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Transportation characteristics of gas-solid two-phase flow in a long-distance pipeline

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Particuology 2015年第4期13卷 196-202页

作者： Xiaoqiang zhang dongfeng zhang An Wang Yide Geng College of Mining Engineering Taiyuan University of Technology China National Coal Group Corporation

In this study, experiments on fly ash conveying were carried out with a home-made long-distance positive-pressure pneumatic conveying system equipped with a high performance electrical capacitance tomography system to observe the transient characteristics of gas-solid two-phase flow. The experimen- tal results indicated that solids throughput increased with increasing solids-gas ratio when the conveying pipeline was not plugged. Moreover, the optimum operating state was determined for the 1000 m long conveying pipeline with a throttle plate of 26 orifices. At this state the solids throughput was about 12.97 t/h. Additionally, the transportation pattern of fly ash gradually changed from sparse-dense flow to partial and plug flows with increasing conveying distance because of the conveying pressure loss, These experimental results provide important reference data for the development of pneumatic conveying technology.

关键词： Pneumatic conveying Electrical capacitance tomography Fly ash Gas-solid two-phase flow Solid concentration

A Sequential Quantitative Trait Locus Fine-Mapping Strategy Using Recombinant-Derived Progeny

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Journal of Integrative Plant Biology 2012年第4期54卷 228-237页

作者： Qin Yang dongfeng zhang Mingliang Xu National Maize Improvement Center of China China Agricultural UniversityBeijing 100193China

A thorough understanding of the quantitative trait loci （QTLs） that underlie agronomically important traits in crops would greatly increase agricultural productivity. Although advances have been made in QTL cloning, the majority of QTLs remain unknown because of their low heritability and minor contributions to phenotypic performance. Here we summarize the key advantages and disad- vantages of current QTL fine-mapping methodologies, and then introduce a sequential QTL fine-mapping strategy based on both genotypes and phenotypes of progeny derived from recombinants. With this mapping strategy, experimental errors could be dramat- ically diminished so as to reveal the authentic genetic effect of target QTLs. The number of progeny required to detect QTLs atvarious R2 values was calculated, and the backcross generation suitable to start QTL fine-mapping was also estimated. This mapping strategy has proved to be very powerful in narrowing down QTL regions, particularly minor-effect QTLs, as revealed by fine-mapping of various resistance QTLs in maize. Application of this sequential QTL mapping strategy should accelerate cloning of agronomically important QTLs, which is currently a substantial challenge in crops.

关键词： Fine-mapping strategy progeny quantitative trait locus recombinant.

Twin-Based DNA Methylation Analysis Takes the Center Stage of Studies of Human Complex Diseases

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Journal of Genetics and Genomics 2012年第11期39卷 581-586页

作者： dongfeng zhang Shuxia Li Qihua Tan Zengchang Pang Department of Public Health Qingdao University Medical College38 Dengzhou StreetQingdao 266021China Institute of Clinical Research Unit of Human GeneticsUniversity of Southern DenmarkSdr.Boulevard 29Odense C DK-5000Denmark Epidemiology Institute of Public HealthUniversity of Southern DenmarkJ.B.WinslOws Vej 9bOdense C DK-5000Denmark Qingdao Center for Disease Control and Prevention 175 Shandong RoadQingdao 266033China

The etiology of complex diseases is characterized by the interaction between the genome and environmental conditions and the interface of epigenetics may be a central mechanism. Current technologies already allow us high-throughput profiling of epigenetic patterns at genome level. However, our understanding of the epigenetic processes remains limited. Twins are special samples in genetic studies due to their genetic similarity and rearing-environment sharing. In the past decades, twins have made a great contribution in dissecting the genetic and environmental contributions to human diseases and complex traits. In the era of functional genomics, the valuable samples of twins are helping to bridge the gap between gene activity and environmental conditions through epigenetic mech- anisms unlimited to DNA sequence variations. We review the recent progresses in using twins to study disease-related molecular epigenetic pbenotypes and link them with environmental exposures especially early life events. Various study designs and application issues will be highlighted and discussed with aim at making uses of twins in assessing the environmental impact on epigenetic changes during the development of complex diseases.

关键词： Twins Complex diseases Epigenetics Environments Genomics

Clinicopathological features and survival analysis of gastroenteropancreatic neuroendocrine neoplasms: a retrospective study in a single center of China

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Chinese Journal of Cancer Research 2015年第3期27卷 258-266页

作者： Xuelong Jiao Yujun Li Hongyan Wang Shanglong Liu dongfeng zhang Yanbing Zhou General Surgery Department The Affiliated Hospital of Qingdao University Pathology Department The Affiliated Hospital of Qingdao University Department of Epidemiology and Health Statistics The Medical College of Qingdao University

Objective： To investigate the clinicopathological features, survival and prognostic factors for gastroenteropancreatic neuroendocrine neoplasms（GEP-NENs） in a Chinese ***： We investigated 154 consecutive patients（88 males, 66 females; median age 56 years, age range 9-86 years） diagnosed with GEP-NENs between 2001 and 2013 at The Affiliated Hospital of Qingdao University. Demographic, clinical and pathological variables and survival data were ***： The pancreas was the most common site of involvement（63/154, 40.9%）. Tumor size varied from 0.3 to 16.0 cm（median, 1.2 cm）. The patients were followed up for a median period of 22 months（range, 1-157 months）. The estimated 3- and 5-year overall survival（OS） rates for all patients were 84.0% and 81.9%, respectively. Multivariate analysis showed that larger tumor size, lymphatic metastases and distant metastases were significant predictors for poor survival ***： Our data provide further information on the clinicopathological features of GEP-NENs in China. Additionally, we identified tumor size, lymphatic metastases and distant metastases as independent prognostic factors for long-term survival.

关键词： Gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN) clinicopathological characteristics survival analysis Ki-67 retrospective study

The Auxin-Regulated Protein ZmAuxRPI Coordinates the Balance between Root Growth and Stalk Rot Disease Resistance in Maize

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Molecular Plant 2019年第3期12卷 360-373页

作者： Jianrong Ye Tao Zhong dongfeng zhang Chuanyu Ma Lina Wang Lishan Yao Qianqian zhang Mang Zhu Mingliang Xu State Key Laboratory of Plant Physiology and Biochemistry/National Maize Improvement Center/College of Agronomy and Biotechnology/Center for Crop Functional Genomics and Molecular Breeding China Agricultural University2 West Yuanmingyuan RoadBeijing 100193P.R.China

To optimize fitness, plants must efficiently allocate their resources between growth and defense. Although phytohormone crosstalk has emerged as a major player in balancing growth and defense, the genetic basis by which plants man age this balance remai ns elusive. We previously ide ntified a quantitative disease . resistance locus, qRfg2, in maize (Zea mays) that protects against the fungal disease Gibberella stalk rot. Here, through map-based cloning, we demonstrate that the causal gene at qRfg2 is ZmAuxRPI, which encodes a plastid stroma-localized auxin-regulated protein. ZmAuxRPI responded quickly to pathogen challenge with a rapid yet transient reduction in expression that led to arrested root growth but enhanced resista nee to Gibberella stalk rot and Fusarium ear rot. ZmAuxRPI was show n to promote the biosynthesis of indole-3-acetic acid (IAA), while suppressing the formation of benzoxazinoid defense compounds. ZmAuxRPI presumably acts as a resource regulator modulating indole-3-glycerol phosphate and/or indole flux at the branch point between the IAA and benzoxazinoid biosynthetic pathways. The concerted interplay between IAA and benzoxazinoids can regulate the growth-defense balance in a timely and efficient manner to optimize plant fitness.

关键词： maize quantitative disease resistance Gibberella stalk rot Fusarium ear rot indole-3-acetic acid benzoxazinoids

TrG2P:A transfer-learning-based tool integrating multi-trait data for accurate prediction of crop yield

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Plant Communications 2024年第7期5卷 16-27页

作者： Jinlong Li dongfeng zhang Feng Yang Qiusi zhang Shouhui Pan Xiangyu Zhao Qi zhang Yanyun Han Jinliang Yang Kaiyi Wang Chunjiang Zhao Information Technology Research Center Beijing Academy of Agriculture and Forestry SciencesBeijing 100097China National Engineering Research Center for Information Technology in Agriculture Beijing 100097China Department of Agronomy and Horticulture University of Nebraska-LincolnLincolnNE 68583USA Center for Plant Science Innovation University of Nebraska-LincolnLincolnNE 68583USA These authors contributed equally to this article

Yield prediction is the primary goal of genomic selection(GS)-assisted crop *** yield is a complex quantitative trait,making predictions from genotypic data is *** learning can produce an effective model for a target task by leveraging knowledge from a different,but related,source domain and is considered a great potential method for improving yield prediction by integrating multi-trait ***,it has not previously been applied to genotype-to-phenotype prediction owing to the lack of an efficient implementation *** therefore developed TrG2P,a transfer-learning-based ***2P first employs convolutional neural networks(CNN)to train models using non-yield-trait phenotypic and genotypic data,thus obtaining pre-trained ***,the convolutional layer parameters from these pre-trained models are transferred to the yield prediction task,and the fully connected layers are retrained,thus obtaining fine-tuned ***,the convolutional layer and the first fully connected layer of the fine-tuned models are fused,and the last fully connected layer is trained to enhance prediction *** applied TrG2P to five sets of genotypic and phenotypic data from maize(Zea mays),rice(Oryza sativa),and wheat(Triticum aestivum)and compared its model precision to that of seven other popular GS tools:ridge regression best linear unbiased prediction(rrBLUP),random forest,support vector regression,light gradient boosting machine(LightGBM),CNN,DeepGS,and deep neural network for genomic prediction(DNNGP).TrG2P improved the accuracy of yield prediction by 39.9%,6.8%,and 1.8%in rice,maize,and wheat,respectively,compared with predictions generated by the best-performing comparison *** work therefore demonstrates that transfer learning is an effective strategy for improving yield prediction by integrating information from non-yield-trait *** attribute its enhanced prediction accuracy to the valuable information ava

关键词： crop genotype to phenotype transfer learning yield prediction multi-trait

Dynamical investigation of tunable magnetism in Au@Ni-carbide nanocrystals by a combined soft and hard X-ray absorption spectroscopy

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Nano Research 2022年第5期15卷 4320-4326页

作者： Weifeng Huang Jianxin Kang Tingwen Chen Dawei Pang Lihua Wang Hang Wei Changchun Yang dongfeng zhang Lin Guo College of Chemistry and Chemical Engineering Inner Mongolia UniversityHohhot 010021China School of Electronic Engineering Jiujiang UniversityJiujiang 332005China School of Chemistry Beihang UniversityBeijing 100191China Institute of Microstructure and Property of Advanced Materials Beijing University of TechnologyBeijing 100124China

Nickel based magnetic nanocrystals have been widely applied in magnetic and catalytic *** magnetic properties of nickel can be easily obtained via non-magnetic doping or phase ***,phase transformation from face centered cubic(fcc)to hexagonal close packed(hcp)induced magnetism adjustment of Ni are always confused with nickel carbide(Ni_(3)C),due to the similar atomic structures of hcp-Ni and ***,we present series of Au@Ni-carbide magnetic materials achieved from the controlled carbonation of Au@Ni core-shell structures,whose magnetism is tunable by adjusting the amount of carbon in the Ni ***-situ hard X-ray absorption spectroscopy(XAS)at the metal K edge and soft XAS at both metal L edge and carbon K edge provide solid evidence for the carbonation process from fcc-Ni to Ni_(x)C,rather than phase transformation to *** investigation reveals that the magnetism of the hybrids is mainly contributed from the residual *** result represents an accurate and effective way to distinguish hexagonal Ni_(3)C from hcp-Ni,and provides the pathway to control magnetism of Ni-based materials for applications.

关键词： X-ray absorption spectroscopy soft X-ray absorption spectroscopy carbide nickel carbonation process magnetism

Performance of RegCM4 over Major River Basins in China

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Advances in Atmospheric Sciences 2017年第4期34卷 441-455页

作者： Xuejie GAO Ying SHI Zhenyu HAN Meili WANG Jia WU dongfeng zhang Ying XU Filippo GIORGI Climate Change Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China National Climate Center China Meteorological AdministrationBeijing 100081China China Meteorological News Press China Meteorological AdministrationBeijing 100081China Shanxi Climate Center Taiyuan 030006China The Abdus Salam International Centre for Theoretical Physics Trieste 34100Italy

A long-term simulation for the period 1990–2010 is conducted with the latest version of the International Centre for Theoretical Physics＇ Regional Climate Model（RegCM4）, driven by ERA-Interim boundary conditions at a grid spacing of 25 km. The Community Land Model（CLM） is used to describe land surface processes, with updates in the surface parameters,including the land cover and surface emissivity. The simulation is compared against observations to evaluate the model performance in reproducing the present day climatology and interannual variability over the 10 main river basins in China,with focus on surface air temperature and precipitation. Temperature and precipitation from the ERA-Interim reanalysis are also considered in the model assessment. Results show that the model reproduces the present day climatology over China and its main river basins, with better performances in June–July–August compared to December–January–February（DJF）.In DJF, we find a warm bias at high latitudes, underestimated precipitation in the south, and overestimated precipitation in the north. The model in general captures the observed interannual variability, with greater skill for temperature. We also find an underestimation of heavy precipitation events in eastern China, and an underestimation of consecutive dry days in northern China and the Tibetan Plateau. Similar biases for both mean climatology and extremes are found in the ERA-Interim reanalysis, indicating the difficulties for climate models in simulating extreme monsoon climate events over East Asia.

关键词： regional climate model RegCM4 China river basin CLM

Climate change in China in the 21st century as simulated by a high resolution regional climate model

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Chinese Science Bulletin 2012年第5期57卷 1188-1195页

作者： GAO XueJie SHI Ying zhang dongfeng GIORGI Filippo National Climate Center China Meteorological Administration Beijing 100081 China Shanxi Climate Center Taiyuan 030006 China The Abdus Salam International Centre for Theoretical Physics Trieste 34100 Italy

Climate change in the 21st century over China is simulated using the Abdus Salam International Centre for Theoretical Physics (ICTP) Regional Climate Model version 3 (RegCM3). The model is one-way nested within the global model CCSR/NIES/FRCGC MIROC3.2_hires (Center for Climate System Research/National Institute for Environmental Studies/Frontier Research Center for Global Change/Model for Interdisciplinary Research on Climate). A 150-year (1951-2100) transient simulation is conducted at 25 km grid spacing, under the Intergovernmental Panel on Climate Change Special Report on Emissions Scenarios (IPCC SRES) A1B scenario. Simulations of present climate conditions in China by RegCM3 are compared against observations to assess model performance. Results show that RegCM3 reproduces the observed spatial structure of surface air temperature and precipitation well. Changes in mean temperature and precipitation in December-January-February (DJF) and June-July-August (JJA) during the middle and end of the 21st century are analyzed. Significant future warming is simulated by RegCM3. This warming becomes greater with time, and increased warming is simulated at high latitude and high altitude (Tibetan Plateau) areas. In the middle of the 21st century in DJF, a general increase of precipitation is found in most areas, except over the Tibetan Plateau. Precipitation changes in JJA show an increase over northwest China and a decrease over the Tibetan Plateau. There is a mixture of positive and negative changes in eastern China. The change pattern at the end of the century is generally consistent with that in mid century, except in some small areas, and the magnitude of change is usually larger. In addition, the simulation is compared with a previous simulation of the RegCM3 driven by a different global model, to address uncertainties of the projected climate change in China.

关键词：中国西北地区区域气候模式模式模拟气候变化高分辨率气候模型气候变暖青藏高原

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