bluuebunny/crossref_metadata_2025 huggingface dataset:
INFLUENCE OF IN-PLANE FIELDS ON THE FORMATION OF HARD BUBBLES
Authors: HAN BAO-SHAN  , LIN JI-WU  , LI BO-ZANG  , NIE XIANG-FU  , TANG GUI-DE  ,   (1)河北师范大学物理系; (2)中国科学院物理研究所
Published: November 2020

The influence of in-plane fields on the formation of hard bubbles in epitaxial garnet films by using single-pulse bias field was investigated in some detail. A critical in-plane field H0in which is related to the parameters of bubble films, was discovered. When Hin>H0in, formation of hard bubbles no longer occurs. Three physical processes, i.e. the increase, quick decrease and slow decrease of the demarcation field for soft and hard bubble formation H[b] with in-plane fields can be qualitatively interpreted in terms of the effect of in-plane field on stripe domains, as well as the formation of multifingered domains.
THERMAL SHIFTS OF SUB-LEVELS R1 AND R2 IN YAlO3:Nd3+
Authors: XU YI-SUN  , MA DONG-PIN  , SONG ZENG-FU  , LI DA-FEN  , GU YING-JUN  ,   (1)北京大学物理系; (2)四川工业学院
Published: November 2020

Thermal shifts of sub-levels R1 and R2 in YA1O3:Nd3+ has been measured. The behavious of the principal value of the integral in the single-phonon term have been investigated and the contribution of optical frequency branch to thermal shifts of sub-levels has been considered.By using the formulas involving Raman term, single-phonon term and term of optical frequency branch, thermal shifts of sub-levels R1 and R2 are calculated. Satisfactory agreement between the results of the theory and experimental values is obtained.
CONVERGENT-BEAM ELECTRON DIFFRACTION STUDY OF DISLOCATIONS
Authors: FENG GUO-GUANG  ,   中国科学院物理研究所
Published: November 2020

Convergent-beam electron diffraction near a dislocation in silicon shows that some of the higher-order Laue zone lines and Kikuchi lines are split. The splitting of crystal-lographically equivalent reflections is different. These can be explained in terms of the theory of diffraction contrast of imperfect crystals. The splitting and unsplitting of the reflections correspond to the visibility and in visibility of the dislocation. Convergent-beam electron diffraction provides a powerful means for the study of crystal defects with high spatial resolution.
THE NONLINEAR AND THERMAL EFFECTS OF REFRACTIVE INDEX OF OPTICAL FIBRE MATERIAL
Authors: ZHU SHI-YAO  , FANG JUN-XIN  ,   上海交通大学应用物理系
Published: November 2020

The refractive index including linear and nonlinear terms, the zero dispersion wavelength and their relation to the temperature have been calculated by using semi-classical method. The theoretical results are consistent with experiment results.
THE V-H AND V-t RELATIONS FOR THE SQUID WITH DOUBLE JUNCTION
Authors: ZHANG YU-HENG  , GAO YI-PING  ,   中国科学技术大学物理系
Published: November 2020

The real relation between average voltage across a two junctions SQUID and applied magnetic field have been derived. The calculations have been carried out on the variations of the instantaneous voltage with time in a given magnetic field. It is also shown theoretically that the V(t) relation is not periodical, and the V(t) amplitude is not constant.Finally, a physical interpretation about the instantaneous voltage process is given.
NEW METASTABLE SUPERCONDUCTING PHASE FORMED DURING PROCESS OF CRYSTALLIZATION IN La72Si28 AMORPHOUS ALLOY
Authors: QIN ZHI-CHENG  , HE SHOU-AN  , LIU ZHEN-XING  , WANG WENG-KUI  ,   中国科学院物理研究所
Published: November 2020

In this paper, we report the synthesis of a new metastable superconducting phase formed during the process of the crystallization of amorphous La72Si28 alloy. As starting material, the La72Si28 amorphous ribbons were prepared from melt by rapid quenching method. The new metastable phase appeared when the amorphous sample was treated at 250℃ for 30 minutes. This phase has a ortborhombic structure with lattice parameters α=9.12l?, b=6.821? and c=3.833?, and exhibits superconducting transition at Tc =3.02 K which is higher than those of all the known La-Si phases.
ELECTRICAL RESISTIVITY STUDY OF THE Fe-BASED AMORPHOUS ALLOYS
Authors: ZHAN WEN-SHAN  , SHEN BAO-GEN  , ZHAO JIAN-GAO  , CHEN JIN-CHANG  ,   (1)北京师范学院物理系; (2)中国科学院物理研究所
Published: November 2020

Temperature dependence of the electrical resistivity of Fe100-xBx,Fe87-xSixB13,(Fe1-xCox)78Si9.5B12.5,(Fe1-xMx)80-84B16-20(M = Zr, V, Nb, Ta, Cr, Mo, W, Mn) amorphous alloys in the range of 4.2-300 K has been studied in this work. The experimental results demonstrated that the resistivity minima phenomena appear in all these samples. The temperature of resistivity minim Tmin increases with increaing Si or B content in the amorphous FeB and FeSiB alloys. It has been shown that as transition metal elements on the right of Fe in the periodic table are added to the Febased amorphous alloys, lower Tmin are observed, and on the other hand, as transition elements on the left of Fe are added, Tmin are shift to higher temperatures. The dependence of the added elements on Tmin of the Febased amorphous alloys shows clear regularities. Below temperature Tmin, their resistivty can be described by alogarithmic temperature dependence and a discussion of this phenomenon is given in terms of the Kondo-like scattering. Above Tmin, a T2 temperature dependence of resistivity can be explained by extended Zi-man theory for FeB, FeSiB and FeCoSiB amorphous alloys and may be originated from both, electron-phonon and localized spin-fluctuation scattering for the Fe-based amorphous alloys with addition of transition elements on the left of Fe.
DEFECTS OF OXYGEN ON WO3 SURFACE
Authors: WU SHU-YAO  , CHEN YUN-QI  , QI SHANG-XUE  , JIANG ZHAO-XUE  , LIN ZHANG-DA  , WANG ZHI-KUAN  , SHU DAI-XUAN  ,   (1)中国科学院化工冶金研究所; (2)中国科学院物理研究所
Published: November 2020

Shift and broadening of W4f peak were observed in the course of reduction of WO3 during Ar+- and H+-bombarding in different energies. Three different doublets W+6, W+4 and W0 corresponding to W4f electrons were obtained by decomposing the spectrum. The reduction is interpreted by defect states of oxygen. The UPS spectrum shows an increase of the density of states near the Fermi energy.
A NEW EPR SPECTRUM IN NEUTRON IRRADIATED SILICON CONTAINING HYDROGEN
Authors: LIN XU-LUN  ,   北京大学物理系
Published: November 2020

The n-type FZ silicon (P～1014/cm3) grown in hydrogen is irradiated with neutrons of the total flux of (2.9-6.0)×1017n/cm2 and with Cd ratio about 10 at room temperature. An S=1/2 EPR spectrum, labeled Si-PK2, is found in X band and at 77K. The angular dependence of the geff values with H in the (011) plane has a tricliuic symmetry. For one of the equivalent defect orientations the principle values of the g tensor and the direction cosines of the principle axes with respect to the cubic axes are as follows: g(±0.0004) n[100] n[010] n[001] g1=2.0028 -0.5154 0.8473 -0.1283 g2=2.0063 -0.7386 -0.5151 -0.4347 g3=1.9971 -0.4344 -0.1293 0.8914 The simulated EPR spectra computed from the g tensor are consistent with the experimental results.The PK2 EPR spectrumappears in the unannealed neutron irradiated samples and remains until 300℃ annealing. It is probebly due to a kind of defects which is depen-tent of the hydrogen.
MEASUREMENT OF THE (5p1/2nd)3 AUTO-IONIZING LEVELS OF STRONTIUM
Authors: WU BI-RU  , ZHANG SEN  , LU JIE  , HU SU-FEN  , QIU JI-ZHEN  , SUN JIA-ZHEN  ,   浙江大学物理系
Published: November 2020

The (5p1/2nd)3 (n=ll—24) auto-ionizing levels of Sr have been measured by the laser melti-step excitation technique. Their effective quantum numbers have been determined. The interaction with the (5p3/2nd)3 series has been discussed.
A COMPUTER SIMULATION OF THE STRUCTURE OF AMORPHOUS ALLOY Ni64B36 (Ⅱ)——THE INFLUENCE OF THE BOUNDARY ON THE STRCTURE OF THE MODEL
Authors: CHEN JIN-CHANG  , WANG JING-HAN  , LI DE-XIU  , CHENG XIAN-AN  , WANG XU-WEI  , CHEN BING-YU  ,   (1)北京航空学院应用数学物理系; (2)北京师范学院物理系; (3)云南大学物理系
Published: November 2020

The model that we have made to simulate the structure of Ni64B36 is taken as the primary configuration. This configuration is then subjected to relaxation under the free boundary, the confined boundary, the periodic boundary and the quasi-dynamical equilibrium boundary through the Morse potential. The energy minimisation method used here is different from that usually taken by other authors in some respects. By comparing and analysing the change of some structure parameters in relaxation, the influence of each kind of boundary on the structure of the model is discussed.
IMPROVEMENT OF QUANTITATIVE EDS ANALYSIS OF THIN FILMS BY MEASURING THE I(L)/I(K) INTENSITY RATIOS
Authors: DUAN JIAN-ZHONG  , WU ZI-QIN  ,   中国科学技术大学基础物理中心
Published: November 2020

The intensity ratios I(L)/I(K) of eight kinds of pure element's thin films from Ge to Sn have been measured in a TEM using X-ray EDS at 40, 80, 100, 120,160 and 200 kV. Using these I(L)/I(K) values, the Cliff-Lorimer factor KXSi and their interpolated values for the K lines, the KXSi values for L lines are obtained. In order to determine which Q ionization cross-section formula in literature is the best, the calculated values I(L)/I(K) using nine formulas of Q were compared with expermental data. It has been found that there are large discrepancies between the expermental data and calculated values. After considering the errors by various parameters used in calculation, it becomes evident that the discrepancy is mainly caused by inaccuacy of cross-section and the best formula of Q proposed by Fabre de la Ripelle must also be revised. The quantitative analysis for several specimens with known composition was done using our revised Q and EDAX-9100's progroms. The results snow that by using our revised formula of Q, the errors of analytical results from K-K and K-L lines at 100 and 200 kV could be reduced significantly.
THE PRESSURE CALIBRATION UP TO MBARS AND THE ACHIEVEMENT OF 5.5 MBARS UNDER HYDROSTATIC AND NONHYDROSTATIC CONDITION
Authors: XU JI-AN  , MAO HE-GUANG  , PETER BELL  ,   (1)美国卡内基研究所地球物理实验室; (2)中国科学院物理研究所,美国卡内基研究所地球物理实验室访问学者
Published: November 2020

Pressure calibrated up to 0.8 Mbar under hydrostatic condition and to 2 Mbars under non-hydrostatic condition. We find the red shift of ruby R fluorescence to 830nm at the highest pressure point in our diamond high pressure cell. The shift correspond to 5.5 Mbars by calibration.
APPLICATION OF SIMPLIFIED EXPRESSION OF EMITTED CHARACTERISTIC X-RAY INTENSITY FOR MICROANALYSIS
Authors: XUE DE-JUN  ,   山东省分析测试中心
Published: November 2020

Based upon the model of depth distribution of X-ray production and consideration of absorption of X-ray by matrix of the sample, the expression of emitted characteristic X-ray intensity I has been derived I = MCI. G, where M is a constant, C is the concentration of measured element, I. is the X-ray intensity factor and G is the correction factor. By this method the results of quantitative analysis under various accelerating voltage are obtained for stainless steel, aluminium alloy, brass and sulfide. Comparing with chemical analysis, the standard deviation of 376 data is 0.62%.
SMALL-ANGLE X-RAY DIFFRACTION STUDY OF AMORPHOUS MULTILAYER AND SINGLE LAYER THIN FILMS
Authors: WU ZHI-QIANG  , LU XIANG-DONG  , HUANG WEN-YONG  , LIU HONG-TU  , JIN HUAI-CHENG  , WANG CHANG-SUI  , ZHOU GUI-EN  , WU ZI-QIN  ,   (1)广东省韩山师范专科学校物理系,教师; (2)中国科学技术大学结构分析开放实验室; (3)中国科学技术大学物理系
Published: November 2020

Small-angle X-ray diffraction study of amorphous a-Si:H/(a-SiNx:H) periodical multilayer thin films and some single layer films has been undertaken. A number of satellite peaks were found in the lower side of Bragg diffraction peaks of multilayer thin films with a less number of periods. A number of diffraction peaks were also found for the small-angle diffraction of single layer films. We have presented a simple formula for calculating the X-ray diffraction intensity of multilayer and single layer films. A satisfactory explaination of experimental results was obtained. Consequently, a simple method for measuring the total thickness of both multilayer and single layer thin films has been presented.
CALCULATION OF THE SPECTRA FOR TOPPONIUM WITH A NONZERO GLUON EFFECTIVE MASS
Authors: XIE FENG-XIAN  ,   中国人民解放军海军工程学院
Published: November 2020

In this paper, we calculate the spectra for topponium, using a quarkoniun potential with a nonzero gluon effective mass.
THE THEORY OF NONLINEAR FREQUENCY MIXING IN TRANSVERSE ZEEMAN LASER
Authors: JIN HAO-RAN  , WANG QING-JI  , ZHENG LE-MIN  ,   北京大学无线电电子学系
Published: November 2020

We have studied the high-order nonlinear frequency-mixing effect in transverse Zeeman La-ser medium by using Lamb's semiclassical theory and vector field model, and obtained the analytical expressions of dielectrical polarization and light intensity. The results could explain the phenomena of high-order harmonic in σ-π light and σ, π light, and give the physical interpretation of beat wave deformation.
A RESEARCH FOR THE ENTIRE BREAKDOWN PROCEDURE IN THIN DIELECTRIC FILMS
Authors: CHEN DOU-NAN  ,   华南工学院物理系
Published: November 2020

A new model used to interpret the phenomena of dielectric breakdown is proposed over the whole range of applied field. There are two main mechanisms that one of which is the avalanche breakdown, so-call intrinsic type, and the other is the filament heating transport leading to the destructive breakdown exist in the breakdown process. The theoretical analysis and the experimental data indicate that the field strength of intrinsic breakdown depends on the band gap and the thickness of film, but the filament heating transport which induces a destructive breakdown depends on the properties of film. In particular, the defect is the main origin leading to the occurrence of destructive breakdown. In addition, the effect of various physical parameters, testing conditions and process factors on the breakdown are discussed briefly.
MEASUREMENTS OF THE WHOLE SET OF THE ELASTIC AND PIEZOELECTRIC PARAMETERS OF THE SINGLE CRYSTALS Fe:LiNbO3 AND Cr:LiNbO3 BY BRILLOUIN SCATTERING OF LIGHT
Authors: JIANG ZUI-MIN  , LIU YU-LONG  , ZHANG PENG-XIANG  ,   中国科学院物理研究所
Published: November 2020

Brillouin scattering of light from certain crystal plane of polished single crystal spheres was measured. From the obtained data of sound velocity anisotropy, all the elastic and piezoelectric parameters of the single crystals of Fe and Cr doped LiNbO3 were deduced. The results were compared with pure LiNbO3. Discussion indicated that the sign uncertainty of some elements of the elastic tensor was due to the choice of the coordinates.
THE INFLUENCE OF THE BAND STRUCTURE ON DEEP LEVEL WAVE FUNCTION
Authors: FAN XI-QING  , ZHANG DE-XUAN  , SHEN SAN-GUO  ,   郑州大学物理系
Published: November 2020

Numerical results of A1, T2 symmetric sp3 bonded deep level wave function in Si arc calculated in the third neighbors TB frame work, and compared with the existing TB calculations. The influence of different band structure approach on the wave function is given quantitatively.
LOCAL AND QUASI-LOCAL MODES OF Zn IN CdTe
Authors: LU WEI  , YE HONG-JUAN  , YU ZHI-YI  , ZHANG SU-YING  , FU YING  , XU WEN-LAN  , SHEN XUE-CHU  ,   中国科学院上海技术物理研究所红外开放实验室
Published: November 2020

We report here the far infrared absorption and reflection spectra of the mixed crystals ZnxCd1-xTe with small x in the temperature range of 4.2-300 K and the frequency region of 20-350 cm-1. The local and quasi-local modes induced by Zn and ZnTe in CdTe and the CdTe-like 2TA two-phonon absorption are observed. The frequencies of the modes are estimated by useing the mass-defect model combined with Green's function method. The random element isodisplacement (REI) model is used to calculated the two mode behaviors of the mixed crystals and to best fit the reflection spectra. Besides, the temperature dependence of the phonon absorption and the relaxation factor of CdTe-like and ZnTe-like modes are calculated and explained.
A COMPUTER SIMULATION ON LOCAL STRUCTURE AND ATOMIC-LEVEL STRESS VARIATIONS IN AMORPHOUS IRON UNDER HIGH PRESSURE
Authors: SHEN ZHONG-YI  , HONG JIN-XIN  , YIN XIU-JUN  , ZHANG YUN  , HE SHOU-AN  ,   (1)中国科学院物理研究所; (2)中国科学院物理研究所,齐鲁石油化学工业公司设计院计算站
Published: November 2020

Using the static simulation method, the variations of local structure (Voronoi polyhedra statistics) and atomic-level stress in a model of amorphous iron under pressure are examined in this paper. The results show that external pressure increases the local stress and energy on each atom in the system, extends their distribution range of values and enhances the extent of fluctuation, though a homogenization of Voronoi polyhedra is promoted by the same procedure. The calculation shows that the local stresses in the structure studied divided into compressed and expansed regions, embeded each other with some percolative character. The compressed region which covers about 50 per cent atoms of the system at normal pressure and plays a role of rigid framwork of the body, will grow on increasing pressure at the expense of cosuming the expanded region. It is suggested that as the oppositely stressed regions are essentially in distinct physical conditions, they are expected to show different behaviours and give different contributions in a thermo-activated transport process. For this reason, it would be more reasonable to treat a metglas as an inhomogeneous medium on analyzing its structural relaxation mechanisms.
ELECTROMAGNETIC MODES IN SUPERLATTICES WITH NONLOCAL DIELECTRIC FUNCTION
Authors: SHI HANG  , CAI JIAN-HUA  ,   (1)南京大学固体物理研究所; (2)上海交通大学凝聚态物理研究所
Published: November 2020

Electromagnetic modes are studied in the long wavelength limit, with a nonlocal dielectric tensor valid in this limit and at low temperatures and adaptable to type-l semiconductor superlauices, such as GaAs/GaAlAs alternative multilayers. The TM and TE modes are considered and dispersion relations are obtained respectively.
CALCULATIONS OF ELASTIC CONSTANTS AND ULTRASONIC VELOCITIES FOR LaNbO4 CRYSTAL
Authors: TAO RUI-BAO  , CHEN CHUAN-HONG  , CHEN SHI-JIE  ,   (1)美国阿贡国家实验室; (2)厦门大学物理系; (3)中国高等科学技术中心(世界实验室)理论物理中心,复旦大学物理系
Published: November 2020

General expressions for elastic constants and analytic formulas for calculating force constants from the elastic constants were derived by means of group theory. On the basis of an approxomation of four nearest neighbour force constants, several ultrasonic wave velocities were calculated for LaNbO4 crystal.
SHORT-RANGE CORRELATIONS IN MOLECULAR THEORIES OF NEMATIC LIQUID CRYSTALS
Authors: YANG GUO-CHEN  , ZHANG ZHI-DONG  ,   河北工学院基础课部
Published: November 2020

A cell theory of nematic liquid crystals is presented, which provides a calculable theoretical model for investigation of molecular short-range correlations. Numerical calculations are made for PAA The theoretical values are improved in compared with the other theories'. The effects of molecular correlations on calculated results and relations between the cell theory and the other theories are discussed.
CHARACTERISTICS OF ELECTRON WAVE FUNCTIONS IN ONE-DIMENSIONAL INCOMMENSURATE SYSTEMS
Authors: YUAN JIAN  , XIONG SHI-JI  , CAI JIAN-HUA  ,   (1)南京大学固体物理研究所;; (2)上海交通大学凝聚态物理研究所
Published: November 2020

The characteristics of electron wave functions in one-dimensional incommensurate systems with or without disorder are studied. In disordered systems, the wave functions are always exponentially localized in contrast to systems without disorder.
Spatial and temporal activity patterns of Golden takin (Budorcas taxicolor bedfordi) recorded by camera trapping
Authors: Li Jia , Xue Yadong , Zhang Yu , Dong Wei , Shan Guoyu , Sun Ruiqian , Hacker Charlotte , Wu Bo , Li Diqiang
Published: November 2020

Understanding animals’ migration, distribution and activity patterns is vital for the development of effective conservation action plans; however, such data for many species are lacking. In this study, we used camera trapping to document the spatial and temporal activity patterns of golden takins (Budorcas taxicolor bedfordi) in Changqing National Nature Reserve in the Qinling mountains, China, from April 2014 to October 2017. Our study obtained 3,323 independent detections (from a total of 12,351 detections) during a total camera trapping effort of 93,606 effective camera trap days at 573 sites. Results showed that: (1) the golden takin’s utilization distributions showed seasonal variation, with larger utilization distributions during spring and autumn compared to summer and winter; (2) the species was recorded at the highest elevations in July, and lowest elevations in December, with the species moving to higher-elevations in summer, lower-elevations in spring and autumn; (3) during all four seasons, golden takins showed bimodal activity peaks at dawn and dusk, with activity intensity higher in the second peak than the first, and overall low levels of activity recorded from 20:00–06:00; and (4) there were two annual activity peaks, the first being in April and the second in November, with camera capture rate during these two months higher than in other months, and activity levels in spring and autumn higher than in summer and winter. This study is the first application of camera traps to assess the spatial and temporal activity patterns of golden takins at a population level. Our findings suggest that the proposed national park should be designed to include golden takin habitat and that ongoing consistent monitoring efforts will be crucial to mitigating novel and ongoing threats to the species.
The m6A reader protein YTHDC2 is a potential biomarker and associated with immune infiltration in head and neck squamous cell carcinoma
Authors: Li Yang , Zheng Ji-Na , Wang En-Hao , Gong Chan-Juan , Lan Keng-Fu , Ding XiaoJun
Published: November 2020

Background

Increasing evidence has shown that N6-methyladenosine (m6A) RNA methylation regulators have important biological functions in human cancers. However, there are few studies on the value of m6A reader protein YTHDC2 in the diagnosis and tumor-infiltrating of head and neck squamous cell carcinoma (HNSCC). Therefore, it is important to understand the potential clinical value of YTHDC2 in the prognosis and immune infiltration of HNSCC.

Methods

In this study, gene expression profiles and the corresponding clinical information of 270 HNSCC patients were downloaded from the Gene Expression Omnibus (GEO) database. The gene co-expression network was established to verify whether YTHDC2 was related to the prognosis of HNSCC and verified again in the public database. The correlations between YTHDC2 and immune infiltration was investigated via Tumor Immune Estimation Resource (TIMER) and Gene Expression Profiling Interactive Analysis (GEPIA).

Results

The results showed that YTHDC2 appeared in the blue module related to survival time and survival state and had a close correlation with the prognosis and immune infiltration level of HNSCC in public database. Patients with low expression of YTHDC2 had poor overall survival (OS) and recurrence-free survival (RFS) than those with high expression. In addition, the expression of YTHDC2 was positively correlated with the level of CD4+ T cell subpopulations infiltration in HNSCC.

Conclusions

Through this study, we found that YTHDC2 is a tumor suppressor gene with high expression in normal tissues and low expression in tumor tissues. In addition, YTHDC2 is correlated with the immune infiltrating levels of B cells, CD8+ T cells, CD4+ T cells, neutrophils, and dendritic cells in HNSCC, which may become a potential marker for prognosis and immune infiltration of HNSCC.
Cyber Partner Abuse: Recognizing Patterns and Breaking the Cycle
Authors: Singh Ritu , Mehra Manisha
Published: November 2020

In present era, virtual and real worlds have become profoundly interwoven and cyber-mediated communications have permanently altered the dynamics of every relationship. Use of Information and Communication Technologies (ICT) makes communication process more progressive and dynamic enhancing emotional intimacy and commitment in relationships. But, at the same time they present various threats and abuse. It incites individuals into publicizing their personal lives [especially intimate matters]. This has led to conceptualization of various modes for perpetrating intimate partner violence or in simpler terms cyber partner abuse. This form of abuse involves practices such as stalking, spamming, posting intimate information to embarrass or humiliate the partner and so on. The purpose of this study was to systematically review the existing literature on cyber partner abuse. This review examines the characteristics and conceptualizations in the cyber partner abuse literature as well as the major topics the research has explored. This will help in early detection of such crimes and strengthening of support systems for victims through provision of direct services and policies.
Effect of the Escalating Cost of Tuition in Higher Education in the United States
Authors: Boateng Solomon A.
Published: November 2020

Higher education has always been a fundamental cornerstone for development and prosperity in the United States. It is incumbent upon the government and other stakeholders to formulate policies to ensure our institutions of higher education are well resourced and funded to enable economic development. The unprecedented price hikes in tuition at universities and colleges, coupled with high student loan interest rate has compelled a lot of students to drop out of college [1]. Majority of the dropouts are now resorting to drug sale and other nefarious activities in order to sustain their lives. The current pandemic has put a huge strain on the American economy with over a million death and unemployment is at all-time high. This article critically examines the severity of insufficient funding for higher education and the adverse impact of the escalating tuition fees. To regulate the rising tuition fees, suggestions are made with reference to sustainability of strategies and policies to stem this phenomenon.
Large‐Scale Multifunctional Carbon Nanotube Thin Film as Effective Mid‐Infrared Radiation Modulator with Long‐Term Stability
Authors: Sun Yue , Chang Huicong , Hu Jun , Wang Yangyang , Weng Yudong , Zhang Ce , Niu Shuai , Cao Longfei , Chen Zhao , Guo Nan , Liu Junku , Chi Jiawei , Li Guohua , Xiao Lin
Published: November 2020

Mid‐infrared tunable materials have attracted increasing attention for thermal radiation management in various applications ranging from infrared camouflage to radiative thermoregulation. Functional films based on graphene and carbon nanotubes by electrical gating are promising candidates because of their ultrawide spectral range from visible to terahertz and structural flexibility. However, challenges in practical applications remain, such as short cycle life, rapid performance degradation, and difficulties in the synthesis of large‐scale electrochromic films. In this paper, a scalable strategy to produce large‐scale mid‐infrared electrochromic films with long‐term stability is demonstrated, in which a sandwich‐structured thin film based on multiwalled carbon nanotubes (MWCNTs) is fabricated via a universal roll‐to‐roll process. By ionic liquid gating, the electrochromic films exhibit tunable thermal emissivity from ≈0.15–0.7 and excellent stability with 96% modulation retention over 3500 cycles. This mid‐infrared electromodulation behavior is mainly ascribed to the change in free carrier concentration of few‐walled carbon nanotubes in MWCNT films via a reversible ion‐induced doping process. The electrochromic films are found to enable effective radiative thermal regulation, dependent on tunable thermal emissivity. Moreover, applications in infrared displays for secret communication and infrared camouflage for varied environmental backgrounds are also demonstrated with 10 × 10 multipixel arrays.
Construct Achromatic Polymer Microlens for High‐Transmission Full‐Color Imaging
Authors: Xiong Bo , Wang Jia‐Nan , Peng Ru‐Wen , Jing Hao , Fan Ren‐Hao , Qi Dong‐Xiang , Chen Fei , Wang Mu
Published: November 2020

Traditional microlens focuses the beam with spherical convex surface, which achieves high transmission by restraining the scattering loss yet brings spherical aberration and chromatic aberration. While recently‐developed metalens, which relies on phase modulation by elaborately designing local resonators, has realized diffraction‐limited focusing. Yet, the issues of scattering loss of nanoresonators and chromatic aberration remain serious. Here, the design strategies of both metalens and traditional microlens are combined by introducing accurate phase modulation for the wavefront into microlens designing; and a broadband, polarization‐independent, and achromatic microlens with high efficiency is realized. With concentric‐circular polymer (phenolic resin) terrace as basic building blocks, a precise thickness profile is constructed and a high‐index polymer microlens is formed by electron‐beam grayscale lithography. The diffraction‐limited focusing possesses less than 5% change of focal length when the wavelength varies from 425 to 700 nm, showing the full‐color imaging and detection with a focusing efficiency of 80% (at 700 nm wavelength). Moreover, the rotation symmetry of the microstructures of microlens makes it work for arbitrary polarization. The achromatic imaging capability of the microlens is verified by whitelight imaging. It is expected that this high‐efficiency polarization‐independent broadband achromatic polymer microlens may have wide applications in high‐efficient imaging and sensing.
Nanowire Solar Cell Above the Radiative Limit
Authors: Korzun Ksenia , Castellanos Gabriel W. , de Boer Dick K. G. , Gómez Rivas Jaime , Haverkort Jos E. M.
Published: November 2020

A lossless solar cell operating at the Shockley–Queisser limit generates an open circuit voltage (Voc) equal to the radiative limit. At Voc, the highly directional beam of photons from the sun is absorbed and subsequently externally re‐emitted into a 4π solid angle, providing a large photon entropy loss. A solar cell can beat the Shockley–Queisser limit and approach the 46.7% ultimate limit by decreasing the output solid angle of the light emission at open circuit conditions. Here, a design for an indium phosphide single nanowire solar cell capable to operate 159 mV above the radiative limit is presented. The spontaneous emission factor is first optimized into a guided mode of the nanowire toward 68%. The authors subsequently launch a guided mode at the bottom straight part of the tapered nanowire yielding a photon escape probability of 81% for a tapering angle of θ = 1.2° and a top facet with a radius of 83 nm. When assuming homogeneous light emission along the nanowire, an outcoupling efficiency of 42% of the emitted light is obtained. The final optimization is the reduction of the emission cone toward 11 × 10−3 sr by focusing the guided mode with an external lens.
Homogeneous 3D Vertical Integration of Parylene‐C Based Organic Flexible Resistive Memory on Standard CMOS Platform
Authors: Chen Qingyu , Wang Zongwei , Lin Min , Qi Xin , Yu Zhizhen , Wu Lindong , Bao Lin , Ling Yaotian , Qin Yabo , Cai Yimao , Huang Ru
Published: November 2020

3D integration of vertical resistive random access memory (VRRAM) with organic materials is promising for ultra‐high density flexible data storage. However, it is extremely challenging to heterogeneously fabricate an organic 3D VRRAM due to complicated issues such as chemical/thermal robustness, compatibility of organic/inorganic materials, and processes of stacking/patterning multi‐layer organic/metal films. Herein, an organic flexible 3D VRRAM based on parylene‐C is experimentally demonstrated on a standard complementary metal oxide semiconductor platform for the first time. The proposed 3D VRRAM can be homogenously fabricated based solely on parylene‐C (except the metal electrodes), significantly facilitating the 3D integration owing to chemical stability and compatibility with standard photolithography patterning. The flexible 3D organic memory arrays demonstrate great memory characteristics including retention time >105 s, endurance cycles >300, and resistance ON/OFF ratio >10. Further, a finite element analysis is established to model and investigate the scaling potential of the organic 3D VRRAM. The simulation results indicate the elevated temperature during programming could be catastrophic for ultra‐high density 3D VRRAM if the feature size approaches ≈100 nm or below, urging the containment of programming power to avoid thermal issues as well as to save energy consumption.
Fabrication of zeolitic imidazolate frameworks based mixed matrix membranes and mass transfer properties of C4H6 and N2 in membrane separation
Authors: Haq Ihtisham Ul , Wang Tao , Zhang Ao‐Shuai , Mao Heng , Khan Rehan , Xu Li‐Hao , Zhao Zhi‐Ping
Published: November 2020

1,3‐Butadiene (BD) is a petrochemical‐based volatile organic compound, extensively used for the manufacture of synthetic rubber. There is no method reported for its recovery from nitrogen mixture. Herein, for the first time, BD is efficiently recovered by gas separation through facile and novel mixed‐metal ZIF‐8 based mixed matrix membranes (MMMs). Addition of Ni‐ZIF‐8 nanoparticles in PDMS matrix, significantly improved the penetrant‐membrane interactions and the solution‐diffusion properties of BD. Positron annihilation lifetime spectroscopy analysis showed that the well dispersion of Ni‐ZIF‐8 in PDMS enhanced the free volume of membrane and created efficient continuous paths for BD diffusion. Then, 15 wt% Ni‐ZIF‐8 MMM exhibited the BD permeance of 323 GPU and the BD/N2 ideal selectivity of 19.5, which were 60 and 81% higher than pure PDMS membrane, respectively. The simultaneous enhancement of BD permeance and BD/N2 ideal selectivity indicated that Ni‐ZIF‐8 was an effective filler applied in MMMs for efficient BD recovery.
The Role of Stressful Life Events among Women Experiencing Homelessness: An Intragroup Analysis
Authors: Rodriguez‐Moreno Sara , Panadero Sonia , Vázquez José Juan
Published: November 2020

The aim of this study is to examine stressful life events (SLEs) among homeless women and how SLEs were related to patterns and trajectories of homelessness. Specifically, the study aimed to replicate and build upon by Muñoz et al. (2005) by using cluster and discriminant analysis in a sample of 116 homeless women. The sample was classified based on SLEs, and the relationship between the resulting subgroups and sociodemographic characteristics, homeless trajectories, physical and mental health, and social support was examined. The results suggest that the three‐cluster solution was theoretically and structurally meaningful: (a) the “Shorter homelessness trajectories and best health and mental health” subgroup was characterized by low levels of SLEs, a shorter homeless trajectory, lower prevalence of physical and mental health problems, and lower rates of alcohol and substances consumption; (b) the “Early onset of homelessness and poorer health and poorer mental health” subgroup was characterized by a higher prevalence of childhood and adolescence SLEs, an early onset of homelessness and greater chronification, mental health problems, and alcohol consumption; and (c) the “Chronic homelessness and poorest health and mental health” subgroup was mainly characterized by a higher prevalence of typically adulthood SLEs, as well as some SLEs that may be unique to women, a greater number of periods of homelessness, physical health problems, disabilities, and substance misuse. Increased knowledge about the different subgroups and trajectories of homeless women, as well as their specific characteristics and needs, will help us design social services and policies sensitive to all these differences.
Fabricating patterned polyelectrolyte brushes by dynamic microprojection lithography for selective electroless metal deposition
Authors: Hu Fenghuai , Zhao Haili , Pan Yunfei , Yang Dasheng , Sha Jin , Gao Yang
Published: November 2020

The emerging need for flexible and wearable electronics has been pushing the edge of the traditional electroless deposition (ELD) technique. With the rapid development of polymer‐assisted ELD (PAELD), its time‐consuming and possess‐complicated procedures have hindered the application of the technique. Here, for purpose of addressing the challenge, the work demonstrates a highly efficient and versatile method, based on the procedure consisting of the customized polyelectrolyte brushes patterns fabrication with the assistance of mask‐free dynamic microprojection lithography and sequential selective ELD (DML‐ELD), for the fabrication of arbitrary electrode on the silicon dioxide/silicon (SiO2/Si) substrate. The resistivity of the patterned copper electrode maintained around 0.062 Ω∙mm at room temperature, indicating the high reproducibility and stability of the method. Furthermore, an interdigital copper electrode fabricated with the DML‐ELD method was coated with a poly(vinyl alcohol) sensing layer, forming a sandwich structure for the ambient humidity detection. The sensitivity of the lab‐made humidity sensor achieves 0.82 pF/%RH (<80%RH) and 19.3 pF/%RH (>80%RH). The work has demonstrated the broad prospect of the proposed DML‐ELD method in the rapid and customized manufacturing of microcircuit fabrication for electronic devices.
Polylactide films produced with bixin and acetyl tributyl citrate: Functional properties for active packaging
Authors: Stoll Liana , Domenek Sandra , Hickmann Flôres Simone , Nachtigall Sonia Marli B. , de Oliveira Rios Alessandro
Published: November 2020

Packaging materials are decisive to preserve the quality and nutritional value of food. Polylactide (PLA) is a biodegradable polymer with adequate mechanical properties for packaging applications, but its moderate oxygen barrier properties and high UV light transmission hamper its performance as packaging for oxygen‐ and light‐sensitive products. Bixin, a carotenoid with coloring and antioxidant character, was used to improve the light barrier of PLA films plasticized or not with acetyl tri‐butyl citrate (ATBC). The films were subjected to thermal treatment mimicking polymer processing temperatures. Despite more than 74 wt% of bixin degraded during heat treatment, films were still blocking up to 95% of UVA and 90% of UVB transmission. Plasticizing PLA with ATBC accelerated up to six times the bixin release into a food simulant, which allowed to reach relevant concentrations for food preservation. In conclusion, bixin is a promising natural antioxidant and UV‐shielding additive of biodegradable packaging.
Surface functionalization of poly(vinylidene fluoride) membrane by radiation‐induced emulsion polymerization of hydroxyethyl acrylates in an aqueous medium
Authors: Mohamad Siti Fatahiyah , Karoji Muhamad Nurfalah , Mustaqim Azzian Muhammad Irfan , Mohd Hassani Muhamad Hisyamuddin , Wan Salleh Wan Norharyati
Published: November 2020

Decades ago, surface modification of poly(vinylidene fluoride) (PVDF) membrane became an essential subject. The change is mainly to enhance the hydrophilicity properties of the membrane in order to increase the adsorption capacity, thus making as a novel adsorbent. This study aims to used radiation‐induced polymerization and compares the final properties of PVDF grafted hydroxyethyl acrylates (HEA) prepare by two different approaches. The PVDF‐grafted‐HEA has achieved either direct polymerization or emulsion polymerization. Tween‐20 has been used as a surfactant in emulsion polymerization. The final PVDF‐grafted poly‐HEA was analyzed using several different instruments to observe the changes in terms of morphological structure, topography properties, thermal stability, mechanical strength, and hydrophilicity. Significant differences were seen in morphology and contact angles properties. By emulsion polymerization, poly‐HEA grafted in the shape of micelles compare to by direct polymerization shown a thin homogenous layer. Thus, the surface roughness of PVDF by emulsion is higher lead to higher contact angles. Even though both approaches demonstrate significant changes in the physicochemical properties of the PVDF membrane, it is revealed that radiation‐induced direct polymerization approaches could achieve a hydrophilic PVDF‐grafted HEA.
Recyclable Transition Metal Catalysis using Bipyridine‐Functionalized SBA‐15 by Co‐condensation of Methallylsilane with TEOS
Authors: Han Ye Ri , Kim Jae Soon , Park Woo‐Jin , Lee Chang‐Hee , Cheon Jinwoo , Jun Chul‐Ho
Published: November 2020

Well‐defined recyclable Pd‐ and Rh‐bipyridyl group‐impregnated SBA‐15 catalysts were prepared for C−C bond coupling reaction and selective hydrogenation reactions, respectively. These SBA‐15 derived ligands for the catalysts were prepared by direct and indirect co‐condensation method using bipyridyl‐linked methallylsilane. This indirect method, involving methoxysilane generated from methallylsilane shows higher loading efficiency of transition metal catalysts on SBA‐15 than the direct use of methallylsilane.
Allogeneic stem cell transplant in patients with acute myeloid leukemia and karnofsky performance status score less than or equal to 80%: A study from the acute leukemia working party of the European Society for Blood and Marrow Transplantation (EBMT)
Authors: Saraceni Francesco , Labopin Myriam , Forcade Edouard , Kröger Nicolaus , Socié Gerard , Niittyvuopio Riitta , Cornelissen Jan J. , Labussière‐Wallet Hélène , Blaise Didier , Choi Goda , Byrne Jenny L. , Guillerm Gaelle , Marchand Tony , Esteve Jordi , Bazarbachi Ali , Savani Bipin , Olivieri Attilio , Nagler Arnon , Mohty Mohamad
Published: November 2020

Limited data are currently available on the outcome of patients with acute myeloid leukemia (AML) undergoing allogeneic stem cell transplantation (allo‐SCT) with a reduced performance status. We herein present the results of a registry study on 2,936 AML patients undergoing allo‐SCT in first remission (CR1) with a Karnofsky Performance Status (KPS) score less than or equal to 80%. Two‐year leukemia‐free survival (LFS), overall survival (OS) and graft‐versus‐host disease (GVHD)‐free, and relapse‐free survival (GRFS) rates were 54%, 59%, and 41%, respectively. In multivariable analysis, patients with a KPS score = 80% had lower non‐relapse mortality (NRM) and superior OS in comparison to patients with a KPS score <80% (p < 0.001). In the subgroup of patients with a KPS score =80%, a reduced‐intensity conditioning (RIC) regimen was associated with an increased risk of relapse (p = 0.002) and lower GRFS (p < 0.001) compared to myeloablative conditioning (MAC). Differently, in patients with a KPS score <80%, a RIC regimen resulted in lower NRM (p < 0.001), whereas relapse incidence did not differ, thus leading to an improved GRFS (p = 0.008) as compared to MAC. A transplant from a matched sibling donor (MSD) was associated with a reduced incidence of grade III‐IV acute GVHD (p < 0.01) and NRM (p < 0.01) in comparison to other donor types. In conclusion, allo‐SCT appears feasible in AML patients with a jeopardized KPS score. Survival is significantly affected by the conditioning intensity, which should be adjusted according to the severity of KPS impairment.
A Calix[4]arene‐Based Cyclic Dinuclear Ruthenium Complex for Light‐Driven Catalytic Water Oxidation
Authors: Noll Niklas , Würthner Frank
Published: November 2020

A cyclic dinuclear ruthenium(bda) (bda: 2,2’‐bipyridine‐6,6’‐dicarboxylate) complex equipped with oligo(ethylene glycol)‐functionalized axial calix[4]arene ligands has been synthesized for homogenous catalytic water oxidation. This novel Ru(bda) macrocycle showed significantly increased catalytic activity in chemical and photocatalytic water oxidation compared to the archetype mononuclear reference [Ru(bda)(pic)2]. Kinetic investigations, including kinetic isotope effect studies, disclosed a unimolecular water nucleophilic attack mechanism of this novel dinuclear water oxidation catalyst (WOC) under the involvement of the second coordination sphere. Photocatalytic water oxidation with this cyclic dinuclear Ru complex using [Ru(bpy)3]Cl2 as a standard photosensitizer revealed a turnover frequency of 15.5 s−1 and a turnover number of 460. This so far highest photocatalytic performance reported for a Ru(bda) complex underlines the potential of this water‐soluble WOC for artificial photosynthesis.
Chiral single‐walled carbon nanotubes as chiral selectors in multimode enantioselective sensors
Authors: Stefan‐van Staden Raluca‐Ioana , Comnea‐Stancu Ionela Raluca
Published: November 2020

Single‐walled carbon nanotube‐(7,6) chirality was used for the design of multimode enantioselective sensors using different carbon matrices such as graphene paste, graphite paste, and carbon nanopowder‐based paste. l‐ and d‐malic acids were used as model analytes. The responses of the multimode sensors were evaluated for potentiometric and differential pulse voltammetry (DPV) modes. When carbon nanopowder was used as matrix, the multimode sensor was enantioselective for d‐malic acid in the concentration range 10−3 to 10−15 mol/L for the potentiometric mode and 10−5 to 10−8 mol/L for the DPV mode. The graphite paste‐based sensor was enantioselective for l‐malic acid in the ranges: 10−10 to 10−13 for the potentiometric mode and 10−4 to 10−7 mol/L for the DPV mode. The sensors based on graphene and chiral single‐walled carbon nanotubes were enantioselective for d‐malic acid, and a response was obtained only in the DPV mode. Accordingly, the matrix influenced both the enantioselectivity and the sensitivity of the measurements. The application of the sensors was for the enantioanalysis of malic acid in wines and apple juice samples. The proposed method is fast and reliable and allows the quantification of l‐ and d‐malic acids using electrochemical methods based on different principles, from the real samples after a buffering of the samples. The enantioanalysis of malic acid in wine and juice samples was performed with high recoveries (higher than 90.00%) and low relative standard deviation (RSD) (%) values (lower than 1.00%).
Spatial Evolution of CO2‐Contaminated Water Bubble Flows in a Vertical Pipe
Authors: Sa'adiyah Devy Setiorini , Hayashi Kosuke , Kurimoto Ryo , Tomiyama Akio
Published: November 2020

Experiments on CO2‐water bubble flows in a vertical pipe were carried out for clean water, an aqueous NaCl solution, and an aqueous NaCl solution with 1‐octanol to obtain databases of spatial evolutions of the flows with the impurities. Mass transfer correlations for bubbles in these liquids were implemented into a one‐way bubble tracking method. Numerical predictions of the spatial evolution, e.g., transition from a bubbly to a slug flow, depending on the impurities agreed well with the experiments.
On uncertainty estimation in functional linear mixed models
Authors: Maiti Tapabrata , Safikhani Abolfazl , Zhong Ping‐Shou
Published: November 2020

Functional data analysis has proven useful in many scientific applications where a physical process is observed as a curve. In many applications, several curves are observed due to multiple subjects, providing replicates in the statistical sense. Recent literature develops several techniques for registering curves and estimating associated models in a regression framework. Standard regression models ignore heterogeneity among curves. Functional linear mixed models are one popular way to combine several curves and capture variability among curves via random effects. Although there is a good amount of work available for analyzing functional data using mixed models, limited attention has been paid to inference. After estimation, we concentrate on measuring uncertainty in terms of mean squared error when functional linear mixed models are used for prediction. Although measuring uncertainty is of paramount interest in any statistical prediction, there is no theoretically valid expression available for functional mixed effect models. The quality of theoretical approximations depends on the number of curves observed. In many real life applications, only a finite number of curves can be observed. In such situations, it is important to asses the error rate for any valid statistical statement. In this article, we derive a theoretically valid approximation of uncertainty measurements for prediction. We also provide some modifications for model estimation. The empirical performance of the proposed method is investigated by numerical examples and is compared with existing literature as appropriate. Our method is computationally simple and often outperforms other existing methods.