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Ab initio calculations of the elastic,electronic,optical,and vibrational properties of PdGa compound under pressure

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Chinese Physics B 2012年第9期21卷 422-429页

作者： H. Koc A. Yildirim e. Deligoz Department of Physics Siirt University Department of Physics Aksaray University

The structural, elastic, electronic, optical, and vibrational properties of cubic PdGa compound are investigated using the norm-conserving pseudopotentials within the local density approximation （LDA） in the framework of the density functional theory. The calculated lattice constant has been compared with the experimental value and has been found to be in good agreement with experimental data. The obtained electronic band structures show that PdGa compound has no band gap. The second-order elastic constants have been calculated, and the other related quantities such as the Young＇s modulus, shear modulus, Poisson＇s ratio, anisotropy factor, sound velocities, and Debye temperature have also been estimated. Our calculated results of elastic constants show that this compound is mechanically stable. Furthermore, the real and imaginary parts of the dielectric function and the optical constants such as the electron energy-loss function, the optical dielectric constant and the effective number of electrons per unit cell are calculated and presented in the study. The phonon dispersion curves are also derived using the direct method.

关键词： PdGa vibrational properties optical properties elastic constants

Dipole (hyper)polarizabilities of neutral silver clusters

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Chinese Physics B 2016年第12期25卷 217-222页

作者： Francisco e Jorge Luiz G M de Macedo Departarnento de Fisica Universidade Fedoral do Espirito Santo 29060-900 Vitoria Brazil Unidade Academica de Fisica Universidade Federal de Campina Grande 58429-900 Campina Grande Brazil Faculdade de Biotecnologia ICB Universidade Federal do Para 66075-110 Belem Brazil

At the Douglas-Kroll-Hess （DKI4） level, the B3PW91 functional along with the all-eleclron relativistic basis sets of valence triple and quadruple zeta qualities are used to determine the structure, stability, and electronic properties of the small silver clusters （Agn, n ≤ 7）. The results presented in this study are in good agreement with the experimental data and theoretical values obtained at a higher level of theory from the literature. Static polarizability and hyperpolarizability are also reported. It is verified that the mean dipole polarizability per atom exhibits an odd-even oscillation and that the polarizability anisotropy is directly related to the cluster shape. In this article, the first study of hyperpolarizabilities of small silver clusters is presented. except for the monomer, the second hyperpolarizabilities of the silver clusters are significantly larger than those of the copper clusters.

关键词： B3PW91 functional all-electron basis sets non-relativistic and DKH2 calculations silver clusters,dipole (hyper)polarizabilities

Natural regeneration responses to thinning and burning treatments in ponderosa pine forests and implications for restoration

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Journal of Forestry Research 2022年第3期33卷 741-753页

作者： Tzeidle N.Wasserman Amy e.M.Waltz John Paul Roccaforte Judith D.Springer Joseph e.Crouse ecological Restoration Institute Northern Arizona UniversityP.O.Box 15017FlagstaffAZ86011-5017USA

Understanding naturally occurring pine regeneration dynamics in response to thinning and burning treatments is necessary not only to measure the longevity of the restoration or fuels treatment,but also to assess how well regeneration meets forest sustainability guidelines and whether natural regeneration is sufficient for maintaining a sustainable forest structure and composition.A synthesis review was carried out on the effects of mechanical thinning and prescribed burn treatments on natural pine regeneration response in frequent-fire ponderosa pine forests across the western United *** focus was on site-specific variability in pine regeneration dynamics,temporal trends in regeneration presence and abundance,and response to treatment as described in the current literature using 29 studies that met our evidence-based review *** showed that the effects of thinning and burning treatments on regeneration depended on time since *** thinning,prescribed burning,and thinning plus burn treatments all increased seedling density,but there was high variability among sites and *** were mixed results in the short-term(ears)with both increasing and decreasing regeneration,and a general increase in regeneration 11−20 years *** long-term studies(>20 years)concluded that stands can return to pre-treatment densities in terms of total trees per hectare and forest floor duff levels when there are no maintenance treatments *** studies showed the average ponderosa pine seedling presence,survival and growth found in today’s forests to be at a high density;this combined with missed fire cycles could contribute to future fire risk and reduce the efficacy of maintaining fuel reduction goals.

关键词： Regeneration Ponderosa pine Frequent-fire Treatments Thinning Burning

When and how does brain-derived neurotrophic factor activate Nrf2 in astrocytes and neurons？

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Neural Regeneration Research 2018年第5期13卷 803-804页

作者： Tetsuro Ishii Giovanni e.Mann University of Tsukuba Tsukuba Japan School of Cardiovascular Medicine and Sciences King's British Heart Foundation Centre of Excellence Faculty of Life Sciences and Medicine King's College Iondon London UK

Circadian rhythm protects neurons：Although the master clock entrains the whole body rhythm,peripheral tissues also express core clock transcription factors Clock and Bmal1,which regulate expression of clock genes including period（per）and Cryptochrome（Cry）*** of per and Cry proteins repress Bmal1-and Clock-mediated transcription forming a negative feedback loop,which regulates nearly a 24 hours self-sustained rhythm including energy metabolism.

关键词： When and how does brain-derived neurotrophic factor activate Nrf2 in astrocytes and neurons NGF

Muscular activity patterns in 1-legged vs. 2-legged pedaling

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Journal of Sport and Health Science 2021年第1期10卷 99-106页

作者： Sangsoo Park Graham e.Caldwell Department of Kinesiology University of Massachusetts AmherstAmherstMA 01003USA

Background:One-legged pedaling is of interest to elite cyclists and ***,muscular usage in 1-legged vs.2-legged pedaling is not fully ***,the study was aimed to examine changes in leg muscle activation patterns between 2-legged and 1-legged ***:Fifteen healthy young recreational cyclists performed both 1-legged and 2-legged pedaling trials at about 30 Watt per *** electromyography electrodes were placed on 10 major muscles of the left *** envelope electromyography data were integrated to quantify muscle activities for each crank cycle quadrant to evaluate muscle activation ***:Overall,the prescribed constant power requirements led to reduced downstroke crank torque and extension-related muscle activities(vastus lateralis,vastus medialis,and soleus)in 1-legged ***-related muscle activities(biceps femoris long head,semitendinosus,lateral gastrocnemius,medial gastrocnemius,tensor fasciae latae,and tibialis anterior)in the upstroke phase increased to compensate for the absence of contralateral leg crank *** the upstroke,simultaneous increases were seen in the hamstrings and uni-articular knee extensors,and in the ankle plantarflexors and *** the top of the crank cycle,greater hip flexor activity stabilized the ***:The observed changes in muscle activities are due to a variety of changes in mechanical aspects of the pedaling motion when pedaling with only 1 leg,including altered crank torque patterns without the contralateral leg,reduced pelvis stability,and increased knee and ankle stiffness during the upstroke.

关键词： electromyography Muscle activity One-leg Pedaling

Diversity in chemical compositions of essential oil of myrtle leaves from various natural habitats in south and southwest Iran

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Journal of Forestry Research 2015年第4期26卷 971-981页

作者： Abdollah Ghasemi Pirbalouti Lyle e.Craker Department of Medicinal Plants Islamic Azad UniversityShahrekord Branch Medicinal Plants Program Stockbridge School of AgricultureCollege of Natural SciencesUniversity of Massachusetts

Myrtle, Myrtus communis L. （Myrtaceae）, an evergreen shrub also known as wild myrtle, has a history of use as a culinary and medicinal plant. To determine the diversity within the species, plant leaves of myrtle were collected in 12 natural habitats in Iran for investigation of chemical constituents in the essential oil. extraction of the essential oils produced yields ranging from 0.7 to 1.5 mL per 100 g dry tissue. An analysis of the oils by GC and GC/MS revealed 40 compounds, constituting 90.1-99.9 % of the essential oils. Chemical constituents varied with the site of sample origin, although the principal essential oil compo- nents from all populations, were pinene （17.5-37.1%）, 1,8-cineole （9.9-29.8 %）, linalool （7.0-23.1%）, and a-ter- pineol （5.3-8.3 %）. Limonene （tr, 22.7 %） was a major constituent in three populations. Characterized chemotypes included Chemotype pinene/1,8-cineole/linalool, Chemotype II： a-pinene/linalool, Chemotype III： a-pinene/1,8- cineole, and Chemotype IV： pinene/1,8-cineole/*** main source of variabifity in chemical composition and oil yield appeared to be differences in environmental conditions and chemotypes as plant populations collected from close geographical areas could be classified in a cluster.

关键词： Chemotypes Myrtus communis Limonene Linalool 1,8-Cineole Pinene Variation

Subcellular western blotting of single cells

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Microsystems & Nanoengineering 2017年第1期3卷 405-413页

作者： Kevin A.Yamauchi Amy e.Herr Department of Bioengineering University of CaliforniaBerkeleyCA 94720USA The UC Berkeley—UCSF Graduate Program in Bioengineering University of CaliforniaBerkeleyCA 94720USA

Although immunoassays are the de facto standard for determining subcellular protein localization in individual cells,antibody probe cross-reactivity and fixation artifacts remain confounding *** enhance selectivity while providing single-cell resolution,we introduce a subcellular western blotting technique capable of separately assaying proteins in the 14 pL cytoplasm and 2 pL nucleus of individual *** confer precision fluidic control,we describe a passive multilayer microdevice that leverages the rapid transport times afforded by *** isolating single cells in microwells,we apply single-cell differential detergent fractionation to lyse and western blot the cytoplasmic lysate,whereas the nucleus remains intact in the ***,we lyse the intact nucleus and western blot the nuclear *** index each protein analysis to the originating subcellular compartment,we utilize bi-directional electrophoresis,a multidimensional separation that assays the lysate from each compartment in a distinct region of the separation ***-cell bi-directional electrophoresis eliminates the need for semi-subjective image segmentation algorithms required in *** subcellular,single-cell western blot is demonstrated for six targets per cell,and successfully localizes spliceosome-associated proteins solubilized from large protein and RNA complexes,even for closely sized proteins(a 7 kDa difference).Measurement of NF-κB translocation dynamics in unfixed cells at 15-min intervals demonstrates reduced technical variance compared with *** chemical cytometry assay directly measures the nucleocytoplasmic protein distribution in individual unfixed cells,thus providing insight into protein signaling in heterogeneous cell populations.

关键词： cytometry microfluidic design proteomics single-cell analysis

F4-TCNQ concentration dependence of the current voltage characteristics in the Au/P3HT:PCBM:F4-TCNQ/n-Si(MPS) Schottky barrier diode

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Chinese Physics B 2014年第11期23卷 512-522页

作者： e.Yaglioglu O.Tzn Ozmen Department of Physics Faculty of Arts and Sciences Dzce University

In this study, we investigate some main electrical parameters of the gold/poly（3-hexylthiophene）：[6,6]-phenyl C61 bu- tyric acid methyl ester：2,3,5,6-tetrafluoro-7,7,8,8-tetracyanoquinodimethane/n-type silicon （Au/P3HT：PCBM：F4-TCNQ/n- Si） metal-polymer-semiconductor （MPS） Schottky barrier diode （SBD） in terms of the effects of F4-TCNQ concentration （0%, 1%, and 2%）. F4-TCNQ-doped P3HT：PCBM is fabricated to figure out the p-type doping effect on the device per- formance. The main electrical parameters, such as ideality factor （n）, barrier height （ФB0）, series resistance （Rs）, shunt resistance （Rsh）, and density of interface states （Nss） are determined from the forward and reverse bias current-voltage （l-V） characteristics in the dark and at room temperature. The values of n, Rs, ФB0, and Nss are significantly reduced by using the 1% F4-TCNQ doping in P3HT：PCBM：F4-TCNQ organic blend layer, additionally, the carrier mobility and current are increased by the soft （1%） doping. The most ideal values of electrical parameters are obtained for 1% F4-TCNQ used diode. On the other hand, the carrier mobility and current for the hard doping （2%） become far away from the ideal diode values due to the unbalanced generation of holes/electrons and doping-induced disproportion when compared with 1% F4-TCNQ doping. These results show that the electrical properties of MPS SBDs strongly depend on the F4-TCNQ doping and doping concentration of interfacial P3HT：PCBM：F4-TCNQ organic layer. Moreover, the soft F4-TCNQ dop- ing concentration （1%） in P3HT：PCBM：F4-TCNQ organic layer significantly improves the electrical characteristics of the Au/P3HT：PCBM：F4-TCNQ/n-Si （MPS） SBDs which enables the fabricating of high-quality electronic and optoelectronic devices.

关键词： P3HT:PCBM:F4-TCNQ interfacial organic layer F4-TCNQ doping concentration Schottky bar-rier diodes I-V characteristics

Chasing Sequencing perfection:Marching Toward Higher Accuracy and Lower Costs

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Genomics, Proteomics & Bioinformatics 2024年第2期22卷 1-12页

作者： Hangxing Jia Shengjun Tan Yong e.Zhang CAS Key Laboratory of Zoological Systematics and evolution&State Key Laboratory of Integrated Management of Pest Insects and Rodents Institute of ZoologyChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China CAS Center for excellence in Animal evolution and Genetics Chinese Academy of SciencesKunming 650223China

Next-generation sequencing(NGS),represented by Illumina platforms,has been an essential cornerstone of basic and applied ***,the sequencing error rate of 1 per 1000 bp(10^(−3))represents a serious hurdle for research areas focusing on rare mutations,such as somatic mosaicism or microbe *** examining the high-fidelity sequencing methods developed in the past decade,we summarized three major factors underlying errors and the corresponding 12 strategies mitigating these *** then proposed a novel framework to classify 11 preexisting representative methods according to the corresponding combinatory strategies and identified three trends that emerged during methodological *** further extended this analysis to eight long-read sequencing methods,emphasizing error reduction ***,we suggest two promising future directions that could achieve comparable or even higher accuracy with lower costs in both NGS and long-read sequencing.

关键词： Sequencing error High-fidelity sequencing Consensus sequencing Single-molecule sequencing Rare mutation