bluuebunny/crossref_metadata_2025_split huggingface dataset:
Origin of Ferroelectric Phase in Undoped HfO2 Films Deposited by Sputtering
Authors: Mittmann Terence , Materano Monica , Lomenzo Patrick D. , Park Min Hyuk , Stolichnov Igor , Cavalieri Matteo , Zhou Chuanzhen , Chung Ching‐Chang , Jones Jacob L. , Szyjka Thomas , Müller Martina , Kersch Alfred , Mikolajick Thomas , Schroeder Uwe 
Published: April 2019

AbstractThin film metal–insulator–metal capacitors with undoped HfO2 as the insulator are fabricated by sputtering from ceramic targets and subsequently annealed. The influence of film thickness and annealing temperature is characterized by electrical and structural methods. After annealing, the films show distinct ferroelectric properties. Grazing incidence X‐ray diffraction measurements reveal a dominant ferroelectric orthorhombic phase for thicknesses in the 10–50 nm range and a negligible non‐ferroelectric monoclinic phase fraction. Sputtering HfO2 with additional oxygen during the deposition decreases the remanent polarization. Overall, the impact of oxygen vacancies and interstitials in the HfO2 film during deposition and annealing is correlated to the phase formation process.
Recent Progress in Metal Halide Perovskite Micro‐ and Nanolasers
Authors: Wei Qi , Li Xiaojun , Liang Chao , Zhang Zhipeng , Guo Jia , Hong Guo , Xing Guichuan , Huang Wei 
Published: April 2019

AbstractLead halide perovskites are considered as very promising photovoltaic materials due to their tunable direct bandgaps, large absorption coefficients, long carrier diffusion lengths, and ultralow trap state densities, etc. With these unique properties, the lead halide perovskites have also demonstrated great potential for use as semiconductor gain materials. In this review, a snapshot on the recent advances of lead halide perovskite micro‐ and nanolasers is given. The dependence of lasing performance on the perovskite dimensionality, crystal size, and operation temperature is systematically discussed. Furthermore, the development of continuous wave (cw) pumped perovskite lasers and lead‐free perovskite lasers is also summarized. In the final section, the challenges and future prospects of metal halide perovskite lasers are provided. These pieces of knowledge would help advancing the development of perovskite on‐chip coherent light sources.
(De)bonding on Demand with Optically Switchable Adhesives
Authors: Hohl Diana Kay , Weder Christoph 
Published: April 2019

AbstractAdhesives that enable bonding and especially debonding on demand (DoD) have attracted rapidly growing interest in the last decade, as these capabilities greatly improve the functionality of adhesives, particularly in connection with temporal fixation, repair, and recycling. Indeed, DoD techniques have already entered commercial exploitation in applications such as easily removable wound dressings, temporal fixation in semiconductor manufacturing, and the repair, replacement, or recycling of components. While most approaches to debonding rely on heat to reduce the adhesive strength via physical property changes of the adhesive, optically switchable adhesives have been much less explored. However, light is an attractive stimulus, as it allows an efficient, contactless, remote stimulation that can be temporally and spatially controlled. In this Progress Report, recent developments in the domain of photoswitchable adhesive materials are highlighted. After a discussion of main strategies for the irreversible debonding of various adhesive types, options are presented for reversible (de)bonding enabled by different optical processes. The report emphasizes strategies based on photodegradable groups, photoisomerization, as well as the dissociation of supramolecular and dynamic covalent bonds based on either photochemical or light–heat conversion processes.
Flexible and Stretchable Photonic Sensors Based on Modulation of Light Transmission
Authors: Peng Wang , Wu Hao 
Published: April 2019

AbstractEmerging technologies, such as soft robotics, electronic skin, wearable devices, and flexible display, demand the practical application of photonic sensors that are bendable and stretchable, as conventional photonic sensors are fabricated with rigid materials and substrates, rendering their applications in deformable state or soft systems infeasible. Thus, the development of flexible and stretchable photonic sensors, which can be wrapped onto curved surfaces and easily deformed into different shapes and sizes, has inspired great research interest. This article presents recent progress in the development of flexible and stretchable photonic sensors, particularly photonic sensors based on the modulation of light transmission, from the aspects of materials synthesis and selection, structure design, fabrication methods, sensing characteristics, and performances. The challenges and future research opportunities related to flexible and stretchable photonic sensors and their potential application prospects are also discussed.
Amplified Spontaneous Emission Realized by Cogrowing Large/Small Grains with Self‐Passivating Defects and Aligning Transition Dipoles
Authors: Bai Yujie , Qin Jiajun , Shi Lei , Zhang Jia , Wang Miaosheng , Zhan Yiqiang , Zou Han , Haacke Stefan , Hou Xiaoyuan , Zi Jian , Hu Bin 
Published: April 2019

AbstractThis paper reports an amplified spontaneous emission (ASE) initiated by intrinsically passivating grain boundary defects and aligning transition dipoles in polycrystalline perovskite (MAPbBr3) films. The method is developed by using concurrently occurring fast and slow growths to attach small grains on surfaces of large grains toward low‐threshold ASE. This materials processing utilizes one‐step solution method of mixing two MAPbBr3 precursor (PbBr2‐based and Pb(Ac)2 · 3H2O‐based) solutions to control two subsequent growths: quickly growing large grains followed by slowly growing small grains, leading to unique emitting centers from large grains and self‐doping agents from small grains. With this design, spectral narrowing phenomenon is observed from the large grains with the full width at half maximum decreasing from 21 to 4 nm when the pumping fluence is increased from 2 to 10 µW, generating an efficient ASE. Concurrently, the observed ASE shows a linear polarization reaching 21.1%, indicating that the transition dipoles in large grains are linearly polarized with coherent interaction. Therefore, this processing strategy presents a unique method to intrinsically passivate grain boundary defects and align transition dipoles toward developing ASE by attaching small grains (serving as passivation agent) to the surfaces of large grains (functioning as light‐emitting centers).
Simulation of Sintering across Scales
Authors: Raether Friedrich , Seifert Gerhard , Ziebold Heiko 
Published: April 2019

AbstractSintering controls microstructure and quality of powder‐metallurgical and ceramic products and the efficiency of heating processes. A survey on computational tools for the simulation and optimization of sintering processes is presented including both microstructural models and continuum mechanical models. A new integrated microstructure model on sintering (IMS) is introduced. It includes the most important aspects of current computational microstructural models on solid state sintering: local equilibrium structures controlled by interface energy, randomness of diffusion processes, and particle rearrangement. The model assumptions and the underlying equations are described in detail. Simulations based on the IMS model show a very realistic evolution of microstructure. They require reasonable computer time and show small statistical variations. Various applications of the new model are suggested and its limitations are discussed. For the prediction of shrinkage and shape distortions during sintering, continuum models are required which are based on input from sintering experiments. Adequate functions of the different models and criteria for their efficient interplay with measurements are proposed according to an integrated computational materials engineering approach for sintering.
Selenium Vacancy–Enhanced Gas Adsorption of Monolayer Hafnium Diselenide (HfSe2) from a Theoretical Perspective
Authors: Yang Guofeng , Yan Pengfei , Zhu Chun , Gu Yan , Lu Naiyan , Xue Junjun , Zhang Xiumei , Sun Rui , Fang Xiudong 
Published: April 2019

AbstractThe gas adsorption properties of monolayer selenium vacancy–defective (VSe) hafnium diselenide (HfSe2) compared with that of pure monolayer HfSe2 for CO, NO, NO2, SO2, CO2, H2O, H2S, and NH3 molecules are theoretically investigated using density functional theory (DFT) based on first‐principle calculations. The equilibrium distance, adsorption energy, charge transfer, and electron localization function of pure and Se vacancy–defective HfSe2 (VSe‐HfSe2) monolayers with absorbed gases are systematically calculated. It is demonstrated that monolayer VSe‐HfSe2 exhibits enhanced adsorption energy and charge transfer than that of pure HfSe2, and the band structures reveal that the adsorption of CO, NO, NO2, and SO2 molecules can significantly modify the electronic structure of VSe‐HfSe2 monolayer. In addition, the atom projected density of states suggests the existence of orbital hybridization between the gas molecules, and VSe‐HfSe2 is the primary cause of high charge transfer. The results demonstrate that selenium vacancy will effectively enhance the gas adsorption ability for HfSe2 monolayer, especially for CO, NO, NO2, and SO2 molecules.
Electrokinetic Phenomena Enhanced Lithium‐Ion Transport in Leaky Film for Stable Lithium Metal Anodes
Authors: Li Guoxing , Liu Zhe , Wang Daiwei , He Xin , Liu Shuai , Gao Yue , AlZahrani Atif , Kim Seong H. , Chen Long‐Qing , Wang Donghai 
Published: April 2019

AbstractThe application of lithium (Li) metal anodes in Li metal batteries has been hindered by growth of Li dendrites, which lead to short cycling life. Here a Li‐ion‐affinity leaky film as a protection layer is reported to promote a dendrite‐free Li metal anode. The leaky film induces electrokinetic phenomena to enhance Li‐ion transport, leading to a reduced Li‐ion concentration polarization and homogeneous Li‐ion distribution. As a result, the dendrite‐free Li metal anode during Li plating/stripping is demonstrated even at an extremely high deposition capacity (6 mAh cm−2) and current density (40 mA cm−2) with improved Coulombic efficiencies. A full cell battery with the leaky‐film protected Li metal as the anode and high‐areal‐capacity LiNi0.8Co0.1Mn0.1O2 (NCM‐811) (≈4.2 mAh cm−2) or LiFePO4 (≈3.8 mAh cm−2) as the cathode shows improved cycling stability and capacity retention, even at lean electrolyte conditions.
Direct Observation of Dissipation in Dynamical Search Algorithm using Transmon Qubits
Authors: Homid Ali H. , Abdel‐Aty Mahmoud , Farouk Ahmed , Obada Abdel‐Shafy F. 
Published: April 2019

AbstractFollowing recent work [Fortschritte der Physik 66, 1700080 (2018)], the dissipation effect of the dynamical quantum search algorithm (DQSA) is investigated. Such an algorithm is realized with the interaction of multi superconducting transmon qubits inside a 3D bus cavity. The dissipation of such system is caused by managing the sensitivity to charge noise via tuning the qubit frequency by employing Josephson energy. The probabilities of marked and unmarked states for the present algorithm have been calculated analytically and numerically. Such probabilities of marked states are sensitive to any change in the dissipation parameter. A deficiency causes the dissipation for the marked states, and that deficiency is added to the unmarked states. It is interesting to mention that one of the datasets at large dissipation rates gives an observation of the marked states probabilities which is related to the decoherence free subspace. It is predicted that the algorithm can be successfully implemented in the current experiments.
Production of 6,8‐Dihydroxy Fatty Acids by Recombinant Escherichia coli Expressing T879A Variant 6,8‐Linoleate Diol Synthase from Penicillium oxalicum
Authors: Shin Kyung‐Chul , Seo Min‐Ju , Ju Jeong‐Hun , Oh Deok‐Kun 
Published: April 2019

AbstractRecombinant Escherichia coli expressing T879A variant 6,8‐linoleate diol synthase (LDS) from Penicillium oxalicum showed 2.1‐fold higher activity than recombinant E. coli expressing wild‐type 6,8‐LDS for the production of 6,8‐dihydroxy fatty acids (DiHFA) from linoleic acid. The optimal conditions for the production of 6,8‐DiHFA by recombinant E. coli expressing T879A variant 6,8‐LDS were pH 6.5, 35°C, 50 g L−1 cells, 10 g L−1 (35.7 mM) substrate, and 5% (v/v) dimethyl sulfoxide. Under these optimized conditions, 6.6 g L−1 (22.1 mM) 6,8‐dihydroxy‐9,12(Z,Z)‐octadecadienoic acid (DiHODE) and 7.1 g L−1 (22.6 mM) 6,8‐dihydroxy‐9(Z)‐octadecenoic acid (DiHOME) were produced from linoleic acid and oleic acid in 40 min, respectively. The volumetric productivities of 6,8‐DiHODE and 6,8‐DiHOME under these conditions were 9.9 and 10.7 mg L−1 h−1, respectively. The volumetric productivities of 6,8‐DiHODE and 6,8‐DiHOME were the highest values among those of all reported regiospecific DiHODE and DiHOME, respectively. To the best of our knowledge, this is the first quantitative biotechnological production of 6,8‐DiHFA.
Stability of Tocopherol Homologs in Bulk Oils at 60°C Oxidation and Chlorophyll Photosensitization by the Action of Moisture
Authors: Ryu Jiwon , Lee Chankyu , Kim Mi‐Ja , Lee Jaehwan 
Published: April 2019

AbstractThe effects of deuterium oxide (D2O) on the stability of tocopherol homologs were evaluated in corn oil stored at 60°C or in the process of chlorophyll photosensitization. The degree of oxidation, changes in moisture, and the levels of tocopherol homologs were analyzed. The moisture content in corn oil incubated with deuterium‐free water (H2O) was significantly (P < 0.05) higher than that in corn oil incubated with D2O. The presence of D2O accelerated the rate of lipid oxidation in corn oil, irrespective of whether it has been oxidized at 60°C or has been photosensitized by chlorophyll. After exposure to either of the oxidative stresses, the stability of β + γ‐tocopherols present in corn oil was enhanced in the presence of D2O compared to corn oil incubated in the presence of H2O, or control corn oil without the addition of moisture. However, the stability of α‐tocopherol in corn oil incubated with D2O was significantly lower after oxidation at 60°C compared to the other conditions (P < 0.05), whereas it was significantly higher than under the other conditions after chlorophyll photosensitization (P < 0.05). The moisture and type of oxidative stress, therefore, play important roles in the stability of tocopherol homologs in bulk oils.
Effect of chemical etching of resistance wire surface on the strength and failure mechanism of the resistance‐welded joint of polyetherimide composites
Authors: Xiong Xuhai , Zhao Pu , Ren Rong , Zhang Zhongbao , Cui Xu , Ji Shude 
Published: April 2019

ABSTRACTThe surface modification of stainless‐steel (SS) mesh was carried out by chemical etching for different time, and then, the etched SS meshes were used as the interlayer heating element for resistance welding of glass fabric‐reinforced polyetherimide (GF/PEI) composite laminates. The hydrophobicity and tensile strength of the etched and untreated SS wires and interfacial shear strength (IFSS) between SS wire and PEI resin were investigated by dynamic contact angle (DCA) analyzer and single fiber pull‐out test to evaluate the influence of the degree of chemical etching on the bonding strength of PEI resin and SS surface. Tensile lap‐shear strength (LSS) and scanning electron microscope (SEM) analysis were performed to investigate the welding interface strength and fracture morphologies of the resistance‐welded joint of the GF/PEI laminates. The hydrophobicity and tensile strength of SS wires were increased and decreased respectively with etching time (te). The IFSS of SS wire/PEI resin showed an improvement with te. The LSS was increased first and then decreased with te, and the optimal te was 30 min when LSS reached the maximum. Fracture analysis showed the main failure mode of the welded joints was the interlayer debonding when welding time (tw) was insufficient. With the extension of tw, the failure mode gradually switched into the intralayer tearing of the SS implant. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47879.
Effect of segment structures on the hydrolytic degradation behaviors of totally degradable poly(L‐lactic acid)‐based copolymers
Authors: Fan Tiantang , Ye Wuyou , Du Beibei , Zhang Qin , Gong Li , Li Jiafeng , Lin Shengli , Fan Zhongyong , Liu Qing 
Published: April 2019

ABSTRACTA series of high‐molecular‐weight terpolymers named PTG‐b‐LG and PT‐b‐LG were synthesized based on the macroinitiators of PTG copolymers and PTMC, respectively. In vitro degradation of PTG‐b‐LG and PT‐b‐LG was carried out by immersing into PBS, in comparison with that of PLLA. Mass loss, water uptake, GPC, DSC, WAXD, and 1H NMR were examined for the degradation study. It was found that PTG‐b‐LG degraded faster than PT‐b‐LG and PLLA due to the Di‐random block structure, which had lower regularity of chain and lower crystallinity. The compositional changes appeared to be more complex, but the molar mass decreased owing to chain fragmentation caused by hydrolysis. Moreover, morphological changes were also observed during the degradation in all situations with the crystallization of by‐products and a preferential degradation of amorphous domains. Specifically, PTG‐b‐LG presented an adjustable degradation rate and may be used for the fabrication of totally biodegradation stents in the future. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2019, 136, 47887.
CACNA1C (rs1006737) may be a susceptibility gene for schizophrenia: An updated meta‐analysis
Authors: Zhu Dongjian , Yin Jingwen , Liang Chunmei , Luo Xudong , Lv Dong , Dai Zhun , Xiong Susu , Fu Jiawu , Li You , Lin Juda , Lin Zhixiong , Wang Yajun , Ma Guoda 
Published: April 2019

AbstractIntroductionSchizophrenia is a serious mental illness with a genetic predisposition. Genome‐wide association studies (GWAS) have identified the α‐1C subunit of the L‐type voltage‐gated calcium channel (CACNA1C) gene as a significant risk gene for schizophrenia. However, there are inconsistent conclusions in case–control studies.MethodsWe performed a comprehensive meta‐analysis of all available samples from existing studies under four different genetic models (recessive model, dominant model, additive model and allele model) to further confirm whether CACNA1C rs1006737 is an authentic risk single nucleotide polymorphism (SNP) for schizophrenia.ResultsA statistically significant difference under the four models (all p < 0.05) was observed by pooling nine Asian and European studies, including a total of 12,744 cases and 16,460 controls. For European‐decent samples, a significant difference was identified between patients and controls for the four models (all p < 0.05). We observed a significant difference between patients and controls for the recessive model and allele model (GG vs. GA + AA: p < 0.00001; G vs. A: p < 0.00001) using a fixed effect model, but the dominant model (GG + GA vs. AA: OR: p = 0.15) and additive model (GG vs. AA: p = 0.11) showed no significant difference between patients and controls in the Asian samples.ConclusionOur findings provide important evidence for the establishment of CACNA1C as a susceptibility gene for schizophrenia across world populations, but its roles in the pathogenesis of schizophrenia need to be further investigated.
Pseudo‐Bartter syndrome in children with cystic fibrosis
Authors: Faraji‐Goodarzi Mojgan 
Published: April 2019

AbstractCystic fibrosis (CF) is an autosomal recessive genetic disorder. We report a case of a boy aged 4.5 years with cystic fibrosis, presenting under‐weightness, hypocalcemia, metabolic alkalosis, hypokalemia, and hyponatremia. Sweat analysis of the patients concluded pseudo‐Bartter syndrome, which was successfully treated using antibiotics, physiotherapy, fluids, vitamin supplements, and pancreatic enzyme therapy.
Pillarquinone‐Based Porous Polymer for a Highly‐Efficient Heterogeneous Organometallic Catalysis
Authors: Lan Shang , Yang Xuan , Shi Kejia , Fan Rong , Ma Da 
Published: April 2019

AbstractPillar[5]quinone (PQ[5])‐based porous polymer has been prepared by crosslinking and oxidating pillar[5]arene (PA[5]). Quinone was used as an unorthodox ligand to load palladium‐catalyst with high loading ratio (up to 12.0 wt %). Catalyst was well dispersed on solid support in the form of Pd2+‐specie. Pd‐loaded PQ[5]‐based heterogeneous catalyst was highly efficient for Suzuki‐coupling reactions (22‐ to 1485‐fold higher than Pd/C based on turnover frequency). It was superior compared to other existing heterogeneous catalysts for selective catalytic reaction. This heterogeneous catalyst had good thermo‐stability, and could be reused and recycled.
Data Mining the C−C Cross‐Coupling Genome
Authors: Sawatlon Boodsarin , Wodrich Matthew D. , Meyer Benjamin , Fabrizio Alberto , Corminboeuf Clémence 
Published: April 2019

AbstractThe speed and precision of machine‐learning (ML) techniques in determining quantum chemical properties has resulted in a considerable computational speed up in comparison to traditional quantum chemical methods, and now allows a desired property of thousands of molecules to be assessed virtually instantaneously. The large databases that result from employing ML can, in turn, be mined with the goal of uncovering relationships that may be missed through more commonly used small scale screening procedures. Due to its prominent place in chemistry, catalysis represents a particularly fruitful playground, where drawing connections between the quantum chemical properties of catalysts and their overall catalytic performance may lead to the identification of new, highly functional species. In this spirit, we previously trained ML models to predict the performance of 18000 prospective catalysts for a Suzuki coupling reaction using molecular volcano plots. Here, we apply concepts from big data to probe a type of “C−C cross‐coupling genome” that explores results from many different named cross‐coupling reactions. The use of interactive dimensionality‐reducing data‐clustering maps facilitates the identification of relationships between the thermodynamics of different catalysts and the chemical properties of their constituent metal and ligands. Analyzing large numbers of species in this manner leads to the identification of not only unexpected catalysts that have thermodynamically ideal profiles to catalyze C−C cross‐coupling reactions, but also reveals a wealth of interesting chemical trends regarding the influence played by different metals and ligands, as well as their unique combinations.