bluuebunny/crossref_metadata_2025 huggingface dataset:
Governance of Eswatini Apparel Regional Value Chains and the Implications of Covid-19
Authors: Pasquali Giovanni , Godfrey Shane
Published: March 2021

There is a growing literature on the impact of Covid-19 on commercial and labour conditions at suppliers in apparel global value chains (GVCs). Yet much less is known about the implications for suppliers operating in regional value chains (RVCs) in the global South. In this article, we focus on Eswatini, which has grown to become the largest African manufacturer and exporter of apparel to the region. We draw on a combination of firm-level export data and interviews with stakeholders before and after the Covid-19 lockdown to shed light on the influence of private and public governance on suppliers’ economic and social upgrading and downgrading. We point to the coexistence of two separate private governance structures: the first characterised by direct contracts between South African retailers and large manufacturers (direct suppliers); the second operating through indirect purchasing via intermediaries from relatively smaller producers (indirect suppliers). While direct suppliers enjoyed higher levels of economic and social upgrading than indirect suppliers before Covid-19, the pandemic reinforced this division, with severe price cuts for indirect suppliers. Furthermore, while retailers provided some direct suppliers with support throughout the crisis, this was not the case for indirect suppliers, who remain comparatively more vulnerable. In terms of public governance, the negative consequences of the lockdown on firms’ income and workers’ livelihoods have been compounded by the state’s ineffective response. Our paper contributes to the research on RVCs in the global South, enhancing our understanding of how different governance structures and external shocks affect firms’ and workers’ upgrading and downgrading prospects.
Attosecond state-resolved carrier motion in quantum materials probed by soft x-ray XANES
Authors: Buades Bárbara , Picón Antonio , Berger Emma , León Iker , Di Palo Nicola , Cousin Seth L. , Cocchi Caterina , Pellegrin Eric , Martin Javier Herrero , Mañas-Valero Samuel , Coronado Eugenio , Danz Thomas , Draxl Claudia , Uemoto Mitsuharu , Yabana Kazuhiro , Schultze Martin , Wall Simon , Zürch Michael , Biegert Jens
Published: March 2021

Recent developments in attosecond technology led to table-top x-ray spectroscopy in the soft x-ray range, thus uniting the element- and state-specificity of core-level x-ray absorption spectroscopy with the time resolution to follow electronic dynamics in real-time. We describe recent work in attosecond technology and investigations into materials such as Si, SiO2, GaN, Al2O3, Ti, and TiO2, enabled by the convergence of these two capabilities. We showcase the state-of-the-art on isolated attosecond soft x-ray pulses for x-ray absorption near-edge spectroscopy to observe the 3d-state dynamics of the semi-metal TiS2 with attosecond resolution at the Ti L-edge (460 eV). We describe how the element- and state-specificity at the transition metal L-edge of the quantum material allows us to unambiguously identify how and where the optical field influences charge carriers. This precision elucidates that the Ti:3d conduction band states are efficiently photo-doped to a density of 1.9 × 1021 cm−3. The light-field induces coherent motion of intra-band carriers across 38% of the first Brillouin zone. Lastly, we describe the prospects with such unambiguous real-time observation of carrier dynamics in specific bonding or anti-bonding states and speculate that such capability will bring unprecedented opportunities toward an engineered approach for designer materials with pre-defined properties and efficiency. Examples are composites of semiconductors and insulators like Si, Ge, SiO2, GaN, BN, and quantum materials like graphene, transition metal dichalcogens, or high-Tc superconductors like NbN or LaBaCuO. Exiting are prospects to scrutinize canonical questions in multi-body physics, such as whether the electrons or lattice trigger phase transitions.
Hamilton–Jacobi formalism on locally conformally symplectic manifolds
Authors: Esen Oğul , de León Manuel , Sardón Cristina , Zajşc Marcin
Published: March 2021

In this article, we provide a Hamilton–Jacobi formalism on locally conformally symplectic (lcs) manifolds. We are interested in the Hamilton–Jacobi as an alternative method for formulating the dynamics, while our interest in the locally conformal character will account for physical theories described by Hamiltonians defined on well-behaved line bundles, whose dynamic takes place in open subsets of the general manifold. We present a lcs Hamilton–Jacobi equation in subsets of the general manifold and then provide a global view by using the Lichnerowicz–deRham differential. We show a comparison between the global and local description of a lcs Hamilton–Jacobi theory, and how actually the local behavior can be glued to retrieve the global behavior of the Hamilton–Jacobi theory. A particular example is the case of Gaussian isokinetic dynamics in which we apply our structure in certain submanifolds of the phase space.
Generation of synthetic 4 s utility-scale PV output time series from hourly solar irradiance data
Authors: Keeratimahat Kanyawee , Copper Jessie , Bruce Anna , MacGill Iain
Published: March 2021

The short-term characteristics of utility-scale PV variability become increasingly important for power system operation as PV penetrations grow. However, understanding how these characteristics and their aggregated impacts will change with new PV deployments is challenging given the limited and highly site dependent availability of high-resolution PV output data. This study proposes a methodology to generate a synthetic 4 s utility-scale PV output time series for a PV plant anywhere in a power system using hourly satellite-derived irradiance data, which is globally available, to select a set of 4 s output from models created from four PV plants operating within the Australian national electricity market (NEM). The method resamples 4 s clear sky PV output index variability from statistical distributions which are binned according to hourly clear sky index pairs of global horizontal irradiance and direct normal irradiance. The method is cross-validated against the observations from the four utility PV plants located in different climate zones. The monthly Kolmogorov–Smirnov Integral (KSI) tests on the modeled variability distributions show that they are not statistically different from the observed time series with most KSI values remaining under 80%. Finally, the method is applied to all 20 utility PV plants that were registered in the NEM as of 2019. The modeled result shows good agreement with the measured aggregated 4 s variability. Hence, our method can be usefully applied for modeling the short-term variability of future power system scenarios with high PV penetrations if at least some existing utility PV plant generation data are available.
Ferroelectric polarization retention with scaling of Hf0.5Zr0.5O2 on silicon
Authors: Mohan Jaidah , Hernandez-Arriaga Heber , Jung Yong Chan , Onaya Takashi , Nam Chang-Yong , Tsai Esther H. R. , Kim Si Joon , Kim Jiyoung
Published: March 2021

In this paper, we investigate the polarization retention of Hf0.5Zr0.5O2 (HZO)-based metal–ferroelectric–insulator–Si (MFIS) capacitors with scaling of the ferroelectric (FE) layer thickness from 5 nm to 20 nm. The capacitors have a constant interface layer capacitance of ∼24 μF/cm2, developed due to the integration of HZO on a degenerated Si as a bottom conducting electrode. It is observed that 20 nm HZO films show a small change (∼5%) in FE polarization (PFE) between short (10 μs) and long (6 s) retention time, while 5-nm-thick films exhibit a large difference (∼90%). The dependence of PFE retention loss on the FE thickness can be understood by the presence of a built-in electric field in the FE layer, generated due to charge continuity between the FE and the interface layers in the ground state without any external bias. A direct experimental observation also confirms that a residual voltage is developed at the node between the metal–ferroelectric–metal and metal–oxide–semiconductor capacitors connected in series, in the ground state with zero external bias. It is expected that a proper understanding of the built-in field developed in the FE layer in an MFIS stack is crucial for FE memory retention characteristics.
Measuring the phase noise of Raman lasers with an atom-based method
Authors: Wang Yaning , Yan Shuhua , Xu Dongyang , Hu Mei , Li Qixue , Zhang Xu , Zhang Huankai , Lv Mengjie , Jia Aiai , Wang Guochao , Zhu Lingxiao , Yang Jun
Published: March 2021

Phase noise of Raman lasers is a major source of noise for a Raman-type cold atom interferometer, which is traditionally measured using the signal source analyzer. We report here an atom-based method to measure the phase noise performance between two Raman lasers. By analyzing and calibrating the system noise sources, we can characterize the contribution of phase noise from the total deviation of the relative atom population at the middle of the interference fringe. Knowing the transfer function specified by the operation sequence of the interferometer, we can obtain the transfer function and power spectrum density of the phase noise term. By varying the time sequences of the interferometer, we can measure the white phase noise floor and the phase noise performance over a large range of Fourier frequencies from 1 to 100 000 Hz with a minor difference of 1 dB compared with results from the traditional method using a signal analyzer, which proves the validity of the atom-based method. Compared with the traditional measurement method, the atom-based method can have higher accuracy and have the ability of self-calibrating.
Selectivity of ion transport in narrow carbon nanotubes depends on the driving force due to drag or drive nature of their active hydration shells
Authors: Gao Haiqi , Wang Jing , Liu Yuzhen , Xie Yannan , Král Petr , Lu Ruifeng
Published: March 2021

Molecular dynamics simulations have revealed the important roles of hydration shells of ions transported through ultrathin carbon nanotubes (CNTs). In particular, ions driven by electric fields tend to drag their hydration shells behind them, while for ions transported by pressure, their hydration shells can actively drive them. Given the different binding strengths of hydration shells to ions of different sizes, these active roles of hydration shells affect the relative entry rates and driving speeds of ions in CNTs.
In situ spectroscopic ellipsometry as a pathway toward achieving VO2 stoichiometry for amorphous vanadium oxide with magnetron sputtering
Authors: Xu C. , Heinemeyer F. , Dittrich A. , Bäumer C. , Reineke-Koch R.
Published: March 2021

As a special class of materials, transition metal oxides exhibit in their crystalline phase a variety of interesting properties, such as metal–insulator transition, ferroelectricity, magnetism, superconductivity, and so forth. However, for industrially widely applied methods such as room temperature magnetron sputtering, during initial fabrication steps of these materials, they are mostly amorphous, and control of stoichiometry during fabrication is challenging. It is, therefore, of pivotal importance to control the stoichiometry of transition metal oxides during growth in the amorphous state. One particularly important example for the necessity of stoichiometry control is vanadium dioxide (VO2), where small deviations in stoichiometry during fabrication result in unfavorable changes in the electronic and structural properties, for example, the metal–insulator transition temperature and optical permittivity. In this work, the stoichiometry of amorphous vanadium oxides is adjusted to VO2 using in situ spectroscopic ellipsometry (in situ SE) and verified by x-ray photoelectron spectroscopy. After an annealing process, a monoclinic VO2 crystalline structure is observed through x-ray diffraction at 30 °C. At an elevated temperature of 150 °C, which is higher than the typical metal–insulator transition temperature in VO2 of around 67 °C, a rutile crystalline structure is observed, which verifies the correctness of the stoichiometry of VO2. A Mott metal–insulator transition is revealed by the change in the imaginary part of optical permittivity through SE as well.
Combining wavefunction frozen-density embedding with one-dimensional periodicity
Authors: Fink Karin , Höfener Sebastian
Published: March 2021

We present the combination of wavefunction frozen-density embedding (FDE) with a periodic repetition in one dimension (1D) for molecular systems in the KOALA program. In this periodic orbital-uncoupled FDE ansatz, no wavefunction overlap is taken into account, and only the electron density of the active subsystem is computed explicitly. This density is relaxed in the presence of the environment potential, which is obtained by translating the updated active subsystem density, yielding a fully self-consistent solution at convergence. Treating only one subsystem explicitly, the method allows for the calculation of local properties in condensed molecular systems, while no orbital band structure is obtained preventing the application, e.g., to systems with metallic bonding. In order to illustrate possible applications of the new implementation, selected case studies are presented, ranging from ground-state dipole moments using configuration interaction methods via excitation energies using time-dependent density-functional theory to ionization potentials obtained from equation-of-motion correlation methods. Different levels of approximations are assessed, revealing that an active subsystem consisting of two or three molecules leads to results that are converged with respect to the environment contributions.
Upgrades and redesign of the National Ignition Facility’s soft x-ray opacity spectrometer (OpSpec)
Authors: Wallace M. S. , Heeter R. F. , Knight R. A. , Durand A. M. , Heinmiller J. M. , Lara R. B. , Max D. A. , Dutra E. C. , Huffman E. J. , Ayers J. , Emig J. A. , Archuleta T. N. , Urbatsch T. J. , Perry T. S.
Published: March 2021

The soft x-ray Opacity Spectrometer (OpSpec) used on the National Ignition Facility (NIF) has recently incorporated an elliptically shaped crystal. The original OpSpec used two convex cylindrical crystals for time-integrated measurements of point-projection spectra from 540 to 2100 eV. However, with the convex geometry, the low-energy portion of the spectrum suffered from high backgrounds due to scattered x-rays as well as reflections from alternate crystal planes. An elliptically shaped crystal allows an acceptance aperture at the crossover focus between the crystal and the detector, which reduces background and eliminates nearly all reflections from alternate crystal planes. The current elliptical design is an improvement from the convex cylindrical design but has a usable energy range from 900 to 2100 eV. In addition, OpSpec is currently used on 18 NIF shots/year, in which both crystals are typically damaged beyond reuse, so efficient production of 36 crystals/year is required. Design efforts to improve the existing system focus on mounting reliability, reducing crystal strain to increase survivability between mounting and shot time, and extending the energy range of the instrument down to 520 eV. The elliptical design, results, and future options are presented.
Engineering adjustable two-pore devices for parallel ion transport and DNA translocations
Authors: Chou Yung-Chien , Chen Joshua , Lin Chih-Yuan , Drndić Marija
Published: March 2021

We report ionic current and double-stranded DNA (dsDNA) translocation measurements through solid-state membranes with two TEM-drilled ∼3-nm diameter silicon nitride nanopores in parallel. Nanopores are fabricated with similar diameters but varying in effective thicknesses (from 2.6 to 10 nm) ranging from a thickness ratio of 1:1 to 1:3.75, producing distinct conductance levels. This was made possible by locally thinning the silicon nitride membrane to shape the desired topography with nanoscale precision using electron beam lithography (EBL). Two nanopores are engineered and subsequently drilled in either the EBL-thinned or the surrounding membrane region. By designing the interpore separation a few orders of magnitude larger than the pore diameter (e.g., ∼900 vs 3 nm), we show analytically, numerically, and experimentally that the total conductance of the two pores is the sum of the individual pore conductances. For a two-pore device with similar diameters yet thicknesses in the ratio of 1:3, a ratio of ∼1:2.2 in open-pore conductances and translocation current signals is expected, as if they were measured independently. Introducing dsDNA as analytes to both pores simultaneously, we detect more than 12 000 events within 2 min and trace them back with a high likelihood to which pore the dsDNA translocated through. Moreover, we monitor translocations through one active pore only when the other pore is clogged. This work demonstrates how two-pore devices can fundamentally open up a parallel translocation reading system for solid-state nanopores. This approach could be creatively generalized to more pores with desired parameters given a sufficient signal-to-noise ratio.
Direct product-type grid representations for angular coordinates in extended space and their application in the MCTDH approach
Authors: Zhao Bin , Manthe Uwe
Published: March 2021

Multi-configurational time-dependent Hartree (MCTDH) calculations using time-dependent grid representations can be used to accurately simulate high-dimensional quantum dynamics on general ab initio potential energy surfaces. Employing the correlation discrete variable representation, sets of direct product type grids are employed in the calculation of the required potential energy matrix elements. This direct product structure can be a problem if the coordinate system includes polar and azimuthal angles that result in singularities in the kinetic energy operator. In the present work, a new direct product-type discrete variable representation (DVR) for arbitrary sets of polar and azimuthal angles is introduced. It employs an extended coordinate space where the range of the polar angles is taken to be [−π, π]. The resulting extended space DVR resolves problems caused by the singularities in the kinetic energy operator without generating a very large spectral width. MCTDH calculations studying the F·CH4 complex are used to investigate important properties of the new scheme. The scheme is found to allow for more efficient integration of the equations of motion compared to the previously employed cot-DVR approach [G. Schiffel and U. Manthe, Chem. Phys. 374, 118 (2010)] and decreases the required central processing unit times by about an order of magnitude.
Spatio-temporal heterogeneity in hippocampal metabolism in control and epilepsy conditions
Authors: Brancati Giulio E. , Rawas Chahinaz , Ghestem Antoine , Bernard Christophe , Ivanov Anton I.
Published: March 2021

Significance

The dorsal part of the hippocampus is involved in spatial learning and memory processes, while the ventral is implicated in motivational and emotional behavior. These functions change during the night and day cycle, and they are altered in epilepsy. Here, we show that energy production (glycolysis versus oxidative phosphorylation) varies along the dorsoventral axis in a circadian manner ex vivo in control mice. These rules are altered in experimental epilepsy. Thus, energy production may be tailored to the function performed by hippocampal subdivisions and to the time of the day. Alterations in epilepsy may contribute to seizure generation and cognitive deficits.
Statistical evidence for the Proto-Indo-European-Euskarian hypothesis
Authors: Blevins Juliette , Sproat Richard
Published: March 2021

Based on a new reconstruction of Proto-Basque, and regular sound correspondences between this Proto-Basque and Proto-Indo-European as standardly reconstructed,Blevins (2018)argues that Proto-Basque and Proto-Indo-European have a common ancestor that pre-dates the two proto-languages. Part of this argument is based on proposed Proto-Indo-European/Proto-Basque cognate sets that include basic vocabulary items. In this study we offer statistical support for Blevins’ conclusions by using a Monte Carlo simulation that allows us to estimate the probability that the proposed lexical correspondences could have arisen by chance. The method makes use of phonotactic language models to generate possible words in a pair of languages, and then attempts to discover consistent correspondences between the words, producing a list of possible “cognates”. The method differs from some previous approaches by considering matches between all segments in the word pairs. By running such a simulation a large number of times, we can estimate the probability that two languages with the given phonotactics could have produced the number of cognate pairs observed in the actual data. The method is independently assessed by comparing wordlists from 100 pairs of languages, related and unrelated, where relations are known. Our conclusion is that the proposed correspondences are unlikely to have arisen by chance, supporting a distant relationship between Proto-Basque as reconstructed byBlevins (2018)and Proto-Indo-European.
Welfare implications for dairy bull calves
Authors: Alley Mark L. , Smith Geof W. , Pairis-Garcia Monique D. , Wagner Brooklyn , Cramer Mary Caitlin
Published: March 2021

Dairy bull calves may experience compromised welfare as a result of production practices and management techniques implemented on farm. This includes high disease incidence due to poor ventilation, pain experienced as a by-product of processing procedures, social isolation, and hunger from inappropriate nutrition. Although dairy heifer calves may experience similar issues, these conditions are often exacerbated for dairy bull calves due to the low economic value of the individual animal. In addition, given the bull calf will likely not remain on the farm, this group of animals are more likely to receive less adequate care in the first weeks of life. Welfare issues such as increased rates of dystocia, failure of passive transport, dehorning, castration, and long transportation distances are all critical and will be discussed in this review. Therefore, the objectives of this article are to (1) evaluate current welfare concerns specific to dairy bull calves, (2) identify areas for improvement to mitigate poor welfare outcomes, and (3) review proper euthanasia techniques and protocols specific for calves. Ultimately there is still much to learn about specific areas for improvement relating to the welfare of dairy bull calves and future studies are needed. However, the industry should properly manage the welfare challenges of bull calves, identify opportunities within the industry to increase their value, and uphold our ethical responsibility to these animals.
Root pruning - a growth regulation practice in fruit crops
Authors: Mathiyazhagan Kavino , Subash Mani , Bose Chandra
Published: March 2021

Root pruning is a horticultural practice from ages ago that has potential benefits on tree crop growth regulation and production. It is followed in orchards as a growth control mechanism of vigorously growing fruit trees. The growth regulation in trees is brought about by many physiological mechanisms involving water stress and assimilates partitioning to maintain the root: shoot equilibrium. Root pruning of structural roots increases the function and efficiency of functional roots in trees. It is widely practiced in transplanting of saplings which ensures better establishment. Time and selection of the distance from the trunk by root pruning may play an important role not only on vigour control but also on vegetative response and flower induction, fruit set; hence, they should be addressed as well. However, it will require additional experience, horticultural insight and better understanding of the physiological basis of the technique. It favours the large-scale adoption of root pruning in perennial fruit crops under high-density planting system in order to regulate the canopy size and regular bearing.
Tobacco dependence and motivation to quit smoking: an identity-based framework (Adicción al tabaco y motivación para dejar de fumar: una perspectiva identitaria)
Authors: Blondé Jérôme , Falomir-Pichastor Juan-Manuel
Published: March 2021

Literature has extensively shown that tobacco dependence is negatively associated with motivation to quit smoking. In this research, we aimed to account for this negative relationship by adopting an identity-based framework. More specifically, we hypothesized that tobacco dependence constitutes an identity threat that smokers seek to manage by diminishing their motivation to quit. To assess whether such a mechanism is at work, we used a self-affirmation manipulation across two independent studies that were pooled into one ( N = 308). More specifically, we asked daily smokers to report their tobacco dependence prior to manipulating self-affirmation. Then, we assessed their motivation to quit. Results demonstrated that, among high-dependent smokers, those who were self-affirmed reported higher motivation to quit than those who were not. Self-affirmation had no effect among low-dependent smokers. These findings illuminate the idea that an interpretation in terms of identity processes can offer new insights into understanding tobacco dependence and its consequences on smokers’ motivation to quit.
An asymmetric junctional mechanoresponse coordinates mitotic rounding with epithelial integrity
Authors: Monster Jooske L. , Donker Lisa , Vliem Marjolein J. , Win Zaw , Matthews Helen K. , Cheah Joleen S. , Yamada Soichiro , de Rooij Johan , Baum Buzz , Gloerich Martijn
Published: March 2021

Epithelia are continuously self-renewed, but how epithelial integrity is maintained during the morphological changes that cells undergo in mitosis is not well understood. Here, we show that as epithelial cells round up when they enter mitosis, they exert tensile forces on neighboring cells. We find that mitotic cell–cell junctions withstand these tensile forces through the mechanosensitive recruitment of the actin-binding protein vinculin to cadherin-based adhesions. Surprisingly, vinculin that is recruited to mitotic junctions originates selectively from the neighbors of mitotic cells, resulting in an asymmetric composition of cadherin junctions. Inhibition of junctional vinculin recruitment in neighbors of mitotic cells results in junctional breakage and weakened epithelial barrier. Conversely, the absence of vinculin from the cadherin complex in mitotic cells is necessary to successfully undergo mitotic rounding. Our data thus identify an asymmetric mechanoresponse at cadherin adhesions during mitosis, which is essential to maintain epithelial integrity while at the same time enable the shape changes of mitotic cells.
Endoplasmic reticulum maintains ion homeostasis required for plasma membrane repair
Authors: Chandra Goutam , Sreetama Sen Chandra , Mázala Davi A.G. , Charton Karine , VanderMeulen Jack H. , Richard Isabelle , Jaiswal Jyoti K.
Published: March 2021

Of the many crucial functions of the ER, homeostasis of physiological calcium increase is critical for signaling. Plasma membrane (PM) injury causes a pathological calcium influx. Here, we show that the ER helps clear this surge in cytoplasmic calcium through an ER-resident calcium pump, SERCA, and a calcium-activated ion channel, Anoctamin 5 (ANO5). SERCA imports calcium into the ER, and ANO5 supports this by maintaining electroneutrality of the ER lumen through anion import. Preventing either of these transporter activities causes cytosolic calcium overload and disrupts PM repair (PMR). ANO5 deficit in limb girdle muscular dystrophy 2L (LGMD2L) patient cells compromises their cytosolic and ER calcium homeostasis. By generating a mouse model of LGMD2L, we find that PM injury causes cytosolic calcium overload and compromises the ability of ANO5-deficient myofibers to repair. Addressing calcium overload in ANO5-deficient myofibers enables them to repair, supporting the requirement of the ER in calcium homeostasis in injured cells and facilitating PMR.
Teaching optics in Covid-19 pandemic through project-based learning
Authors: Siddiq Nur Abdillah
Published: March 2021

The Covid-19 pandemic has forced educational institutions to adjust their learning process to distance education or online learning. This paper explains how to teach optics during the Covid-19 pandemic by implementing project-based learning that can be supervised online. Students are instructed to design, characterize, and optimize droplet lenses to produce the highest possible lens resolving power by using the USAF-1951 test chart. To do project-based learning correctly, students must understand various optics concepts, such as the principle behind light propagation (Fermat’s principle), determining focal lengths, compound lenses, lens aberrations, and lens resolving power. This paper also describes how to optimize droplet lenses to produce high resolving power with easy to handle and inexpensive materials.
Lightweight pixel-wise segmentation for efficient concrete crack detection using hierarchical convolutional neural network
Authors: Kim Jin , Shim Seungbo , Cha Yohan , Cho Gye-Chun
Published: March 2021

The aging of concrete structures is a threat to public safety; therefore, maintenance and repair of these structures have been highly emphasized. However, regular inspections to detect concrete cracks that rely on operators lack objectivity and consume a lot of time. To overcome this limitation, high-resolution image processing and deep learning have been adopted. Nevertheless, cracks on structure surfaces are still challenging to detect owing to the variety of shapes of cracks and the dependence of recognition performance on image conditions. Herein, we propose a new concrete crack detection method that applies the semantic segmentation technique using 1196 concrete crack images and labeled images produced in this study. A new segmentation algorithm is developed using a hierarchical convolutional neural network to improve speed, and a multi-loss update method is proposed to improve accuracy. The performance of the proposed network is evaluated in terms of accuracy and speed. The results show that the proposed network produces a 2.165% increase in the intersection over union of crack, 65.90% decrease in the average inference time, and 99.90% decrease in the number of parameters compared with the best accuracy results using existing segmentation networks. It is expected that the application of this improved crack detection method will result in faster and more accurate crack detection and, consequently, improved safety, thereby making it suitable for application in structure safety inspections.
The orthogonality speed of two-qubit state interacts locally with spin chain in the presence of Dzyaloshinsky–Moriya interaction
Authors: Abo-Kahla D A M , Abd-Rabbou M Y , Metwally N
Published: March 2021

The orthogonality time is examined for different initial states settings interacting locally with different types of spin interaction:XX, Ising and anisotropic models. It is shown that the number of orthogonality increases, and consequently the time of orthogonality decreases as the environment qubits increase. The shortest time of orthogonality is displayed for theXXchain model, while the largest time is shown for the Ising model. The external field increases the numbers of orthogonality, while Dzyaloshinsky–Moriya interaction decreases the time of orthogonality. The initial state settings together with the external field has a significant effect on decreasing/increasing the time of orthogonality.
Feasibility study of CP violation in

decays at the Super Tau Charm Facility *
Authors: Sang Haoyu , Shi Xiaodong , Zhou Xiaorong , Kang Xianwei , Liu Jianbei
Published: March 2021

We report a feasibility study for violation in

decays at a Super Tau Charm Facility (STCF). With an expected luminosity of 1 ab

collected by STCF per year at a center-of-mass energy of 4.26 GeV, the statistical sensitivity for CP violation is determined to be of order

by measuring the decay-rate difference between

and

. The analysis is performed using a reliable fast simulation software package, which can describe the detector responses properly and vary the responses flexibly for further optimization. Moreover, the energy-dependent efficiencies for reconstructing

are presented. The expected CP sensitivity is proportional to

in the energy region from 4.0 to 5.0 GeV. The sensitivity of CP violation is of order

with 10 ab

integrated luminosity, which is equivalent to ten years' data taking in this energy region at STCF.
Quantifying a frequency modulation response biomarker in responsive neurostimulation
Authors: Venkatesh Praveen , Sneider Daniel , Danish Mohammed , Sisterson Nathaniel D , Zaher Naoir , Urban Alexandra , Grover Pulkit , Richardson R Mark , Kokkinos Vasileios
Published: March 2021

Objective. Responsive neurostimulation (RNS) is an effective treatment for controlling seizures in patients with drug-resistant focal epilepsy who are not suitable candidates for resection surgery. A lack of tools for detecting and characterizing potential response biomarkers, however, contributes to a limited understanding of mechanisms by which RNS improves seizure control. We developed a method to quantify ictal frequency modulation, previously identified as a biomarker of clinical responsiveness to RNS. Approach. Frequency modulation is characterized by shifts in power across spectral bands during ictal events, over several months of neurostimulation. This effect was quantified by partitioning each seizure pattern into segments with distinct spectral content and measuring the extent of change from the baseline distribution of spectral content using the squared earth mover’s distance. Main results. We analyzed intracranial electroencephalography data from 13 patients who received RNS therapy, six of whom exhibited frequency modulation on expert evaluation. Patients in the frequency modulation group had, on average, significantly larger and more sustained changes in their squared earth mover’s distances (mean = 13.97 × 10−3 ± 1.197 × 10−3). In contrast, those patients without expert-identified frequency modulation exhibited statistically insignificant or negligible distances (mean = 4.994 × 10−3 ± 0.732 × 10−3). Significance. This method is the first step towards a quantitative, feedback-driven system for systematically optimizing RNS stimulation parameters, with an ultimate goal of truly personalized closed-loop therapy for epilepsy.
Heterogeneity and superspreading effect on herd immunity
Authors: Oz Yaron , Rubinstein Ittai , Safra Muli
Published: March 2021

We model and calculate the fraction of infected population necessary to reach herd immunity, taking into account the heterogeneity in infectiousness and susceptibility, as well as the correlation between those two parameters. We show that these cause the effective reproduction number to decrease more rapidly, and consequently have a drastic effect on the estimate of the necessary percentage of the population that has to contract the disease for herd immunity to be reached. We quantify the difference between the size of the infected population when the effective reproduction number decreases below 1 vs the ultimate fraction of population that had contracted the disease. This sheds light on an important distinction between herd immunity and the end of the disease and highlights the importance of limiting the spread of the disease even if we plan to naturally reach herd immunity. We analyze the effect of various lock-down scenarios on the resulting final fraction of infected population. We discuss implications to COVID-19 and other pandemics and compare our theoretical results to population-based simulations. We consider the dependence of the disease spread on the architecture of the infectiousness graph and analyze different graph architectures and the limitations of the graph models.
Slow quench dynamics in classical systems: kinetic Ising model and zero-range process
Authors: Priyanka  , Chatterjee Sayani , Jain Kavita
Published: March 2021

While a large number of studies have focused on the nonequilibrium dynamics of a system when it is quenched instantaneously from a disordered phase to an ordered phase, such dynamics have been relatively less explored when the quench occurs at a finite rate. Here, we study the slow quench dynamics in two paradigmatic models of classical statistical mechanics, a one-dimensional kinetic Ising model and a mean-field zero-range process, when the system is annealed slowly to the critical point. Starting from the time evolution equations for the spin–spin correlation function in the Ising model and the mass distribution in the zero-range process, we derive the Kibble–Zurek scaling laws. We then test a recent proposal that critical coarsening, which is ignored in the Kibble–Zurek argument, plays a role in the nonequilibrium dynamics close to the critical point. We find that the defect density in the Ising model and a scaled mass distribution in the zero-range process decay linearly to their respective values at the critical point with the time remaining until the end of the quench provided the final quench point is approached sufficiently fast, and sublinearly otherwise. As the linear scaling for the approach to the critical point also holds when a system following an instantaneous quench is allowed to coarsen for a finite time interval, we conclude that critical coarsening captures the scaling behavior in the vicinity of the critical point if the annealing is not too slow.
Reverse –Transcription Spin chain reaction of RNA molecule into DNA molecule
Authors: Roy Subhamoy Singha , Islam Samim , Mallick Sajal
Published: March 2021

Here we have study the conceptual properties of DNA molecules that can be mapped in the Heisenberg spin system, and the reduction in the formation of the effect of temperature through the quantum phase transition (QPT) when the refining time occurs. Delayed free rotation of molecules, reverse replication is a complement that uses RNA molecules to produce single-stranded DNA molecules and aids in the diffusion of DNA molecules. This explains the large ternary stress observed near the reverse copy point. We have projected the curve extent which is created to be in good agreement.
Reliability analysis of wind turbine based on degradation threshold
Authors: Mo Qiuyun , He Shengwen , Guan Huisen , Liu Yanyan , Guo Rongbin
Published: March 2021

The time-dependent reliability model of the structure was established by using the Gamma process and combined with the stress-strength interference model to describe the product strength degradation process. The characteristics of the failure threshold based on strength degradation was analyzed, and the life distribution of the product can be calculated under the condition of given degradation threshold was pointed out. Taking a vertical axis wind turbine as an example, ANSYS finite element analysis software was used to calculate the load at the stress concentration of the shaft end of the wind turbine. According to the distribution of load and based on the threshold of product degradation, the product lifetime distribution subject to Gamma degradation was analyzed, the variation law of reliability at the shaft end of the wind turbine with time was studied, and the probability distribution of lifetime under a given threshold of degradation was solved. By using this method, the product reliability subject to Gamma degradation and the lifetime distribution under a given threshold could be obtained, which provides a method for product reliability evaluation with difficulty in obtaining reliability data.
Power steering control valve structural design optimization
Authors: Xu Jing , Xu Yan
Published: March 2021

This paper analyses the two different structure of the rotary valve structure, and lists the working principle and oil circuit of power steering gear in different tectonic. Through analysis the two kinds of structure proves the more conducive to improve the structure of the rotary valve sensitivity and stability. It can be used for reference in the actual processing.
Kinematics and dynamics analysis of a lower DOF spatial parallel mechanism
Authors: Jincheng Xu , Zhijiang Xie , Zhiyuan Yang , Zhinan Zhao , Yongzheng Wang
Published: March 2021

In order to control the rotation of the end effector in a long and narrow space, a spatial parallel mechanism that can realize 2 degrees of freedom rotation is proposed. In this article, the forward kinematics model is established according to the constraint conditions of the mechanism’s pose, and the closed vector method is used to obtain the inverse kinematics model. Then based on the kinematics results, the dynamic inverse solution model was established by Newton-Euler method, and the dynamic analysis of the whole mechanism was carried out. Finally, the theoretical calculation results are compared with the simulation results of Adams software to verify the accuracy of the solution process.
Research on the Hand-eye calibration Method Based on Monocular Robot
Authors: Deng Shichao , Mei Feng , Yang Long , Liang Chenguang , Jiang Yingliang , Yu Gaoxing , Chen Yihai
Published: March 2021

The measurement system is composed of a single camera and a manipulator, and the conversion relationship between the manipulator tool coordinate system and the camera coordinate system is one of the key technologies of the system. This paper proposes a unit octet hand-eye calibration algorithm, which has better accuracy and anti-noise ability. This algorithm combines the characteristics of data on SO(4) on the basis of traditional dual quaternion, and establishes the conversion equation of AX=XB in combination with robot kinematics, and realizes the eye calibration of the manipulator. Compared with the traditional dual quaternion algorithm, the speed is faster, the robustness is good, and it has better stability and practicability.
Design of CCD thermal control system for SuperView satellite remote sensor and its start debugging in-orbit
Authors: Yang Tao , Zhao Shilei , Gao Teng , Zhao Zhenming , Meng Qingliang , Zhang Ping
Published: March 2021

With the continuous improvement of the resolution of the space remote sensing camera, the temperature stability requirements of the remote charge coupled device (CCD) have gradually become more stringent. This paper presents and designs a distributed heat source precise temperature control Loop heat pipe (LHP) structure which is different from the traditional LHP structure, and realizes a unified and effective thermal management system which can accurately control the temperature of four heat sources. The results show that the LHP system has excellent heat carrying capacity and accurate temperature control effect on distributed heat source. In 2016, the LHP system was applied to the in-orbit temperature control of the remote CCD of SuperView satellite and has been run for nearly 48 months in orbit thus far. The temperature stability of the four CCD heat source devices controlled is superior to ± 0.4 °C. The design method and on orbit flight data of the distributed heat source precise temperature control LHP system in this paper will have a great reference value for the subsequent application of LHP system in the space temperature control field.
English Applied Ability Teaching Reform of Mechanical Design and Manufacturing in ESP Teaching Mode
Authors: Du Juan
Published: March 2021

ESP Teaching method is an approach that is significantly different from the conventional English Language Teaching method. ESP teaching is a market-driven, communicative English teaching model which is based on the overall principle of significantly improving learners’ professional English social skills, learner-centered, and meets the needs of society and individuals. In this study, researcher’s attempt is to integrate ESP teaching model into design and manufacturing English teaching. The study aims to investigate whether ESP teaching method assist learners in mechanical design and manufacturing master the English skills of effective communication in the professional field. The study discusses the teaching reform in the teaching materials, teaching content, teaching methods and teaching assessment for mechanical design and manufacturing English. Some ideas, such as improving teaching methods and students’ learning initiative, have been adopted in teaching practice and the teaching effect is very good.
Research on the Design Scheme of Explosive Dust Removal System and Piping
Authors: Chen Xiaomei , Zhuo Peng , Liu Mingming , Wang Ning
Published: March 2021

In the workplace where the material dust concentration is high and electric sparks are easy to generate, the dust is easy to explode. At this time, the design of the dust removal system and the piping layout plan are particularly important. This paper takes the design of dust removal system in a tobacco factory as an example. According to the working characteristics of the shredding and stem cutting equipment in the silk workshop, the corresponding wet dust removal device is designed in this kind of work environment. The structure of the dust removal system, process flow and piping design are given, Pressure loss calculation and fan selection, provide a reference for the design of dust removal systems in places that are prone to dust explosions.
Study on nonlinear compensation method for signal error of capacitive micro displacement sensor
Authors: Zhou Jiang
Published: March 2021

In order to solve the problems of high error rate and long time in the traditional signal error compensation method, a new nonlinear compensation method for the signal error of capacitance micro displacement sensor is designed. The structure of the capacitive micro displacement sensor is optimized. The signal acquisition module is used to collect the optimized capacitive micro displacement sensor signal, and the collected signal is processed by adding window interpolation FFT. According to the signal processing results, the RBF neural network model is used to realize the nonlinear compensation of the signal error of the capacitive micro displacement sensor. The experimental results show that the method has the advantages of less noise, lower compensation error rate and time consuming, and better practical application effect.
Analysis of Primary Frequency Regulation Ability of Shandong Power Grid Thermal Power Unit
Authors: Liu En Ren , Li Jun , Gao Song , Meng Xiang rong , Shi Shuo , Yu Qingbin , Li Yuan yuan , Yan Qing
Published: March 2021

Shandong Power Grid is about to achieve the development goal of 30% of new energy power generation installed capacity, 30% of foreign power input into Shandong, and 30% of thermal power installed capacity. Neither new energy power generation nor external power has the ability to adjust primary frequency. Thermal power is the main force of primary frequency modulation of Shandong Power Grid. This article counts all primary frequency modulation remote tests of the Shandong Power Grid in 2020, analyzes the current status of Shandong Power Grid’s primary frequency modulation, gives an assessment method for the primary frequency modulation integral power, and summarizes three reasons for the unqualified primary frequency modulation. The reasons are analyzed separately, and optimization suggestions are given.