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Effect of distribution shape on the melting transition, local ordering,and dynamics in a model size-polydisperse two-dimensional fluid

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Chinese Physics b 2024年第7期33卷 419-428页

作者： jackson Pame Lenin SShagolsem Department of Physics National Institute of Technology ManipurImphalIndia

We study the effect of particle size polydispersity(δ) on the melting transition(T*), local ordering, solid–liquid coexistence phase and dynamics of two-dimensional Lennard–Jones fluids up to moderate polydispersity by means of computer simulations. The particle sizes are drawn at random from the Gaussian(G) and uniform(U) distribution *** these systems, we further consider two different kinds of particles, viz., particles having the same mass irrespective of size, and in the other case the mass of the particle scales with its size. It is observed that with increasing polydispersity,the value of T*initially increases due to improved packing efficiency(φ) followed by a decrease and terminates at δ ≈8%(U-system) and 14%(G-system) with no significant difference for both mass types. The interesting observation is that the particular value at which φ drops suddenly coincides with the peak of the heat capacity(CP) curve, indicating a transition. The quantification of local particle ordering through the hexatic order parameter(Q_6), Voronoi construction and pair correlation function reveals that the ordering decreases with increasing δ and T. Furthermore, the solid–liquid coexistence region for the G-system is shown to be comparatively wider in the T –δ plane phase diagram than that for the U system. Finally, the study of dynamics reveals that polydisperse systems relax faster compared to monodisperse systems;however, no significant qualitative differences, depending on the distribution type and mass polydispersity, are observed.

关键词： polydispersity ordering phase diagram dynamics

Theoretical study and optimization of a high power mid-infrared erbium-doped ZbLAN fibre laser

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Chinese Physics b 2011年第3期20卷 239-246页

作者：李剑峰 Stuart D.jackson School of Optoelectronic Information University of Electronic Science and Technology of China Institute of Photonics and Optical Science School of PhysicsUniversity of Sydney

based on the rate equations describing the erbium-doped fluoride glass （ZbLAN） fibre lasers with different pumping configurations being taken into account, this paper presents theoretical calculations related to the dynamic population density and the operation performance of a high power mid-infrared all-fibre erbium-doped ZbLAN fibre laser. It shows that the ground-state absorption, excited-state absorption and energy-transfer-upconversion processes co-exist and produce a population balance, causing the laser to operate stably at a continuous wave state. A good agreement between the theoretical results and recent experimental measurement is obtained. Furthermore, the laser structure parameters including fibre length, reflectance of output fibre bragg grating and pumping configurations are quantitatively optimised to achieve the best performance. The results show, as expected, that the slope efficiency of the fibre laser can be improved significantly through optimisation, which then provides an important guide for the design of high-performance mid-infrared erbium-doped ZbLAN fibre lasers.

关键词： Lerbium-doped fibre laser mid-infrared fibre laser ZbLAN fibre rate equations

C_(2) SWAN bAND EMISSION bY MULTIPHOTON PHOTODISSOCIATION OF C_(4)H_(2)N_(2) MOLECULE AT 193nm

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Chinese Physics Letters 1987年第8期4卷 345-348页

作者： XIE Xiaoxiang J.b.Halpern W.M.jackson Anhui Institute of Optics and Fine Mechanics Chinese Academy of SciencesHefei Department of Chemistry Howard UniversityWashingtonDC20059USA Department of Chemistry University of CaliforniaDavisCA 95616USA

Multiphoton dissociation of C_(4)H_(2)N_(2) molecules at 193nm has been studied at high laser *** spectra are recorded from violet(b ^(2)Σ→X ^(2)Σ)bands of CN and the Swan bands of C_(2)(d ^(3)π_(g) a ^(3)π_(u)).

关键词： bands violet dissociation

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LDA测量方截面U型旋转通道速度分布

推进技术 2001年第3期22卷 261-264页

作者：吉洪湖 LAUNDER bE jackson DC 南京航空航天大学能源与动力学院江苏南京210016 Mechanical Engineering Dept. UMIST Manchester

为了深入了解旋转涡轮叶片内冷通道中的流动特性 ,用激光多谱勒测速仪 (LDA)测量了旋转U型通道中的平均速度分布。通道的横截面积为 5 0mm× 5 0mm ,弯管的平均半径与水利直径的比值为 0 6 5 ,旋转轴与弯管的曲率轴平行。在Re=10 5 时... 详细信息

为了深入了解旋转涡轮叶片内冷通道中的流动特性 ,用激光多谱勒测速仪 (LDA)测量了旋转U型通道中的平均速度分布。通道的横截面积为 5 0mm× 5 0mm ,弯管的平均半径与水利直径的比值为 0 6 5 ,旋转轴与弯管的曲率轴平行。在Re=10 5 时分别测量了转动数Ro =0 ,0 2和 - 0 2三种旋转状态下的速度分布。在这三种情况下弯管内侧θ =90°至下游一定范围内都有流动的分离出现。由于不同的旋转状态二次流的方向和强弱不同 ,导致了分离区大小和通道中速度分布的不同。

关键词：湍流旋转流体流速测量激光多普勒速度计 LDA 燃气涡轮发动机飞行器

Progressive meristem and single-cell transcriptomes reveal the regulatory mechanisms underlying maize inflorescence development and sex differentiation

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Molecular Plant 2024年第7期17卷 1019-1037页

作者： Yonghao Sun Liang Dong Lu Kang Wanshun Zhong David jackson Fang Yang National Key Laboratory of Crop Genetic Improvement Huazhong Agricultural UniversityWuhan 430070China Hubei Hongshan Laboratory Wuhan 430070China Cold Spring Harbor Laboratory Cold Spring HarborNY 11724USA School of Agriculture Sun Yat-Sen UniversityShenzhen 518107China

Maize develops separate ear and tassel inflorescences with initially similar morphology but ultimately different architecture and *** detailed regulatory mechanisms underlying these changes still remain largely *** this study,through analyzing the time-course meristem transcriptomes and floret single-cell transcriptomes of ear and tassel,we revealed the regulatory dynamics and pathways underlying inflorescence development and sex *** identified 16 diverse gene clusters with differential spatiotemporal expression patterns and revealed biased regulation of redox,programmed cell death,and hormone signals during meristem differentiation between ear and ***,based on their dynamic expression patterns,we revealed the roles of two RNA-binding proteins in regulating inflorescence meristem activity and axillary meristem ***,using the transcriptional profiles of 53910 single cells,we uncovered the cellular heterogeneity between ear and tassel *** found that multiple signals associatedwith either enhancedcell death or reduced growth are responsiblefortassel pistil suppression,while part of the gibberellic acid signal may act non-cell-autonomously to regulate ear stamen arrest during sex *** further showed that the pistil-protection gene SILKLESS 1(SK1)functions antagonistically to the known pistil-suppression genes through regulating common molecular pathways,and constructed a regulatory network for pistil-fate ***,our study provides a deep understanding of the regulatory mechanisms underlying inflorescence development and sex differentiation in maize,laying the foundation for identifying new regulators and pathways for maize hybrid breeding and improvement.

关键词： maize inflorescence floral organ sex differentiation single-cell RNA sequencing RNA-binding protein

Vaccinations in immunosuppressive-dependent pediatric inflammatory bowel disease

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World Journal of Gastroenterology 2017年第42期23卷 7644-7652页

作者： Huyen-Tran Nguyen Phillip Minar Kimberly jackson Patricia C Fulkerson Division of Allergy and Immunology Department of Pediatrics Cincinnati Children’s Hospital Medical Center University of Cincinnati College of Medicine Division of Gastroenterology Hepatology and Nutrition Department of Pediatrics Cincinnati Children’s Hospital Medical Center University of Cincinnati College of Medicine

AIM To determine the vaccination rates in pediatric immunosuppression-dependent inflammatory bowel disease(IbD) and review the safety and efficacy of vaccinations in this *** The electronic medical records from October 2009 to December 2015 of patients diagnosed with IbD at 10 years of age or younger and prescribed antitumor necrosis factor alpha(anti-TNF-α) therapy were reviewed for clinical history, medication history, vaccination history, and hepatitis b and varicella titers. Literature discussing vaccination response in IbD patients were identified through search of the MEDLINE database and reviewed using the key words "inflammatory bowel disease", "immunization", "vaccination", "pneumococcal", "varicella", and "hepatitis b". Non-human and non-English language studies were excluded. Search results were reviewed by authors toselect articles that addressed safety and efficacy of immunizations in inflammatory bowel *** A total of 51 patients diagnosed with IbD prior to the age of 10 and receiving anti-TNF-α therapy were identified. Thirty-three percent of patients(17/51) had incomplete or no documentation of vaccinations. Sixteen case reports, cohort studies, cross-sectional studies, and randomized trials were determined through review of the literature to describe the safety and efficacy of hepatitis b, pneumococcal, and varicella immunizations in adult and pediatric patients with IbD. These studies showed that patients safely tolerated the vaccines without significant adverse effects. Importantly, IbD patients receiving immunosuppressive medications, particularly anti-TNF-α treatment, have decreased vaccine response compared to controls. However, the majority of patients are still able to achieve protective levels of specific antibodies. CONCLUSION Immunizations have been shown to be well-tolerated and protective immunity can be achieved in patients with IbD requiring immunosuppressive therapy.

关键词： Vaccination Immunosuppression Earlyonset inflammatory bowel disease Very early-onset inflammatory bowel disease

Data-driven estimates of global nitrous oxide emissions from croplands

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National Science Review 2020年第2期7卷 441-452页

作者： Qihui Wang Feng Zhou Ziyin Shang Philippe Ciais Wilfried Winiwarter Robert b.jackson Francesco N.Tubiello Greet Janssens-Maenhout Hanqin Tian Xiaoqing Cui Josep G.Canadell Shilong Piao Shu Tao Sino-France Institute of Earth Systems Science Laboratory for Earth Surface Processes College of Urban and Environmental Sciences Peking University European Commission Joint Research Centre International Institute for Applied Systems Analysis (IIASA) The Institute of Environmental Engineering University of Zielona Góra Global Carbon Project CSIRO Oceans and Atmosphere Department of Earth System Science Stanford University Statistics Division Food and Agricultural Organization of the United Nations Via Terme di Caracalla International Center for Climate and Global Change Research School of Forestry and Wildlife Sciences Auburn University Laboratoire des Sciences du Climat et de l'Environnement LSCE CEA CNRS UVSQ

Croplands are the single largest anthropogenic source of nitrous oxide(NO) globally, yet their estimates remain difficult to verify when using Tier 1 and 3 methods of the Intergovernmental Panel on Climate Change(IPCC). Here, we re-evaluate global cropland-NO emissions in 1961–2014, using N-rate-dependent emission factors(EFs) upscaled from 1206 field observations in 180 global distributed sites and high-resolution N inputs disaggregated from sub-national surveys covering 15593 administrative units. Our results confirm IPCC Tier 1 default EFs for upland crops in 1990–2014, but give a ～15% lower EF in 1961–1989 and a ～67% larger EF for paddy rice over the full period. Associated emissions(0.82 ±0.34 Tg N yr) are probably one-quarter lower than IPCC Tier 1 global inventories but close to Tier 3 estimates. The use of survey-based gridded N-input data contributes 58% of this emission reduction, the rest being explained by the use of observation-based non-linear EFs. We conclude that upscaling NO emissions from site-level observations to global croplands provides a new benchmark for constraining IPCC Tier 1 and 3 methods. The detailed spatial distribution of emission data is expected to inform advancement towards more realistic and effective mitigation pathways.

关键词： nitrous oxide agricultural soils flux upscaling emission factor emission inventories temporal trend

The Schlager mouse as a model of altered retinal phenotype

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Neural Regeneration Research 2020年第3期15卷 512-518页

作者： Lakshini Y.Herat Aaron L.Magno Márcio G.Kiuchi Kristy L.jackson Revathy Carnagarin Geoffrey A.Head Markus P.Schlaich Vance b.Matthews Dobney Hypertension Centre School of Biomedical Science-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Research Centre Royal Perth HospitalPerthAustralia Dobney Hypertension Centre School of Medicine-Royal Perth Hospital UnitUniversity of Western AustraliaPerthAustralia Neuropharmacology Laboratory Baker Heart and Diabetes InstituteMelbourneAustralia Department of Cardiology and Department of Nephrology Royal Perth HospitalPerthAustralia

Hypertension is a risk factor for a large number of vision-threatening eye *** this study,we investigated for the first time the retinal neural structure of the hypertensive bPH/2J mouse(Schlager mouse)and compared it to its control counterpart,the normotensive bPN/3J *** bPH/2J mouse is a selectively inbred mouse strain that develops chronic hypertension due to elevated sympathetic nervous system *** compared to the bPN/3J strain,the hypertensive bPH/2J mice showed a complete loss of outer layers of the neural retina at 21 weeks of age,which was indicative of a severe vision-threatening disease potentially caused by *** elucidate whether the retinal neural phenotype in the bPH/2J strain was attributed to increased bP,we investigated the neural retina of both bPN/3J and bPH/2J mice at 4 weeks of *** preliminary results showed for the first time that the bPH/2J strain develops severe retinal neural damage at a young *** findings suggest that the retinal phenotype in the bPH/2J mouse is possibly due to elevated blood pressure and may be contributed by an early onset spontaneous mutation which is yet to be identified or a congenital defect occurring in this *** characterization of the bPH/2J mouse strain is likely to i)elucidate gene defects underlying retinal disease;ii)understand mechanisms leading to neural retinal disease and iii)permit testing of molecules for translational research to interfere with the progression of retinal *** animal experiments were performed with the approval of the Royal Perth Hospital Animal Ethics Committee(R535/17-18)on June 1,2017.

关键词： blood pressure eye hypertension mice neural regeneration retina Schlager mouse sympathetic nervous system

Disturbance cues in freshwater prey fishes： Does urea function as an ＇early warning cue＇ in juvenile convict cichlids and rainbow trout？

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Current Zoology 2012年第2期58卷 250-259页

作者： Grant E. bROWN Christopher D. jackson Patrick H. MALKA Elisa JACQUES Marc-Andre COUTURIER Department of biology Concordia University 7141 Sherbrooke St. West Montreal Quebec H4B 1R6 CANADA

Freshwater vertebrate and invertebrate prey species commonly rely on chemosensory information, including non-injury released disturbance cues, to assess local predation threats. We conducted laboratory studies to （1） determine if urea can function as a disturbance cue in juvenile convict cichlids and rainbow trout and （2） determine if the background level of urea influences the behavioral response to a subsequent pulse of urea （＇background noise＇ hypothesis）. In the first series of trials, juve- nile cichlids and trout were exposed to urea at varying concentrations （0 to 0.5 mg L-1 for cichlids and 0 to 1.0 mg L1 for trout）. Our results suggest that both cichilds and trout exhibited functionally similar responses to urea and conspecific disturbance cues and that increasing the concentration of urea results in an increase intensity of antipredator behaviour. In the second series of trials, we pre-exposed cichlids or trout to intermediate or high concentrations of urea （or a distilled water control） and then tested for the response to a second pulse of urea at at intermediate or high concentrations （versus a distilled water control）. Our results demon- strate that pre-exposure to urea reduces or eliminates the response to a second pulse of urea, supporting the background noise hy- pothesis. Together, our results suggest that pulses of urea, released by disturbed or stressed individuals, may function as an early warning signal in freshwater prey species

关键词： Disturbance cue Metabolic wastes Chemosensory risk assessment Predator-prey interactions Convict cichlids Rainbow trout