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155篇 您的检索式:作者名="Na Gu"
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1Transplantation of UC-MSCs on collagen scaffold activates follicles in dormant ovaries of POF patients with long history of infertility显示文摘Premature ovarian failure(POF) is a refractory disease for clinical treatment with the goal of restoring fertility. In this study,umbilical cord mesenchymal stem cells on a collagen scaffold(collagen/UC-MSCs) can activate primordial follicles in vitro via phosphorylation of FOXO3 a and FOXO1. Transplantation of collagen/UC-MSCs to the ovaries of POF patients rescued overall ovarian function, evidenced by elevated estradiol concentrations, improved follicular development, and increased number of antral follicles. Successful clinical pregnancy was achieved in women with POF after transplantation of collagen/UC-MSCs or UC-MSCs. In summary, collagen/UC-MSC transplantation may provide an effective treatment for POF.Lijun Ding Guijun Yan Bin Wang Lu Xu Yan Gu Tong Ru Xiaoying Cui Lei Lei Jingyu Liu Xiaoqiang Sheng Bin Wang Chunxue Zhang Yanjun Yang Ruiwei Jiang Jianjun Zhou Na Kong Feifei Lu Huaijun Zhou Yannan Zhao Bing Chen Yali Hu Jianwu Dai Haixiang Sun 2018Science China(Life Sciences)2018,61,12:43
2Latest Progress of the Chinese Meteorological Satellite Program and Core Data Processing Technologies显示文摘In this paper,the latest progress,major achievements and future plans of Chinese meteorological satellites and the core data processing techniques are discussed.First,the latest three FengYun(FY)meteorological satellites(FY-2H,FY-3D,and FY-4A)and their primary objectives are introduced Second,the core image navigation techniques and accuracies of the FY meteorological satellites are elaborated,including the latest geostationary(FY-2/4)and polar-orbit(FY-3)satellites.Third,the radiometric calibration techniques and accuracies of reflective solar bands,thermal infrared bands,and passive microwave bands for FY meteorological satellites are discussed.It also illustrates the latest progress of real-time calibration with the onboard calibration system and validation with different methods,including the vicarious China radiance calibration site calibration,pseudo invariant calibration site calibration,deep convective clouds calibration,and lunar calibration.Fourth,recent progress of meteorological satellite data assimilation applications and quantitative science produce are summarized at length.The main progress is in meteorological satellite data assimilation by using microwave and hyper-spectral infrared sensors in global and regional numerical weather prediction models.Lastly,the latest progress in radiative transfer,absorption and scattering calculations for satellite remote sensing is summarized,and some important research using a new radiative transfer model are illustrated.Peng ZHANG Qifeng LU Xiuqing HU Songyan GU Lei YANG Min MIN Lin CHEN Na XU Ling Sun Wenguang BAI Gang MA Di XIAN 2019Advances in Atmospheric Sciences2019,36,9:26
3Insight-HXMT observations of the first binary neutron star merger GW170817显示文摘Finding the electromagnetic(EM) counterpart of binary compact star merger, especially the binary neutron star(BNS) merger,is critically important for gravitational wave(GW) astronomy, cosmology and fundamental physics. On Aug. 17, 2017,Advanced LIGO and Fermi/GBM independently triggered the first BNS merger, GW170817, and its high energy EM counterpart,GRB 170817 A, respectively, resulting in a global observation campaign covering gamma-ray, X-ray, UV, optical, IR, radio as well as neutrinos. The High Energy X-ray telescope(HE) onboard Insight-HXMT(Hard X-ray Modulation Telescope) is the unique high-energy gamma-ray telescope that monitored the entire GW localization area and especially the optical counterpart(SSS17 a/AT2017 gfo) with very large collection area(~1000 cm^2) and microsecond time resolution in 0.2-5 MeV. In addition,Insight-HXMT quickly implemented a Target of Opportunity(ToO) observation to scan the GW localization area for potential X-ray emission from the GW source. Although Insight-HXMT did not detect any significant high energy(0.2-5 MeV) radiation from GW170817, its observation helped to confirm the unexpected weak and soft nature of GRB 170817 A. Meanwhile,Insight-HXMT/HE provides one of the most stringent constraints(~10^(-7) to 10^(-6) erg/cm^2/s) for both GRB170817 A and any other possible precursor or extended emissions in 0.2-5 MeV, which help us to better understand the properties of EM radiation from this BNS merger. Therefore the observation of Insight-HXMT constitutes an important chapter in the full context of multi-wavelength and multi-messenger observation of this historical GW event.TiPei Li ShaoLin Xiong ShuangNan Zhang FangJun Lu LiMing Song XueLei Cao Zhi Chang Gang Chen Li Chen TianXiang Chen Yong Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong YuanYuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao CongZhan Liu GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge OU JinLu Qu Na Sai Liang Sun Yin Tan Lian Tao WenHui Tao YouLi Tuo GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BoBing WU Mei Wu GuangCheng Xiao He Xu YuPeng Xu LinLi Yan JiaWei Yang Sheng Yang YanJi Yang AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang Shu Zhang Tong Zhang Wei Zhang WanChang Zhang WenZhao Zhang Yi Zhang Yue Zhang YiFei Zhang YongJie Zhang Zhao Zhang ZiLiang Zhang HaiSheng Zhao JianLing Zhao XiaoFan Zhao ShiJie Zheng Yue Zhu YuXuan Zhu ChangLin Zou 2018Science China(Physics,Mechanics & Astronomy)2018,61,3:12
4Iron-doped nickel disulfide nanoarray: A highly efficient and stable electrocatalyst for water splitting显示文摘特别地为阳极的氧进化反应(OER ) ,发展中的有效切开水的 electrocatalysts 是在精力变换技术的重要挑战。在这研究,我们经由它的 nickel-iron-layered 的 sulfidation 在 Ti 网孔(Fe 0.1-NiS2 NA/Ti ) 上报导做铁的镍二硫化物 nanoarray 的发展两倍氢氧化物先锋(NiFe-LDH NA/Ti ) 。作为三维的 OER 阳极, Fe 0.1-NiS2 NA/Ti 在 1.0 M KOH 展出显著活动和稳定性,与完成 100 mAlecular 解吸附作用的 231 mV 的低过电位的要求。温度的功能在 36 和 44 点显示出解吸附作用山峰的试验性地测量的微分工作功能?Na Yang Chun Tang Kunyang Wang Gu Du Abdullah M. Asiri Xuping Sun 2016Nano Research2016,9,11:11
5Application of brassinolide alleviates cold stress at the booting stage of rice显示文摘The objective of the study was to determine the physiological mechanisms of plants in response to brassinolide(BR) alleviating cold water stress on rice. In this study, physiological responses of rice to exogenous BR and cold water submergence were investigated using the chilling-tolerant cultivar Kongyu 131(KY131) and the chilling-sensitive cultivar Kenjiandao 6(KJD6). A total of 2 mg L^-1 BR increased activities of superoxide dismutase(SOD) and peroxidase(POD) and the contents of soluble sugar, soluble protein, and chlorophyll, but decreased the malondialdehyde(MDA) content in KY131 and KJD6 under cold water stress. The observed decreases in SOD and POD activities and MDA content recovered quickly after plants were returned to irrigation with water at temperatures of about 23.0°C in 2014. Additionally, the contents of nitrogen(N), phosphorous(P), and potassium(K) were increased by BR treatment under cold water stress. Exposure to BR also raised the percentage of high effective leaf area and leaf area index at the heading stage. Furthermore, it promoted soluble sugar synthesis, increased the rate of dry matter accumulation, and enhanced the export and translocation rates of the stem-sheath. The yield in KJD6 was significantly(P≤0.01 and P≤0.05) higher than that of the control in 2013 and 2014, respectively. The effect of BR treatment on rice leaf SOD and POD activities, MDA, chlorophyll, P, and stem-sheath K contents were more significant in KJD6 than in KY131. In conclusion, exogenous BR effectively reduced the physiological and metabolic damage in rice due to cold stress at the booting stage, promoted functional recovery in plants that received irrigation with water at a normal temperature following cold stress, and mitigated the effects of cold water stress on yield.The two varieties exhibited differential responses to BR;the weaker cold-resistant variety was more sensitive to BR and displayed stronger responses to exogenous BR.WANG Shi-qiang ZHAO Hai-hong ZHAO Li-ming GU Chun-mei NA Yong-guang XIE Bao-sheng CHENG Shi-hua PAN Guo-jun 2020Journal of Integrative Agriculture2020,19,4:10
6A Geometric Understanding of Deep Learning显示文摘This work introduces an optimal transportation(OT)view of generative adversarial networks(GANs).Natural datasets have intrinsic patterns,which can be summarized as the manifold distribution principle:the distribution of a class of data is close to a low-dimensional manifold.GANs mainly accomplish two tasks:manifold learning and probability distribution transformation.The latter can be carried out using the classical OT method.From the OT perspective,the generator computes the OT map,while the discriminator computes the Wasserstein distance between the generated data distribution and the real data distribution;both can be reduced to a convex geometric optimization process.Furthermore,OT theory discovers the intrinsic collaborative-instead of competitive-relation between the generator and the discriminator,and the fundamental reason for mode collapse.We also propose a novel generative model,which uses an autoencoder(AE)for manifold learning and OT map for probability distribution transformation.This AE–OT model improves the theoretical rigor and transparency,as well as the computational stability and efficiency;in particular,it eliminates the mode collapse.The experimental results validate our hypothesis,and demonstrate the advantages of our proposed model.Na Lei Dongsheng An Yang Guo Kehua Su Shixia Liu Zhongxuan Luo Shing-Tung Yau Xianfeng Gu 2020Engineering2020,6,3:10
7Response of leaf photosynthetic characteristics of Syringa oblata and Syringa reticulata var.mandshurica to chilling stress显示文摘Syringa species not only have good ornamental properties but also play an important role in the landscaping and environmental purification of cities.To investigate the chilling stress resistance of Syringa oblata Lindl.and Syringa reticulata var.mandshurica and provide theoretical grounds for the practical cultivation of Syringa species,in vitro leaves were used to study photosynthetic gas exchange parameters and chlorophyll fluorescence parameters.After nine hours of chilling,decreasing rates of net photosynthesis,stomatal conductance,and transpiration in S.reticulata var.mandshurica leaves were significantly greater than that of the S.oblata,while intercellular CO2 concentrations in S.oblata leaves were higher than those in S.reticulata var.mandshurica.The quantum yield of PSII reaction center(APSII)declined in S.reticulata and light capture efficiency(Fv 0/Fm 0)was stable.However,reduction percentages of Fv 0/Fm 0,APSII,and Fv/Fm in S.oblata were significant higher than those of S.reticulata var.mandshurica.After nine hours of chilling,the relative variable fluorescence of VJ and VI of S.oblata increased and the increasing rate of VJ was greater than VI.In contrast,the change of VJ and VI in S.reticulata var.mandshurica leaves was relatively small.This suggests that chilling primarily damaged the electron transport process of QA to QB at the receptor site of the PSII reaction center.Photosynthetic capacity of S.oblata was more sensitive to chilling stress compared to S.reticulate var.mandshurica,which the limitations were mainly due to non-stomatal factors such as the decrease in electron transport efficiency,activity in the PSII reaction center,and the destruction of the photodamage defense system.Xiaojia Liu Baiyi An Na Gu Cainan Guo Xiaogang Sun He Wang 2020Journal of Forestry Research2020,31,2:8
8Application of chemical vapor-deposited monolayer ReSe2 in the electrocatalytic hydrogen evolution reaction显示文摘Shaolong Jiang Zhepeng Zhang Na Zhang Yahuan Huan Yue Gong Mengxing Sun Jianping Shi Chunyu Xie Pengfei Yang Qiyi Fang He Li Lianming Tong Dan Xie Lin Gu Porun Liu Yanfeng Zhang 2018Nano Research2018,11,4:6
9Prevalence of late-onset hypogonadism among middle-aged and elderly males in China:results from a national survey显示文摘This study aimed to propose an operational definition of late-onset hypogonadism(LOH)that incorporates both clinical symptoms and serum testosterone measurements to evaluate the prevalence of LOH in aging males in China.A population-based sample of 6296 men aged 40 years-79 years old was enrolled from six representative provinces in China.Serum total testosterone(TT),sex hormone-binding globulin(SHBG),and luteinizing hormone(LH)were measured and free testosterone(cFT)was calculated.The Aging Males’Symptoms(AMS)scale was used to evaluate the LOH symptoms.Finally,5078 men were included in this analysis.The TT levels did not decrease with age(P=0.59),and had no relationship with AMS symptoms(P=0.87 for AMS total score,P=0.74 for≥3 sexual symptoms).The cFT levels decreased significantly with age(P<0.01)and showed a negative association with the presence of≥3 sexual symptoms(P=0.03).The overall estimated prevalence of LOH was 7.8%(395/5078)if a cFT level<210 pmol l−1 combined with the presence of≥3 sexual symptoms was used as the criterion of LOH.Among them,26.1%(103/395)and 73.9%(292/395)had primary and secondary hypogonadism,respectively.After adjustment for confounding factors,primary and secondary hypogonadism was positively related to age and comorbidities.Body mass index was an independent risk factor for secondary hypogonadism.The results suggest that the AMS total score is not an appropriate indicator for decreased testosterone,and that the cFT level is more reliable than TT for LOH diagnosis.Secondary hypogonadism is the most common form of LOH.Yi-Jun Liu Xu-Bo Shen Na Yu Xue-Jun Shang Yi-Qun Gu Lian-Dong Zuo Cheng-Liang Xiong Zhen Ye Yuan-Zhong Zhou 2021Asian Journal of Andrology2021,23,2:6
10Relationship between Sleep Quality and Cognitive Function in Patients with Mild-to-Moderate Parkinson's Disease显示文摘Hui-Miao Liu Miao Chu Na Li Sai Zhang Yong-Zhi Zhang Ping Gu 2018Chinese Medical Journal2018,,8:6
11Natural history of persistent subretinal fluid following the successful repair of rhegmatogenous retinal detachment显示文摘AIM:To provide a detailed description of the natural history of persistent subretinal fluid(SRF)after successful repair of rhegmatogenous retinal detachment(RRD)and its association with visual outcome.METHODS:This was a prospective long-term follow-up for eyes undergoing scleral buckling(SB)surgery for maculaoff RRD.Examinations were carried out preoperatively and postoperatively at 1,3,6,9 and 12 mo,until persistent SRF had completely resolved.One month postoperatively,optical coherence tomography(OCT)was used to classify SRF into three patterns:bleb-like loculated(BL),shallow-diffused(SD),and multiple blebs(MB).Serial OCT imaging was used to evaluate morphological changes in SRF until its complete disappearance.Patients were divided into two groups depending on the presence or absence of persistent SRF.RESULTS:A total of 59 patients(59 eyes)were included.There were no statistical differences between two groups at baseline,except for the proportion of patients with high myopia and a younger age.One month after surgery,OCT detected persistent SRF in 49 eyes(83.1%).The 3 morphological patterns of SRF were observed in 27 eyes(55.1%)with BL,13 eyes(26.5%)with SD,and 9 eyes(18.4%)with MB.The mean time for complete absorption differed significantly across the three SRF patterns(F=8.097,P=0.001),which was 8.8±6.1,20.1±12.1,and 16.7±10.2 mo in BL,SD,and MB,respectively.In 9 of the 13 eyes with SD,the pattern transformed into MB type.In cases involving MB,the size and number of blebs decreased gradually until they had been completely absorbed.Eyes with persistent SRF were more likely to demonstrate disruption of the ellipsoid zone(49.0%vs 10%,P=0.034).The final best-corrected visual acuity of two groups was 0.37±0.11(with SRF)vs 0.34±0.12(without SRF)logMAR(P=0.499),respectively.CONCLUSION:High preoperative myopia and younger age are associated with persistent SRF.BL is the most commonly observed pattern with the shortest duration and gradually disappeared.Most cases involving SD SRF transform into MB type during resolution.The size and number of the MBs decrease gradually until they were completely absorbed.The absence of persistent SRF may contribute to slow visual recovery in the short-term but does not influence the final visual outcome.Yan Fu Song Chen Zhao-Hui Gu Yue-Ling Zhang Li-Ying Li Na Yang 2020International Journal of Ophthalmology(English edition)2020,13,10:5
12N_2O and NH_3 emissions from a bioreactor landfill operated under limited aerobic degradation conditions显示文摘The combination of leachate recirculation and aeration to landfill may be an efficient way for in-situ nitrogen removal.However,nitrogenous substances contained in the landfill layer are concomitantly transformed into N2O and NH3,leading to increased emissions into the atmosphere.In the present study,the emissions of N2O and NH3 were measured under conditions of fresh or partially stabilized refuse with or without leachate recirculation or intermittent aeration.The results showed that the largest N2O emission(12.4 mg-N/L of the column) was observed in the aerated column loaded with partially stabilized refuse and recycled with the leachate of low C/N ratio;while less than 0.33 mg-N/L of the column was produced in the other columns.N2O production was positively correlated with the prolonged aerobic time and negatively related with the C/N ratio in the recycled leachate.NH3 volatilization increased with enhanced gas flow and concentration of free ammonia in the leachate,and the highest cumulative volatilization quantity was 1.7 mg-N/L of the column.Pinjing He Na Yang Huili Gu Hua Zhang Liming Shao 2011Journal of Environmental Sciences2011,23,6:5
13The relationship between groundwater and natural vegetation in Qaidam Basin显示文摘To accurately evaluate ecological risks trigged by groundwater exploitation,it must be clarified the relationship between vegetation and groundwater.Based on remote sensing data sets MOD13Q1,groundwater table depth(WTD)and total dissolved solids(TDS),the relationship between groundwater and natural vegetation was analyzed statistically in the main plain areas of Qaidam Basin.The results indicate that natural vegetation is groundwater-dependent in areas where WTD is less than 5.5 m and TDS is less than 7.5 g/L.Aquatic vegetation,hygrophytic vegetation and hygrophytic saline-alkali tolerant vegetation are mainly distributed in areas with WTD<1.1 m.Salt-tolerant and mesophytic vegetation mainly occur in areas with WTD of 1.4-3.5 m,while the xerophytic vegetation isprimarily present in areas where WTD ranges from 1.4 m to 5.5 m.Natural vegetation does not necessarily depend on groundwater in areas with WTD>5.5 m.For natural vegetation,the most suitable water TDS is less than 1.5 g/L,the moderately suitable TDS is 1.5-5.0 g/L,the basically suitable TDS is 5.0-7.5 g/L,and the unsuitable TDS is more than 7.5 g/L.Xue-ya Dang Na Lu Xiao-fan Gu Xiao-mei Jin 2021Journal of Groundwater Science and Engineering2021,9,4:3
14Effects of two efflux pump inhibitors on the drug susceptibility of Riemerella anatipestifer isolates from China显示文摘The objective of this study was to verify the supposition that efflux might be involved in the drug resistance of Riemerella anatipestifer isolates.Two broad-spectrum efflux pump inhibitors,carbonyl cyanide 3-chlorophenylhydrazone(CCCP)and Phe-Arg-β-naphthylamide(PAβN),on the contribution of minimum inhibitory concentrations of amikacin,streptomycin,chloramphenicol,tetracycline,ceftriaxone,ceftazidime,nalidixic acid,levofloxacin,enrofloxacin,as well as ciprofloxacin against 69 clinical R.anatipestifer isolates were investigated.We first reported that the two efflux pump inhibitors could restore the antimicrobial susceptibility of R.anatipestifer isolates.It is suggested that active efflux system is possible to be linked with the development of resistance in R.anatipestifer isolates.LI Ya-fei JIANG Hong-xia XIANG Rong SUN Na ZHANG Ya-nan ZHAO Li-qing GU Peng WANG Li-qiao ZENG Zhen-ling 2016Journal of Integrative Agriculture2016,15,4:3
15Impacts of climate change and human activities on water resources in the Ebinur Lake Basin, Northwest China显示文摘Changing climatic conditions and extensive human activities have influenced the global water cycle.In recent years,significant changes in climate and land use have degraded the watershed ecosystem of the Ebinur Lake Basin in Xinjiang,Northwest China.In this paper,variations of runoff,temperature,precipitation,reference evapotranspiration,lake area,socio-economic water usage,groundwater level and water quality in the Ebinur Lake Basin from 1961 to 2015 were systematically analyzed by the Mann-Kendall test methods(M-K)mutation test,the cumulative levelling method,the climate-sensitive method and land-use change index.In addition,we evaluated the effects of human activities on land use change and water quality.The results reveal that there was a significant increase in temperature and precipitation from 1961 to 2015,despite a decrease in reference evapotranspiration.The Wenquan station was not significantly affected by human activities as it is situated at a higher altitude.Runoff at this station increased significantly with climate warming.In contrast,runoff at the Jinghe station was severely affected by numerous human activities.Runoff decreased without obvious fluctuations.The contributions of climate change to runoff variation at the Jinghe and Wenquan stations were 46.87%and 58.94%,respectively;and the contributions of human activities were 53.13%and 41.06%,respectively.Land-use patterns in the basin have changed significantly between 1990 and 2015:urban and rural constructed lands,saline-alkali land,bare land,cultivated land,and forest land have expanded,while areas under grassland,lake,ice/snow and river/channel have declined.Human activities have dramatically intensified land degradation and desertification.From 1961 to 2015,both the inflow into the Ebinur Lake and the area of the lake have declined year by year;groundwater levels have dropped significantly,and the water quality has deteriorated during the study period.In the oasis irrigation area below the runoff pass,human activities mainly influenced the utilization mode and quantity of water resources.Changes in the hydrology and quantity of water resources were driven primarily by the continuous expansion of cultivated land and oasis,as well as the growth of population and the construction of hydraulic engineering projects.After 2015,the effects of some ecological protection projects were observed.However,there was no obvious sign of ecological improvement in the basin,and some environmental problems continue to persist.On this basis,this study recommends that the expansion of oasis should be limited according to the carrying capacity of the local water bodies.Moreover,in order to ensure the ecological security of the basin,it is necessary to determine the optimal oasis area for sustainable development and improve the efficiency of water resources exploitation and utilization.WANG Yuejian GU Xinchen YANG Guang YAO Junqiang LIAO Na 2021Journal of Arid Land2021,13,6:3
16Concurrent optimization of structural topology and infill properties with a CBF-based level set method显示文摘In this paper,a parametric level-set-based topology optimization framework is proposed to concurrently optimize the structural topology at the macroscale and the effective infill properties at the micro/meso scale.The concurrent optimization is achieved by a computational framework combining a new parametric level set approach with mathematical programming.Within the proposed framework,both the structural boundary evolution and the effective infill property optimization can be driven by mathematical programming,which is more advantageous compared with the conventional partial differential equatiodriven level set approach.Moreover,the proposed approach will be more efficient in handling nonlinear problems with multiple constraints.Instead of using radial basis functions(RBF),in this paper,we propose to construct a new type of cardinal basis functions(CBF)for the level set function parameterization.The proposed CBF parameterization ensures an explicit impose of the lower and upper bounds of the design variables.This overcomes the intrinsic disadvantage of the conventional RBF-based parametric level set method,where the lower and upper bounds of the design variables oftentimes have to be set by trial and error;A variational distance regularization method is utilized in this research to regularize the level set function to be a desired distanceregularized shape.With the distance information embedded in the level set model,the wrapping boundary layer and the interior infill region can be naturally defined.The isotropic infill achieved via the mesoscale topology optimization is conformally fit into the wrapping boundary layer using the shape-preserving conformal mapping method,which leads to a hierarchical physical structure with optimized overall topology and effective infill properties.The proposed method is expected to provide a timely solution to the increasing demand for multiscale and multifunctional structure design.Long JIANG Yang GUO Shikui CHEN Peng WEI Na LEI Xianfeng David GU 2019Frontiers of Mechanical Engineering2019,14,2:3
17Reactive MnO_(2) template-assisted synthesis of double-shelled PPy hollow nanotubes to boost microwave absorption显示文摘Microwave absorbing materials(MAMs)with wide effective absorption bandwidth(EAB)and low filling ratio are highly desirable for practical applications.Rational design in components and structures is one of the effective strategies to achieve MAMs with high performance.Herein,double-shelled hollow(DSH)polypyrrole(PPy)nanotubes were synthesized with hydrochloric acid(HCl)and sodium pstyrene sulfonate(SS)co-doping polymerization process using manganese dioxide(MnO_(2))nanorods as a self-sacrifice template.With the increase of HCl concentration,the 1D MnO_(2) core diminishes gradually to form the MnO_(2)@PPy coaxial nanostructures and finally the DSH PPy nanotube,which tunes the microwave absorption performance.Importantly,the DSH PPy nanotubes exhibit excellent microwave absorption of an optimal reflection loss of–50.4 dB and a wide EAB of 7.7 GHz with a low filling ratio of 5 wt%in a paraffin wax matrix.The excellent microwave absorption is believed to be mainly attributed to the enhanced synergistic effects of interfacial polarization and conduction loss arising from the unique DSH structure and the co-doping polymerization.Huiling Gu Ji Huang Na Li Hua Yang Gang Chen Chengjun Dong Chunhong Gong Hongtao Guan 2023Journal of Materials Science & Technology2023,,15:3
18LNG (liquefied natural gas): A necessary part in China’s future energy infrastructure显示文摘Wensheng Lin Na Zhang Anzhong Gu 2009Energy2009,,11:2
19Overview to the Hard X-ray Modulation Telescope (Insight-HXMT) Satellite显示文摘As China’s first X-ray astronomical satellite, the Hard X-ray Modulation Telescope (HXMT), which was dubbed as Insight-HXMT after the launch on June 15, 2017, is a wide-band(1-250 ke V) slat-collimator-based X-ray astronomy satellite with the capability of all-sky monitoring in 0.2-3 Me V. It was designed to perform pointing, scanning and gamma-ray burst(GRB)observations and, based on the Direct Demodulation Method (DDM), the image of the scanned sky region can be reconstructed.Here we give an overview of the mission and its progresses, including payload, core sciences, ground calibration/facility, ground segment, data archive, software, in-orbit performance, calibration, background model, observations and some preliminary results.Shuang-Nan Zhang TiPei Li FangJun Lu LiMing Song YuPeng X u CongZhan Liu Yong Chen XueLei Cao QingCui Bu Zhi Chang Gang Chen Li Chen TianXiang Chen YiBao Chen YuPeng Chen Wei Cui WeiWei Cui JingKang Deng YongWei Dong Yuan Yuan Du MinXue Fu GuanHua Gao He Gao Min Gao MingYu Ge YuDong Gu Ju Guan Can Gungor ChengCheng Guo DaWei Han Wei Hu Yue Huang Jia Huo ShuMei Jia LuHua Jiang WeiChun Jiang Jing Jin YongJie Jin Bing Li ChengKui Li Gang Li MaoShun Li Wei Li Xian Li XiaoBo Li XuFang Li YanGuo Li ZiJian Li ZhengWei Li XiaoHua Liang JinYuan Liao GuoQing Liu HongWei Liu ShaoZhen Liu XiaoJing Liu Yuan Liu YiNong Liu Bo Lu XueFeng Lu Tao Luo Xiang Ma Bin Meng Yi Nang JianYin Nie Ge Ou JinLu Qu Na Sai RenCheng Shang GuoHong Shen Liang Sun Ying Tan Lian Tao YouLi Tuo Chen Wang ChunQin Wang GuoFeng Wang HuanYu Wang Juan Wang WenShuai Wang YuSa Wang XiangYang Wen BaiYang Wu BoBing Wu Mei Wu GuangCheng Xiao ShaoLin Xiong LinLi Yan JiaWei Yang Sheng Yang YanJi Yang QiBin Yi Bin Yuan AiMei Zhang ChunLei Zhang ChengMo Zhang Fan Zhang HongMei Zhang Juan Zhang Qiang Zhang ShenYi Zhangs Shu Zhang Tong Zhang WanChang Zhang Wei Zhang WenZhao Zhang Yi Zhang YiFei Zhang YongJie Zhang Yue Zhang Zhao Zhang Zhi Zhang ZiLiang Zhang HaiSheng Zhao XiaoFan Zhao ShiJie Zheng JianFeng Zhou YuXuan Zhu Yue Zhu RenLin Zhuang 2020Science China(Physics,Mechanics & Astronomy)2020,63,4:2
20Diurnal variability of the planetary boundary layer height estimated from radiosonde data显示文摘Diurnal variations in the planetary boundary layer height(PBLH)at different latitudes over different surface characteristics are described,based on 45 years(1973−2017)of radiosonde observations.The PBLH is determined from the radiosonde data by the bulk Richardson number(BRN)method and verified by the parcel method and the potential temperature gradient method.In general,the BRN method is able to represent the height of the convective boundary layer(BL)and neutral residual layer cases but has relatively large uncertainty in the stable BL cases.The diurnal cycle of the PBLH over land is quite different from the cycle over ocean,as are their seasonal variations.For stations over land,the PBLH shows an apparent diurnal cycle,with a distinct maximum around 15:00 LT,and seasonal variation,with higher values in summer.Compared with the PBLH over land,over oceans the PBLH diurnal cycles are quite mild,the PBLHs are much lower,and the seasonal changes are less pronounced.The seasonal variations in the median PBLH diurnal cycle are positively correlated with the near-surface temperature and negatively correlated with the near-surface relative humidity.Finally,although at most latitudes the daytime PBLH exhibits,over these 45 years,a statistically significant increasing trend at most hours between 12:00 LT and 18:00 LT over both land and ocean,there is no significant trend over either land or ocean in the nighttime PBLH for almost all the studied latitudes.Jie Gu YeHui Zhang Na Yang Rui Wang 2020Earth and Planetary Physics2020,4,5:2
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