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Unfolding the complexity of phonon quasi-particle physics in disordered materials

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npj Computational Materials 2020年第1期6卷 1620-1627页

作者： Sai Mu Raina J.Olsen Biswanath dutta Lucas Lindsay german d.samolyuk Tom Berlijn Eliot d.Specht Ke Jin Hongbin Bei Tilmann Hickel Bennet C.Larson George M.Stocks Materials Science and Technology division Oak Ridge National LaboratoryOak RidgeTN 37831USA Max-Planck-Institut für Eisenforschung GmbH D-40237 DüsseldorfGermany Center of Nanophase and Material Science Oak Ridge National LaboratoryOak RidgeTN 37831USA Computational Science and Engineering division Oak Ridge National LaboratoryOak RidgeTN 37831USA Materials department University of CaliforniaSanta BarbaraCA 93106USA

The concept of quasi-particles forms the theoretical basis of our microscopic understanding of emergent phenomena associated with quantum-mechanical many-body ***,the quasi-particle theory in disordered materials has proven difficult,resulting in the predominance of mean-field ***,we report first-principles phonon calculations and inelastic X-ray and neutron-scattering measurements on equiatomic alloys(NiCo,NiFe,AgPd,and NiFeCo)with force-constant dominant disorder—confronting a key 50-year-old assumption in the Hamiltonian of all mean-field quasi-particle solutions for off-diagonal *** results have revealed the presence of a large,and heretofore unrecognized,impact of local chemical environments on the distribution of the species-pair-resolved force-constant disorder that can dominate phonon *** discovery not only identifies a critical analysis issue that has broad implications for other elementary excitations,such as magnons and skyrmions in magnetic alloys,but also provides an important tool for the design of materials with ultralow thermal conductivities.

关键词： alloys particle phonon

A transition from a large open pit into a novel “macroblock variant” block caving geometry at Chuquicamata mine, Codelco Chile

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Journal of Rock Mechanics and Geotechnical Engineering 2019年第3期11卷 549-561页

作者： german Flores Alex Catalan Newcrest Mining Ltd. Melbourne3004Australia Codelco Chile Santiago8320000Chile

With a history of more than 100 years, Chuquicamata has become one of the largest open pits in the world. Its current depth of 1100 m, length of 4500 m and width of 3000 m, resulting in haulage distances of over 11,000 m from pit bottom to the processing plant or waste dumps, with waste/ore ratio greater than 4 and much lower grades, are effectively determining its profitable limit by the end of this decade. Currently, there are over 4300 Mt of geological resources containing 0.7% of copper and 340 ppm (1 ppm = 1 g/t) of molybdenum below the final pit shell. The corresponding orebody geometry is 3000 m northsouth, 300-800 m eastwest and the drilling campaign suggested the existence of more than 900 m of mineable ore from the final pit bottom. This is in spite of the fact that the Chuquicamata orebody is still open at depth. The business case to continue with the mining of the Chuquicamata orebody is to change from the current large open pit to a novel macroblock variant block caving geometry. This requires a production rate of 140,000 t/d (50 Mt per annum), with a continuous material handling system to achieve the 7-year ramp-up to full production. The resolution of a number of known technical, operational and logistical challenges outside current industry practises which Chuquicamata will face over its projected 40-year mine life is therefore essential. These challenges include simultaneous operations of open pit and underground macroblocks and from the initial lift to the second lift, rapid ramp-up and optimum sequencing of the planned macroblocks, early dilution from the west fault and late dilution from potential slope failures, and the potential for major operational hazards. An equally important issue to be addressed is cultural given that the mining history in the northern region of Chile, which includes Chuquicamata, is predominantly open pit. This paper presents a synopsis of the main challenges that the Chuquicamata underground project will face in order t

关键词： Macroblock variant Block caving Cave propagation Early and late dilutions Intensive preconditioning Rib pillar West fault Ore buffer

Relative toxicity of three wheat herbicides to two species of Coccinellidae

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Insect Science 2010年第5期17卷 434-438页

作者： J. P. Michaud german Vargas department of Entomology Kansas State University Hays Kansas USA

On the High Plains of the USA, herbicides specific for broad-leaf weeds are regularly applied to winter wheat in the early spring, sometimes late enough to coincide with the colonization of fields by cereal aphids and their natural enemies. We tested the toxicity of three such herbicides, Ally （dupont）, Rave （Syngenta） and 2,4-d ester （generic）, to neonate larvae of two coccinellid species important in cereal aphid biocontrol, Coleomegilla maculata deGeer and Hippodamia convergens Gurrin-Mrneville. Topical treatment of larvae with 2,4-d resulted in 25% and 60% mortality in the two species, respectively, with surviving C. maculata larvae experiencing a 5% increase in developmental time. No significant effects were noted for the other two materials, save for a 2.5% increase in developmental time for C. maculata larvae exposed to Rave. No material caused significant mortality in either species when larvae were fed on prey （Schizaphis graminum Rondani） treated with herbicide 24 h earlier, although 2,4-d reduced developmental time slightly in C. maculata. When herbicide applications are delayed enough in spring to coincide with aphid activity in wheat, farmers can reduce the risk of disrupting biological control by selecting an alternative to 2,4-d.

关键词： 2,4-d Coleomegilla maculata dicamba Hippodamia convergens Schizaphis graminum thifensulfuron methyl

Notes on the family Brassicaceae in China

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Journal of Systematics and Evolution 2009年第3期47卷 202-219页

作者： dmitry A german Altai State University

A critical revision of the collections of Brassicaceae in some Chinese (PE, XJA, XJBI, XJFA, XJNM, XJU) and foreign (LE, P) herbaria is made. One genus, Neurotropis (dC.) F. K. Mey., and 11 species, Alyssum szarabiacum Nyár., Barbarea stricta Andrz., Erysimum czernjajevii N. Busch, Erysimum kotuchovii d. german, Erysimum mongolicum d. german, Lepidium karelinianum Al-Shehbaz, Matthiola superba Conti, Neurotropis platycarpa (Fisch. & Mey.) F. K. Mey., Ptilotrichum dahuricum Peschkova, Sisymbrium subspinescens Bunge, and Smelowskia micrantha (Botsch. & Vved.) Al-Shehbaz & S. I. Warwick, are reported from China for the first time. Six species, Aphragmus involucratus (Bunge) O. E. Schulz, dontostemon perennis C. A. Mey., Goldbachia torulosa dC., Lepidium amplexicaule Willd., Neotorularia brevipes (Kar. & Kir.) Hedge & J. Léonard, and Parrya stenocarpa Kar. & Kir., are confirmed to occurr in China. Five species, dontostemon integrifolius (L.) C. A. Mey., draba zangbeiensis L. L. Lou, Lepidium alashanicum H. L. Yang, Sinapis arvensis L., and Strigosella brevipes (Bunge) Botsch., are reported as novelties for some provinces in China, and Strigosella hispida (Litv.) Botsch. occurs in Xinjiang, China. However, the occurrence of one genus, Pseudoarabidopsis Al-Shehbaz, O’Kane & Price, and four species, draba huetii Boiss., Eutrema halophilum (C. A. Mey.) Al-Shehbaz & S. I. Warwick, Galitzkya spathulata (Steph. ex Willd.) V. Bocz., and Pseudoarabidopsis toxophylla (Bieb.) Al-Shehbaz, O’Kane & Price, could not be confirmed in China. The occurrence of six species, Aphragmus bouffordii Al-Shehbaz, Barbarea orthoceras Ledeb., Lepidium latifolium L., Ptilotrichum canescens (dC.) C. A. Mey., Strigosella hispida (Litv.) Botsch., and Strigosella scorpioides (Bunge) Botsch., is not confirmed in certain provinces of China. All names follow the latest taxonomic treatment for relevant groups; detailed morphological descriptions of the newly recorded taxa are provided; and distinguishing c

关键词： Brassicaceae China Cruciferae distribution new record.

Pregnancies established through intracytoplasmic sperm injection (ICSI) using spermatozoa with dysplasia of fibrous sheath

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Asian Journal of Andrology 2000年第2期2卷 125-130页

作者： Santiago Brugo Olmedo Vanesa Y.Rawe Florencia N.Nodar german d.Galavema Anibal A.Acosta Hector E.Chemes Centro de Estudios en Ginecologia y Reproduccion CEGyRBuenos AiresArgentina Laboratory of Testicular Physiology and Pathology Endocrinology DivisionChildren's HospitalBuenos AiresArgentina

Aim:dysplasia of the fibrous sheath(dFS)is an anomaly found in asthenozoospermic patients with extremely lowor absent *** order to determine the efficacy of ICSI in these patients,a retrospective analysis of ICSI results indFS patients has been ***:Ten ICSI attempts were performed in 6 patients with diagnosis of dysplasiaof the Fibrous Sheath studied by transmission and scanning electron ***:In the cases studied,sperm concentration was(29.62±18.05)×10^(6)/mL,total motility was 1.14±1.31%.Progressive motility was 0%except for one case with 0.1%.One hundred and three preovulatory oocytes were obtained and 94 metaphaseⅡoocyteswere ***-nine of them showed two pronuclei(fertilization rate:73.4%).Forty-nine embryos were ob-tained and 34 were transferred(mean:3.4 embryos per transfer).Five pregnancies were diagnosed byβ-hCG plasmalevel determinations that resulted to be one preclinical abortion,one clinical abortion and three ***(ongoing)was achieved from a cryopreserved embryo ***:These results showed thatICSI provides a suitable solution for patients suffering from irreversible sperm defects such as ***,it ismandatory to inform couples of possible transmission risks to offspring,which are unknown at *** when theetiology of this problem is disclosed,it will be possible to assess the real genetic risk.

关键词： spermatozoa dysplasia ciliary motility disorders intracytoplasmic sperm injection

Analysis of Atmospheric Turbidity in Clear Skies at Wuhan,Central China

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Journal of Earth Science 2017年第4期28卷 729-738页

作者： Lunche Wang Yisen Chen Ying Niu german Ariel Salaza Wei Gong department of Geography School of Earth SciencesChina University of GeosciencesWuhan 430074China Physics department School of Exact SciencesSalta National UniversitySalta A4408FVYArgentina State Key Laboratory of Information Engineering in Surveying Mapping and Remote SensingWuhan UniversityWuhan 430079China

The Angstr6m turbidity coefficient （β） and Linke turbidity factor （TL） are used to study the atmospheric conditions in Wuhan, Central China, using measureβd direct solar radiation during 2010-2011 in this study. The results show that annual mean β values generally increase from 0.28 in the morning to 0.35 at noon, and then decrease to 0.1 in the late afternoon during the day; annual mean TL generally varies from 3 to 7 in Central China. Both turbidity coefficients have maximum values in spring and summer, while minimum values are observed in winter months. It also reveals that β values show preponderance （52.8%） between 0.15 and 0.35, 78.1% of TL values are between 3.3 and 7.7, which can be compared with other sites around the world. Relationship between turbidity coefficients and main me- teorological parameters （humidity, temperature and wind direction） have been further investigated, it is discovered that the local aerosol concentrations, dust events in northern China and Southwest Monsoon from the Indian Ocean influences the β values in the study area.

关键词： direct solar radiation AngstrOm turbidity coefficient Linke turbidity factor Central China.

determinants of PHGPx Expression in a Cultured Endothelial Cell Line

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Biomedical and Environmental Sciences 1997年第2期10卷 163-176页

作者： REGINA BRIGELIUS-FLOHE B■RBEL FRIEdRICHS STEFANIE MAURER ANd RUdIGER STREICHER (german Institute of Human Nutrition,d-14558 Potsdam-Rehbrucke, germany) germanInstituteofHumanNutrition

Selenoprotein biosynthesis may not only be affected by the availability of selenium and the transcription rate of pertinent genes but also by the activity of components of the selenocysteine incorporation complex, SelA, B, C, or d. Incorporation of selenocysteine into selenoproteins requires a complex co-translational mechanism guaranteeing the correct recoding of the termination codon TGA as selenocysteine codon. A particular tRNASer(Sec) is enzyrnatically transformed by selenophosphate into tRNAsec which recognizes the UGA codon by means of a specific elongation factor (SelB) and a peculiar mRNA secondary structure. Selenophosphate is formed from selenide and ATP by the Seld gene product, selenophosphate synthase (Seld). To further elucidate the biological role of phospholipid hydroperoxide GPx (PHGPx), we transformed cells with a heterologous (pig) PHGPx gene and/or an additional (human) Seld gene and studied the behaviour of these cells under selenium depletion and repletion. Transfection of the endothelial cell line ECV 304 with either PHGPx cdNA or Seld cdNA did not result in a substantial increase of PHGPx activities, independent of selenium supply. However, cells co-trans fected with both, PHGPx and Seld cdNA, expressed significantly higher PHGPx activlty. This effect was much more pronounced under selenium limiting conditions. The enhanced PHGPx activity correlated with two functional pararneters, increased capability to reduce hydroperoxides and less sensitivity against H2O2-induced cytotoxicity. Thus, the ECV cells, stably transfected with PHGPx and Seld cdNA, provide a model to specifically investigate the role of PHGPx in endothelial cell function

关键词： ECV determinants of PHGPx Expression in a Cultured Endothelial Cell Line

Big dNA as a tool to dissect an age-related macular degeneration-associated haplotype

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Precision Clinical Medicine 2019年第1期2卷 1-7页

作者： Jon M.Laurent Xin Fu Sergei german Matthew T.Maurano Kang Zhang Jef d.Boeke Institute for Systems Genetics department of Biochemistry and Molecular Pathology department of Pathology NYU Langone Health Shiley Eye Institute UCSD School of Medicine

Age-related Macular degeneration(AMd)is a leading cause of blindness in the developed world,especially in aging populations,and is therefore an important target for new therapeutic ***,there have been several studies demonstrating strong associations between AMd and sites of heritable genetic variation at multiple loci,including a highly significant association at *** 10q26 risk region contains two genes,HTRA1 and ARMS2,both of which have been separately implicated as causative for the disease,as well as dozens of sites of non-coding *** date,no studies have successfully pinpointed which of these variant sites are functional in AMd,nor definitively identified which genes in the region are targets of such regulatory *** order to efficiently decipher which sites are functional in AMd phenotypes,we describe a general framework for combinatorial assembly of large‘synthetic haplotypes’along with delivery to relevant disease cell types for downstream functional *** demonstrate the successful and highly efficient assembly of a first-draft 119kb wild-type‘assemblon’covering the HTRA1/ARMS2 risk *** further propose the parallelized assembly of a library of combinatorial variant synthetic haplotypes covering the region,delivery and analysis of which will identify functional sites and their effects,leading to an improved understanding of AMd *** anticipate that the methodology proposed here is highly generalizable towards the difficult problem of identifying truly functional variants from those discovered via GWAS or other genetic association studies.

关键词： CRISPR gene editing synthetic biology age related macular degeneration HTRA1

Interaction between xylanase and a proton pump inhibitor on broiler chicken performance and gut function

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Animal Nutrition 2022年第1期8卷 277-288页

作者： Gemma Gonzalez-Ortiz Sophie A.Lee Kirsi Vienola Kari Raatikainen german Jurgens Juha Apajalahti Michael R.Bedford AB Vista MarlboroughWiltshireSN84ANUnited Kingdom Alimetrics Ltd. Koskelontie 19 BEspooFinland

Three hundred thirty-six Ross 308 male broiler chicks were used in a 21-d study to explore performance and gut function when treated with a proton pump inhibitor(PPI;0 or 89 mg/kg)in a 2×2 factorial arrangement with a xylanase(Xyl;0 or 0.1 g/kg)to determine if the beneficial activity of arabinoxylan(AX)depolymerisation,through arabinoxylo-oligosaccharides(AXOS)production,starts in the upper gastrointestinal *** with the PPI started from d 14,and by d 21 animal performance had deteriorated(Pd between PPI and Xyl for feed conversion ratio(FCR)(Pduced the negative effect of PPI on *** of PPI raised digesta pH in the gizzard and caecum(Pd protein concentrations in the lower gut(Pd reduced intake of digestible nutrients(Pdole,p-cresol,ammonia and the ratio of total volatile fatty acid(VFA)to butyric acid were increased with PPI(Pdicating enhanced protein *** activity in the digesta were greatest in the caeca,especially when Xyl was supplemented(Pd and ileal digesta with Xyl supplementation(Pdepolymerisation action of xylanase even under acidic *** data suggest xylanase may function in the gizzard even though pH is not optimal for activity and emphasises the importance of chlorohydric acid secretions in ensuring overall optimum gut *** depolymerisation benefits animal performance although it is still unknown how the AXOS produced with xylanase supplementation in the upper gastrointestinal tract influence the microbial populations and overall gut functionality.

关键词： Xylanase Proton pump inhibitor Arabinoxylan degradation Protein fermentation Broiler chicken