检索结果-南通市图书馆

Comparative Chemical Research in Essential Oils from Six Apiaceae Species Growing in the Northern Region of Vietnam

Phyton-International Journal of Experimental Botany 2024年第7期93卷 1677-1687页

作者： Nguyen Quang Hung Nguyen Thanh Tung Nguyen Phuong hanh Chu Thi Thu ha Nguyen Thi Nhung Nguyen Thai An Vu Xuan Giang Luong Van hao Oleh Koshovyi Ain Raal Institute of Ecology and Biological Resources Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Graduate University of Science and Technology Vietnam Academy of Science and Technology(VAST)Cau GiayHa Noi100000Viet Nam Department of Pharmacognosy Faculty of Pharmacognosy and Traditional MedicineHanoi University of PharmacyHoan KiemHa Noi100000Viet Nam Sa Pa Research Center of Medicinal Materials National Institute of Medicinal MaterialsDien Bien PhuSa PaLao Cai330000Viet Nam Institute of Pharmacy Faculty of MedicineUniversity of TartuTartu50411Estonia

Our study aimed to compare the essential oil(EO)concentration and composition of several Apiaceae species growing in the Northern region of *** yields of EOs from materials ranged from 0.03%(root EO of Angelica acutiloba and aerial parts EO of Heracleum bivittatum)-0.27%(leaf EO of Xyloselinum vietnamense).Gas chromatography-mass spectrometry(GC-MS)allowed the identiﬁcation of 74 components in the EOs of six Apiaceae species,making up 94.4%–100.0%of the *** EO from Angelica acutiloba,(Z)-ligustilide accounted for an extremely large proportion(94.9%).EO of Angelica pubescens was dominated by six character-istic components includingα-pinene(21.5%),β-phellandrene(18.1%),p-cymene(12.2%),3-methylnonane(8.7%),o-cymene(8.1%),and D-sylvestrene(6.2%).The EO from Cryptotaenia japonica was characterized by high amounts ofα-selinene(48.7%),β-selinene(23.7%),and trans-β-farnesene(5.4%).The EOs from leaves and stems of Xyloselinum vietnamense were characterized by high concentrations of sabinene(69.8%and 33.8%),4-terpineol(8.7%and 7.4%)andβ-pinene(4.0%and 6.5%)while EOs from aerial parts and root of Xylo-selinum leonidii comprise four characteristic monoterpenes includingα-pinene(28.2%and 52.8%),β-pinene(7.9%and 10.3%),β-phellandrene(7.6%and 15.3%),and sabinene(3.0%and 4.1%).Additionally,cryptone is also one of the major components in the EO of Xyloselinum leonidii(13.2%in the aerial parts oil and 2.8%in the root oil).In the EOs isolated from the aerial parts and root of Heracleum bivittatum,α-pinene(22.5%and 70.2%)andβ-pinene(43.2%and 20.0%)were the predominant *** appeared in the EO from aerial parts of Heracleum bivittatum with a relatively high concentration(13.5%)while bornyl acetate(5.1%)was also one of the main components in the EO from its aerial parts but was not detected in other Apiaceae species in the present *** databases help identify and control the quality of plant material studied from the family Apiaceae growing in Vietnam.

关键词： Apiaceae essential oil terpenoids gaschromatography-mass spectrometry

来源：

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

Variation of nutrient fluxes by rainfall redistribution processes in the forest canopy of an urban larch plantation in northeast China

引用

Journal of Forestry Research 2022年第4期33卷 1259-1269页

作者： Houcai Sheng na Guo Cunyong Ju Tijiu cai Center for Ecological Research Northeast Forestry UniversityHarbin 150040People’s Republic of China Key Laboratory of Sustainable Forest Ecosystem Management-Ministry of Education Northeast Forestry UniversityHarbin 150040People’s Republic of China College of Food Engineering East University of HeilongjiangHarbin 150040People’s Republic of China

Atmospheric deposition(dry and wet deposition)is one of the primary sources of chemical inputs to terrestrial ecosystems and replenishes the nutrient pool in forest *** often acts as a primary transporting agent and solvent;thus,nutrient cycles in forests are closely linked to hydrological *** collected precipitation data during a growing season to explore variations in nutrient cycling and nutrient balances in the rainfall redistribution process(wet deposition)in a larch plantation in northeast *** measured nutrient(NO_(3)^(-),PO_(4)^(3−),Cl^(−),K,Ca,na,and Mg)inputs via bulk precipitation,throughfall and stemfl ow,and used a canopy budget model to estimate nutrient fl uxes via canopy *** results suggest that the average concentrations of the base cation(K,Ca,na,and Mg)showed the following order:stemfl ow>throughfall>bulk *** and stemfl ow chemistry dramatically fl uctuated over the growing season when net fl uxes(throughfall+stemfl ow—bulk precipitation)of NO−3,PO3−4,SO2−4,Cl−,K,Ca,na,and Mg were−6.676 kg·ha^(-1),−1.094 kg·ha^(-1),−2.371 kg·ha^(-1),1.975 kg·ha^(-1),0.470 kg·ha^(-1),−5.202 kg·ha^(-1),−0.336 kg·ha^(-1),and 1.397 kg·ha^(-1),*** results suggest that NO−3,PO3−4,SO2−4,Ca,and na were retained,while Cl−,K,and Mg were washed off by throughfall and stemfl ow.

关键词： Rainfall redistribution Aqueous fluxes Water chemistry Macronutrients input Plantation forest harbin

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

越南汉语教材《汉语》（中高级）习题编排研究

越南汉语教材《汉语》（中高级）习题编排研究

引用

作者： ThaI THI ha LINH（蔡氏荷玲）山东师范大学

学位级别：硕士

《汉语》是越南汉语教学的常用教材,出版于2002年。本研究针对越南汉语教材《汉语》中高级阶段的练习题,着重探讨其在提升学生语言水平和实际应用能力方面的效果。考虑到当前对该教材练习题的研究相对不足且缺乏与其他教材的对比,本研... 详细信息

《汉语》是越南汉语教学的常用教材,出版于2002年。本研究针对越南汉语教材《汉语》中高级阶段的练习题,着重探讨其在提升学生语言水平和实际应用能力方面的效果。考虑到当前对该教材练习题的研究相对不足且缺乏与其他教材的对比,本研究选择了《汉语》教材作为研究对象,并与其他汉语教材进行对比研究,旨在揭示其独特特点和可能存在的不足之处。本文对《汉语》三册教材中的语言知识习题和言语技能习题进行了统计分析,总结了其编排特征。首先,语言知识习题主要集中在句型和语段习题上,词汇习题较少,汉字习题缺乏,反映了中高级阶段的特点,但存在分布不均衡的问题。题型设计新颖,但高频题型有限,语段习题功能性和趣味性不足。其次,言语技能习题的数量分布不均衡,阅读和口语习题比例最高。写作习题题型数量少,影响学生的写作能力发展和学习体验,教学内容缺乏多样性和灵活性。综上所述,教材在题量和题型分布上存在改进空间,需要在设计时予以重视和调整,以提升学生的语言运用能力和教学效果。本文研究了《汉语》教材中的习题内容,重点分析了语音、词汇、句型、语段和文化等方面的特点。语音习题强调声调和语调训练,词汇习题注重词语运用,句型习题培养灵活运用能力,语段习题重视组织结构和逻辑思维,文化习题通过写作和翻译增强跨文化交际能力。研究发现,教材习题设计全面,注重基础知识和综合运用能力,具有实用性和趣味性,涵盖日常生活和文化因素,有助于提升综合语言素养。建议在教学中灵活运用,进行差异化教学。本文对比了《汉语》教材与范杨洲的《汉语教程》在习题形式和习题内容方面的差异,本文得出了结果:在内容方面,《汉语》还存在不足之处:第一,教材缺乏相应的听力理解习题;第二,在口头表达能力方面,分角色对话习题的数量相对较少;第三,在书面表达能力方面,习题形式相对传统,缺乏创新;最后,在文化方面可以进一步扩展和丰富这方面的内容。在习题形式方面,教材充分考虑了学习者的学习阶段和需求,设计了机械性、理解运用性和交际性三类习题。特别是在理解运用性和交际性习题方面,教材设计了丰富多样的题型。在观察与分析过程中,本人还发现了一些不足之处。特别是在《汉语》(10册)教材中,机械性习题和交际性习题的数量明显不足,而理解运用性习题的比重过大。通过对《汉语》使用者进行问卷调查和访谈,本文发现他们对《汉语》教材习题相对满意。尽管如此,他们也提出《汉语》教材习题还存在一些问题:第一,一些课文的主题内容已显得陈旧;第二,需要增加听力和口语习题;第三,在习题中添加插图;最后,尽管他们对文化因素很满意,但他们还建议增加文化因素。综上所述,本研究的结果对于越南《汉语》教材习题的修订和再版,以及未来越南教材习题的编写具有重要的参考价值。通过对《汉语》教材习题的深入分析和评估,并与范杨洲的《汉语教程》进行对比研究,结合师生对《汉语》习题的使用情况、习题编排的满意度和需求,本研究提出了一系列改进建议。这些建议涵盖增加听力习题、加强文化因素的融入、提高习题的趣味性和多样性等方面。尤其需要加强对中高级水平学习者的习题设计和使用分析,以更好地满足他们的学习需求。本文期望这些建议不仅能够协助改进现有教材的质量,也能够为未来教材编写提供借鉴和参考,进一步促进汉语教学质量的提升。

关键词：汉语教材习题习题分析中高级阶段对比研究

来源：

同方学位论文库评论

在线全文

同方学位论文库

学校读者我要写书评

暂无评论

A study on wildfire impacts on greenhouse gas emissions and regional air quality in South of Orléans,France

引用

Journal of Environmental Sciences 2024年第1期135卷 521-533页

作者： Chaoyang Xue Gisèle Krysztofiak Yangang Ren Min cai Patrick Mercier Frédéric Le Fur Corinne Robin Benoit Grosselin Véronique Daele Max RMcGillen Yujing Mu Valéry Catoire Abdelwahid Mellouki Laboratoire de Physique et Chimie de l’Environnement et de l’Espace(LPC2E) CNRS–UniversitéOrléans–CNES(UMR 7328)Orléans Cedex 245071France Institut de Combustion AérothermiqueRéactivitéEnvironnement(ICARE)CNRSOrléans Cedex 245071France Research Centre for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China Lig’Air-Association de surveillance de la qualitéde l’air en région Centre-Val de Loire Saint-Cyr-en-Val 45590France Mohammed V University RabatMorocco

Wildfire events are increasing globally which may be partly associated with climate change,resulting in significant adverse impacts on local,regional air quality and global *** September 2020,a small wildfire(burned area:36.3 ha)event occurred in Souesmes(Loiret-Cher,Sologne,France),and its plume spread out over 200 km on the following day as observed by the MODIS *** on measurements at a suburban site(~50 km northwest of the fire location)in Orléans and backward trajectory analysis,young wildfire plumes were *** increases in gaseous pollutants(CO,CH_(4),N_(2)O,VOCs,etc.)and particles(including black carbon)were found within the wildfire plumes,leading to a reduced air *** factors,defined as EF(X)=ΔX/ΔCO(where,X represents the target species),of various trace gases and black carbon within the young wildfire plumes were determined accordingly and compared with previous *** in the ambient ions(such as ammonium,sulfate,nitrate,chloride,and nitrite in the particle-and gasphase)and aerosol properties(e.g.,aerosol water content,aerosol p H)were also quantified and ***,we estimated the total carbon and climate-related species(e.g.,CO_(2),CH_(4),N_(2)O,and BC)emissions and compared them with fire emission *** biomass burning emission inventories have uncertainties in estimating small fire burned areas and *** instance,we found that the Global Fire Assimilation System(GFAS)may underestimate emissions(e.g.,CO)of this small wildfire while other inventories(GFED and FINN)showed significant *** that it is the first time to record wildfire plumes in this region,related atmospheric implications are presented and discussed.

关键词： Wildfire Air quality Emission factor Emission inventory VOLTAIRE supersite

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

基于升脾润燥浅谈针灸调节肠道菌群治疗干燥综合征相关干眼病

引用

光明中医 2024年第11期39卷 2301-2304页

作者：邓雯哈国栋蔡定均(指导) 成都中医药大学针灸推拿学院四川成都610075

干燥综合征相关干眼病是一种慢性自身免疫系统疾病。研究发现,部分肠道微生物及其代谢产物可以不同程度改善其病理症状,而肠道菌群又与脾胃功能密切相关。同时,针灸作为传统治疗方法,对干预自身免疫系统疾病及肠道菌群失衡都有较好的疗... 详细信息

干燥综合征相关干眼病是一种慢性自身免疫系统疾病。研究发现,部分肠道微生物及其代谢产物可以不同程度改善其病理症状,而肠道菌群又与脾胃功能密切相关。同时,针灸作为传统治疗方法,对干预自身免疫系统疾病及肠道菌群失衡都有较好的疗效。因此,此文浅析针灸基于“升脾润燥”治则调摄肠道菌群,提高中焦运转、升举精微向上以防治干燥综合征相关干眼病的可行性,以期为临床治疗提供更多视角。

关键词：干燥综合征干眼病肠道菌群升脾润燥针灸疗法综述

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Vertical plane depth-resolved surface potential and carrier separation characteristics in flexible CZTSSe solar cells with over 12% efficiency

引用

Carbon Energy 2024年第3期6卷 36-52页

作者： Dae-Ho Son ha Kyung Park Dae-Hwan Kim Jin-Kyu Kang Shi-Joon Sung Dae-Kue Hwang Jaebaek Lee Dong-Hwan Jeon Yunae Cho William Jo Taeseon Lee JunHo Kim Sang-Hoon nam Kee-Jeong Yang Division of Energy Technology DGISTDaeguRepublic of Korea Research Center for Thin Film Solar Cells DGISTDaeguRepublic of Korea Department of Physics Ewha Womans UniversitySeoulRepublic of Korea Department of Physics Incheon National UniversityIncheonRepublic of Korea Department of Mechanical Engineering Massachusetts Institute of TechnologyCambridgeMassachusettsUSA

Cu2ZnSn(S,Se)4(CZTSSe)solar cells have resource distribution and economic *** main cause of their low efficiency is carrier loss resulting from recombination of photo-generated electron and *** overcome this,it is important to understand their electron-hole behavior *** determine the carrier separation characteristics,we measured the surface potential and the local current in terms of the absorber *** elemental variation in the intragrains(IGs)and at the grain boundaries(GBs)caused a band edge shift and bandgap(Eg)*** the absorber surface and subsurface,an upward Ec and Ev band bending structure was observed at the GBs,and the carrier separation was *** the absorber center,both upward Ec and Ev and downward Ec-upward Ev band bending structures were observed at the GBs,and the carrier separation was *** improve the carrier separation and suppress carrier recombination,an upward Ec and Ev band bending structure at the GBs is desirable.

关键词： carrier separation CZTSSe flexible solar cell local current surface potential

来源：

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

RUFY4 deletion prevents pathological bone loss by blocking endo-lysosomal trafficking of osteoclasts

引用

Bone Research 2024年第2期12卷 407-420页

作者： Minhee Kim Jin Hee Park Miyeon Go nawon Lee Jeongin Seo hana Lee Doyong Kim Hyunil ha Taesoo Kim Myeong Seon Jeong Suree Kim Taesoo Kim han Sung Kim Dongmin Kang Hyunbo Shim Soo Young Lee Department of Life Science Ewha Womans UniversitySeoul 03760South Korea The Research Center for Cellular Homeostasis Ewha Womans UniversitySeoul 03760South Korea Department of Biomedical Engineering Yonsei UniversityWonju 26493South Korea KM Convergence Research Division Korea Institute of Oriental MedicineDaejeon 34054South Korea Chuncheon Center Korea Basic Science InstituteChuncheon 24341South Korea Fluorescence Core Imaging Center and Bioimaging Data Curation Center Ewha Womans UniversitySeoul 03760South Korea Multitasking Macrophage Research Center Ewha Womans UniversitySeoul 03760South Korea

Mature osteoclasts degrade bone matrix by exocytosis of active proteases from secretory lysosomes through a ruffled ***,the molecular mechanisms underlying lysosomal trafficking and secretion in osteoclasts remain largely ***,we show with GeneChip analysis that RUN and FYVE domain-containing protein 4(RUFY4)is strongly upregulated during *** lacking Rufy4 exhibited a high trabecular bone mass phenotype with abnormalities in osteoclast function in ***,deleting Rufy4 did not affect osteoclast differentiation,but inhibited bone-resorbing activity due to disruption in the acidic maturation of secondary lysosomes,their trafficking to the membrane,and their secretion of cathepsin K into the extracellular ***,RUFY4 promotes late endosome-lysosome fusion by acting as an adaptor protein between Rab7 on late endosomes and LAMP2 on primary ***,Rufy4-deficient mice were highly protected from lipopolysaccharide-and ovariectomy-induced bone ***,RUFY4 plays as a new regulator in osteoclast activity by mediating endo-lysosomal trafficking and have a potential to be specific target for therapies against bone-loss diseases such as osteoporosis.

关键词： osteoclast inhibited traffic

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Organic X-Ray Image Sensors Using a Medium Bandgap Polymer Donor with Low Dark Current

引用

Energy & Environmental Materials 2024年第6期7卷 230-237页

作者： Jong-Woon ha Seung Hun Eom Bo Kyung Cha Seyeong Song Hyeong Ju Eun Jong H.Kim Jong Mok Park BongSoo Kim Byoungwook Park Seo-Jin Ko Sung Cheol Yoon Changjin Lee In Hwan Jung Do-Hoon Hwang Department of Chemistry Chemistry Institute for Functional MaterialsPusan National UniversityBusan 46241Korea Division of Advanced Energy Materials Research Center Korea Research Institute of Chemical Technology(KRICT)Daejeon 34114Korea Electro-Medical Device Research Center Korea Electrotechnology Research Institute(KERI)Ansan 15588Korea Graduate School of Carbon Neutrality School of Energy and Chemical EngineeringUlsan National Institute of Science and Technology(UNIST)Ulsan 44919Korea Department of Molecular Science and Technology Ajou UniversitySuwon 16449Korea Research Center for Advanced Specialty Chemicals Korea Research Institute of Chemical TechnologyUlsan 44412Korea Department of Chemistry Ulsan National Institute of Science and Technology(UNIST)Ulsan 44919Korea Department of Organic and nano Engineering Human-Tech Convergence ProgramHanyang University222 Wangsimni-roSeongdong-guSeoul 04763Korea

The development of portable X-ray detectors is necessary for diagnosing fractures in unconscious patients in emergency ***,this is quite challenging because of the heavy weight of the scintillator and silicon *** weight and thickness of X-ray detectors can be reduced by replacing the silicon layer with an organic *** study presents a novel bithienopyrroledione-based polymer donor that exhibits excellent photodetection properties even in a thick photoactive layer(~700 nm),owing to the symmetric backbone and highly soluble molecular structure of *** ability of bithienopyrroledione-based polymer donor to strongly suppress the dark current density(Jd~10−10 A cm^(−2))at a negative bias(−2.0 V)while maintaining high responsivity(R=0.29 A W−1)even at a thickness of 700 nm results in a maximum shot-noise-limited specific detectivity of D_(sh)^(*)=2.18×10^(13)Jones in the organic *** organic photodetectors are developed by slot-die coating for use in X-ray detectors,which exhibit D_(sh)^(*)=2.73×10^(12)Jones with clear rising(0.26 s)and falling(0.29 s)response times upon X-ray *** reliability is also proven by linear response of the X-ray detector,and the X-ray detection limit is 3 mA.

关键词： low dark current low detection limit organic photodetector printable X-ray

来源：

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

强噪环境下分频段数字音频信号精细化采集研究

引用

现代电子技术 2024年第11期47卷 64-68页

作者：哈筝山西大学音乐学院山西太原030006

在强噪环境下,为了获取高质量、低失真度的数字音频信号,提出一种强噪环境下分频段数字音频信号精细化采集方法。通过麦克风设备获取音频信号,利用LM4550芯片对其作采样、编码等处理后生成数字音频信号,基于AC-97单元接收数字音频信号,... 详细信息

在强噪环境下,为了获取高质量、低失真度的数字音频信号,提出一种强噪环境下分频段数字音频信号精细化采集方法。通过麦克风设备获取音频信号,利用LM4550芯片对其作采样、编码等处理后生成数字音频信号,基于AC-97单元接收数字音频信号,利用频段分割器对其作频带分解,获得互不重叠子频段数字音频信号。采用多窗谱谱减法对其去噪,利用数据通信接口将其传输给LM4550芯片,在完成模拟信号转换后,通过耳机输出,实现数字音频信号精细化采集。实验结果表明,该方法处理后的各子频段数字音频信号有用信息得以完整保留,并提高了信号波形的规整度和规律性,强噪声环境下数字音频信号的PESQ指标达到4.08以上,最大失真度为3.74%。

关键词：强噪环境分频段数字音频信号 FPGA 频段分割器多窗谱谱减法通信接口模拟信号

来源：

维普期刊数据库博看期刊

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

新兴和发展中经济体的资本管制与美国货币政策的传导

引用

新金融 2024年第4期 21-28,36页

作者： Jongrim ha haiqin Liu John Rogers 李丽丽(译) 周正铭(译) 世界银行复旦大学不详

与发达经济体相比,新兴市场和发展中经济体(EMDEs)的资产收益波动性要大得多。学术界对此现象的研究结果是“各国无法从全球金融周期中脱钩”。文章利用1995—2019年间78个国家的结构向量自回归模型,以及文献中识别美国货币政策冲击的... 详细信息

与发达经济体相比,新兴市场和发展中经济体(EMDEs)的资产收益波动性要大得多。学术界对此现象的研究结果是“各国无法从全球金融周期中脱钩”。文章利用1995—2019年间78个国家的结构向量自回归模型,以及文献中识别美国货币政策冲击的不同方法,检验了资本账户开放程度较低的国家对美国货币政策冲击的系统性反应小于资本管制宽松的国家这一命题。文章还考虑了汇率制度和外汇干预等其他制度特征在解释各国对冲击的反应差异方面的作用。实证结果表明:较严格的资本管制会使利率和汇率对美国货币政策冲击的反应较小,该结果在新兴市场经济国家中更为显著;只有微弱的证据表明汇率的灵活程度会影响美国对外国利率和汇率的溢出效应。本刊编译此篇世界银行的研究报告,以飨读者。

关键词：资本管制溢出效应资本流动管理全球金融周期美联储

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：