst for the selective hydroboration of carbonyl compounds, which represents the first example of the use of nanoparticles as a catalyst for this process.
A new dehydrogenative [4 + 1] annulation between para-quinone methides (p-QMs) and iodonium ylides for the synthesis of 2,3-dihydrobenzofurans
Authors: Xiong Yan-Jie , Shi Shao-Qing , Hao Wen-Juan , Tu Shu-Jiang , Jiang Bo
Published: October 2018

A new dehydrogenative [4 + 1] annulation of para-quinone methides (p-QMs) with acyclic and cyclic iodonium ylides has been established, delivering a variety of functionalized 2,3-dihydrobenzofurans with the retention of the quinone methide unit in generally good yields.
Direct construction of benzimidazo[l,2-c]quinazolin-6-onesviametal-free oxidative C–C bond cleavage
Authors: Li Ping-Gui , Yan Cheng , Zhu Shuai , Liu Shu-Hui , Zou Liang-Hua
Published: October 2018

A highly regioselective protocol has been developed for the synthesis of benzimidazo[l,2-c]quinazolin-6-onesviaC–C bond cleavage and triple C–N bond formation.
Ni-Catalyzed 1,2-iminoacylation of alkenes via a reductive strategy
Authors: Wang Lin , Wang Chuan
Published: October 2018

The reductive difunctionalization strategy was successfully applied in the Ni-catalyzed 1,2-iminoacylation reaction of oxime ester-tethered olefins with electrophilic acylating reagents, providing an efficient entry to diverse pyrrolines under safe and mild reaction conditions.
Using a traceless directing group for the silver-mediated synthesis of 3-trifluoromethylpyrazoles: a computational study on the mechanism and origins of regioselectivity
Authors: Jia Feiyun , Luo Jiewei , Zhang Bo
Published: October 2018

The silver-mediated one-pot synthesis of 3-trifluoromethylpyrazoles using a traceless directing group was investigated by density functional theory (DFT) calculations.
Ultralow power consumption gas sensor based on a self-heated nanojunction of SnO2 nanowires
Authors: Ngoc Trinh Minh , Van Duy Nguyen , Hung Chu Manh , Hoa Nguyen Duc , Trung Nguyen Ngoc , Nguyen Hugo , Van Hieu Nguyen
Published: October 2018

We realize the local self-heated nanojunction in nanowires for ultralow power consumption gas sensor by a simple design and fabrication process.
Bis-(salicylaldehyde-benzhydrylimino)nickel complexes with different electron groups: crystal structure and their catalytic properties toward (co)polymerization of norbornene and 1-hexene
Authors: He Xiaohui , Tu Guangshui , Zhang Feng , Huang Shengmei , Cheng Changwen , Zhu Chuanyi , Duan Yapeng , Wang Suli , Chen Defu
Published: October 2018

Ni(ii) complexes were successfully synthesized and characterized, and were highly active toward (co)polymerization of norbornene, and the 1-hexene content could be controlled.
Correction: Synthesis and characterization of amorphous precipitated silica from alkaline dissolution of olivine
Authors: Raza Nadeem , Raza Waseem , Madeddu Silvia , Agbe Henry , Kumar R. V. , Kim Ki-Hyun
Published: October 2018

Correction for ‘Synthesis and characterization of amorphous precipitated silica from alkaline dissolution of olivine’ by Nadeem Raza et al., RSC Adv., 2018, 8, 32651–32658.
Click to enter: activation of oligo-arginine cell-penetrating peptides by bioorthogonal tetrazine ligations
Authors: Bode Saskia A. , Timmermans Suzanne B. P. E. , Eising Selma , van Gemert Sander P. W. , Bonger Kimberly M. , Löwik Dennis W. P. M.
Published: October 2018

The cellular uptake of a cell-penetrating peptide is controlled by reconstitution of two inactive halves using bioorthogonal tetrazine ligations and is applied to a fluorescently labelled protein.
A novel nematic-like mesophase induced in dimers, trimers and tetramers doped with a high helical twisting power additive
Authors: Mandle Richard J. , Goodby John W.
Published: October 2018

Several liquid crystalline dimers and n-mers are found to exhibit a previously undiscovered nematic-like ground state (NX) when doped with a high helical twisting power additive.
“Reversible” photochromism of polyoxomolybdate–viologen hybrids without the need for proton transfer
Authors: Li Li , Wang Jun-Ren , Hua Yang , Guo Yu , Fu Chen , Sun Ya-Nan , Zhang Hong
Published: October 2018

The “reversible” photochromism of polyoxomolybdate–viologen hybrids can be achieved without proton transfer, and the weak electron-withdrawing ability of viologen favors photoreduction of Mo(vi).
Diallyl sulfide treatment protects against acetaminophen-/carbon tetrachloride-induced acute liver injury by inhibiting oxidative stress, inflammation and apoptosis in mice
Authors: Li Ming , Wang Shuo , Li Xianjie , Kou Ruirui , Wang Qiong , Wang Xujing , Zhao Ning , Zeng Tao , Xie Keqin
Published: October 2018

The purpose of the present study was to investigate the effects and underlying mechanisms of diallyl sulfide (DAS), an organosulfur compound extracted from garlic, on drug-induced or chemical-induced liver injury caused by acetaminophen (APAP) or carbon tetrachloride (CCl4) in mice.
Long non-coding RNA DANCR regulates proliferation and apoptosis of chondrocytes in osteoarthritis via miR-216a-5p-JAK2-STAT3 axis
Authors: Zhang Lei , Zhang Pin , Sun Xiangyi , Zhou Liwu , Zhao Jianning
Published: October 2018

Osteoarthritis (OA) is one of the most common chronic joint disease. Long non-coding RNAs (lncRNAs) have been confirmed to play important roles in a variety of diseases including OA. However, the underlying mechanism of lncRNA differentiation antagonizing non-protein coding RNA (DANCR) in OA has not been well elucidated. The expression of DANCR in cartilage tissues from OA patients was detected using quantitative real-time PCR. After cell transfection, the effects of DANCR inhibition on the proliferation, apoptosis and inflammatory factors of OA chondrocytes were detected using Cell Counting Kit-8 assay and flow cytometry assay. Novel target of DANCR was then identified through bioinformatics analysis and confirmed by luciferase reporter assay and RNA immunoprecipitation assay. The expression of DANCR was significantly increased in OA patients. Function assays demonstrated that DANCR suppression inhibited the proliferation, inflammation, and promoted apoptosis of chondrocytes cells. Additionally, DANCR regulated survival of OA chondrocytes through acting as a competitive endogenous RNA for miR-216a-5p. Furthermore, JAK2 was a direct target of miR-216a-5p, and DANCR regulated the JAK2/STAT3 signal pathway through miR-216a-5p in OA chondrocytes. In the present study, we concluded that DANCR promoted the proliferation, inflammation, and reduced cell apoptosis in OA chondrocytes through regulating miR-216a-5p/JAK2/STAT3 signaling pathway, indicating DANCR might be a useful biomarker and potential therapeutic target for OA treatment.
Block‐sparse signal recovery based on truncated minimisation in non‐Gaussian noise
Authors: Feng Qingrong , Wang Jianjun , Zhang Feng
Published: October 2018

This study addresses the issue of block‐sparse recovery in compressive sensing in the presence of non‐Gaussian measurement noise. By using the generalised ‐norm noise constraint for to replace the popular ‐norm, in this study, the authors put forward a truncated model for recovering block‐sparse signal. A theoretical analysis is first presented to guarantee the validity of proposed method. If the measurement matrix satisfies an extended block restricted isometry property, the reconstruction error is bounded in the optimisation. Moreover, in order to solve the induced optimisation problem effectively, they present an alternating direction method of multipliers via embedding Karush–Kuhn–Tucker system of ‐norm functions into the frame structure of augmented Lagrangian methods. When compared with some of the state‐of‐the‐art methods, the proposed method becomes more competitive.
SR‐Crossbar topology for large‐scale RF MEMS switch matrices
Authors: Zhou Weiwei , Sheng Wexing , Cui Jie , Han Yubing , Ma Xiaofeng , Zhang Renli
Published: October 2018

With the development of multifunctional satellites, the integration and multiplexing of satellite resources become increasingly important. Large‐scale radio‐frequency microelectromechanical system (RF MEMS) switch matrix technology is one of the key technologies to design a multifunctional satellite. This study proposed a novel sequential rotation crossbar (SR‐Crossbar) topology for large‐scale RF MEMS switch matrices. A specifically designed novel configuration scheme or arraying method for SR‐Crossbar topology is also proposed. The number of switch elements in the SR‐Crossbar RF MEMS switch matrix is significantly reduced; hence, the reliability and performance of the matrix can be improved simultaneously. For an RF MEMS switch matrix, in a fully configured scenario, the maximum number of switch elements in all the paths are . When , the proposed SR‐Crossbar RF MEMS switch matrix topology is better than the planar Benes topology, which is already an optimised planar switch matrix topology with the minimum number of nodes.
Assessment method and metrics of power system resilience after disasters
Authors: Zhang Han , Bie Zhaohong , Li Gengfeng , Lin Yanling
Published: October 2018

How to restore the load of power system after disasters, especially to guarantee the power supply of the important load, is a significant segment of the research on power system resilience. Nowadays, quantities of research existing has been done to reduce the load loss after disasters. However, there is no clear methodologies or metrics available to evaluate the effects of restoration strategies. Here, a method for evaluating the recovery and economic efficiency of the power system post‐disaster recovery strategy is explored, and assessment metrics related are defined. The method considers the repair and recovery process of transmission lines, generators, and the distributed generation at load nodes. After given the repair strategies, components state sampling and system power flow calculation will be conducted to analyse the running state of the system, then simulate the component repair and the load recovery procedure, and finally calculate corresponding metrics. This novel method can obtain and compare the expected effects of different restoration strategies in advance, providing more reliable reference information for system decision makers. Finally, the proposed method is applied to IEEE 14‐bus system and verifies its effectiveness and application value.
Mutual inductance calculation for coils with misalignment in wireless power transfer
Authors: Zhang Xian , Meng Hao , Wei Bin , Wang Songcen , Yang Qingxin
Published: October 2018

In wireless power transfer (WPT) systems, the energy transmission channel is established by the coupling relationship between transmitting coil and receiving coil, and the coupling strength is usually measured by coupling coefficient. Therefore, it is necessary to calculate the mutual inductance between transmitting coil and receiving coil when describing their coupling strength. Here, filamentary circular coils and cylindrical helix coils are taken as the object of study, and the formulas for mutual inductance of two coils with misalignment are derived based on Neumann's formula. In addition, the influence of multiple factors, such as axial distance, lateral distance and angle, on mutual inductance is analysed, and the calculated results are verified by experiments. The research results of this paper can be used to estimate the mutual inductance between the couplers in WPT systems, especially when there is misalignment.
LVRT Test data analysis of converter‐interfaced wind turbines
Authors: Chen Can , Liu Hui , Wu Linlin , Shen Chen , Ju Yuntao
Published: October 2018

Doubly Fed Induction Generator (DFIG) and Permanent Magnet Synchronous Generator (PMSG) are converter‐interfaced wind turbines, which have much more complex short circuit behaviour after grid voltage drops. The research on short circuit current contributions provided by the wind turbines is very important for power system planning and relay protection's setting. Here, the Low Voltage Ride Through (LVRT) test data in north China are used to study the short circuit behaviour of DFIGs and PMSGs. The characteristics of two featured quantities, fundamental frequency component and peak current, are investigated. Unlike simulation or theoretical analysis, the field test data of real wind turbines from different manufacturers help utility operators to better understand the fault characteristics of converter‐interfaced wind turbines.
Real‐time optimisation of emergency demand response and HVDC power modulation to improve short‐term frequency stability of the receiving‐end power systems
Authors: Wang Luping , Xie Xiaorong , Peng Long , Hu Yinghong , Zhao Yuan
Published: October 2018

In recent years, large‐capacity high‐voltage direct currents (HVDCs) have been employed to transfer electricity from the west to the east of China. However, the frequent frequency drops due to HVDC blockings seriously threaten the short‐term frequency stability of receiving‐end power systems. The existing emergency frequency control strategy is not adaptive to the varying operation conditions and may cause excessive or deficient actions, which could result in inefficient control or high risk of frequency instability. Therefore, a real‐time coordinated control strategy is proposed in this study based on the online‐updated frequency response model. The model is designed to incorporate multiple types of generators and to reflect the dynamic frequency response of loads. The new control strategy combines multiple control resources, including the emergency demand response and HVDC power modulation, to improve the short‐term frequency stability after HVDC failures. By online data preparation and cubic fitting, the nadir of the frequency is expressed as an analytic function of the control variables. A real‐time optimisation of emergency controls is achieved to improve the short‐term frequency dynamics. Case studies show that the proposed scheme is robust to the varying operation conditions and has lower control cost than the existing control strategy.
Soft start‐up scheme for the hybrid distribution transformer
Authors: Liu Yibin , Liang Deliang , Zhang Mingkang , Liang Yang , Chen Qixu , Wang Qingshan
Published: October 2018

Hybrid distribution transformer (HDT) is an integrated system of the conventional distribution transformer and the PWM converters, which can greatly enhance the controllability of the conventional distribution transformer and is important for the intelligence of the future distribution network, since HDT can support the AC–DC power network and control the voltage and current in real time. However, the impact current, over voltage, and saturation will lead to the start‐up failure when an incorrect start‐up scheme is adopted in HDT. Therefore, it is significant to design a reliable start‐up scheme to guarantee a safe operation for HDT. Here, a three‐phase circuit scheme and the control system of HDT are proposed. Then, a soft start‐up scheme that can realise the constant‐current charging for the DC bus capacitor is proposed. Specifically, the soft start‐up scheme is based on the following measures, bypassing the DC‐bus current‐limiting resistors when the voltage of DC‐bus capacitor exceeds the threshold, limiting the output of PI controllers during the start‐up, separating the integral coefficient according to the DC‐bus voltage error. Finally, the proposed start‐up scheme is verified in MATLAB, which lays the foundation for the optimal design of the start‐up scheme of HDT.
Day‐ahead optimal energy dispatch schedule for integrated energy system based on AC/DC interconnected infrastructure
Authors: Aidong Zeng , Sipeng Hao , Qingshan Xu , Yujun Liu , Ling Jiang
Published: October 2018

This study proposes a day‐ahead optimal energy dispatch model for integrated energy system based on AC/DC interconnected infrastructure. In the infrastructure, micro‐turbines turn high‐frequency AC power into industrial‐frequency AC power and incorporate it into the energy system's power system. Within the process, waste heat is sent into the waste heat boiler and lithium bromide chillier to interconnect with the heating and cooling systems. DC battery and photovoltaic generations connected with the energy system's power grid through the inverter are used as the flexible energy storage and power generation unit to build an autonomous integrated energy system based on AC/DC interconnection. In the optimisation model, the goal is set as system's lowest daily operation cost and lowest energy consumption. The constraints include system operation constraints and equipment constraints. Simulation results show that by performing the schedule made by the dispatch model, the operating efficiency of various types of AC/DC equipment in the energy system has been improved, energy waste scene has been reduced significantly and energy consumption in the energy system is reduced by 16% compared with other energy supply structure without AC/DC interconnected infrastructure under traditional schedule strategies.
Prediction of oil flow and temperature distribution of transformer winding based on multi‐field coupled approach
Authors: Li Longnv , Liu Wei , Chen Hai , Liu Xiaoming
Published: October 2018

For large oil‐filled transformers, the oil flow and temperature distribution in transformer windings are an essential issue to be addressed. However, the computation of the oil flow and temperature distribution is a complicated engineering problem because of the complex physical structure of the winding area and the coupled effect of electromagnetic, fluid and thermal fields. This study presents a multi‐filed coupled approach to compute and analyse the oil flow and temperature distribution of the winding area for an ODFS‐334 MVA/500 kV single‐phase auto‐transformer. The eddy current losses of the transformer winding discs are computed based on the combined finite element and analytical method, and the computational fluid dynamics based on 3D fluid‐thermal coupled method is used to calculate the oil flow and temperature properties of the prototype. The computation of the oil flow and temperature distribution reveals accurately the hot spot of the transformer. To validate the feasibility and applicability of the proposed method, the numerical results obtained using the proposed method are compared with those of the experimental ones.
Extended control strategies of voltage source converter stations linked to converter dominated systems
Authors: Lou Boliang , Zhou Hua , Lu Shaoqi , Ying Chaonan , Hua Wen , Xu Zheng
Published: October 2018

The state of the art of control strategies of modular multi‐level converter based high‐voltage DC systems can be categorised into two classes according to the connecting system, i.e. the active control strategies such as the vector control and the passive control ones such as the voltage and frequency control. These two control modes need to be transformed to each other under some circumstances. The traditional method to deal with this problem is to switchover the control modes. However, this process takes time and there is risk to lose stability during this period. Thus, an extended control strategy to control the converter in both modes is wanted. An extended control strategy is designed by introducing supplementary feedback property into the traditional vector control strategy. The extended and traditional vector control strategies are compared under various cases by simulation. Simulations show that the system controlled by the traditional vector control strategy loses stability when synchronous machines drop out. However, the extended vector control strategy is superior under weak or even passive grid conditions.
Influence on the energy conservation of the power system by introducing UPFC
Authors: Chen Feng , Wang Bowen , Xu Weiwei , Lu Haiqing , Wu Jun , Lu Chengyu
Published: October 2018

The unified power flow controller (UPFC) is an excellent flexible alternating current transmission device, which has a wide range application in the power system. It can be expected that more UPFC engineering applications will be introduced to the power system in the future, and they will have an unignorable impact on the power grid. It is of great significance to analyse the influence of UPFC on power system energy conservation. First of all, the basic characteristics of UPFC are briefly introduced. Secondly, the influence of voltage quality, reactive power index, and energy saving after UPFC is introduced to the power system is analysed in detail from reactive power compensation and power flow regulation. Finally, comparison simulation of a three‐machine nine‐node system is simulated, the simulation results show that the power system with UPFC introduced can make the power flow distribution more reasonable, reduce the voltage sag, improve the voltage quality, and power transmission capacity, thus reducing the loss of the power system.
Real‐time calculation of three core cable conductor temperature based on thermal circuit model with thermal resistance correction
Authors: Zhan Qinghua , Ruan Jiangjun , Tang Ke , Tang Liezheng , Liu Yijun , Li Hengzhen , Ou Xiaomei
Published: October 2018

The conductor temperature of cable in operation is the basis for determining whether the cable reaches the ampacity. For the three core cable, it is difficult to calculate the thermal resistance of the filling layer accurately due to its irregularity shape, resulting in a large error in the temperature calculation of the cable conductor using the thermal circuit model. Therefore, it is proposed to calculate the thermal resistance of the filling layer by temperature field, and then calculate the conductor temperature by thermal circuit model. The conductor temperature of three core cable in steady state and transient state is calculated using the thermal circuit model, and the results are compared with the finite element simulation results. The results show that the maximum temperature difference of the two methods is about 2°C, showing a high accuracy of the proposed method. Finally, the effectiveness of the method is verified by the experimental data, the results show that the relative error between the calculated temperature of cable conductor and the experimental data is within 10%, which meets the needs of engineering application. The research results of this paper contribute to improving the operation and maintenance of three core cables.
Comparison of natural contamination accumulation characteristics between composite rod insulators and standard suspended insulator strings
Authors: Te Li , Shaohua Wang , Haojun Liu , Yangyong Xu , Yuntu Jiang , Peng Jiang
Published: October 2018

In order to attain the pollution characteristics difference between composite rod insulators and standard disc‐type suspended insulator which is critical to the insulation selection of transmission line, pollution accumulated on composite rod insulators and standard form suspended insulators suspended in the same tower near typical pollution sources in Zhejiang province were tested, including the equivalent salt deposit density (ESDD) and the non‐soluble deposit density (NSDD). Also the factors caused the difference were analysed for the first time. It is shown that in Zhejiang area, the contamination on upper surface of composite insulators is more serious than that of standard form suspended insulators, and the situation is inverse on the lower surface; the entire shed value of ESDD and NSDD from composite insulator is 0.8, 1.27 times of the values from standard form suspended insulators, respectively. The contamination difference of upper surface and lower surface of the composite insulators is smaller than that of standard form suspended insulators. According to the analysis, the rainfall and PM10 concentration could notably effect the ESDD difference between composite insulators and standard form suspended insulators. With stronger rainfall and less PM10 concentration, the ESDD ration of composite insulators and standard form suspended insulators trend to be smaller.
Impact of natural disasters on the western Hubei power grid and its anti‐disaster enhancement measures
Authors: Cai Defu , Li Xiaoping , Shi Tongqin , Wang Ying , Zhou Kunpeng , Lu Shengwei , Cao Kan , Wang Wenna
Published: October 2018

The western mountain area of Hubei Province has obvious vertical climate and micro‐climate features. It is a place where natural disasters occur frequently. The natural disasters have recently caused several large‐scale and long‐time power blackouts in the western mountain area of Hubei Province. This study analyses the damage to the power grid with voltage level from 220 to 10 kV in western Hubei Province caused by natural disasters from 2008 to 2016. The influence features of natural disasters on the western Hubei power grid are researched from four aspects, including natural disaster type, grid voltage level, occurrence time of natural disaster and line outage frequency. The causes of damage to the western Hubei power grid are studied from five aspects, including grid structure, design, equipment, construction, operation and maintenance. Also, the anti‐disaster enhancement measures of the western Hubei power grid are proposed from the aspects of grid planning, design, equipment transformation, construction, operation and maintenance. The research results can provide a reference for other regional power grids to carry out research on resisting natural disasters and provide a guidance to improve anti‐disaster ability of the power grid.
Control strategy of doubly‐fed induction generator during the grid voltage swell
Authors: Le Zou , Xueguang Wu , Longze Kou , Dong Liu , Fangyuan Li , Mingxiao Han
Published: October 2018

This study firstly derives the relationship between the grid voltage and the rotor current of doubly‐fed induction generator (DFIG) during the grid voltage swell. Then, an effective control strategy aiming to restrain rotor over‐current is proposed and the control strategy of the grid‐side converter is also improved. The proposed rotor current suppression and grid voltage suppression method, cooperating with the DC chopper, can not only solve the problem of short circuit of the rotor side converter resulting from the frequent switching of crowbar device, but also maximally improve the capability of wind turbine in dynamic reactive power support without adding any other power electronic devices. With the help of this control strategy, the wind turbine could maintain its normal operation even during the fault and the high voltage ride through of wind turbine can be achieved. As a result, the stability of the wind power integration is significantly improved. Finally, the simulations and analysis in the power systems computer aided design (PSCAD)/electromagnetic transients including DC (EMTDC) verify the effectiveness and feasibility of the proposed control scheme.
Optimal configuration method of capacitor isolation device against DC bias on improved niche GA algorithm
Authors: Liu Chunming , Ganebo Yared S. , Wang Donghui
Published: October 2018

The capacitance isolation device is a kind of effective suppression of DC bias in transformers caused by HVDC monopolar operation. However, according to the actual operation of the system, the capacitive isolation device at the neutral point of a transformer will probably cause more serious DC bias in other adjacent transformers while inhibiting its internal bias current at the same time. Since autotransformers are applied widely in the high‐voltage network, in this paper, we considered the structural characteristics of it and introduced the concept of effective bias current to describe the influence of magnetic bias current on the transformer more accurately. Then, the authors choose the bias current at any substations in the target grid less than the limit value as the constraint condition. Aiming at the minimum number of installed capacitors, the genetic algorithm based on improved niche is used to solve the optimal configuration problem. Taking the Ethiopia power grid as a test case, the authors work out the optimal quantity and installed location of capacitance isolation devices which satisfy the constraint condition. Compared with the traditional method, the cost is greatly reduced.
Feasibility of applying inductive filtering technology to the HVDC transmission system
Authors: Rong‐Yan Shang , Chang‐Qing Peng , Rui‐Ming Fang
Published: October 2018

This study explores the feasibility of applying inductive filtering technology to high‐voltage direct‐current (HVDC) transmission system since only filtering in the net side may lead to a lot of harmonics in the converter transformer. Basic principles of inductive filtering technology are presented and detail analyses are discussed from the aspects of filtering, vibration, commutation, short circuit, and AC system strength. Simulations and experimental tests show that when inductive filtering technology is applied, most of the harmonics do not enter the net side of the converter transformer but are directly filtered in the valve side. Thus, the harmonics flowing in the converter transformer reduce and the vibration of the converter transformer becomes smaller. The commutation reactance decreases sharply which greatly reduces the overlap angle and improves the commutation characteristics. Moreover, the short‐circuit reactance almost keeps unchanged and the short‐circuit characteristics do not deteriorate, and so the requirement for the AC system strength is much lower. This study finally concludes that applying inductive filtering technology to the HVDC transmission system is feasible, based on a successful engineering application in the high‐power rectifier system.
Unbalanced power flow algorithm for AC&DC hybrid distribution network with diverse‐controlled VSC‐MTDC converts
Authors: Chen Dehua , Ji Xingquan , Yu Yongjin , Bai Xingzhen , Liu Jinxiao
Published: October 2018

The paper aims to propose an algorithm to calculate the power flow of an AC&DC hybrid distribution system. AC&DC distribution networks have recently attracted increasing attention, for the distributed generations (DGs) and DC loads can be integrated in DC networks in more simple and flexible ways than AC networks. Many efforts have been made to deal with the power flow problem of hybrid networks, however, the DC‐side power flow's effect on three‐phase unbalanced AC side and the influence to entire distribution system which DG directly connected in the DC side are both not considered. Therefore, this paper discusses the grid architecture with multiple AC&DC feeders. Then, models of VSC‐MTDC, DC/DC converters, DGs, and other elements are formulated for power flow calculation. Furthermore, power flow equations of DC distribution and VSC converters are deduced in detail. As for converters under different control strategies and diverse forms of linking combinations between AC&DC grids, calculating approaches are considered to be of partial differences. Considering these distinct cases, a specific and improved sequential method is employed to compute distribution network's power flow. Simulation results on a modified IEEE 13 Node Test Feeder demonstrate the rapidity, accuracy, and easy‐convergence of the algorithm.
Vacuum‐free fabrication of a low‐voltage multi‐bit memory device based on a ferroelectric polymer and photosensitive film
Authors: Kim Woo Young
Published: October 2018

A multi‐bit memory device was fabricated using a ferroelectric polymer. For multi‐bit storage, a capacitive‐type memory was configured to have two different thicknesses: a thinner sub‐capacitor to represent the polarization reversal at a lower voltage and a thicker sub‐capacitor that allows the two sub‐capacitors to operate in different voltage ranges. The thin film was composed of a single ferroelectric polymer film and the thick film was composed of a hybrid film of a ferroelectric polymer and a photosensitive polymer. The photosensitive polymer reacted with ultraviolet light, so it was patterned by a conventional lithography process. The external voltage was divided into two layers, the ferroelectric layer and the photosensitive layer, which resulted in polarisation reversal at a higher voltage region. The most important feature of this work is that no vacuum equipment was used in the manufacturing process of the memory device. In the manufacturing process of the conventional multi‐bit memory device, vacuum equipment was required to remove the polymer film. Therefore, the size of the substrate is limited and the productivity is inevitably lowered. The proposed multi‐bit memory device and its fabrication process will be useful because it has many advantages in terms of productivity compared to existing processes.