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FY-4A卫星闪电资料与ADTD闪电资料在四川省冕宁暴雨中的对比分析及数值模拟 被引量:3
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作者 赵婥 徐国强 +1 位作者 黄守友 程佳佳 《大气科学》 CSCD 北大核心 2023年第3期769-785,共17页
FY-4A卫星闪电资料与地基ADTD(Advanced Direction and Time of arrival Detecting system)闪电资料对于研究暴雨等强对流天气具有一定的指示意义,通过对四川省冕宁暴雨个例的研究,对比分析了这两种闪电资料的差别,设计了将两种闪电资... FY-4A卫星闪电资料与地基ADTD(Advanced Direction and Time of arrival Detecting system)闪电资料对于研究暴雨等强对流天气具有一定的指示意义,通过对四川省冕宁暴雨个例的研究,对比分析了这两种闪电资料的差别,设计了将两种闪电资料引入数值预报模式的多组数值试验。结果表明:(1)两种闪电资料在不同地区有不同的探测效果,ADTD闪电资料范围更广且分散,FY-4A卫星监测到的闪电数量更密集、分布更集中;两种闪电资料在进入模式之后所转化成的代理雷达回波具有很好的一致性;对于低频次的闪电来说,ADTD闪电定位仪可能比FY-4A闪电成像仪探测效率更高。(2)引入任何一种闪电资料都对降水预报具有正效果,其中ADTD闪电资料的应用对于短时降水预报准确率的提高更为有效。(3)两种闪电资料对于云微物理量的调整作用,在不同的区域有不同效果,说明这两种闪电资料的分布不完全一致,揭示出这两种闪电资料具有一定的互补性。 展开更多
关键词 闪电资料 对比分析 云分析 数值试验
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Prognostic value of the long noncoding RNA AFAP1-AS1 in cancers 被引量:1
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作者 Lixiu Zhu Jiawen Yan +6 位作者 guoqiang xu Qiaoli Wang Tianrui xu Ruixue Cao Chuanzheng Sun Yan Xi Wei Xiong 《Oncology and Translational Medicine》 CAS 2023年第3期133-146,共14页
Objective This meta-analysis explored whether the expression of actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1)is related to the prognosis and clinicopathological features of patients with cancer.Method... Objective This meta-analysis explored whether the expression of actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1)is related to the prognosis and clinicopathological features of patients with cancer.Methods PubMed,EMBASE,and Cochrane Library were systematically searched.Hazard ratios(HRs)with 95%confidence intervals(CIs)were used to assess the prognostic value based on overall survival(OS),disease-free survival(DFS),and progression-free survival(PFS).Odds ratios(ORs)with 95%CIs were used to determine the relationships between AFAP1-AS1 and clinicopathological features,such as large tumor size(LTS),high tumor stage(HTS),poor histological grade(PHG),lymph node metastasis(LNM),and distant metastasis(DM).Results Thirty-five eligible articles and 3433 cases were analyzed.High AFAP1-AS1 expression,compared to low AFAP1-AS1 expression,correlated with significantly shorter OS(HR=2.15,95%CI=1.97-2.34,P<0.001),DFS(HR=1.37,95%CI=1.19-1.57,P<0.001),and PFS(HR=1.97,95%CI=1.56-2.50,P<0.001)in patients with cancer.In various cancers,elevated AFAP1-AS1 expression was significantly associated with LTS(OR=2.76,95%CI=2.16-3.53,P<0.001),HTS(OR=2.23,95%CI=1.83-2.71,P<0.001),and PHG(OR=1.39,95%CI=1.08-1.79,P=0.01)but not LNM(OR=1.59,95%CI=0.88-2.85,P=0.12)or DM(OR=1.81,95%CI=0.90-3.66,P=0.10).Conclusion High AFAP1-AS1 expression was associated with prognostic and clinicopathological features,suggesting that AFAP1-AS1 is a prognostic biomarker for human cancers. 展开更多
关键词 long noncoding RNA(lncRNA) actin filament-associated protein 1 antisense RNA 1(AFAP1-AS1) PROGNOSTIC META-ANALYSIS
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基于核质遗传原理建立多重PCR检测方法鉴定阿胶中马、驴源性成分及皮张种源 被引量:9
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作者 谌阳 王文君 +3 位作者 付明 徐国强 周翔 刘榜 《遗传》 CAS CSCD 北大核心 2020年第10期1028-1035,共8页
阿胶(Asini Colla Corii)及其原料皮张源性成分的鉴定是对阿胶真实性的一种保障,阿胶生产企业和市场监管部门急需马、驴、骡皮张以及阿胶中源性成分鉴别的有效检测方法。本研究基于马、驴核基因组和线粒体基因组筛选物种特异性DNA序列... 阿胶(Asini Colla Corii)及其原料皮张源性成分的鉴定是对阿胶真实性的一种保障,阿胶生产企业和市场监管部门急需马、驴、骡皮张以及阿胶中源性成分鉴别的有效检测方法。本研究基于马、驴核基因组和线粒体基因组筛选物种特异性DNA序列作为检测靶标,设计马、驴特异性引物,建立了鉴别马、驴、骡皮张以及鉴定阿胶中马和驴源性成分的多重PCR方法。结果显示,本文所建立的方法可用于阿胶源性成分及皮张种源的鉴别,其特异性强,只在目标物种中扩增出目的条带,而非目标物种中没有任何扩增产物,而且灵敏度能达到0.2 ng,可为阿胶生产企业和市场监管部门提供技术支撑。 展开更多
关键词 阿胶 核基因 线粒体基因 多重PCR 马、驴源性成分
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A Sun Tracking System Design for a Large Dish Solar Concentrator
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作者 Xiaoshan Jin guoqiang xu +2 位作者 Rongjiu Zhou Xiang Luo Yongkai Quan 《International Journal of Clean Coal and Energy》 2013年第2期16-20,共5页
Energy crisis promotes the development of renewable energy, especially the solar energy. Sun tracking system proposed in this paper is such a device for efficiency improvement. This closed loop tracking system with tw... Energy crisis promotes the development of renewable energy, especially the solar energy. Sun tracking system proposed in this paper is such a device for efficiency improvement. This closed loop tracking system with two axis sun tracking method is controlled by a programmable logic controller (PLC) and is used for a large dish solar collector. A combination tracking mode combined active and passive tracking methods used in the design make the tracker efficient whatever the circumstances. Two stepper motors and two reduction boxes move the device towards the sun with chain transmission. Besides sun tracking, the system also has functions of overheat monitoring, wind speed monitoring and measurement of illumination. 展开更多
关键词 RENEWABLE ENERGY Solar ENERGY SUN TRACKING PLC COMBINATION TRACKING Mode
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Anemoside B4 inhibits SARS-CoV-2 replication in vitro and in vivo 被引量:1
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作者 Mingyue Xiao Ronghua Luo +7 位作者 Qinghua Liang Honglv Jiang Yanli Liu guoqiang xu Hongwei Gao Yongtang Zheng Qiongming xu Shilin Yang 《Chinese Herbal Medicines》 CAS 2024年第1期106-112,共7页
Objective: Anemoside B4(AB4), the most abundant triterpenoidal saponin isolated from Pulsatilla chinensis, inhibited influenza virus FM1 or Klebsiella pneumoniae-induced pneumonia. However, the anti-SARS-CoV-2 effect ... Objective: Anemoside B4(AB4), the most abundant triterpenoidal saponin isolated from Pulsatilla chinensis, inhibited influenza virus FM1 or Klebsiella pneumoniae-induced pneumonia. However, the anti-SARS-CoV-2 effect of AB4 has not been unraveled. Therefore, this study aimed to determine the antiviral activity and potential mechanism of AB4 in inhibiting human coronavirus SARS-CoV-2 in vivo and in vitro.Methods: The cytotoxicity of AB4 was evaluated using the Cell Counting Kit-8(CCK8) assay. SARS-CoV-2 infected HEK293T, HPAEpiC, and Vero E6 cells were used for in vitro assays. The antiviral effect of AB4 in vivo was evaluated by SARS-CoV-2-infected hACE2-IRES-luc transgenic mouse model. Furthermore,label-free quantitative proteomics and bioinformatic analysis were performed to explore the potential antiviral mechanism of action of AB4. Type Ⅰ IFN signaling-associated proteins were assessed using Western blotting or immumohistochemical staining.Results: The data showed that AB4 reduced the propagation of SARS-CoV-2 along with the decreased Nucleocapsid protein(N), Spike protein(S), and 3C-like protease(3CLpro) in HEK293T cells. In vivo antiviral activity data revealed that AB4 inhibited viral replication and relieved pneumonia in a SARS-CoV-2 infected mouse model. We further disclosed that the antiviral activity of AB4 was associated with the enhanced interferon(IFN)-β response via the activation of retinoic acid-inducible gene Ⅰ(RIG-1) like receptor(RLP) pathways. Additionally, label-free quantitative proteomic analyses discovered that 17 proteins were significantly altered by AB4 in the SARS-CoV-2 coronavirus infections cells. These proteins mainly clustered in RNA metabolism.Conclusion: Our results indicated that AB4 inhibited SARS-CoV-2 replication through the RLR pathways and moderated the RNA metabolism, suggesting that it would be a potential lead compound for the development of anti-SARS-CoV-2 drugs. 展开更多
关键词 anemoside B4 INTERFERON RNA metabolism quantitative proteomics SARS-CoV-2
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miR-504 knockout regulates tumor cell proliferation and immune cell infiltration to accelerate oral cancer development
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作者 Xiaotang Wang Xiaona Song +8 位作者 Yunhui Ma Junting Yang Jiping Gao Tian Wang guoqiang xu Xiaoqi Chang Shuxuan Shi Rui Sun Guohua Song 《Journal of Genetics and Genomics》 SCIE CAS CSCD 2024年第10期1040-1054,共15页
miR-504 plays a pivotal role in the progression of oral cancer.However,the underlying mechanism remains elusive in vivo.Here,we find that miR-504 is significantly down-regulated in oral cancer patients.We generate miR... miR-504 plays a pivotal role in the progression of oral cancer.However,the underlying mechanism remains elusive in vivo.Here,we find that miR-504 is significantly down-regulated in oral cancer patients.We generate miR-504 knockout mice(miR-504^(-/-))using CRISPR/Cas9 technology to investigate its impact on the malignant progression of oral cancer under exposure to 4-Nitroquinoline N-oxide(4NQO).We show that the deletion of miR-504 does not affect phenotypic characteristics,body weight,reproductive performance,and survival in mice,but results in changes in the blood physiological and biochemical indexes of the mice.Moreover,with 4NQO treatment,miR-504^(-/-)mice exhibit more pronounced pathological changes char-acteristic of oral cancer.RNA sequencing shows that the differentially expressed genes observed in samples from miR-504^(-/-)mice with oral cancer are involved in regulating cell metabolism,cytokine acti-vation,and lipid metabolism-related pathways.Additionally,these differentially expressed genes are significantly enriched in lipid metabolism pathways that influence immune cell infiltration within the tumor microenvironment,thereby accelerating tumor development progression.Collectively,our results suggest that knockout of miR-504 accelerates malignant progression in 4NQO-induced oral cancer by regulating tumor cell proliferation and lipid metabolism,affecting immune cell infiltration. 展开更多
关键词 miR-504 CRISPR/Cas9 Oral cancer animal model 4NQO Malignant proliferation Lipid metabolism
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Local resistance characteristics of elbows for supercritical pressure RP-3 flowing in serpentine micro-tubes
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作者 Yanchen Fu Yinlong Liu +3 位作者 Juan Wang Yu Wang guoqiang xu Jie Wen 《Propulsion and Power Research》 SCIE 2024年第2期245-256,共12页
Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection on aero-engines,the elbow localflow resistance charac-teristics for supercritical pressure aviation fu... Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection on aero-engines,the elbow localflow resistance charac-teristics for supercritical pressure aviation fuel RP-3flowing in adiabatic horizontal serpentine tubes with the inner diameter of 1.8 mm and the massflux of 1179 kg/(m^(2)·s)were experimen-tally studied.The long-short-tube method was used to obtain the elbow pressure drop from the total serpentine tube pressure drop,and the effects of system pressures(P/Pc=1.72-2.58)and geometry parameters including bend numbers(n=5-11),bend diameters(D/d=16.7-27.8),and bend distances(L/d=20-60)on elbow pressure drops and local resistance co-efficients are analyzed on the basis of the thermal physical property variation.The results show that both the increase in the elbow pressure drop and the decrease in the local resistance coef-ficient with temperatures speed up at the near pseudo-critical temperature region of T>0.85Tpc.And the growth of the elbow local pressure drop could be inhibited by the increase of system pressures,while the local resistance coefficient is slightly affected by pressures.The influence of bend diameters on the local resistance coefficient is mild when D/d is larger than 22.2 in the premise of fully developedflow in straight tubes.Furthermore,a piecewise empir-ical correlation considering the bend diameter and physical property ratio is developed to pre-dict the elbow pressure drop of the serpentine tube and optimize the layout of the cooling tube system on aero-engines. 展开更多
关键词 Supercritical pressure Aviation fuel Local resistance coefficient ELBOW Serpentine tube Empirical correlation
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Thin,soft,skin-integrated electronics for real-time and wireless detectionof uricacid in sweat 被引量:2
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作者 Yue Hu Lan Wang +16 位作者 Jian Lia Yawen Yang Guangyao Zhao Yiming Liu Xingcan Huang Pengcheng Wu Binbin Zhang Yanli Jia Mengge Wu Shengxin Jia Qiang Zhang guoqiang xu Rui Shi Dengfeng Li Yingchun Li Zhengchun Peng Xinge Yu 《International Journal of Smart and Nano Materials》 SCIE EI 2023年第4期406-419,共14页
Wearable sweat sensors are gaining significant attention due to their unparalleled potential for noninvasive health monitoring.Sweat,as a kind of body fluid,contains informative physiological indicators that are relat... Wearable sweat sensors are gaining significant attention due to their unparalleled potential for noninvasive health monitoring.Sweat,as a kind of body fluid,contains informative physiological indicators that are related to personalized health status.Advances in wearable sweat sampling and routing technologies,flexible,and stretchable materials,and wireless digital technologies have led to the development of integrated sweat sensors that are comfortable,flexible,light,and intelligent.Herein,we report a flexible and integrated wearable device via incorporating a microfluidic system and a sensing chip with skin-integrated electronic format toward in-situ monitoring of uric acid(UA)in sweat that associates with gout,cardiovascular,and renal diseases.The microfluidic system validly realizes the real-time capture perspiration from human skin.The obtained detection range is 5-200μM and the detection limit is 1.79μM,which offers an importance diagnostic method for clinical relevant lab test.The soft and flexible features of the constructed device allows it to be mounted onto nearly anywhere on the body.We tested the sweat UA in diverse subjects and various body locations during exercise,and similar trends were also observed by using a commercial UA assay kit. 展开更多
关键词 Sweat sensors skinintegrated electronics in-situ detection microchannels wearable device
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Stretchable,skin-conformable neuromorphic system for tactile sensory recognizing and encoding
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作者 Mengge Wu Qiuna Zhuang +11 位作者 Kuanming Yao Jian Li Guangyao Zhao Jingkun Zhou Dengfeng Li Rui Shi guoqiang xu Yingchun Li Zijian Zheng Zhihui Yang Junsheng Yu Xinge Yu 《InfoMat》 SCIE CSCD 2023年第12期87-99,共13页
Expanding wearable technologies to artificial tactile perception will be of significance for intelligent human-machine interface,as neuromorphic sensing devices are promising candidates due to their low energy consump... Expanding wearable technologies to artificial tactile perception will be of significance for intelligent human-machine interface,as neuromorphic sensing devices are promising candidates due to their low energy consumption and highly effective operating properties.Skin-compatible and conformable features are required for the purpose of realizing wearable artificial tactile perception.Here,we report an intrinsically stretchable,skin-integrated neuromorphic system with triboelectric nanogenerators as tactile sensing and organic electrochemical transistors as information processing.The integrated system provides desired sensing,synaptic,and mechanical characteristics,such as sensitive response(~0.04 kPa^(-1))to low-pressure,short-and long-term synaptic plasticity,great switching endurance(>10000 pulses),symmetric weight update,together with high stretchability of 100%strain.With neural encoding,demonstrations are capable of recognizing,extracting,and encoding features of tactile information.This work provides a feasible approach to wearable,skin-conformable neuromorphic sensing system with great application prospects in intelligent robotics and replacement prosthetics. 展开更多
关键词 neural encoding neuromorphic sensing system organic electrochemical transistors tactile sensation triboelectric nanogenerators
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谷氨酸棒杆菌一步法发酵糖质原料生产γ-聚谷氨酸 被引量:1
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作者 程慧 陈园园 +5 位作者 朱亚鑫 曹蓉 徐国强 张晓梅 史劲松 许正宏 《生物工程学报》 CAS CSCD 北大核心 2020年第2期295-308,共14页
γ-聚谷氨酸在食品、化妆品、生物医药等领域具有广泛的应用,目前主要的生产菌株是谷氨酸依赖型菌株,在生产过程中需要添加谷氨酸作为前体,因而生产γ-聚谷氨酸的成本较高。文中主要研究从糖质原料一步法发酵合成γ-聚谷氨酸的生产工艺... γ-聚谷氨酸在食品、化妆品、生物医药等领域具有广泛的应用,目前主要的生产菌株是谷氨酸依赖型菌株,在生产过程中需要添加谷氨酸作为前体,因而生产γ-聚谷氨酸的成本较高。文中主要研究从糖质原料一步法发酵合成γ-聚谷氨酸的生产工艺。首先,从产γ-聚谷氨酸的菌株枯草芽孢杆菌中克隆γ-聚谷氨酸合成酶的基因簇pgs BCA,在谷氨酸棒杆菌模式菌株ATCC13032中进行诱导型和组成型表达,结果显示,仅诱导型表达菌株可以积累γ-聚谷氨酸,产量为1.43 g/L。进一步对诱导条件进行优化,确定诱导时间为2 h,IPTG浓度为0.8 mmol/L,γ-聚谷氨酸产量为1.98g/L。在此基础上,在一株高产谷氨酸的谷氨酸棒杆菌F343中外源表达pgs BCA,对重组菌进行发酵,结果表明,在摇瓶发酵中γ-聚谷氨酸产量达到10.23g/L,在5L发酵罐中产量达到20.08g/L;继而对γ-聚谷氨酸进行分子量测定,结果显示,产自F343重组菌的γ-聚谷氨酸的重均分子量比产自枯草芽孢杆菌的提高34.77%。文中构建了一步法发酵糖质原料生产γ-聚谷氨酸的新途径,同时为开发其潜在应用奠定了基础。 展开更多
关键词 Γ-聚谷氨酸 谷氨酸棒杆菌 一步法发酵 糖质原料 pgsBCA
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Insulating materials for realising carbon neutrality:Opportunities,remaining issues and challenges 被引量:18
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作者 Chuanyang Li Yang Yang +25 位作者 guoqiang xu Yao Zhou Mengshuo Jia Shaolong Zhong Yu Gao Chanyeop Park Qiang Liu Yalin Wang Shakeel Akram Xiaoliang Zeng Yi Li Fangwei Liang Bin Cui Junpeng Fang Lingling Tang Yulin Zeng Xingtao Hu Jiachen Gao Giovanni Mazzanti Jinliang He Jianxiao Wang Davide Fabiani Gilbert Teyssedre Yang Cao Feipeng Wang Yunlong Zi 《High Voltage》 SCIE EI 2022年第4期610-632,共23页
The 2050 carbon-neutral vision spawns a novel energy structure revolution,and the construction of the future energy structure is based on equipment innovation.Insulating material,as the core of electrical power equipm... The 2050 carbon-neutral vision spawns a novel energy structure revolution,and the construction of the future energy structure is based on equipment innovation.Insulating material,as the core of electrical power equipment and electrified transportation asset,faces unprecedented challenges and opportunities.The goal of carbon neutral and the urgent need for innovation in electric power equipment and electrification assets are first discussed.The engineering challenges constrained by the insulation system in future electric power equipment/devices and electrified transportation assets are investigated.Insulating materials,including intelligent insulating material,high thermal conductivity insulating material,high energy storage density insulating material,extreme environment resistant insulating material,and environmental-friendly insulating material,are cat-egorised with their scientific issues,opportunities and challenges under the goal of carbon neutrality being discussed.In the context of carbon neutrality,not only improves the understanding of the insulation problems from a macro level,that is,electrical power equipment and electrified transportation asset,but also offers opportunities,remaining issues and challenges from the insulating material level.It is hoped that this paper en-visions the challenges regarding design and reliability of insulations in electrical equipment and electric vehicles in the context of policies towards carbon neutrality rules.The authors also hope that this paper can be helpful in future development and research of novel insulating materials,which promote the realisation of the carbon-neutral vision. 展开更多
关键词 NEUTRAL INSULATION EXTREME
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Development of secondary flow field under rotating condition in a straight channel with square cross-section 被引量:3
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作者 Ruquan YOU Kuan WEI +2 位作者 Zhi TAO Haiwang LI guoqiang xu 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第8期1703-1715,共13页
The developing secondary flow fields in the entrance section of a rotating straight channel were experimentally investigated using Particle Image Velocimetry(PIV). The effects of streamwise position, Reynolds number... The developing secondary flow fields in the entrance section of a rotating straight channel were experimentally investigated using Particle Image Velocimetry(PIV). The effects of streamwise position, Reynolds number and rotation number on the development of the secondary flow fields were revealed. The results show that the absolute values of vorticity flux of the trailing side roll cells increase with increasing radius of the measured plane and rotation number. When the absolute value of vorticity flux exceeds a critical value, the merging of the trailing side roll cells appears. Moreover, when the number of the trailing side vortex pairs is even, the absolute values of vorticity flux of the leading side vortices increase along streamwise direction. Otherwise, the absolute values decrease along the streamwise direction. By the circulation analysis, this phenomenon was found to have relationship with the merging of the trailing side roll cells, and further concluded that the secondary flow field in a rotating channel has to be treated as a whole. At last,the increase of the Reynolds number was found to be able to induce the merging position moves upstream. 展开更多
关键词 Circulation analysis Entrance section Field Programmable GataArray (FPGA) Particle Image Velocimetry(PlV) Rotating channel Secondary flow
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Buoyancy effect on heat transfer in rotating smooth square U-duct at high rotation number 被引量:6
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作者 Yang Li guoqiang xu +1 位作者 Hongwu Deng Shuqing Tian 《Propulsion and Power Research》 SCIE 2014年第3期107-120,共14页
The buoyancy effect on heat transfer in a rotating,two-pass,square channel is experimentally investigated in curent work.The classical copper plate technique is performed to measure the regional averaged heat transfer... The buoyancy effect on heat transfer in a rotating,two-pass,square channel is experimentally investigated in curent work.The classical copper plate technique is performed to measure the regional averaged heat transfer cofficients.In order to perform a fundamental research,all turbulators are removed away.Two approaches of altering Buoyancy numbers are selected:varying rotation number from 0 to 2.08 at Reynolds number ranges of 10000 to 70000,and varying inlet density ratio from 0.07 to 0.16 at Reynolds number of 10000.And thus,Buoyancy numbers range from 0 to 12.9 for both cases.According to the experimental results,the relationships between heat transfer and Buoyancy numbers are in accord with those obtained under different rotation numbers.For both leading and trailing surface,a critical Buoyancy number exists for each X/D location.Before the critical point,the effect of Buoyancy number on heat transfer is limited;but after that,the Nusselt number ratios show different increase rate.Given the same rotation number,higher wall temperature ratios with its corresponding higher Buoyancy numbers substantially enhance heat transfer on both passages.And the critical exceed-point that heat transfer from trailing surface higher than leading surface happens at the same Buoyancy number for different wall temperature ratios in the second passage.Thus,the stronger buoyancy effect promotes heat transfer enhancement at high rotation number condition. 展开更多
关键词 Buoyancy effect Heat transfer Wall temperature ratio Rotating U-duct High rotation number
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Investigation of flow resistance characteristics of endothermic hydrocarbon fuel under supercritical pressures 被引量:6
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作者 Chunben Zhang guoqiang xu +1 位作者 Hongwu Deng Kun Zhu 《Propulsion and Power Research》 SCIE 2013年第2期119-130,共12页
The characteristics of flow resistance of a typical hydrocarbon fuel(RP-3)flowthrough adiabatic horizontal miniature tubes at supercritical pressures are experimentallyinvestigated for both laminar and turbulent flow.... The characteristics of flow resistance of a typical hydrocarbon fuel(RP-3)flowthrough adiabatic horizontal miniature tubes at supercritical pressures are experimentallyinvestigated for both laminar and turbulent flow.The experiments are conducted by using along tube measuring section and a short tube measuring section simultaneously in order toeliminate the effect of local pressure drop.In these experiments,the temperature of RP-3changes from(295 to 789)K and the reduced pressure(P/Pc,Pc=2.33 MPa)ranges from 1 to2.58,the mass flux is up to 1572.7 kg/(m^(2).s).Test results indicate that frictional pressuredrops for various supercritical pressures at the same mass flux can be considered as equalwith each other when the reduced temperature Tb/Tpc<0.95.When Tb/Tpc>0.95,differenceappears and increases with the increase of Tb/Tpc.Additionally,the friction factor(f)of thesupercritical fluid for turbulent flow has a critical value at Tb/Tpc=1,the values of f at thispoint for all pressures and mass fluxes are equal with each other.Moreover,at the same massflux,there are two comresponding friction factors for the same Re,one is in the region of Tb/Tpc<1,the other is in the region of Tb/Tpc> 1.Finally, classical conelations of frictionfactor is inapplicable when Tb/Tpc>0.95 at supercritical pressure and a new coelation hasbeen obtained based on the experimental data. 展开更多
关键词 SUPERCRITICAL Hydrocarbon fuel Flow resistance Friction factor Pressure drop
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Highly sensitive detection of phosphopeptides with superparamagnetic Fe_(3)O_(4)@mZrO_(2) core-shell microspheres-assisted mass spectrometry 被引量:2
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作者 Ruifang Gao Jin Li +6 位作者 Rui Shi Yang Zhang Fuzhou Ouyang Ting Zhang Lihua Hu guoqiang xu Jian Liu 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2020年第24期234-242,共9页
Protein phosphorylation is one of the most important post-translational modifications.It is an active research area to study phosphoproteomics for discovery of disease biomarkers and druggable targets.Here we report t... Protein phosphorylation is one of the most important post-translational modifications.It is an active research area to study phosphoproteomics for discovery of disease biomarkers and druggable targets.Here we report the development of superparamagnetic Fe_(3)O_(4)@mZrO_(2) core-shell microspheres with mesoporous structures for highly efficient enrichment of phosphopeptides.We have demonstrated that the mesoporous ZrO_(2) layer dramatically improves the selective enrichment of phosphopeptides.Our approach allows for in-situ elution and sensitive identification of both mono-phosphorylated and multiphosphorylated peptides in MALDI-TOF mass spectrometry,with the detection limit of down to the femtomole range.The target phosphopeptides can reliably be enriched for MS analysis from various complex samples including the spiked protein digests and tumor cell lysates.The Fe_(3)O_(4)@mZrO_(2) coreshell microspheres promise a useful tool for phosphoproteomics by allowing for highly efficient and selective enrichment of the crucial signaling regulators in a low abundance. 展开更多
关键词 Core-shell microspheres Mesoporous structure Protein phosphorylation MALDI-TOF mass spectrometry Enrichment technologies
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Integral Real-time Locomotion Mode Recognition Based on GA-CNN for Lower Limb Exoskeleton 被引量:1
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作者 Jiaqi Wang Dongmei Wu +4 位作者 Yongzhuo Gao Xinrui Wang Xiaoqi Li guoqiang xu Wei Dong 《Journal of Bionic Engineering》 SCIE EI CSCD 2022年第5期1359-1373,共15页
The wearable lower limb exoskeleton is a typical human-in-loop human–robot coupled system,which conducts natural and close cooperation with the human by recognizing human locomotion timely.Requiring subject-specific ... The wearable lower limb exoskeleton is a typical human-in-loop human–robot coupled system,which conducts natural and close cooperation with the human by recognizing human locomotion timely.Requiring subject-specific training is the main challenge of the existing approaches,and most methods have the problem of insufficient recognition.This paper proposes an integral subject-adaptive real-time Locomotion Mode Recognition(LMR)method based on GA-CNN for a lower limb exoskeleton system.The LMR method is a combination of Convolutional Neural Networks(CNN)and Genetic Algorithm(GA)-based multi-sensor information selection.To improve network performance,the hyper-parameters are optimized by Bayesian optimization.An exoskeleton prototype system with multi-type sensors and novel sensing-shoes is used to verify the proposed method.Twelve locomotion modes,which composed an integral locomotion system for the daily application of the exoskeleton,can be recognized by the proposed method.According to a series of experiments,the recognizer shows strong comprehensive abilities including high accuracy,low delay,and sufficient adaption to different subjects. 展开更多
关键词 Locomotion mode recognition Gait mode detection Lower limb exoskeleton Convolutional neural network Genetic algorithm Bionic design
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Frictional resistance of supercritical pressure RP-3 flowing in a vertically downward tube at constant heat fluxes 被引量:1
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作者 Yinlong LIU guoqiang xu +3 位作者 Yanchen FU Jie WEN Geng GONG Lulu LYU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第9期117-128,共12页
Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection, the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertic... Based on the demands of compact heat exchangers and micro cooling channels applied for aviation thermal protection, the flow resistance characteristics of aviation kerosene RP-3 were experimentally studied in a vertically downward circular miniature tube with an inner diameter of 1.86 mm at supercritical pressures and constant heat fluxes. A long and short tube method was used to accurately calculate the frictional pressure drop, and experimental conditions are supercritical pressures of 4 MPa, mass flow rates of 2–4 g/s(i.e., mass fluxes of 736–1472 kg/(m^(2)·s)), heat fluxes of 100–500 kW/m^(2), and inlet temperatures of 373–673 K. Results show that the sharp variations of thermophysical properties, especially density, have significant influences on frictional resistances.Generally, the frictional pressure drop and the friction factor increase with increasing inlet temperatures, and this trend speeds up in the relatively high-temperature region. However, the friction factor has a sudden decline when the fuel outlet temperature exceeds the pseudo-critical temperature.The frictional pressure drop and the friction factor basically remain unchanged with increasing heat flux when the inlet temperature is relatively low, but increase quickly when the inlet temperature is relatively high. Besides, a larger mass flux yields a higher pressure drop but does not necessarily yield a higher friction factor. Finally, an empirical friction factor correlation is proposed and shows better predictive performance than those of previous models. 展开更多
关键词 Aviation kerosene RP-3 Constant heat flux Empirical correlation Friction factor Supercritical pressure Vertical tube
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Airside pressure drop characteristics of three analogous serpentine tube heat exchangers considering heat transfer for aero-engine cooling 被引量:1
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作者 Yinlong LIU guoqiang xu +3 位作者 Yanchen FU Jie WEN Shaoshuai QI Lulu LYU 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2022年第12期32-46,共15页
This study explores the design,analysis,and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number aero-engines.In hig... This study explores the design,analysis,and air pressure drop assessment of three analogous air–fuel heat exchangers consisting of thin serpentine tube bundles intended for use in high Mach number aero-engines.In high speed flight,the compressor bleed air used to cool high temperature turbine blades and other hot components is too hot.Hence,aviation kerosene is applied to precool the compressor bleed air by means of novel air–fuel heat exchangers.Three light and compact heat exchangers including dozens of in-line thin serpentine tube bundles were designed and manufactured,with little difference existing in aspects of tube pitches and outer diameters among three heat exchangers.The fuel flows inside a series of parallel stainless serpentine tubes(outer diameter:2.2,1.8,1.4 mm with 0.2 mm thickness),while the air externally flows normal to tube bundles and countercurrent with fuel.Experimental studies were carried out to investigate the airside pressure drop characteristics on isothermal states with the variation of air mass flow rates and inlet temperatures.Non-isothermal measurements have also been performed to research the effect of heat transfer on pressure drops.The experimental results show that inlet temperatures have significant influence on pressure drops,and higher temperatures lead to higher pressure drops at the same mass flow rate.The hydraulic resistance coefficient decreases quickly with Reynolds number,and the descent rate slows down when Re>6000 for all three heat exchangers.Additionally,the pressure drop on heat transfer states is less than that on isothermal states for the same average temperatures.Moreover,the pressure drop through heat exchangers is greatly affected by attack angles and transverse pitches,and an asymmetric M-shaped velocity profile is generated in the crosssection of sector channels. 展开更多
关键词 AERO-ENGINE Heat exchanger Heat transfer Pressure drop Serpentine tube
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Survey of Safety Management Approaches to Unmanned Aerial Vehicles and Enabling Technologies 被引量:1
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作者 xuejun Zhang Yanshuang Du +2 位作者 Bo Gu guoqiang xu Yongxiang Xia 《Journal of Communications and Information Networks》 2018年第4期1-14,共14页
Unmanned aerial vehicle(UAV)has a rapid development over the last decade.However,an increasing number of severe flight collision events caused by explosive growth of UAV have drawn widespread concern.It is an importan... Unmanned aerial vehicle(UAV)has a rapid development over the last decade.However,an increasing number of severe flight collision events caused by explosive growth of UAV have drawn widespread concern.It is an important issue to investigate safety management approaches of UAVs to ensure safe and efficient operation.In this paper,we present a comprehensive overview of safety management approaches in large,middle and small scales.In large-scale safety management,path-planning problem is a crucial issue to ensure safety and ordered operation of UAVs globally.In middle-scale safety management,it is an important issue to study the conflict detection and resolution methods.And in small-scale safety management,real-time collision avoidance is the last line of ensuring safety.Moreover,a UAV can be regarded as a terminal device connected through communication and information network.Therefore,the enabling technologies,such as sensing,command and control communication,and collaborative decision-making control technology,have been studied in the last. 展开更多
关键词 UAV safety management PATH-PLANNING conflict detection and resolution collision avoidance enabling technologies
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