bluuebunny/crossref_metadata_2025 huggingface dataset:
Dipolar defect complexes in single-crystal PbWO4
Authors: Feng Xi-Qi  , Tong B.Tang  ,   (1)香港浸会大学物理系，香港; (2)中国科学院上海硅酸盐研究所高性能陶瓷和超微结构国家重点实验室，上海  2000 50
Published: December 2020

We have previously demonstrated the presence of the defects complex ［2(La3 + Pb)·-V″Pb］in La-doped lead tungs tate (PWO). That earl ier experimental technique was supplemented with x-ray photoelectron, visible ab sorption and infrared absorption spectroscopies in the present investigation on PWO crystals doped with 3+, 4+ or 5+ cations, or co-doped with 3+ and 5+ impurit ies. Useful information has been deduced on dopant lattice sites, dipolar defect s complexes, their relation with materials properties, and their transformation during annealing. Some of the deductions have also been corroborated with comput er simulation. The present work argues against the conception that impedance spe ctroscopy cannot provide definite conclusions on defect structures in ionic soli ds.
Thermodynamic effect on transmitted intensity perturbance of air-gaped Glan-typ e polarizing prisms
Authors: Li Hong-Xia  , Wu Fu-Quan  , Fan Ji-Yang  ,   (1)曲阜师范大学激光研究所，曲阜  273165; (2)曲阜师范大学物理系，曲阜  273165
Published: December 2020

An analytical study on transmitted intensity perturbance of air-gaped Glan-type polarizing prisms with varying rotation angle is given. The perturbance strongly affects the quality of transmitted polarizing light. Our study shows that the t ransmitted intensity sensitively relies on the incident angle. The minute random variation of the incident angle around the structure angle of air-gaped Glan-ty pe polarizing prism gives rise to the perturbance found in the experiment. The i nfluence of the variation of temperature on the disturbance is discussed. Effect ive ways for reducing the disturbance are presented.
Study on the reverse characteristics of Ti/6H-SiC Schottky contacts
Authors: Shang Ye-Chun  , Liu Zhong-Li  , Wang Shu-Rui  ,   中国科学院半导体研究所微电子研究与发展中心,北京  100083
Published: December 2020

The reverse I(V) measurement and analytic calculation of the electron transport across a Ti/6H-SiC Schottky barrier are presented. Based on the consideration of the barrier fluctuations and the barrier height shift caused by image charge and the applied voltage drop across Ti/SiC interfical layer, a comprehensive analytical model for the reverse tunneling current is developed using a WKB calculation of the tunneling probability through a reverse biased Schottky barrier. This model takes into account the main reverse conduction mechanism, such as field emission, thermionic field emission and thermionic emission. The fact that the simulated results are in good agreement with the experimental data indicates that the barrier height shift and barrier fluctuation can lead to reverse current densities orders of magnitude higher than that obtained from a simple theory. It is shown that the field and thermionic field emission processes, in which carries can tunnel through the barrier but cannot surmount it with insufficient thermal energy, dominate the reverse characteristics of a SiC Schottky contacts in a normal working condition.
Study on modifying the output properties of BaF2 scintilation spectru m
Authors: Xu Rong-Kun  , Guo Chun  , Wen Shu-Huai  , Xia Guang-Xin  , Ning Jia-Min  , Song Feng-Jun  , He Xi-Jun  , Wu Yong-Gang  , Gu Mu  , Chen Ling-Yan  , Wu Xiang  ,   (1)同济大学波耳固体物理研究所，上海  200902; (2)中国工程物理研究院核物理与化学研究所，绵阳  621900
Published: December 2020

In order to extend the scope of application of BaF2 scintillators in the diagnosis of the fast-pulse-radiation-field, an ultraviolet-light-filter has been dev eloped for the modification of the scintillation spectrum. The experimental resu lts reveal that the filter, which is composed of Al2O3, Mg F2, and Al, has a very low transmittance to the slow component light emitted by BaF2 in the in cident angles from 0°to 45° with respect to the surface normal, but has a rela tively high transmittance to the fast component light also emitted by it. The pr operty of the temporal response curve has been obtained by use of a pulse x-rays source, and the damage effect induced by the irradiation of the neutron with an energy of 14.1 MeV is also introduced in this paper.
Numerical simulation of nc-Si:H/ c-Si heterojunction solar cells
Authors: Hu Zhi-Hua  , Liao Xian-Bo  , Zeng Xiang-Bo  , Xu Yan-Yue  , Zhang Shi-Bin  , Diao Hong-Wei  , Kong Guang-Lin  ,   (1)中国科学院半导体研究所,凝聚态物理中心,表面物理国家重点实验室,北京  100083; (2)中国科学院半导体研究所,凝聚态物理中心,表面物理国家重点实验室,北京  100083;云南师范大学太阳能研究所,昆明  650092
Published: December 2020

AMPS simulator, which was developed by Pennsylvania State University, has been used to simulate photovoltaic performances of nc-Si:H/ c-Si solar cells. It is shown that interface states are essential factors prominently influencing open circuit voltages (VOC) and fill factors (FF) of these structured solar cells. Short circuit current density (JSC) or spectral response seems more sensitive to the thickness of intrinsic a-Si:H buffer layers inserted into n+-nc-Si:H layer and p-c-Si substrates. Impacts of bandgap offset on solar cell performances have also been analyzed. As ΔEC increases, degradation of VOC and FF owing to interface states are dramatically recovered. This implies that the interface state cannot merely be regarded as carrier recombination centres, and impacts of interfacial layer on devices need further investigation. Theoretical maximum efficiency of up to 3117%(AM15, 100mW/cm2, 040—11μm) has been obtained with BSF structure, idealized light-trapping effect(RF=0, RB=1) and no interface states.
Electronic theoretical study on the modification mechanism of rare earth element s in zinc-aluminum cast alloys
Authors: Liu Gui-Li  , Li Rong-De  ,   沈阳工业大学材料科学与工程学院，沈阳  110023
Published: December 2020

The atomic structural model of the α phase-liquid interface region in ZA27 allo ys was set up by combining molecular dynamics theory with computer programming.T he electronic structure of α phase solid solution with rare earth elements and that of crystal-liquid growth front enriched with rare earth elements in the ZA2 7 casing alloy were investigated by the recursion method.The calculated results show that rare earth elements are more stable in the phase interface region than in α phase.This explains the fact that the solid solubility of rare earth elem ents in α phase is very small,but large in the crystal-liquid growth front.The structural energy difference between the rare earth elements in the crystal-liqu id growth front and in the α phase is greater than that in Al,which support the view point that rare earth elements enriched in the crystal-liquid growth front can make α crystal-branch melt and break down,dissociate,and propagate.Calcula tions of bond order integrals (BOIs) also show that rare earth elements in the α phase-liquid growth front are not easier than Al to solidify on the surface o f α phase,so that the growth of α grains is blocked,and the alloy is refined,t hus illucidating the modification mechanism of rare earth elements from an elect ronic level for the zinc-aluminum cast alloys.
Study on the structure and energy of the (0001) surface of α-Al2O3 substrate
Authors: Yang Chun  , Li Yan-Rong  , Xue Wei-Dong  , Tao Bai-Wan  , Liu Xing-Zhao  , Zhang Ying  , Huang Wei  ,   (1)电子科技大学微电子与固体电子学院，成都  610054; (2)电子科技大学微电子与固体电子学院，成都  610054;四川师范大学数学与软件科学学院，成都  610068; (3)中国物理工程研究院，绵阳  621000
Published: December 2020

There are three different structures of the α-Al2O3(0001) crystal surface b ecause different atoms are terminated on the outermost layer. Our calculations a re based on the density functional theory in local density approximation, and on ultra-soft pseudopotential methods, with the valence orbital expanded in plane- wave by using three-dimensional periodic boundary conditions in κ-space, first ly, the calculation result is that α-Al2O3(0001) crystal surface structure which the outermost layer is terminated by a single layer of Al atoms is much mo re stable than the other two structures. Secondly, a rhombohedral primitive cell is employed to perform cell optimizations, with ten atoms in the unit cell, and the calculated equilibrium parameters are:a0＝0.48178nm,γ＝120.16, which are in excellent agreement with recent experimental values(a0＝0.47591nm ),with a difference of less than 1.3%. Moreover, our calculations are performed with a su per-cell slab model in vacuum environment, in which the outermost layer is termi nated by single Al atoms. By investigating the four-layer relaxation and Al-O a toms population of the surface, we obtain results that the top single Al layer i s an inward relaxation of 0.0792 nm—0.098nm, that is, the second-layer O atoms are turned into the top layer,and the top O and Al atoms population analysis sho w that the valence electrons are concentrated on the surface oxygen ions with a greater probability,it is obvious that the α-Al2O3(0001) crystal surface ap pears in the O-surface state,which is discussed from the microstructure of α-Al 2O3(0001)crystals in details.
Structure and infrared absorption characterizations of yttrium silicides formed by ion beam synthesis
Authors: Wang Wen-Wu  , Xie Er-Qing  , He De-Yan  ,   兰州大学物理系,兰州  730000
Published: December 2020

Buried hexagonal YSi2 layers were formed using 100 keV yttrium ions to a dose of 1×1018 Y+cm-2 implanted into (111) oriented silicon wafers by a metal vapor vacuum arc ion source. The structure and infrared absorption spectra of the compound layers have been investigated by x-ray diffraction (XRD), Rutherford backscattering spectrometry (RBS) and Fourier transform infrared (FT-IR) transmittance spectrometry. It was shown that YSi2 has been directly formed during the implantation. A tendency of preferred growth was found in the following process of infrared irradiation. RBS measurements revealed that, after infrared irradiation, the average atomic density ratio of Si to Y in the buried layers decreases from 24 down to around 20, which is close to the stoichiometry of hexagonal YSi2. The characteristic vibration absorption spectra of the silicides have been obtained by FT-IR transmittance measurements.
Study on the evolvement of plasma generated by pulsed laser deposition of thin film
Authors: Zhang Duan-Ming  , Guan Li  , Li Zhi-Hua  , Zhong Zhi-Cheng  , Hou Si-Pu  , Yang Feng-Xia  , Zheng Ke-Yu  ,   (1)湖北襄樊学院物理系,襄樊  441053; (2)华中科技大学［主校区］物理系,武汉  430074；华中科技大学激光技术国家重点实验室,武汉  430074
Published: December 2020

By finite difference method, the evolvement of plasma generated by a pulsed laser is studied for pulsed laser deposition of KTa065Nb035O3(KTN) thin film. We have discussed the movement of particles in plasma in isothermal and adiabatic expansion stages in more detail. At the same time, we have simulated the change of figure of plasma at different time. Moreover, the physics mechanism in expansion of the plasma have been explained. The theoretical results are compared with our experiments and other author's conclusions.
Adaptive fuzzy synchronization of chaotic systems with uncertainties
Authors: Yue Dong  , Jun Yoneyama  ,   (1)Departmant of Electronics and Electrical Engineering,Aoyama Gakuin University,Tokyo,Japan; (2)南京师范大学信息与控制工程技术研究中心，南京  210042
Published: December 2020

This paper is concerned with the synchronization problem of a class of chaotic systems with uncertainties.A novel design method for the adaptive fuzzy synchronization is proposed based on a Takagi-Sugeno(T-S) fuzzy dynamical model.The proposed methods can be appliced not only to the chaotic systems with the same structures,but also to the chaotic systems with different structures.To demonstrate the effectiveness of our method,simulation results of synchronization are finally given for the Lorenz system and Rossler system.
The x rescaling parameter′ formula of the extended x rescaling model and the nuclear effect 1-A DIS process
Authors: Gao Yong-Hua  , He Ming-Zhong  , Duan Chun-Gui  ,   (1)河北师范大学电子系，石家庄  050031; (2)河北师范大学物理系，石家庄  050016; (3)石家庄师范专科学校物理系，石家庄  050801;河北师范大学物理系，石家庄  050016
Published: December 2020

In this paper we present an x rescaling paramenters' formula for partons in the extended x rescaling model,where we have established the connection between the rescaling parameter and the mean binding energy.Using x rescaling parameters obtained by the x rescaling parameters' formula,we calculate the average nucleon structure function ratio of DIS process in l-A(Al,Ca,Pb)collision to l-C collision respectively.The result is in good agreement with experimental data.
Fused biconical taper all-wave coupler
Authors: Zhang Rui-Feng  , Ge Chun-Feng  , Wang Shu-Hui  , Hu Zhi-Yong  , Li Shi-Chen  ,   天津大学精密仪器与光电子工程学院，光电科学技术教育部重点实验室，天津  300072
Published: December 2020

This paper, on the basis of coupled-mode equations, analyzes the bandwidth characteristic of asymmetric fused biconical taper (FBT) coupler, and proposes and proves a solution of all-wave coupler (O+E+S+C+L band).We also succeed in making all-wave couplers with a bandwidth of 390nm, while the excess loss is only 0.1 dB and the coupling ratio is 1∶99
The dependence of exchange bias of Ni81Fe19/Ni100-xMnx bilayers on the Mn content and the thickness of Ni100-xMnx
Authors: Dai Bo  , Cai Jian-Wang  , Lai Wu-Yan  ,   中国科学院物理研究所磁学国家重点实验室，北京  100080
Published: December 2020

By adjusting the Mn concentration,we systematically investigated the magnetic properties,especially the exchange bias field(Hex),in Ni81Fe19/Ni100-xMnx bilayers.In the range of 534≤x≤600,the largest exchange bias field(～175kA/m)was achieved,and at the same time the reduction of magnetic moment due to the Mn diffusion into the Ni81Fe19 layer was lower than 20%.High-angle x-ray diffraction(XRD)showed a variation of Ni１００-xMnx lattice parameters when altering the Mn content:the more the Mn content,the larger the lattice parameters.It was found that the as-deposited Ni100-xMnx films with their lattice parameters close to those of θ-phase of NiMn alloy could be transformed into θ-phase relatively easily.Finally, the exchange bias of the bilayers with different Ni100-xMnx thicknesses was studied.We first obtain a 80 kA/m exchange bias field in the Ni81Fe19(150nm)/Ni100-xMnx(90nm)bilayers when Mn content increases to 706% after annealed at 240℃ for 5h,while the magnetic moment of the ferromagnetic layer was nearly umchanged.
On the mechanism of signature inversion in the yrast band of 84Rb
Authors: Shen ShuiFa  , Shi ShuangHui  , Gu JiaHui  , Liu JingYi  , Shen WenQing  ,   中国科学院上海原子核研究所，上海  201800
Published: December 2020

The angular momentum projected shell model(PSM) is applied to the nucleus 84Rb. The results of theoretical calculations about the positiveparity yrast band with configuration πg9/2νg9/2 and the negativeparity yrast band with configuration π(p3/2,f5/2)νg9/2 are comparedwith experimental data;especially,the mechanism of signature inversion in the positiveparity yrast band is discussed.The interpretation within the PSM shows that this signature pattern is a signal of a substantial quadrupole shape change with increasing spin,where the nucleus evolves from a prolate shape at low spins through a triaxial shape to an oblate shape at high spins.In addition,the nuclear shape for these two bands are also specified.
Chaos-based weak sinusoidal signal detection approach under colored noise background
Authors: Li Yue  , Yang Bao-Jun  , Shi Yao-Wu  ,   (1)吉林大学地球探测科学与技术学院, 长春  130026; (2)吉林大学通信工程学院,  长春  130012
Published: December 2020

In this paper we consider a new weak signal detection scheme which uses the sensitivity of chaos to the parameters under a certain status to realize weak signal detection- This scheme can effectively extract the weak sinusoidal signal from the strong colored noise background- We present a chaos-based signal detection approach, analyze the influence of noise to the system status in the chaos detection process- Simulation experiments show that the chaos detection system is very sensitive to weak signal and have strong constraint to any colored noise with zero mean value-
Spectral characterization of double-driven x-ray laser plasmas
Authors: Wang Rui-Rong  , Wang Wei  , Wang Chen  , Dong Jia-Qin  , Sun Jin-Ren  , Wan Bing-Gen  ,   上海激光等离子体研究所高功率激光物理国家重点实验室，上海〓2018 00
Published: December 2020

A soft x-ray spectra of double-driven laser-produced Ta plasmas is measured by a time-integrated space-resolved keV crystal spectrometer from 045 to 075nm- Some resonant transition of the Ni-like, Co-like and Fe-like ions and some intrashell transition of the Ni-like ions are identified- The experimental results have been processed, the spectroscopic line intensity of the higher ionization stages is obtained- The effect of the double-laser driven time difference on the plasma condition is inferred through the spectroscopic line ratio diagnostics- The results obtained can, at least in part, give a good explanation of the upper lasing level population and the ionization properties of the plasmas-
The structure and electronic properties of carbon nanotube heterojunction
Authors: Liu Hong  , Chen Jiang-Wei  ,   南京大学物理系,南京  210093
Published: December 2020

In this paper we study the structures of defects in carbon nanotube and the influences of defects on the electronic properties. The geometric constructions of carbon nanotube heterojunctions are investigated, and a simple way is found to connect two carbon nanotubes with different chirals.
Thermal conductivity of two-energy-gap superconductor MgB2
Authors: Yang Dong-Sheng  , Wu Bai-Mei  , Li Bo  , Zheng Wei-Hua  , Li Shi-Yan  , Fan Rong  , Chen Xian-Hui  , Cao Lie-Zhao  ,   中国科学技术大学结构分析开放实验室，物理系，合肥  230026
Published: December 2020

We present in this paper the thermal conductivity of the superconductor MgB2 between 5—300 K. The temperature dependence of the thermal conductivity can be fitted with the BRT thermal conductivity method by a phenomenological two-gap model. The sizes of the two energy gaps are 16 and 51meV. The analysis about electronic thermal conductivity indicates that the σ-band impurity scattering rate is small relative to the π-band scattering rate. In contrast to the single-crystal sample, our result indicates that the scattering of phonons from the σ-band quasi-particles exist in the c-axial direction heat transport of a polycrystalline sample. This result demonstrates the anisotropic energy transport in MgB2.
Effective anisotropy and coercivity in nanocomposite permanent materials
Authors: Gao Ru-Wei  , Feng Wei-Cun  , Wang Biao  , Chen Wei  , Han Guang-Bing  , Zhang Peng  , Liu Han-Qiang  , Li Wei  , Guo Yong-Quan  , Li Xiu-Mei  ,   (1)钢铁研究总院功能材料研究所，北京  100081; (2)山东大学物理与微电子学院，济南  250100
Published: December 2020

The effects of exchange-coupling interactions between grains on the effective anisotropy and the variation in Nd2Fe14B/α-Fe nanocomposite permanent materials were investigated. The calculatied results showed that due to the exchange-coupling interactions, the effective anisotropy Keffof the nanocomposite decreases with the decrease of grain size and the increase of magnetically soft phase component. When the average grain size decreases to 4nm, Keff decreases to about 1/3—1/4 of the value of the ordinary anisotropy constant. This variation character is basically similar to that of the coercivity. The decrease of coercivity for the nanocomposite permanent materials is mainly due to the decrease of the effective anisotropy.
Experimental investigation of photoluminescence spectrum of two erbium-doped glass samples in series
Authors: Li Cheng-Ren  , Song Chang-Lie  , Rao Wen-Xiong  , Li Shu-Feng  ,   (1)大连理工大学物理系 ，大连  116024; (2)大连理工大学物理系 ，大连  116024;辽宁师范大学物理系 ，大连  116029
Published: December 2020

Fabrication technology of erbium-doped glass samples is introduced. Photoluminescence（PL）characterization of one sample or two samples in series are measured.The results show that the PL intensity of two samples is higher than that of one sample,and the full width at half maximum of two samples is approximately equal to that of a high concentration Er-doped sample.In the formation of two samples in series,the PL intensity with the high-concentration sample facing the pump laser source is higher than that with the low-concentration sample facing the pump laser source .The ratio of PL intensity of two low-concentration samples to PL intensity of a single sample is bigger than the ratio of PL intensity of two high-concentration samples to PL intensity of a single sample.
Temperature character of electromagnetic levitation melting
Authors: Ma Wei-Zeng  , Ji Cheng-Chang  , Li Jian-Guo  , Xu Zhen-Ming  ,   上海交通大学材料科学与工程学院,上海200030
Published: December 2020

Utilizing the formula of electromagnetic force and input power, we have derived the expression of input power of a spherical sample for a general electromagnetic levitation inductor without including the current of the inducer. Combining the power dissipation model of the spherical sample in free-convection gas medium and the expression of input power without including the current of inducer, the relation between processing parameters of electromagnetic levitation and temperature of levitation sample is established. The electromagnetic melting of spherical (TbDy)Fe2 alloys under the protection of Ar is employed as an example to study the effect of processing parameters on the temperature of levitation sample obtained by numerical computation. According to computation results and the character of actual electromagnetic levitation, the methods to decrease the temperature of the levitation melted sample are obtained: i.e. reducing the radius of the levitation melted sample, employing low frequencies of the inducer, adjusting the position of the levitated sample to a position at which the lowest levitation melting temperature can be obtained, reducing the radius of the lower levitation coil, increasing the space interval between the upper stability controlling coil and the lower levitation coil, increasing the radius of the upper stability controlling coil, and increasing the turns of the upper stability controlling coil.
Production of beat waves using S-band klystron amplifier
Authors: Fang Jin-Yong  , Ning Hui  , Zhang Shi-Long  , Qiao Deng-Jiang  ,   西北核技术研究所，西安  710024
Published: December 2020

A method of producing beat waves by a single klystron amplifier is introduced in this paper. The experimental results have been obtained that the main frequency of the beat wave is in S-band, the beat frequency ranges from 10 to 120MHz, the peak power of the pulsed beat wave is 1MW, and the maximal repetitive frequency is 500pps. This method has been successfully used in certain electrical system high-power microwave vulnerability effect experiments.
The specific heat of polyaniline at low-temperature
Authors: Xu Jie  , Luo Jian-Lin  , Chen Zhao-Jia  , Long Yun-Ze  , Bai Hai-Yang  , Wan Mei-Xiang  , Wang Wan-Lu  ,   (1)中国科学院化学研究所，北京  100080; (2)中国科学院物理研究所，北京  100080; (3)中国科学院物理研究所，北京  100080;重庆大学数理学院应用科学与技术系，重庆  400044; (4)重庆大学数理学院应用科学与技术系，重庆  400044
Published: December 2020

The specific heat of the emeraldine base form of polyaniline and the emeradine salt of polyaniline has been measured at temperatures between 1.8 and 45K. The experimental results have been interpreted in terms of the contributions from both the crystalline and the amorphous phases characterizing the polymer. Anomaly of the specific heat, which is much larger than that expected from the Debye theory, has been successfully explained by the phonon-fracton model at low temperatures. The electronic specific heat has not been observed from the present data.
Theoretical study of the structure and magnetism of Fe1-xPdx alloys
Authors: Shi Yi-Sheng  ,   盐城师范学院物理系，盐城  224002
Published: December 2020

An ab initio linearized augmented plane wave (LAPW) method has been employed to calculate the electronic and magnetic structures for the fcc and bcc Fe1-xPdx alloys with x=000, 025, 050, 075, and 100, respectively. By decreasing the Pd content, the magnetism of fcc Fe1-xPdx alloys changes from paramagnetism to ferromagnetism, ferrimagnetism, and finally antiferromagnetism or ferromagnetism. On the other hand, the magnetism of bcc Fe1-xPdx alloys changes from paramagnetism to ferromagnetism. Our calculations are in good agreement with previous experimental results. And we predict that the Fe075Pd025 alloys are ferrimagnetism.
A Study of Isolation and Identification of Multidrug Resistant Pseudomonas aeruginosa from Wound Specimen
Authors: Muddassir Maria , Munir Sadaf , Raza Almas , Iqbal Adeel , Ahmed Muddassir , Basirat Usama , Malik Arif , Naqvi Syed Zeeshan Haider
Published: December 2020

Background: Pseudomonas aeruginosa is a clinically important pathogenic microbe in hospitalized patients. It is a major cause of mortality and morbidity having a number of mechanisms that make it antibiotic resistant. Considering the dearth of antimicrobial drugs to treat infection with this pathogen, it has become a necessity to open up new arena for treatment with this organism. Recently, there has been an up rise in the number of multidrug resistant pathogenic strains of Pseudomonas aeruginosa.

Objective: Isolation and identification of multidrug resistant Pseudomonas aeruginosa from wound specimens and to evaluate the antibiotic resistant strains of this microbe.

Methodology: One hundred and fifty clinical samples of wound were taken from hospitalized patients at Jinnah hospital Lahore during the period of October 2019 to April 2020. In total, twenty (20) isolates of Pseudomonas aeruginosa were identified using the cultural features, morphological characteristics and various biochemical tests plus the Vitek 2 system. Blue/green, brown /blue and yellow/green pigment production showed the presence and growth of Pseudomonas aeruginosa.

Results: Percentage of Pseudomonas aeruginosa in females came out to be 15% as compared to 11.42% in males. This was followed by testing susceptibility of isolates of Pseudomonas aeruginosa to various antimicrobial drugs. Piperacillin/tazobactam and meropenem showed the highest efficacy against Pseudomonas aeruginosa. Highest resistance was exhibited against trimethoprim/sulfamethoxazole which was 75%.

Conclusion: Most isolates showed multidrug resistance to four or more drugs. Development of multidrug resistance has emerged as a global problem with pathogens commonly causing infections becoming increasingly resistant to antimicrobial agents.
Design of disturbance observer based on adaptive‐neural control for large‐scale time‐delay systems in the presence of actuator fault and unknown dead zone
Authors: Janbazi Vida , Hashemi Mahnaz
Published: December 2020

This article presents an adaptive neural compensation scheme for a class of large‐scale time delay nonlinear systems in the presence of unknown dead zone, external disturbances, and actuator faults. In this article, the quadratic Lyapunov–Krasovskii functionals are introduced to tackle the system delays. The unknown functions of the system are estimated by using radial basis function neural networks. Furthermore, a disturbance observer is developed to approximate the external disturbances. The proposed adaptive neural compensation control method is constructed by utilizing a backstepping technique. The boundedness of all the closed‐loop signals is guaranteed via Lyapunov analysis and the tracking errors are proved to converge to a small neighborhood of the origin. Simulation results are provided to illustrate the effectiveness of the proposed control approach.
4D Chiral Photonic Actuators with Switchable Hyper‐Reflectivity
Authors: Zhang Pei , Zhou Guofu , de Haan Laurens T. , Schenning Albert P. H. J.
Published: December 2020

Cholesteric liquid crystals (CLCs) are chiral photonic materials reflecting only circularly polarized light with the same handedness as the helical polymer structure. Concurrent shape and color changes can be achieved using CLCs, but the fabrication of CLCs with switchable 3D shape, structural color, and hyper‐reflectivity, that is, reflecting both left‐ and right‐handed circularly polarized light simultaneously, has not yet been achieved. Here, CLC elastomer (CLCE) actuators are reported to reflect equal amounts of left‐ and right‐handed circularly polarized light. Hyper‐reflectivity is achieved by uniaxially stretching the partially crosslinked film to induce helix deformation which is then fully crosslinked to fix the deformed helical structure. The shape, structural color, and hyper‐reflectivity of the polymer film are switchable with temperature. At high temperatures, only right‐handed circularly polarized light is reflected and the color is redshifted. The film can be shaped in three dimensions: a structural colored 3D shaped beetle is fabricated using molding, which reflects both left‐ and right‐handed circularly polarized light and shows reversible, temperature responsive structural color and 3D shape changes. Hence, 4D engineered bioinspired multifunctional materials are fabricated, which are interesting for applications ranging from sensing actuators to switchable hyper‐reflective films and objects.
Inorganic Electron Transport Materials in Perovskite Solar Cells
Authors: Lin Liangyou , Jones Timothy W. , Yang Terry Chien‐Jen , Duffy Noel W. , Li Jinhua , Zhao Li , Chi Bo , Wang Xianbao , Wilson Gregory J.
Published: December 2020

In the past decade, the perovskite solar cell (PSC) has attracted tremendous attention thanks to the substantial efforts in improving the power conversion efficiency from 3.8% to 25.5% for single‐junction devices and even perovskite‐silicon tandems have reached 29.15%. This is a result of improvement in composition, solvent, interface, and dimensionality engineering. Furthermore, the long‐term stability of PSCs has also been significantly improved. Such rapid developments have made PSCs a competitive candidate for next‐generation photovoltaics. The electron transport layer (ETL) is one of the most important functional layers in PSCs, due to its crucial role in contributing to the overall performance of devices. This review provides an up‐to‐date summary of the developments in inorganic electron transport materials (ETMs) for PSCs. The three most prevalent inorganic ETMs (TiO2, SnO2, and ZnO) are examined with a focus on the effects of synthesis and preparation methods, as well as an introduction to their application in tandem devices. The emerging trends in inorganic ETMs used for PSC research are also reviewed. Finally, strategies to optimize the performance of ETL in PSCs, effects the ETL has on J–V hysteresis phenomenon and long‐term stability with an outlook on current challenges and further development are discussed.
Dynamic Oscillation via Negative Differential Resistance in Type III Junction Organic/Two‐Dimensional and Oxide/Two‐Dimensional Transition Metal Dichalcogenide Diodes
Authors: Choi Wonjun , Hong Sungjae , Jeong Yeonsu , Cho Yongjae , Shin Hyung Gon , Park Ji Hoon , Yi Yeonjin , Im Seongil
Published: December 2020

Among many of 2D semiconductor‐based devices, type III PN junction diodes are given special attentions due to their unique function, negative differential resistance (NDR). However, it has been found uneasy to achieve well‐matched type III PN junctions from 2D–2D van der Waals heterojunctions. Here, the authors present other alternatives of type III heterojunctions, using 2D p‐MoTe2/organic n‐type dipyrazino[2,3‐f:2′,3′‐h]quinoxaline‐2,3,6,7,10,11‐hexacarbonitrile (HAT‐CN) and 2D p‐WSe2/n‐MoOx systems. Those junction diodes appear to well‐demonstrate static and dynamic NDR behavior via resonant tunneling and electron–hole recombination. Extended to an inverter circuit, p‐MoTe2/n‐HAT‐CN diode enables multilevel inverter characteristics as monolithically integrated with p‐MoTe2 channel field effect transistor. The same NDR diode shows dynamic LC oscillation behavior under a constant DC voltage, connected to an external inductor. From p‐WSe2/n‐MoOx oxide diode, similar NDR behavior to those of p‐MoTe2/n‐HAT‐CN is again observed along with LC oscillations. The authors attribute these visible oscillation results to high peak‐to‐valley current ratios of their organic or oxide/2D heterojunction diodes.
Reversible Crystal–Glass Transition in a Metal Halide Perovskite
Authors: Singh Akash , Jana Manoj K. , Mitzi David B.
Published: December 2020

Crystalline metal halide perovskites (MHPs) have provided unprecedented advances in interdisciplinary fields of materials, electronics, and photonics. While crystallinity offers numerous advantages, the ability to access a glassy state with distinct properties provides unique opportunities to extend the associated structure–property relationship, as well as broaden the application space for MHPs. Amorphous analogs for MHPs have so far been restricted to high pressures, limiting detailed studies and applications. Here, a 2D MHP is structurally tailored using bulky chiral organic cations to exhibit an unusual confluence of exceptionally low melting temperature (175 °C) and inhibited crystallization. The chiral MHP can thus be melt‐quenched into a stable glassy state, otherwise inhibited in the analogous racemic MHP. Facile and reversible switching between glassy and crystalline states is demonstrated for the chiral MHP, each with distinct optoelectronic character, opening new opportunities for applications including, for example nonvolatile memory, optical communication, and neuromorphic computing.
Retracted: Nanozyme‐Initiated In Situ Cascade Reactions for Self‐Amplified Biocatalytic Immunotherapy
Authors: Zhao Yajie , Xiao Xiao , Zou Man , Ding Binbin , Xiao Hui , Wang Meifang , Jiang Fan , Cheng Ziyong , Ma Ping'an , Lin Jun
Published: December 2020

Biocatalytic nanomaterials have been verified to modulate the immunosuppressive state of an extensive range of solid tumors and directly induce antitumor immune response, which effectively combats the holdbacks in cancer immunotherapy. Herein, biomimetic cascade enzyme‐initiated toxic‐radical‐generating devices (GHZD NCs) are fabricated by enveloping glucose oxidase (GOx), artificial nanozyme hemin, and sesquiterpene lactone endoperoxide derived dihydroartemisinin (DHA) into zeolitic imidazolate framework (ZIF‐8) for enhanced biocatalytic immunotherapy. The GHZD NCs exhibit amplified multienzyme‐mimic (glucose oxidase, peroxidase, and glutathione peroxidase) cascade reactions in artificial nanoscale proximity. Concurrently, a glutathione (GSH)‐stimulated labile iron‐current amplifier boosts C‐centered free radicals, which endows the GHZD NCs with tumor‐specific and self‐circulating generation ability of vicious C‐centered free radicals. Irreversible free radicals (·C and ·OH) and sustainable H2O2 from sequential catalytic processes logically and selectively elevate the oxidative stress in the tumor, which further triggers an efficient immunogenic cell death (ICD) progress. In addition, the in situ nanozyme‐based immunotherapy employed for tumor suppression successfully elicits the long‐lasting immunological memory effect, which hinders the growth of distant tumors and lung metastasis.
Graphene K‐Tape Meshes for Densely Distributed Human Motion Monitoring
Authors: Lin Yun‐An , Zhao Yingjun , Wang Long , Park Yujin , Yeh Yi‐Jui , Chiang Wei‐Hung , Loh Kenneth J.
Published: December 2020

Wearable sensors that measure parameters associated with physical activity and bodily motions have been regarded as an indispensable tool for assessing personal wellness. Recent advances in nanocomposite strain sensors have been successfully used for monitoring skin strains and other strain‐derived physiological parameters. This study complements the existing body of work and presents a flexible, self‐adhering, fabric‐based wearable sensor for measuring skin strains and human motions. Graphene nanosheet thin films are directly spray‐coated onto kinesiology tape (K‐Tape) to obtain a self‐adhering strain sensor of high sensitivity and linearity. Their stable sensing performance and high repeatability are verified, while human subject tests confirm that they adequately capture muscle engagement during functional movements. In addition, densely distributed strain monitoring can be achieved using an electrical impedance tomography measurement approach and algorithm. Spatial strain sensing is successfully demonstrated using a single strip of piezoresistive K‐Tape, as well as when a K‐Tape network or mesh pattern is formed. The results show promise for using graphene K‐Tape meshes to measure how specific major muscle groups engage during different physical activities.
Reflective‐Emissive Representation by Combining Ru(II)‐Complex‐Based Electrochemiluminescence and Localized‐Surface‐Plasmon‐Resonance‐Based Electrochromism
Authors: Tsuneyasu Shota , Kawara Masashi , Enomoto Koshin , Nakamura Kazuki , Kobayashi Norihisa
Published: December 2020

This paper demonstrates a novel display device with four optical states: transparent, mirror, black coloration, and orange light emission. The device is constructed by sandwiching a gel electrolyte containing silver ions and a ruthenium (II) complex between a pair of indium tin oxide electrodes. The electrochemiluminescent orange emission from the ruthenium (II) complex is obtained by applying alternative current (AC) voltage. In contrast, the application of direct current (DC) voltage results in the mirror state due to silver electrodeposition. Moreover, the DC application of a higher voltage results in the device exhibiting the black state owing to the distribution of size and roughness of the silver nanoparticles (NPs) on the indium tin oxide electrode. Both the reflective states reverted to their initial transparent state, owing to the dissolution of silver deposits during the DC application of oxidative voltage of silver NPs.
4D Printing of Stretchable Supercapacitors via Hybrid Composite Materials
Authors: Zhou Yihao , Parker Charles B. , Joshi Pooran , Naskar Amit K. , Glass Jeffrey T. , Cao Changyong
Published: December 2020

Stretchable supercapacitors (SCs) have attracted significant attention in developing power‐independent stretchable electronic systems due to their intrinsic energy storage function and unique mechanical properties. Most current SCs are generally limited by their low stretchability, complicated fabrication process, and insufficient performance and robustness. This study presents a facile method to fabricate arbitrary‐shaped stretchable electrodes via 4D printing of conductive composite from reduced graphene oxide, carbon nanotube, and poly(3,4‐ethylenedioxythiophene) polystyrene sulfonate. The electrode patterns of an arbitrary shape can be deposited onto prestretched substrates by aerosol‐jet printing, then self‐organized origami (ridge) patterns are generated after releasing the substrates from holding stretchers due to the mismatched strains. The stretchable electrodes demonstrate superior mechanical robustness and stretchability without sacrificing its outstanding electrochemical performance. The symmetric SC prototype possesses a gravimetric capacitance of ≈21.7 F g−1 at a current density of 0.5 A g−1 and a capacitance retention of ≈85.8% from 0.5 to 5 A g−1. A SC array with arbitrary‐shaped electrodes is also fabricated and connected in series to power light‐emitting diode patterns for large‐scale applications. The proposed method paves avenues for scalable manufacturing of future energy‐storage devices with controlled extensibility and high electrochemical performance.
van der Waals Magnets: Material Family, Detection and Modulation of Magnetism, and Perspective in Spintronics
Authors: Yang Shengxue , Zhang Tianle , Jiang Chengbao
Published: December 2020

van der Waals (vdW) materials exhibit great potential in spintronics, arising from their excellent spin transportation, large spin–orbit coupling, and high‐quality interfaces. The recent discovery of intrinsic vdW antiferromagnets and ferromagnets has laid the foundation for the construction of all‐vdW spintronic devices, and enables the study of low‐dimensional magnetism, which is of both technical and scientific significance. In this review, several representative families of vdW magnets are introduced, followed by a comprehensive summary of the methods utilized in reading out the magnetic states of vdW magnets. Thereafter, it is shown that various electrical, mechanical, and chemical approaches are employed to modulate the magnetism of vdW magnets. Finally, the perspective of vdW magnets in spintronics is discussed and an outlook of future development direction in this field is also proposed.
Making meaning through connections for people with Alzheimer's or associated dementia and their care partners: Creating engagement
Authors: Abbott‐Anderson Kristen C , Chiou Hsinhuei Sheen
Published: December 2020

Background

Alzheimer’s disease or other associated dementias (AD/OAD) is associated with social isolation for both the individual living with the disease as well as their care partners. Addressing the impact of stigma and social isolation for these individuals is imperative. Few meaningful activity opportunities exist for mutual engagement. Music has been shown to benefit cognitive processing and quality of life for individuals living with AD/OAD (Cooke, Moyle, Shum, Harrison, & Murfield, 2010). This study explores experiences of individuals living with AD/OAD, their care partners, and choral volunteers, in a formal chorus program; aims include: 1. To explore the experience of individuals living with AD/OAD, their care partners, and volunteers participating in a formal chorus; 2. To explore perceived benefits of choral group participation during rehearsals as well as in life outside of rehearsal.

Method

Research participants included the individuals with AD/OAD (n=5); their care partners (n=5); and chorus volunteers (n=8) in a chorus program in a small community in the Midwest. The participants attended the chorus program consisting of 16‐week sessions including rehearsal, social interaction and concert performance. Survey questions include items about ability to participate in choral activities, social aspects of the chorus, participation in activities outside of choral activities, and perception of socialization since becoming a member in the chorus. Research data will be collected at two time points: 1. Day one of the chorus season and 2. The final day for each chorus season.

Result

Longitudinal data will be analyzed by the research team using descriptive and correlational statistics as well as descriptive content analysis of qualitative data.

Conclusion

Findings will provide information about the ability of individuals living with AD/OAD to participate in this social and music‐related program as well as any benefits of participation in choral activities for both the individual living with AD/OAD and their care partner.
Development of novel blood‐based biomarkers of Alzheimer’s disease
Authors: Dey Sharmistha
Published: December 2020

Background

Alzhemier’s disease (AD) is the most common cause of dementia in the elderly. Due to increasing longevity and the lack of a therapy, AD has become not only a major health problem but also imposes substantial social and economic burden worldwide. Alzheimer’s disease are associated with molecular changes that manifest several years before the onset of clinical symptoms. At present, the gold standard for confirmation of neurodegeneration is the neuropathological screening however that is only possible via autopsy of a deceased patient. So, there is a demand for effective diagnostic marker for valid detection. The present studies exploited novel biological molecules having neuropathological role for the development of blood based molecular markers in AD.

Method

We have determined the level of sirtuins (SIRT), tau, p‐tau, sestrins (SESN) and 5‐LOX proteins for early diagnosis of AD by estimating their serum level in patients through Surface Plasmon Resonance. For developing therapeutics targeting specific proteins, we have used modulator both synthetic and plant product, which specifically modulates the target proteins.

Result

The serum level of SIRT1, SESN1 & SESN2 were found to be downregulated in AD compare to mild cognitive impairment (MCI) and control elderly group. However, tau, p‐tau and 5‐LOX were found to be significantly upregulated in AD compare to MCI and control. The significant difference in all the proteins level also noticed between control and MCI. ROC result significantly differentiated AD, MCI and control group. The modulator of 5‐LOX, and SIRT1 have been successfully developed.

Conclusion

Our research will help establish these potential proteins as a plausible candidate for detection and open exciting avenues for therapeutic interventions.
Trajectories of subjective cognitive decline, and the risk of mild cognitive impairment and dementia
Authors: Liew Tau Ming
Published: December 2020

Background

In cognitively‐normal individuals, subjective cognitive decline (SCD) has been reported to predict MCI and dementia (MCI/dementia). However, prior studies mostly captured SCD at single time‐points without considering the longitudinal course of SCD. This study examined whether the trajectories of SCD provide any added information – beyond one‐time assessments of SCD – on the risk of MCI and dementia (MCI/dementia).

Method

This cohort study included 5,661 participants from the Alzheimer’s Disease Centers across USA, who were ≥50 years and had normal cognition in the first‐four annual visits (Year 1 to Year 4). The participants were evaluated for SCD in the first‐four annual visits (Year 1 to Year 4), and followed‐up almost annually (from Year 4 up to Year 14) for incident MCI/dementia. SCD trajectories – as identified from latent‐class‐growth‐curve‐analysis – were included in Cox‐regression to estimate their risks of MCI/dementia.

Result

Compared to those without SCD (in the first‐four annual visits), the presence of Intermittent SCD (i.e. reported in 1–2 of the first‐four annual visits) predicted a higher risk (HR 1.4) while Persistent SCD (i.e. reported in 3–4 of the first‐four annual visits) predicted the highest risk (HR 2.2). A quarter of those with Persistent SCD developed MCI/dementia within 4.7 years; in contrast to 5.8 years among those with Intermittent SCD, and 8.0 years among those without SCD. The results remained significant even after adjusting for baseline SCD.

Conclusion

The findings demonstrate the added utility of SCD trajectories – beyond cross‐sectional assessments of SCD – in identifying high‐risk populations for preventive interventions and trials. They also suggest a potential modification in the current SCD criteria, with the inclusion of ‘persistent SCD over several years’ as one of the key features within SCD plus.