检索结果-南通市图书馆

Comparisons of electrical and optical properties between graphene and silicene A review

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2018年第2期27卷 299-313页

作者： wirth-Lima A J Silva M G Sombra A S B Laboratory of Telecommunications and Materials Science and Engineering-www.locem.ufc.br-Fortaleza CearaBrazil Department of Physics Science CenterFederal University of Ceara(U.F C.)-FortalezaCear4Brazil State University of Vale do Acarau SobralCeardBrasil

Two-dimensional （2D） metamaterials are considered to be of enormous relevance to the progress of all exact sciences. Since the discovery of graphene, researchers have increasingly investigated in depth the details of electrical/optical proper- ties pertinent to other 2D metamaterials, including those relating to the silicene. In this review are included the details and comparisons of the atomic structures, energy diagram bands, substrates, charge densities, charge mobilities, conductivities, absorptions, electrical permittivities, dispersion relations of the wave vectors, and supported electromagnetic modes related to graphene and silicene. Hence, this review can help readers to acquire, recover or increase the necessary technological basis for the development of more specific studies on graphene and silicene.

关键词： graphene silicene electrical/optical properties

Graphene's photonic and optoelectronic properties——A review

在线全文

学校读者我要写书评

暂无评论

Chinese Physics B 2020年第3期29卷 13-35页

作者： A J wirth-Lima P P Alves-Sousa W Bezerra-Fraga Department of Physics Federal Institute of EducationScience and Technology of Ceara Campus SobralCearaBrazil Postgraduate Program in Electrical Engineering and Computing Federal University of Ceara(U.F.C.)Sobral CearaBrazil

Due to its remarkable electrical and optical properties,graphene continues to receive more and more attention from researchers around the *** excellent advantage of graphene is the possibility of controlling its charge density,and consequently,the management of its conductivity and dielectric constant,among other *** is noteworthy that the control of these properties enables the obtaining of new optical/electronic devices,which would not exist based on conventional ***,to work in this area of science,it is necessary to have a thorough knowledge regarding the electrical/optical properties of *** this review paper,we show these graphene properties very well detailed.

关键词： absorbance conductivity dielecric constant dispersion relation

3omorbidity and survival of patients selected for radica prostatectomy at an age of 75 years or older

在线全文

学校读者我要写书评

暂无评论

Asian Journal of Andrology 2013年第5期15卷 667-671页

作者： Michael Froehner Rainer Koch Manfred P wirth Departments of Urology University Hospital 'Carl Gustav Carus' Dresden University of Technology Dresden D-01307 Germany Department of Medical Statistics and Biometry University Hospital 'Carl Gustav Carus' Dresden University of Technology Dresden D-01307 Germany

Radical prostatectomy in elderly patients is controversial. To identify very old candidates for radical prostatectomy with the highest probability of long-term survival, we studied 47 consecutive men who underwent radical prostatectomy between 1992 and 2005 at an age of 75 years or older. A heuristic approach was used to search for subgroups with particularly high long-term survival. Several two-sided comorbidity measures and combinations of these measures were investigated to find classifications best identifying healthy, long-living elderly candidates for radical prostatectomy. Four of the 25 two-sided comorbidity classifications or combinations reached the significance level with hazard ratios between 4.00 and 4.80. After 10 years, patients identified as healthy patients according to these comorbidity measurements had exhibited relative survival rates between 129% and 137% and overall survival rates between 86% and 95%, whereas those with comorbidities had exhibited relative survival rates of only 66%-84% and overall survival rates of 44%-58%. In conclusion, classifying comorbidity may identify a meaningful proportion of men selected for radical prostatectomy at an age of 75 years or older with an excellent long-term survival probability superseding that of the general population.

关键词： comorbidity old age overall survival prostate cancer radical prostatectomy relative survival

Boosting T cell immunity against cytomegalovirus:a potential strategy combating human aging and age-related diseases

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Signal Transduction and Targeted Therapy 2023年第10期8卷 4417-4418页

作者： Matthias wirth Walburgis Brenner Oliver H.Kramer Department of Hematology Oncology and Cancer ImmunologyCampus Benjamin FranklinCharite-Universitatsmedizin Berlincorporate member of Freie Universitat Berlin and Humboldt-Universitat zu BerlinBerlinGermany University Medical Center Gottingen Department of GeneralVisceral and Pediatric SurgeryGottingenGermany German Cancer Consortium(DKTK) German Cancer Research Center(DKFZ)HeidelbergGermany Clinic for Obstetrics and Women's Health University Medical CenterJohannes Gutenberg University MainzLangenbeckstr.155131 MainzGermany Department of Toxicology University Medical CenterMainzGermany

In a recent publication in Cell,Hasegawa and colleagues reveal that cytotoxic CD4-positive cytotoxic T lymphocytes(CD4+CTLs)eliminate senescent fibroblasts with a surface expression of the immunologically important human leukocyte antigen class Il(HLA-)and the human cytomegalovirus glycoprotein B(HCMV-gB).1 This implies that a virome-immune cell interaction controls the fate of human skin cells that are linked to the aging process and associated diseases.

关键词： immunity cytomegalovirus cytotoxic

Short-Term Response of Soil Respiration to Addition of Chars:Impact of Fermentation Post-Processing and Mineral Nitrogen

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Pedosphere 2015年第5期25卷 761-769页

作者： Giacomo LANZA Stephan wirth Arthur GESSLER Jrgen KERN Leibniz Institute for Agricultural Engineering Leibniz Centre for Agricultural Landscape Research (ZALF) Swiss Federal Institute for Forest Snow and Landscape Research WSL

The biodegradability of chars derived from pyrolysis and hydrothermal carbonisation(HTC) was studied in short-term dynamic incubation experiments under controlled conditions. Carbon dioxide C(CO2) emissions from soil-char mixtures in combination with solid digestate or mineral nitrogen(N) fertiliser were measured in dynamic chambers for 10 d. Compared to the original material(maize straw), pyrolysis and HTC chars showed significantly lower CO2 emissions and slower decay dynamics; and compared to the soil control, HTC char increased soil respiration to a significant extent, while pyrolysis char did not. The addition of mineral N resulted in a delayed respiration dynamics for HTC char, while the addition of digestate resulted in an increase in the respired CO2 for pyrolysis char and a decrease for HTC char. For the first time, a peculiar two-stage decay kinetics was observed for HTC char,indicating a highly inhomogeneous substrate consisting at least of two C pools.

关键词： biodegradability CO2 emission decay dynamics hydrothermal carbonisation char pyrolysis char

Affairs happen---to whom？ A study on extrapair paternity in common nightingales

在线全文

学校读者我要写书评

暂无评论

Current Zoology 2017年第4期63卷 421-431页

作者： Conny LANDGRAF Kerstin WILHELM Jutta wirth Michael WEISS Silke KIPPER Leibniz Institute for Zoo and Wildlife Research (IZW) Alfred-Kowalke-StraBe 17 10315 Berlin Germany Animal Behavior Group Free University of Berlin TakustraBe 6 14195 Berlin Germany Institute of Evolutionary Ecology and Conservation Genomics University of UIm Albert Einstein Allee 11 89069 UIm Germany Behavioural Ecology Group Department of Animal Sciences Wageningen University De Elst 1 6708 WD Wageningen The Netherlands Department of Exposition Unit Epidemiology Statistics and Mathematical Modelling Federal Institute for Risk Assessment (BfR) Max-Dohrn-Str. 8-10 10589 Berlin Germany Chair of Zoology School of Life Sciences Weihenstephan Technische Universitat Munchen LieseI-Beckmann-StraBe 4 85350 Freising Germany

Most birds engage in extrapair copulations despite great differences across and within species. Besides cost and benefit considerations of the two sex environmental factors have been found to alter mating strategies within or between populations and/or over time. For socially monogamous species, the main advantage that females might gain from mating with multiple males is probably increasing their offspring＇s genetic fitness. Since male （genetic） quality is mostly not directly meas- urable for female birds, （extrapair） mate choice is based on male secondary traits. In passerines male song is such a sexual ornament indicating male phenotypic and/or genetic quality and song repertoires seem to affect female mate choice in a number of species. Yet their role in extrapair mating behavior is not well understood. In this study, we investigated the proportion of extrapair paternity （EPP） in a population of common nightingales Luscinia megarhynchos. We found that EPP rate was rather high （21.5% of all offspring tested） for a species without sexual dimorphism and high levels of paternal care. Furthermore, the occurrence of EPP was strongly related to the spatial distribution of male territories with males settling in densely occupied areas having higher proportions of extrapair young within their own brood. Also, song repertoire size affected EPP： here larger repertoires of social mates were negatively related to the probability of being cuck- olded. When directly comparing repertoires sizes of social and extrapair mates, extrapair mates tended to have larger repertoires. We finally discuss our results as a hint for a flexible mating strat- egy in nightingales where several factors--including ecological as well as male song features-- need to be considered when studying reproductive behavior in monogamous species with complex song.

关键词： common nightingale direct fitness extrapair paternity Luscinia megarhynchos repertoire size territorial settlement.

Epigenetic modulations rendering cell-to-cell variability and phenotypic metastability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Genetics and Genomics 2016年第8期43卷 503-511页

作者： Shawal Spencer Agustina Gugliotta Natascha Godecke Hansjorg Hauser Dagmar wirth Model Systems for Infection and Immunity Helmholtz Centre for Infection ResearchBraunschweig 38124Germany Experimental Hematology Hannover Medical SchoolHannover 30625Germany cell culture laboratory faculty of biochemistry and biological sciencesnational university of the littoralSanta Fe 3000Argentina

Tumor cells display phenotypic plasticity and heterogeneity due to genetic and epigenetic variations which limit the predictability of therapeutic interventions. Chromatin modifications can arise stochas- tically but can also be a consequence of environmental influences such as the microenvironment of cancer cells. A better understanding of the impact and dynamics of epigenetic modulation at defined chromosomal sites is required to get access to the underlying mechanisms. We investigated the epige- netic modulations leading to cell-to-cell heterogeneity in a tumor cell line model. To this end, we analyzed expression variance in 80 genetically uniform cell populations having a single-copy reporter randomly integrated in the genorne. Single-cell analysis showed high intraclonal heterogeneity. Epige- netic characterization revealed that expression heterogeneity was accompanied by differential histone marks whereas contribution of DNA methylation could be excluded. Strikingly, some clones revealed a highly dynamic, stochastically altered chromatin state of the transgene cassette which was accompanied with a metastable expression pattern. In contrast, other clones represented a robust chromatin state of the transgene cassette with a stable expression pattern. Together, these results elucidate locus-specific epigenetic modulation in gene expression that contributes to phenotypic heterogeneity of cells and might account for cellular plasticity.

关键词： lntraclonal heterogeneityEpigenetic regulationDNA methylationDifferential histone marksMetastable expression

Assessing stress conditions and impact velocities in fluidized bed opposed jet mills

在线全文

学校读者我要写书评

暂无评论

Particuology 2020年第6期18卷 12-22页

作者： Alexander Strobel Benedikt Koninger Stefan Romeis Florian Schott Karl-Ernst wirth Wolfgang Peukert Institute of Particle Technology(LFG) Friedrich-Alexander-Universitat Erlangen-NiirnbergCauerstrae 491058 ErlangenGermany

Fluidized bed opposed jet mills are capable of meeting the continuously growing dema nd for contamination-free fine *** this type of jet mill,the solid material is entrained and accelerated by expanding gas jets that are focused onto a focal point in side a fluidized *** resulting particle collisions induce *** process is affected by the relative particle velocities and the number of particle-particle ***,both quantities are ***,to date,neither relative particle velocities nor collision frequencies in such units have been *** present work introduces an innovative method to assess the stressing conditions in jet mills *** this end,mixtures of glass and ductile metal microspheres were used,with the latter employed in small ***-particle collisions between the aluminum and glass spheres lead to the formation of dents on the *** size and number of these dents are associated with the individual collision velocities and overall collision *** correlation between dent size and collision velocity was obtained from finite element calculations based on empirical *** proposed approach was validated using particle image velocimetry during secondary gas injection into a fluidized bed *** this case the effect of the distance between two opposed nozzles was *** a lab-scaled fluidized bed opposed jet mill the effects of gas pressure and hold-up were *** particle velocities were found to be sign ificantly lower tha n the gas velocities,while the nu mber of contacts per particle was determined to be extremely high.

关键词： Fluidized bed opposed jet mill Single particle probes Finite element modeling Stress number distribution Relative velocity distribution

手性高价碘试剂诱导的烯烃不对称官能团化反应研究进展

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

有机化学 2021年第1期41卷 65-79页

作者：张怀远 Thomas wirth 兰州石化职业技术学院应用化学工程学院兰州730060 卡迪夫大学化学学院卡迪夫CF103AT

手性高价碘试剂诱导的烯烃官能团化是获得对映体富集的手性分子和具有生物活性天然产物的基本方法,是不对称合成中一个崭新且富有成效的领域之一.纵观20年来该领域的发展,在手性高价碘诱导下,一方面通过分子间的官能团化实现了双键的双... 详细信息

手性高价碘试剂诱导的烯烃官能团化是获得对映体富集的手性分子和具有生物活性天然产物的基本方法,是不对称合成中一个崭新且富有成效的领域之一.纵观20年来该领域的发展,在手性高价碘诱导下,一方面通过分子间的官能团化实现了双键的双磺酰氧基化、双乙酰氧基化、双卤化、双胺化、羟基化-磺酰氧基化、卤化-烷基化及羰基化等,对映选择性地合成了各种官能团化的产物;另一方面通过分子内的氧化内酯化、醚化、酰胺化、芳基化等反应,对映选择性地合成了γ-丁内酯、色满环、异色满环、噁唑烷酮、哌啶、吡咯烷、氮杂环丙烷等各种环状化合物,为手性杂环化合物的合成提供了有效途径.此外,由于手性高价碘高效诱导烯烃发生各种官能团化,提供了优秀的产率和对映选择性,因此,该方法学已被用于天然产物的全合成中.就近二十年来手性高价碘试剂诱导的烯烃官能团化及其在天然产物全合成中的应用进行综述.

关键词：手性高价碘试剂烯烃官能团化不对称合成