bluuebunny/crossref_metadata_2025 huggingface dataset:
Photocatalytic decarboxylative [2 + 2 + 1] annulation of 1,6-enynes with N-hydroxyphthalimide esters for the synthesis of indene-containing polycyclic compounds
Authors: Jiao Meng-Jie , Liu Dan , Hu Xiu-Qin , Xu Peng-Fei
Published: October 2019

An efficient photoredox-mediated [2 + 2 + 1] annulation of 1,6-enynes with N-hydroxyphthalimide esters was reported for the synthesis of spiro and non-spiro indene-containing polycyclic frameworks.
Correction: A formal [4 + 2] cycloaddition of sulfur-containing alkylidene heterocycles with allenic compounds
Authors: Dočekal Vojtěch , Formánek Bedřich , Císařová Ivana , Veselý Jan
Published: October 2019

Correction for ‘A formal [4 + 2] cycloaddition of sulfur-containing alkylidene heterocycles with allenic compounds’ by Vojtěch Dočekal et al., Org. Chem. Front., 2019, 6, 3259–3263.
Study on the thermal decomposition mechanism of graphene oxide functionalized with triaminoguanidine (GO-TAG) by molecular reactive dynamics and experiments
Authors: Zhang Chongmin , Fu Xiaolong , Yan Qilong , Li Jizhen , Fan Xuezhong , Zhang Guofang
Published: October 2019

The edge carbon atoms on the GO promote the decomposition of TAG.
Unraveling the effect of Gd doping on the structural, optical, and magnetic properties of ZnO based diluted magnetic semiconductor nanorods
Authors: Obeid Mohammed M. , Jappor Hamad R. , Al-Marzoki Kutaiba , Al-Hydary Imad Ali , Edrees Shaker J. , Shukur Majid M.
Published: October 2019

Gd doped ZnO nanorods.
Distribution, contents and health risk assessment of heavy metal(loid)s in fish from different water bodies in Northeast China
Authors: Huang XiaoLi , Qin DongLi , Gao Lei , Hao Qirui , Chen Zhongxiang , Wang Peng , Tang Shizhan , Wu Song , Jiang Haifeng , Qiu Wei
Published: October 2019

This study aimed at investigating the accumulation and potential risks of eight metal(loid)s in fish from natural and culturing water samples in Northeast China.
Unveiling the effect of 11-MUA coating on biocompatibility and catalytic activity of a gold-core cerium oxide-shell-based nanozyme
Authors: Jain Vidhi , Bhagat Stuti , Singh Mandeep , Bansal Vipul , Singh Sanjay
Published: October 2019

Replacement of CTAB and CeO2 nanoparticle layer by 11-MUA from the surface of Au core-CeO2 shell nanoparticle.
Electrochemical fabrication and evaluation of a self-standing carbon nanotube/carbon fiber composite electrode for lithium-ion batteries
Authors: Liu Yi-Hung , Lin Heng-Han , Tsai Tsung-Yu , Hsu Chun-Han
Published: October 2019

A binder-free CNT/CF composite electrode is developed via electrophoretic deposition, offering favorable electrochemical performances and stability as a self-standing lithium-ion battery anode.
Gram-scale synthesis of nitrogen doped graphene quantum dots for sensitive detection of mercury ions and l-cysteine
Authors: Mao Yuang , Zhao Chang , Ge Shuyan , Luo Tao , Chen Jie , Liu Jiyang , Xi Fengna , Liu Junjie
Published: October 2019

One-step and gram-scale synthesis of nitrogen doped graphene quantum dots is realized for their sensitive detection of Hg2+ and l-Cys.
The antitumor activity of 4,4′-bipyridinium amphiphiles
Authors: Wang Senlin , Wu Hongshuai , Chen Fanghui , Zhang Yu , Zhang Yuchen , Sun Baiwang
Published: October 2019

The cell growth inhibition and apoptosis induction of 4,4′-bipyridinium amphiphiles.
Optimizing sandwich-structured composites based on the structure of the filler and the polymer matrix: toward high energy storage properties
Authors: Cui Yang , Wang Xuan , Zhang Tiandong , Zhang Changhai , Chi Qingguo
Published: October 2019

Inorganic composite fillers and sandwich-structured composite films have been designed for further increasing the energy storage density.
Fe2+ doped in CsPbCl3 perovskite nanocrystals: impact on the luminescence and magnetic properties
Authors: Hu Yue , Zhang Xinyue , Yang Chaoqun , Li Ji , Wang Li
Published: October 2019

The CsPb1−xFexCl3 NCs were synthesized and an appropriate amount of Fe2+ doping can enhance PLQY and average PL lifetimes. Meanwhile, an obvious hysteresis behavior has been observed for the NCs.
Analyzing explanations of substitution reactions using lexical analysis and logistic regression techniques
Authors: Dood Amber J. , Dood John C. , Cruz-Ramírez de Arellano Daniel , Fields Kimberly B. , Raker Jeffrey R.
Published: October 2019

Assessments that aim to evaluate student understanding of chemical reactions and reaction mechanisms should ask students to construct written or oral explanations of mechanistic representations; students can reproduce pictorial mechanism representations with minimal understanding of the meaning of the representations. Grading such assessments is time-consuming, which is a limitation for use in large-enrollment courses and for timely feedback for students. Lexical analysis and logistic regression techniques can be used to evaluate student written responses in STEM courses. In this study, we use lexical analysis and logistic regression techniques to score a constructed-response item which aims to evaluate student explanations about what is happening in a unimolecular nucleophilic substitution (i.e., SN1) reaction and why. We identify three levels of student explanation sophistication (i.e., descriptive only, surface levelwhy, and deeperwhy), and qualitatively describe student reasoning about four main aspects of the reaction: leaving group, carbocation, nucleophile and electrophile, and acid–base proton transfer. Responses scored as Level 1 (N= 113, 11%) include only a description of what is happening in the reaction and do not address the why for any of the four aspects. Level 2 responses (N= 549, 53%) describe why the reaction is occurring at a surface level (i.e., using solely explicit features or mentioning implicit features without deeper explanation) for at least one aspect of the reaction. Level 3 responses (N= 379, 36%) explain the why at a deeper level by inferring implicit features from explicit features explained using electronic effects for at least one reaction aspect. We evaluate the predictive accuracy of two binomial logistic regression models for scoring the responses with these levels, achieving 86.9% accuracy (with the testing data set) when compared to human coding. The lexical analysis methodology and emergent scoring framework could be used as a foundation from which to develop scoring models for a broader array of reaction mechanisms.
Regulation of spatiotemporal patterning in artificial cells by a defined protein expression system
Authors: Yoshida Aoi , Kohyama Shunshi , Fujiwara Kei , Nishikawa Saki , Doi Nobuhide
Published: October 2019

Spatiotemporal patterning regulation in artificial cells by synthesizing a bacterial spatiotemporal regulator using a defined protein expression system.
A “Double-Locked” and enzyme-activated molecular probe for accurate bioimaging and hepatopathy differentiation
Authors: Liu Yongchao , Teng Lili , Xu Chengyan , Liu Hong-Wen , Xu Shuai , Guo Haowei , Yuan Lin , Zhang Xiao-Bing
Published: October 2019

A “double-locked” and enzyme-activated molecular fluorescent probe for accurate bioimaging and hepatopathy differentiation.
Endoplasmic reticulum targeting fluorescent probes to image mobile Zn2+
Authors: Fang Le , Trigiante Giuseppe , Crespo-Otero Rachel , Hawes Chris S. , Philpott Michael P. , Jones Christopher R. , Watkinson Michael
Published: October 2019

Two endoplasmic reticulum (ER) targeting probes were developed to image mobile Zn2+ to help understand Zn2+ related biological processes in the ER.
High performance polyanthraquinone/Co–Ni(OH)2 aqueous batteries based on hydroxyl and potassium insertion/extraction reactions
Authors: Liu Chang , Ma Ting , Xia Kexin , Hou Xuesen , Nian Qingshun , Cai Yichao , Liang Jing
Published: October 2019

A high performance poly(1,4-anthraquinone)/Ni(OH)2 dual-ion battery is designed with high energy/power density and good cycling performance.
Mechanical properties of lipid bilayers: a note on the Poisson ratio
Authors: Terzi M. Mert , Deserno Markus , Nagle John F.
Published: October 2019

Experimental and simulation data are brought to bear on the Poisson ratio to answer the question, just how soft are biomembranes?
A rational approach to form disulfide linked mucin hydrogels
Authors: Joyner Katherine , Song Daniel , Hawkins Robert F. , Silcott Richard D. , Duncan Gregg A.
Published: October 2019

In this work, we demonstrate how crude mucins, incapable of forming gels, may be restored to behave like natural mucus.
Spatially arranging interfacial droplets at the oil–solid interface
Authors: Zhang Ran , Wang Yao , Yang Zhongqiang
Published: October 2019

A new strategy was provided to site-selectively control the accumulation of water molecules between an oil and solid interface.
Tolerance to carbon corrosion of various carbon structures as catalyst supports for polymer electrolyte membrane fuel cells
Authors: Lee Sung Won , Choi Sung Ryul , Jang Jeongyun , Park Gu-Gon , Yu Seung Ho , Park Jun-Young
Published: October 2019

We introduce a material-based mitigation strategy to improve the toughness of the carbon supports of high performance PEMFC through the hybridization of active spherical carbon and mechanochemically durable PCNF featuring a wide range of fiber stems.
Rational design of 3D N-doped carbon nanosheet framework encapsulated ultrafine ZnO nanocrystals as superior performance anode materials in lithium ion batteries
Authors: Li Jianding , Zhao Huajun , Wang Meimei , Zhu Yongyang , Li Bo , Yu Xueqing , Xu Jincheng , Cheng Yajun , Ouyang Liuzhang , Shao Huaiyu
Published: October 2019

A ZnO encapsulated in a 3D NCNF composite exhibits excellent electrochemical performances both in a half cell and full cell. The improved performances are mainly explained based on the two aspects of structural integrity and kinetics enhancement.
A trimethylol melamine functionalized polyvinyl alcohol network for high performance nano-silicon anodes
Authors: Shan Xiaojian , Cao Zhang , Zhu Guobin , Wang Yan , Qu Qunting , Liu Gao , Zheng Honghe
Published: October 2019

Cross-linking between TMM and PVA chains contributes to good mechanics of the binder and high Li diffusion coefficient, thus a Si anode with high rate capability and excellent cycling stability is obtained.
Efficient polymer light-emitting diodes (PLEDs) based on chiral [Pt(C^N)(N^O)] complexes with near-infrared (NIR) luminescence and circularly polarized (CP) light
Authors: Fu Guorui , He Yani , Li Wentao , Wang Baowen , Lü Xingqiang , He Hongshan , Wong Wai-Yeung
Published: October 2019

Chiral NIR-light emitters [Pt(iqbt)(S-Ln)] (1–4) were used as dopants to produce CP-NIR-PLEDs displaying λem of 732 nm, ηMaxEQE of 0.87–0.93%, and gEL of up to 10−3.
An excellent bipolar host material exhibiting EQE of 24.0% with small efficiency roll-off in solution-processable thermally activated delayed fluorescence OLEDs
Authors: Godumala Mallesham , Yoon Jiwon , Jeong Cheol Hun , Lee Chiho , Jeong Ji-Eun , Park Sungnam , Woo Han Young , Cho Min Ju , Choi Dong Hoon
Published: October 2019

The D–A–D′-type novel organic material APC was designed and synthesized as a host for TADF emitters. APC realized an external quantum efficiency of 24.0% and also retained 23.1 and 21.7% at high brightness of 500 and 1000 cd m−2, respectively.
From bulk to porous GaN crystal: precise structural control and its application in ultraviolet photodetectors
Authors: Yu Ruixian , Wang Guodong , Shao Yongliang , Wu Yongzhong , Wang Shouzhi , Lian Gang , Zhang Baoguo , Hu Haixiao , Liu Lei , Zhang Lei , Hao Xiaopeng
Published: October 2019

The effects of porous structures on the performance of a GaN UV photodetector were investigated for the first time.
Inorganic perovskite engineering through incorporation of a carboxylic acid containing ligand for performance enhancement in perovskite light-emitting diodes
Authors: Chen Jiayue , Chen Xiaojie , Ma Dongyu , Li Guangfu , Zhao Juan , Zhu Dongxia , Chi Zhenguo
Published: October 2019

A perovskite engineering strategy of incorporating a carboxylic acid containing ligand is proposed to enhance device performance of perovskite LEDs.
Highly efficient nondoped blue organic light-emitting diodes with high brightness and negligible efficiency roll-off based on anthracene-triazine derivatives
Authors: Liu Futong , Man Xiaxia , Liu Hui , Min Jiarui , Zhao Shiyuan , Min Wenrong , Gao Lei , Jin Haixu , Lu Ping
Published: October 2019

A nondoped device based on the PIAnTAZ emitter shows blue electroluminescence with a maximum EQE of 7.96%, a maximum luminance of 58 675 cd m−2 and negligible efficiency roll-offs.
Meta-analysis of randomized controlled trials on vitamin D supplement and cancer incidence and mortality
Authors: Zhang Xinran , Niu Wenquan
Published: October 2019

Objectives: We aimed to meta-analyze the results of published randomized controlled trials to test the hypothesis that low vitamin D supplement is associated with an increased risk of cancer incidence and mortality.

Methods: Randomized controlled trials that explored the association between vitamin D supplement and cancer incidence or mortality as primary outcomes were identified through searching the PubMed and EMBASE. Literature search and data extraction were performed independently and in duplicate.

Results: Ten randomized controlled trials pooled in 81362 participants. The incidence rate of cancer was 9.16% (3716 cases) and 9.29% (3799 cases) in vitamin D intervention group and placebo group, respectively, resulting in a nonsignificant relative risk (RR) (95% confidence interval (95% CI)) of 0.99 (0.94–1.03) (P=0.532). The mortality rate of cancer was 2.11% (821 cases) and 2.43% (942 cases) in vitamin D intervention group and placebo group, respectively, resulting in a significant reduction in risk (RR = 0.87, 95% CI: 0.79–0.95, P=0.003). There was no observable heterogeneity or publication bias. Subgroup analyses revealed that history of cancer, extra use of vitamin D and calcium supplement were potential sources of heterogeneity.

Conclusions: Our findings support a beneficial effect of vitamin D supplement on lowering cancer mortality, especially in subpopulations with no history of cancer, extra use of vitamin D, or calcium supplement.
Malignant fibrous histiocytoma amplified sequence 1 alleviates inflammation and renal fibrosis in diabetic nephropathy by inhibiting TLR4
Authors: Lian Huan , Cheng Yi , Wu Xiaoyan
Published: October 2019

Background: Diabetic nephropathy (DN) is the most common complication of diabetes mellitus (DM). The signal pathway and molecular mechanism of renal fibrosis are not fully understood. In the present study, we aimed to explore the function of malignant fibrous histiocytoma amplified sequence 1 (MFHAS1) in DN.

Method: Mouse mesangial cells (MMCs) were treated with low glucose (LG) or high glucose (HG). TAK242 or short hairpin TLR4 (shTLR4) were employed to down-regulate Toll-like receptor 4 (TLR4). The effect of MFHAS1 knockdown or overexpression on fibrosis-related factors, inflammatory factors and TLR4 in MMCs were examined after transfecting with short hairpin RNA (shRNA) or MFHAS1 overexpressed plasmid, respectively. The expression levels of MFHAS1, inflammatory factors, fibrosis factors and TLR4 in db/db or streptozotocin (STZ) mice tissues and MMCs were examined by quantitative real-time polymerase chain reaction (qRT-PCR) and Western blot. The effect of MFHAS1 overexpression in vivo was also evaluated.

Results: The expression of MFHAS1 in db/db or STZ mice and HG-treated MMCs were significantly increased compared with normal control mice and LG-treated MMCs. Overexpression of MFHAS1 inhibited the expression of inflammatory and fibrotic factors, while knockdown of MFHAS1 promoted them. MFHAS1 suppressed the activation of TLR4 pathway via inhibiting the expression of TLR4, and then alleviating inflammation and fibrosis in DN. MFHAS1 overexpression in vivo improved the symptoms of STZ-induced DN mice.

Conclusion: The current study demonstrated that MFHAS1 relieved inflammation and renal fibrosis in DN mice via inhibiting TLR4. The results revealed that the MFHAS1 may be a molecular target in DN therapy.
Predictors of Purchasing a Hearing Aid After an Evaluation Period: A Prospective Study in Dutch Older Hearing Aid Candidates
Authors: Pronk Marieke , Meijerink Janine F. J. , Kramer Sophia E. , Heymans Martijn W. , Besser Jana
Published: October 2019

Purpose

The current study aimed to identify factors that distinguish between older (50+ years) hearing aid (HA) candidates who do and do not purchase HAs after having gone through an HA evaluation period (HAEP).

Method

Secondary data analysis of the SUpport PRogram trial was performed (
n
= 267 older, 1st-time HA candidates). All SUpport PRogram participants started an HAEP shortly after study enrollment. Decision to purchase an HA by the end of the HAEP was the outcome of interest of the current study. Participants' baseline covariates (22 in total) were included as candidate predictors. Multivariable logistic regression modeling (backward selection and reclassification tables) was used.

Results

Of all candidate predictors, only pure-tone average (average of 1, 2, and 4 kHz) hearing loss emerged as a significant predictor (odds ratio = 1.03, 95% confidence interval [1.03, 1.17]). Model performance was weak (Nagelkerke
R
2
= .04, area under the curve = 0.61).

Conclusions

These data suggest that, once HA candidates have decided to enter an HAEP, factors measured early in the help-seeking journey do not predict well who will and will not purchase an HA. Instead, factors that act during the HAEP may hold this predictive value. This should be examined.
Logarithmic Versus Linear Change in Step Size When Using an Adaptive Threshold-Seeking Procedure in a Frequency Discrimination Task: Does It Matter?
Authors: Zaltz Yael , Roth Daphne Ari-Even , Amir Noam , Kishon-Rabin Liat
Published: October 2019

Different rules for changing step sizes (e.g., logarithmic, linear) are alternately used in adaptive threshold-seeking procedures, with no clear justification. We hypothesized that the linear rule may yield more accurate thresholds for poor performers because the step sizes are predetermined and fixed across listeners and thus can be small, in contrast to the logarithmic rule, in which step sizes are changed with respect to the listener's performance.

Purpose

The aim of this study was to test the effect of logarithmic and linear rules on frequency discrimination (FD) thresholds.

Method

Three experiments involving human subjects and Monte Carlo computer simulations were designed and conducted. In the 1st experiment, FD thresholds were estimated in 40 young adults with either 3-interval 2-alternative forced choice (3I2AFC;
n
= 19) or 2-interval 2AFC (
n
= 21) in a within-subject design. In the 2nd experiment, thresholds were estimated in 16 children (7–8 years old) in a within-subject design, using 3I2AFC. In the 3rd experiment, thresholds were estimated in 30 young adults in a between-subjects design using 3I2AFC.

Results

No significant differences were shown between the 2 rules, regardless of age group, method, or level of FD performance. Computer simulations supported the empirical findings, predicting similar FD thresholds for both rules in the majority of runs. However, they also yielded more accurate thresholds with the linear rule, but with a larger number of outliers, which increased as the listener's attention level decreased.

Conclusion

Overall, the use of a particular rule has little influence on FD thresholds. Possible outliers may be minimized by monitoring the participant's attention at the beginning of the run.
End‐to‐end double JPEG detection with a 3D convolutional network in the DCT domain
Authors: Ahn W. , Nam S.‐H. , Son M. , Lee H.‐K. , Choi S.
Published: October 2019

Detection of double JPEG compression is essential in the field of digital image forensics. Although double JPEG compression detection methods have greatly improved with the development of convolutional neural networks (CNNs), they rely on handcrafted features such as discrete cosine transform (DCT) histograms. In this Letter, the authors propose an end‐to‐end trainable 3D CNN in the DCT domain for double JPEG compression detection. Moreover, they also propose a new type of module, called feature rescaling, to insert the quantisation table into the network suitably. The experiments show that the proposed method outperforms state‐of‐the‐art methods.
Carrier‐storage‐enhanced superjunction IGBT with n‐Si and p‐3C‐SiC pillars
Authors: Li Rui , Huang Mingmin , Yang Zhimei , Ma Yao , Gong Min
Published: October 2019

A carrier‐storage‐enhanced superjunction (SJ) insulated gate bipolar transistor (IGBT) with n‐Si and p‐3C‐SiC pillars (Si/SiC SJ IGBT) is studied. At the on‐state, the n‐Si/p‐SiC heterojunction acts as a barrier for holes in the n‐Si pillar, which helps to enhance the carrier‐storage effect in the n‐Si pillar and improves the tradeoff between turn‐off loss (Eoff) and on‐state voltage drop (VCE(sat)). It is found by simulations that VCE(sat) of the Si/SiC SJ IGBT can be 0.35 V lower than that of the conventional SJ IGBT with the same breakdown voltage (VB = 1450 V). Under Eoff = 5 mJ/cm2, VCE(sat) of the Si/SiC SJ IGBT is 1.22 V, which is 0.30 and 0.81 V lower than VCE(sat) of the conventional SJ IGBT and the field stop IGBT, respectively.
2D flat Luneburg lens antenna for multibeam scanning application
Authors: Liu Kunning , Yang Shiwen , Qu Shi‐Wei , Chen Yikai , Hu Jun
Published: October 2019

A two‐dimensional (2D) flat Luneburg lens antenna (LLA) operating at Ka‐band is presented in this Letter. Based on the transformation optics, the 2D conventional Luneburg lens is compressed to the flat form. The proposed flat LLA is composed of six discretised dielectric layers with different permittivity, two metallic parallel plates and an E‐shaped microstrip patch antenna array. By switching on/off the array elements, the lens antenna is able to achieve 1D beam‐scanning with a scan coverage of ±30° at 28 GHz. The proposed lens antenna has a low profile of 7 mm, a focus‐to‐diameter ratio of 0.42, and the simulated/measured aperture efficiency for the on‐axis beam is 56.8/36% at 28 GHz. The proposed 2D flat LLA is highly suitable for 5G mm‐wave wireless communication with the advantages of low profile, wide beam‐scanning range, low cost, and easy fabrication.
Compact filtering power divider with extended stopband using out‐of‐phase feeding scheme
Authors: Shen Guangxu , Feng Wenjie , Che Wenquan
Published: October 2019

A compact filtering power divider is proposed with very wide stopband suppression in this letter. First, the dual‐composite right‐ and left‐handed (D‐CRLH) resonator is employed, while one extended stopband can thus be achieved due to its inherently slow‐wave response. Secondly, one out‐of‐phase feeding scheme is introduced to realise D‐CRLH filtering power divider. By putting the input and output ports on the different sides of D‐CRLH resonators, the mismatching can be realised for the harmonics below 10 GHz and wide stopband suppression is obtained accordingly. For experimental verification, a compact filtering power divider is designed, fabricated, and measured. Wide stopband suppression is observed until 5f0 without using bandstop structures or complex coupling topology.
Three‐dimensional electric field simulation and flashover path analysis of ice‐covered suspension insulators
Authors: Shu Lichun , Liu Yanqing , Jiang Xingliang , Hu Qin , He Gaohui , Yu Zhou , Xiao Longfang
Published: October 2019

Flashover of ice‐covered insulators seriously affects the safe operation of transmission lines. It is necessary to study the electric field distribution for flashover analysis of ice‐covered insulators. The electric field of ice‐covered insulators was mostly calculated by a two‐dimensional (2D) axisymmetric model that cannot be well corresponded to actual icing situations. In this study, a 3D electric field simulation model of ice‐covered suspension insulators under moderate icing condition with applied DC voltage was established. Two characteristic parameters, Eav and Emax were proposed to measure electric field distortion degree. Based on the simulation results, the effects of water film conductivity, icicle length, icicle deviation angle, and icicle distribution on Eav and Emax were studied. The results showed that icicles have a significant influence on the electric field distribution of insulators. Eav increases with the increase of icicle length and decreases with the increase of icicle deviation angle. Emax increases with the increase of the icicle length, icicle spacing and adjacent icicle length difference. When the icicle deviation angle is 45°, Emax is the largest. Lastly, the possible flashover paths were analysed based on the simulation results, which would provide a theoretical basis for building a flashover model of ice‐covered insulators.
Effect of surface modification of electrodes on charge injection and dielectric characteristics of propylene carbonate
Authors: Wu Shilin , Yang Qing , Shao Tao , Zhang Zhaotian , Huang Lingyu
Published: October 2019

Space charge injected into a liquid dielectric by an electrode under an impulse voltage causes the electric field to be distorted, which affects the dielectric's insulation performance. In this study, the authors study the surface modification of three‐electrode materials, namely aluminium, copper, and stainless steel, by sputtering of titanium dioxide (TiO2) based on magnetron sputtering. The breakdown voltage of propylene carbonate and the surface morphology of the electrodes before and after modification were examined. Furthermore, the distribution of the space charge injected into the propylene carbonate from the different electrode materials was also measured based on the Kerr electro‐optic effect. These results indicate that the breakdown voltage of propylene carbonate increased by 7, 4, and 9% after surface modification of aluminium, copper, and stainless steel, respectively. After sputtering of TiO2, micro‐grooves on the surface of the three‐electrode materials became smooth, and the surface roughness decreased, which changed the barrier height of the solid–liquid interface. The space charge injection mode of the three‐electrode materials before and after surface modification was bipolar injection; however, the space charge injection amounts were markedly lower for the modified electrodes.
Maiden application of cascade tilt‐integral–tilt‐derivative controller for performance analysis of load frequency control of interconnected multi‐source power system
Authors: Kumari Sandhya , Shankar Gauri
Published: October 2019

This study presents a maiden application of cascade tilt‐integral–tilt‐derivative (CC‐TI‐TD) controller for the performance analysis of load frequency control (LFC) of interconnected multi‐source power system (MSPS). The studied controller is realised based on cascade control theory and fractional order calculus. TI controller is used as a master controller and TD controller served as slave controller in the proposed CC‐TI‐TD controller. To demonstrate the performance of proposed CC‐TI‐TD controller, first, it is applied to single‐area MSPS followed by two‐area MSPS in the presence of electric vehicles (EVs). The proposed controller gains' parameters are optimised by state‐of‐the‐art water cycle algorithm (WCA) according to the minimisation of fitness function. First, the effectiveness of proposed WCA‐tuned CC‐TI‐TD controller over the WCA‐tuned cascade proportional‐integral–proportional‐derivative (CC‐PI‐PD) controller and modified grey wolf optimisation‐based tuned proportional‐integral derivative and CC‐PI‐PD controllers has been explored in single‐area‐studied power system. Second, the performance of WCA‐tuned CC‐TI‐TD controller with and without presence of EVs in a two‐area interconnected MSPS is assessed with respect to another class of the fractional order controller termed as integral tilt‐derivative controller. Lastly, sensitivity analysis and the effect of time delay on LFC performance are carried out to show the robustness of proposed CC‐TI‐TD controller.
Testing of a hydropower plant's stability and performance using PMU and control system data in closed loop
Authors: Hofsmo Jakobsen Sigurd , Uhlen Kjetil
Published: October 2019

In response to recent concerns regarding deteriorating frequency quality in the Nordic power system, the Nordic transmission system operators have developed draft requirements for the provision of frequency containment reserves (FCR). These requirements outline extensive tests, which the power plant owners must perform to qualify to deliver FCR. In this study, the authors demonstrate that one can check these requirements by standard system identification techniques while the plant is in normal operation and by using measurements readily available from the plant's control system or from a phasor measurement unit (PMU). The validity of the proposed method is demonstrated using Monte Carlo Simulation, where they investigate the effects of the main assumption and potential non‐linearities affecting the approach. Data from real power system operation is used to demonstrate the performance of the method.
Analysis, reduction and robust stabiliser design of sub‐synchronous resonance in an IEEE FBM augmented by DFIG‐based wind farm
Authors: Shah Nilay Narendrakumar , Joshi Sanjay.R.
Published: October 2019

This study modifies the IEEE first benchmark model (FBM) by connecting nearby doubly‐fed induction generator (DFIG) wind farms to utilize the inbuilt convertor controller for damping the sub‐synchronous resonance (SSR) oscillations. The overall model was evaluated to determine the induction generator effect (IGE) and torsional interaction (TI) of sub‐synchronous resonance (SSR) at various compensation levels, wind speeds, and system parameter settings both with and without a DFIG wind farm. The results of this detailed analysis demonstrated that augmenting an IEEE FBM with a DFIG wind farm suppresses SSR‐induced IGE in the power system. An optimal orientation was investigated from rotor‐side converter (RSC) and grid‐side converter (GSC) of DFIG wind farm using residue configuration to design a SSR supplementary damping controller (SSDC). To suppress the TI effect of SSR, the SSDC implements damping control using three different feedback signals: line current, line power, and voltage across a series capacitor. A robust signal for achieving smooth damping under various operating conditions was defined in terms of several key characteristics, namely, high average residue magnitude, average phase angle of residue and avoidance of destabilisation of other dominant modes. The proposed model was validated using eigenvalue analysis, participation factor calculation and time‐domain simulation.
Enabling market participation of distributed energy resources through a coupled market design
Authors: Farrokhseresht Mana , Paterakis Nikolaos G. , Slootweg Han , Gibescu Madeleine
Published: October 2019

In this study, a new market model is proposed to enable the smooth integration of distributed energy resources (DERs) in day‐ahead (DA) and balancing (BL) markets. The DA market is a joint energy and reserve market. DERs participate in the local market operated by the distribution market operator (DMO) which is coordinated with the wholesale market. During local market clearing, the DMO considers the technical constraints of the distribution grid to keep the operation of the distribution grid within limits. Moreover, the DMO, through preliminary scheduling, estimates preliminary prices for energy, reserve and balancing services. These can be seen as offer prices by which the DMO will bid into the TMO DA and BL market. The uncertainty of renewable‐based DERs is considered through the use of stochastic programming. The proposed market model is compared with a centralised market model. Results show that adding the distribution network constraints to the proposed market model is capable of alleviating overloading and appropriately accounting this effect in terms of increasing the operational cost. Moreover, it has been shown that the scalability of the proposed market model is higher compared to the currently applied centralised market models.
Feasibility analysis of non‐orthogonal waveforms for multiple input multiple output passive radar application
Authors: Wang Qing , Li Tong , Dou Tongdong , Zhu Weifeng
Published: October 2019

New non‐orthogonal multiple access technology is proposed with the development of 5G, which is expected to support higher spectrum efficiency and massive terminal access, it enables the communication system to achieve better bit error rate performance and alleviate the spectrum congestion problem effectively under limited resources. With the design of spectrum sharing for radar and communication getting more attention, 5G non‐orthogonal signal has become potential passive radar illumination source. In this article, an orthogonal multiple input multiple output (MIMO) radar waveform design metric by minimising the integration sidelobe level, is introduced firstly. Then based on sparse code multiple access (SCMA) technology, the non‐orthogonal waveform is designed as the passive radar illumination sources. The distance and Doppler resolution of non‐orthogonal waveform are evaluated by a more generalised MIMO ambiguity function. Simulation results demonstrate that non‐orthogonal SCMA signals have competitive performance with orthogonal code division multiple access signals.
Four‐channel monopulse angle estimation for phased array radar with elliptical plane
Authors: Cao Xuemin , Xu Zhenhai , Liu Xinghua , Wang Luoshengbin , Dong Wei
Published: October 2019

The four‐channel monopulse angle estimation is a common and important algorithm for search and tracking radars. However, its application in elliptical planar array remains to be validated. Here, the authors first analyse the properties of monopulse ratio curves for phased array radar with elliptical plane. Then, formulas about the weighted fusion monopulse angle estimation are derived according to the theory of four‐channel monopulse. Finally, the relationship between the angle estimation performance and the target position is examined by simulation experiments, and the result is compared with that of the traditional monopulse method. The results show that the weighted fusion four‐channel monopulse angle estimation method can effectively improve the accuracy of angle estimation, and this improvement would be more salient when the target deviation angle increases.
Fuzzy decision implications: interpretation within fuzzy decision context
Authors: Zhang Jing , Zhai Yanhui , Li Deyu
Published: October 2019

Fuzzy decision implication is an extension of decision implication in the fuzzy setting, serving to uncover the dependencies of fuzzy attributes. This study presents the interpretation of fuzzy decision implication in the fuzzy decision context. Specially, they will show that from fuzzy decision contexts one can obtain a closed fuzzy set of fuzzy decision implications, and the semantical characteristic of the obtained fuzzy set can be interpreted by fuzzy decision context and can be represented by some operators of fuzzy decision context. Conversely, starting from a fuzzy set of fuzzy decision implications, they can form a fuzzy decision context, from which the given fuzzy set can be derived. The result actually implies that they have constructed a correspondence between closed fuzzy sets of fuzzy decision implications and fuzzy decision contexts, and thus shows the equivalence of two interpretations of fuzzy decision implications.
A few StePS forward in unveiling the complexity of galaxy evolution: light-weighted stellar ages of intermediate-redshift galaxies with WEAVE
Authors: Costantin L. , Iovino A. , Zibetti S. , Longhetti M. , Gallazzi A. , Mercurio A. , Lonoce I. , Balcells M. , Bolzonella M. , Busarello G. , Dalton G. , Ferré-Mateu A. , García-Benito R. , Gargiulo A. , Haines C. , Jin S. , La Barbera F. , McGee S. , Merluzzi P. , Morelli L. , Murphy D. N. A. , Peralta de Arriba L. , Pizzella A. , Poggianti B. M. , Pozzetti L. , Sánchez-Blázquez P. , Talia M. , Tortora C. , Trager S. C. , Vazdekis A. , Vergani D. , Vulcani B.
Published: October 2019

Context. The upcoming new generation of optical spectrographs on four-meter-class telescopes, with their huge multiplexing capabilities, excellent spectral resolution, and unprecedented wavelength coverage, will provide invaluable information for reconstructing the history of star formation in individual galaxies up to redshifts of about 0.7.

Aims. We aim at defining simple but robust and meaningful physical parameters that can be used to trace the coexistence of widely diverse stellar components: younger stellar populations superimposed on the bulk of older ones.

Methods. We produced spectra of galaxies closely mimicking data from the forthcoming Stellar Populations at intermediate redshifts Survey (StePS), a survey that uses the WEAVE spectrograph on the William Herschel Telescope. First, we assessed our ability to reliably measure both ultraviolet and optical spectral indices in galaxies of different spectral types for typically expected signal-to-noise ratios. We then analyzed such mock spectra with a Bayesian approach, deriving the probability density function of r- and u-band light-weighted ages as well as of their difference.

Results. We find that the ultraviolet indices significantly narrow the uncertainties in estimating the r- and u-band light-weighted ages and their difference in individual galaxies. These diagnostics, robustly retrievable for large galaxy samples even when observed at moderate signal-to-noise ratios, allow us to identify secondary episodes of star formation up to an age of ∼0.1 Gyr for stellar populations older than ∼1.5 Gyr, pushing up to an age of ∼1 Gyr for stellar populations older than ∼5 Gyr.

Conclusions. The difference between r-band and u-band light-weighted ages is shown to be a powerful diagnostic to characterize and constrain extended star-formation histories and the presence of young stellar populations on top of older ones. This parameter can be used to explore the interplay between different galaxy star-formation histories and physical parameters such as galaxy mass, size, morphology, and environment.
Risk-regulatory increase of trajectory safety, productivity and energy efficiency of motor transport operations in conditions of uncertainty
Authors: Khabutdinov Arseniy
Published: October 2019

The proposed method of complex increase of trajectory safety, productivity and energy efficiency of motor transport operations taking into account the laws of vehicle algorithmic control in difficult traffic conditions. Proceeding from the provisions of the theory of energy efficiency of a generalized type car and the laws of its adaptively-discrete energy of motion, the processes of functioning of the transport-ergatic systems “Driver-Vehicle” (TESDV) and control of the car using adaptive driving procedures (productive, safe, energy-efficient) in the conditions of information uncertainty of locally trajectory situations (LTS). In this work presents logic-procedural and mathematical models for the analysis of risk-regulatory algorithms for control of vehicle, taking into account the functioning of TESDV and quantitative assessment of operator-interface complexity of road sections. The basis of the method of estimating the information complexity of the operator-road interface in relation to any element of the road is the mathematical model of the entropy of the object (as a measure of disorder), which is used in technical cybernetics. For each section of the road, the total indicator of information complexity is determined, which takes into account three levels of uncertainty: low, medium and high. At medium and high levels of complexity of the road section, TESDV implements a risk-regulating automobile control algorithm. Proceeding from the essence of the regulatory labor procedures of driving, as well as their role in the formation of the modes of the TESDV, proposed results of operational simulation of algorithms regulation of locally-trajectory driving risks (LTR): counterproductive, sensory-tempo, incidental and anergic.
The concept of a hybrid traction power supply system
Authors: Sychenko Viktor , Kuznetsov Valeriy , Kosarev Yevheniy , Beh Petro. , Sayenko Yuriy , Styslo Bohdan , Pavlichenko Mihail , Vasilev Ihor , Pulin Mykola
Published: October 2019

The growing shortage of energy resources to provide heavy traffic and high-speed traffic necessitates the development of a new power supply scheme for a traction network using sources of distributed generation of electric energy. Application of asymmetric distributed traction power system with the use of distributed generation allows to increase electric energy efficiency of the feed system of rolling stock, reduce its material capacity and increase the reliability of the functioning of the railway system as a whole. The proposed structure of the hybrid electric traction system involves the creation of a new paradigm aimed at ensuring high demands on the voltage and specific power in the traction network, which will allow to improve the quality and safety of the transportation process when increasing the energy performance indicators. This paradigm will allow to form a new philosophy of building traction power systems. The key elements of this philosophy are decentralization of generation and consumption of electric energy, the use of intelligent electric equipment, distributed power supply management in a single information space of the energy process during transportation. The peculiarity of the proposed work is the optimal combination of technological processes of transmission, consumption of electric energy and transportation, taking into account the specific conditions of functioning of the electrified section: points of connection of power sources and their type, profile of the track, schedule of trains, types of rolling stock and equipment. Conceptually, the hybrid traction power system is an electric hub, in which the inputs are generating points, and the output is the power supply system of the rolling stock. The internal structure of the electric power objects of the hub is determined by the type of transformation and accumulation of electric energy and ways of managing these objects in real time.
Railway transportation of dangerous goods: a bibliometric aspect
Authors: Kolesnykova Tetiana , Matveyeva Olena , Manashkin Lev , Mìshchenko Maxym
Published: October 2019

The purpose of this paper is to research and define the promising worldwide scientific trends in the field of railway transportation of various dangerous goods. To obtain relevant empirical data, the authors reviewed the world literature on paper topic using Scopus and Web of Science citation bases. We determined that this research was focused on several major thematic areas: 1) automation and telematics systems; 2) navigation systems; 3) logistics; 4) energy; 5) locomotives; 6) freight cars; 7) materials; 8) rails; 9) impact on the environment and people. The article used mapping, ensuring a visual perspective for researchers and helping to understand general situations in specific subject areas of the research. This study provides useful information concerning the development of the field of research for the railway transportation of dangerous goods, identifying those academics (authors, countries and institutions) that have made the greatest contribution to its development and defining the priority research directions
Implementation of road charging in the city of Žilina – a tool for reducing negative externalities
Authors: Kalašová Alica , Harantová Veronika , Kubíková Simona , Mikulski Jerzy
Published: October 2019

It has been proven on several implementations worldwide, that introducing of road charging scheme in urban area is very simple and efficient way to reduce traffic volumes, lower congestions and shorten travel time. Herewith, there is a possibility of utilization of charged money, e.g. for financing of public transportation. In our paper, based on analysis of traffic intensities and results of social survey, we describe a proposal of charging schema for the central part of the city of Žilina in Slovakia.
Identification of the railway reconstruction parameters at imposition of high speed traffic on the existing lines
Authors: Lebid Iryna , Kravchenya Irina , Dubrovskaya Tatyana , Luzhanska Nataliia , Berezovyi Mykola , Demchenko Yevhen
Published: October 2019

The problems of railroad design technical reconstruction aimed at ensuring train protection in introduction of high-speed traffic on the rail lines have been addressed. The description of railroad technical system with certain specific features has been proposed. The pair of mutually dual problems regarding the optimal reconstruction of railway curves for raising train speeds at minimal capital investments has been addressed. The problem of determining the optimal speeds of trains of each category under optimum outer rail cant, increase of the unbalanced acceleration value, compliance with the condition of uniform load on rail tracks, comfortable carriage of passengers, in which reduced costs on increased speeds in curved tracks will be minimal has been formulated. To achieve the goals of the study, mathematical optimization techniques and algorithms of analysis of the rail lines of different nature are used. This, by finding and value engineering optimization, allows to minimize high-value and lengthy procedures of physical simulation. As a problem-solving technique, Lagrange multiplier method and its applicability have been proposed. Numeral solution to the problem of selection of certain stretches for increasing rolling stock speeds on operating lines without reconstruction or with minimum expenses on reconstruction of contour of track has been reviewed.
Rationing of the number of signals and interlockings in the operational stock of railway stations
Authors: Lebid Iryna , Shevchenko Dmitrii , Kravchenya Irina , Luzhanska Nataliia , Prokudin Georgii , Oliskevych Myroslav
Published: October 2019

The operational stock of signals and interlockings is necessary to ensure the uninterrupted operation of the electric interlocking systems in the event of their component failure. The existing standards for the composition and number of signals and interlockings available in the operational stock of railway stations are not mathematically based. It is considered the task of justifying the number of signals and interlockings in the operational stock of railway stations, and the factors affecting its quantity are indicated. It is proposed the mathematical model for rationing the amount of equipment necessary to ensure the uninterrupted operation of station signals and interlocking systems with a specified probability. The process of using and replenishment of reserve equipment is described using the the single-channel Markov queuing system model with a limited queue. The proposed probabilistic methodology approbation for the rationing of the amount of reserve equipment was carried out at the stations of the two Belarusian Railway divisions totaling to 58 stations equipped with relay and computer-based electric interlocking. It is shown the efficiency of the calculated amount of equipment in comparison with the existing values.