检索结果-南通市图书馆

On the Discrepancy of Coronal magnetic Fields in Solar Optics and Radio

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 1997年第1期14卷 77-80页

作者： ma Yue-hua LI Xiao-qing Purple Mountain Observatory Chinese Academy of SciencesNanjing 210042

The discrepancy on the coronal magnetic field between solar optics and radio is analysed by using magnetic fibril concept with filling factor and fractal structure *** magnetic field of about 100 G considered in solar optics is the mean value in a large scale,and that of about 1000 G in solar radio should be the value of fine structures inside“macro”loop.

关键词： Solar optics magnetic

Existence of Positive Solutions of Second-order Periodic Boundary Value Problems with Sign-Changing Green＇s Function

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta mathematicae Applicatae Sinica 2017年第2期33卷 263-268页

作者： Cheng-hua GAO Fei ZHANG Ru-yun ma Department of mathematics Northwest Normal University Lanzhou 730070 China

In this paper, we consider the existence of positive solutions of second-order periodic boundary value problem where 0 〈 ε 〈 1/2, g ： [0, 2π] →R is continuous, f ： [0, ∞） →R is continuous and λ 〉 0 is a pa... 详细信息

关键词： periodic boundary value problem existence positive solutions sign-changing Green's functions

High-Efficiency Electromagnetic Interference Shielding of rGO@FeNi/Epoxy Composites with Regular Honeycomb Structures

在线全文

学校读者我要写书评

暂无评论

Nano-Micro Letters 2022年第3期14卷 244-256页

作者： Ping Song Zhonglei ma hua Qiu Yifan Ru Junwei Gu Shaanxi Key Laboratory of macromolecular Science and Technology School of Chemistry and Chemical EngineeringNorthwestern Polytechnical UniversityXi’an 710072People’s Republic of China Queen mary University of London Engineering School Northwestern Polytechnical UniversityXi’an 710072People’s Republic of China

With the rapid development of fifth-generation mobile com-munication technology and wearable electronic devices,electromagnetic interference and radiation pollution caused by electromagnetic waves have attracted worldwide ***,the design and development of highly efficient EMI shielding materials are of great *** this work,the three-dimensional graphene oxide(GO)with regular honeycomb structure(GH)is firstly constructed by sacrificial template and freeze-dry-ing ***,the amino functionalized FeNi alloy particles(f-FeNi)are loaded on the GH skeleton followed by in-situ reduction to prepare rGH@FeNi ***,the rGH@FeNi/epoxy EMI shielding com-posites with regular honeycomb structure is obtained by vacuum-assisted impregnation of epoxy *** from the construction of regular honeycomb structure and electromagnetic synergistic effect,the rGH@FeNi/epoxy composites with a low rGH@FeNi mass fraction of 2.1 wt%(rGH and f-FeNi are 1.2 and 0.9 wt%,respectively)exhibit a high EMI shielding effectiveness(EMI SE)of 46 dB,which is 5.8 times of that(8 dB)for rGO/FeNi/epoxy composites with the same rGO/FeNi mass *** the same time,the rGH@FeNi/epoxy composites also possess excellent thermal stability(heat-resistance index and temperature at the maximum decomposition rate are 179.1 and 389.0°C respectively)and mechanical properties(storage modulus is 8296.2 MPa).

关键词： Electromagnetic interference shielding rGO@FeNi Epoxy resins Honeycomb structures

Incurable and refractory spinal cystic echinococcosis: A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2021年第33期9卷 10337-10344页

作者： Tao Zhang Li-hua.ma hua Liu Song-Kai Li Department of Spine Surgery the 940th Hospital of Joint Logistics Support Force of Chinese PLALanzhou 730050Gansu ProvinceChina the First Hospital of Lanzhou University Lanzhou 730050Gansu ProvinceChina

BACKGROUND Although the incidence and cure rate of spinal hydatidosis are low,the recurrence rate of spinal hydatidosis is high,and the prognosis of spinal hydatidosis is ***,we report a typical case of refractory spinal hydatidosis to increase spine surgeons’awareness of the disease and reduce misdiagnosis and *** SUMmaRY A 48-year-old man presented with back pain,significant weight loss,and paralysis of both lower *** patient was misdiagnosed with spinal tuberculosis in an outside ***,spinal magnetic resonance imaging(MRI)showed hyperintense cystic components on T2-weighted images and hypointensity on T1-weighted images.A lobulated,multiocular,honeycombappearance,septated cystic mass protruding intraspinally and compressing the spinal cord at segments T8–T9 was *** polycystic lobular lesions presented as a“bunch of grapes”.The ELISA test result for Echinococcus granulosus was ***,a diagnosis of spinal hydatidosis and lung hydatid disease was made,and the patient underwent left transthoracic approach lobectomy,paravertebral lesion debridement,and subtotal vertebrectomy with vertebral body replacement of segments T8 and T9 by a mesh *** patient also underwent albendazole chemotherapy before and after *** year after stopping the drug therapy,the patient developed recurrent T5 vertebral lesions and underwent a second subtotal vertebrectomy *** patient is currently in good condition and is receiving long-term medication and *** The MRI feature of a“bunch of grapes”is a typical imaging indication of spinal *** vertebrectomy is a risk factor for postoperative *** spondylectomy makes it possible to cure spinal hydatidosis,but antiparasitic drug therapy is also an important supplementary therapy to multimodal *** is preferable for patients with spinal hydatidosis to receive life-long antiparasitic medication therapy and follow-up.

关键词： Cystic echinococcosis Spinal hydatidosis Recurrence Case report

Comparative transcriptomic analysis of Rosa sterilis inflorescence branches with different trichome types reveals an R3-MYB transcription factor that negatively regulates trichome formation

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2022年第10期21卷 2926-2942页

作者： ma Wen-tao LU Min AN hua-ming YI Yin Guizhou Engineering Research Center for Fruit Crops Agricultural CollegeGuizhou UniversityGuiyang 550025P.R.China Key Laboratory of Plant Resource Conservation and Germplasm Innovation in Mountainous Region(Ministry of Education) Institute of Agro-bioengineeringCollege of Life ScienceGuizhou UniversityGuiyang 550025P.R.China Key Laboratory of Plant Physiology and Development Regulation Guizhou Normal UniversityGuiyang 550025P.R.China

Rosa sterilis *** is an important economic tree in China that produces fruits with high nutritional and medicinal *** of ***’organs are covered with different types of trichomes or prickles that directly affect fruit appearance and plant *** study used RNA sequencing technology to analyze the transcriptomes of two parts of the inflorescence branch,namely inflorescence stems with flagellated trichomes and pedicels with both flagellated and glandular *** transcriptomic analysis showed that many transcription factors(TFs)are potentially involved in the formation and development of *** accumulation of RsETC1,a TF of the R3-MYB family,was significantly higher in inflorescence stems than in pedicels;quantitative reverse transcription PCR(qRTPCR)verified that its expression was significantly higher in inflorescence stems than in pedicels during the first three development stages,indicating its inhibitory action on the initiation of glandular trichomes in *** mRNA level of RsETC1 accumulated to significantly higher levels in trichomeless tissues than in tissues with trichromes,suggesting that this gene may inhibit the formation of trichomes in ***-expression of RsETC1 in Arabidopsis resulted in glabrous phenotypes,and the expression of trichome-related endogenous genes,except for TTG1,was markedly *** addition,the contents of the phytohormones jasmonic acid(JA),gibberellin A3(GA_(3)),and cytokinins(CKs)in pedicels were significantly higher than those in inflorescence stems,and the expression patterns of the genes related to hormone biosynthesis and signal transduction presented consistent responses,suggesting that the transduction of these hormones might be crucial for trichome initiation and *** data provide a new perspective for revealing the molecular mechanism of trichome formation in ***.

关键词： comparative transcriptome inflorescence stem pedicels R3-MYB transcription factor trichome

Microstructure and mechanical property of Mg-10Gd-2Y-1.5Zn-0.5Zr alloy processed by eight-pass equal-channel angular pressing

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第4期42卷 1371-1377页

作者： huan Liu Jia Ju Xiao-Wei Yang Yu-hua Li Jing-hua Jiang Ai-Bin ma College of Mechanics and materials Hohai UniversityNanjing211100China Suqian Research Institute of Hohai University Suqian223800China College of materials Engineering Nanjing Institute of TechnologyNanjing211167China

In this work,a high-strength Mg-10Gd-2Y-1.5Zn-0.5Zr(wt%)alloy was prepared via eight passes of equal-channel angular pressing(ECAP).The microstructures and mechanical properties of as-cast and ECAP alloys were systematically investigated by X-ray diffraction(XRD),optical microscopy(OM),scanning electron microscopy(SEM),transmission electron microscopy(TEM)and electronic universal testing *** obtained results indicate that the microstructure of as-cast alloy consists ofα-Mg dendrite,network Mg3(Gd,Y,Zn)phase and lamellar 14H long-period stacking ordered(LPSO)phase which is precipitated near the boundary of Mg3(Gd,Y,Zn)*** eight-pass ECAP,the network Mg3(Gd,Y,Zn)phase is deformed and ***,the refined Mg_3(Gd,Y,Zn)particles are not distributed uniformly in the matrix,but still aggregated at the interdendritic ***,the content of 14H lamellas increases obviously,and they become bent and kinked during severe *** is activated in the region between Mg3(Gd,Y,Zn)particles and 14H *** test at room temperature indicates that the ECAP alloy exhibits excellent mechanical property with compressive strength of 518 MPa and fracture strain of 21.6%.The comprehensive high strength and toughness could be ascribed to the refined Mg_3(Gd,Y,Zn)particles,DRX grains and kinked 14H LPSO phase.

关键词： Mg-Gd-Y-Zn-Zr Long-period stacking ordered phase Equal-channel angular pressing Compression strength Fracture strain

Modeling of acute cadmium toxicity in solution to barley root elongation using biotic ligand model theory

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2016年第4期28卷 112-118页

作者： Xuedong Wang Mingyan Wu Jingxing ma Xiaolin Chen Luo hua The Key Lab of Resource Environment and GIS College of Resource Environment and TourismCapital Normal University

Protons（H^＋）as well as different major and trace elements may inhibit cadmium（Cd）uptake in aquatic organisms and thus alleviate Cd ***,little is known about such interactions in soil *** this study,the independent effects of the cations calcium（Ca^2＋）,magnesium（Mg^2＋）,potassium（K^＋）,H^＋ and zinc（Zn^2＋）on Cd toxicity were investigated with 5-day long barley root elongation tests in nutrient *** tested concentrations of selected cations and trace metal ions were based on the ranges that occur naturally in soil pore *** toxicity of Cd decreased with increasing activity of Ca^2＋,Mg^2＋,H^＋and Zn^2＋,but not K^＋.Accordingly,conditional binding constants were obtained for the binding of Cd^2＋,Ca^2＋,Mg^2＋,H^＋,and Zn^2＋ with the binding ligand：log K（CdBL）5.19,logK（CaBL）2.87,logK（MgBL）2.98,logK（HBL）5.13 and logK（ZnBL）5.42,***,it was calculated that on average 29% of the biotic ligand sites needed to be occupied by Cd to induce a 50% decrease in root *** the estimated constants,a biotic ligand model was successfully developed to predict the Cd toxicity to barley root elongation as a function of solution *** feasibility and accuracy of its application for predicting Cd toxicity in soils were discussed.

关键词： Cadmium Biotic ligand model (BLM) Toxicity Barley

A study of instability in a miniature flying-wing aircraft in high-speed taxi

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2015年第3期28卷 749-756页

作者： Song Lei Yang hua Yan Xufeng ma Cong huang Jun School of Aeronautic Science and Engineering Beihang University

Abstract This study investigates an instability that was observed during highspeed taxi tests of an experimental flyingwing aircraft. In order to resolve the reason of instability and probable solution of it, the instability was reproduced in simulations. An analysis revealed the unique stability char acteristics of this aircraft. This aircraft has a rigid connection between the nose wheel steering mech anism and an electric servo, which is different from aircraft with a conventional tricycle landing gear system. The analysis based on simulation results suggests that there are two reasons for the insta bility. The first reason is a reversal of the lateral velocity of the nose wheel. The second reason is that the moment about the center of gravity created by the lateral friction force from the nose wheel is larger than that from lhe lateral friction force from the main wheels. These problems were corrected by changing the ground pitch angle. Simulations show that reducing the ground pitch angle can eliminate the instability in highspeed taxi.

关键词： Dynamic analysisFlying wing Stability Takeoff Taxiing

Numerical simulation of oxide nanoparticle growth characteristics under the gas detonation chemical reaction by space-time conservation element-solution element method

在线全文

学校读者我要写书评

暂无评论

Particuology 2017年第6期15卷 78-83页

作者： Ning LUO hua Shen Hongwen Jing Zhangguo ma Weiming Yang State Key Laboratory for Geo-mechanics and Deep Underground Engineering School of Mechanics and Civil Engineering China University of Mining and Technology Xuzhou 221116 China Laboratory for Precision and Nano Processing Technologies School of Mechanical and Manufacturing Engineering The University of New South Wales Sydney 2052 Australia Department of Mechanics and Engineering Science College of Engineering Peking University Beijing 100871 Chino

Under harsh conditions （such as high temperature, high pressure, and millisecond lifetime chemical reaction）, a long-standing challenge remains to accurately predict the growth characteristics of nanosize spherical particles and to determine the rapid chemical reaction flow field characteristics, The growth characteristics of similar spherical oxide nanoparticles are further studied by successfully introducing the space-time conservation element-solution element （CE/SE） algorithm with the monodisperse Kruis model. This approach overcomes the nanosize particle rapid growth limit set and successfully captures the characteristics of the rapid gaseous chemical reaction process. The results show that this approach quantitatively captures the characteristics of the rapid chemical reaction, nanosize particle growth and size distribution. To reveal the growth mechanism for numerous types of oxide nanoparticles, it is very important to choose a rational numerical method and particle physics model.

关键词： Oxide nanoparticles Growth characteristics Space-time conservation element-solutionelement method Kruis model Gas detonation