检索结果-南通市图书馆

Effect of thinning intensity on tree growth and temporal variation of seed and cone production in a Pinus koraiensis plantation

引用

Journal of Forestry Research 2019年第3期30卷 835-845页

作者： Thanh Tuan nguyen Dinh tien Tai Peng Zhang Muhammad Razaq Hai-Long Shen School of Forestry Northeast Forestry University Harbin 150040People’s Republic of China Department of Forestry Vietnam Forestry University-Second CampusOkayamaDongnai 810000Vietnam Graduate School of Environmental and Life Science Okayama UniversityOkayamaJapan

Thinning of Korean pine (Pinus koraiensis Sieb. et Zucc.) is used to facilitate timber and cone production. The present study in Northeast China investigated the effects of thinning intensity on individual tree growth, temporal variation in cone yield, and seed quality in Korean pine plantation. In 2005, five thinning intensity levels (none, extreme, heavy, moderate and light) were set in 15 permanent plots in a 32-year-old Korean pine plantation at Mengjiagang Forest Farm, Jiamusi City, Heilongjiang Province. We recorded tree growth and seed cone production from 2013 to 2016, i.e., from 8 to 11 years after thinning. Except for height growth, thinning increased tree growth (diameter at breast height and crown size) and improved cone yield. The extreme thinning treatment (to 300 trees per hectare) resulted in the largest tree diameter, tree volume, crown size and 4-year cone production per tree. The highest cone yield per tree in the mast year (2014) was observed when stands were thinned to 500 trees per hectare (heavy thinning). Although the best cone and seed quality and the largest cone and seed mass per tree were recorded in the heavily thinned stand, no significant differences were found between heavy and moderate thinning stands (750 trees per hectare). At the stand level, the moderately thinned stand had the highest basal area, stock volume and seed cone production per stand. Our results suggest that thinning to 750 trees per hectare will improve timber and cone productivity in 40-year-old P. koraiensis stands.

关键词： Korean pine Thinning intensity Seed yield Tree growth Temporal variation in cone yield

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

Zirconium metal organic framework for design of tetragonal rare earth-doped zirconia nanoparticles

引用

Journal of Rare Earths 2019年第11期37卷 1230-1236页

作者： Lam Thi Kieu Giang Lukasz Marciniak Krzysztof Kamil Zur Dinh Manh tien nguyen Vu nguyen Thanh Binh Tran Kim Anh Le Quoc Minh Institute of Materials Science Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Graduate University of Science and Technology Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Institute of Low Temperature and Structural Research Polish Academy of Sciencesul.Okolna 250-422 WroclawPoland Faculty of Mechanical Engineering Bialystok University of TechnologyWiejska 45C15-351 BialystokPoland Institute of Applied Physics and Scientific Instrument Vietnam Academy of Science and Technology18 Hoang Quoc VietCau GiayHanoiViet Nam Duy Tan University 03 Quang TrungDa NangViet Nam

Zirconium metal-organic frameworks ZrOBDC(where BDC=C6H4(COOH)2,terephthalic acid)doped and co-doped with rare earth ions Ln(ZrOBDC:Ln^3+,where Ln^3+=Eu3+and Tb^3+as well as Er^3+and Yb^3+)were used as precursors for the design of tetragonal rare earth doped zirconia nanoparticles(t-ZrO2:Ln^3+NPs)through annealing ***,characterization and luminescence properties of ZrOBDC:Ln^3+and ZrO2:Ln^3+NPs were *** as-obtained t-ZrO2:Ln^3+NPs have high purity with an average size of 20-30 *** luminescence spectra of ZrOBDC:Tb^3+and ZrOBDC:Eu3+display strong green and red emission at around 544 and 611 nm which correspond to 5D4→7F5 and 5D0→7F2 transitions of Tb^3+and Eu3+ions,*** green and red up-conversion emissions of ZrO2:Er^3+,Yb^3+NPs due to 2H11/2,4S3/2→4I15/2 and 4F9/2→4I15/2 transitions of the Er^3+ions are observed under 976 nm laser excitation.

关键词： Zirconium Rare earth ZrOBDC ZrOBDC:Ln3+ ZrO2:Ln3+ Up-conversion

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

Damage detection in steel plates using feed-forward neural network coupled with hybrid particle swarm optimization and gravitational search algorithm

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2021年第6期22卷 467-480页

作者： Long Viet HO Duong Huong nguyen Guido de ROECK Thanh BU-tien Magd Abdel WAHAB Soete Laboratory Department of Electrical EnergyMetalsMechanical Constructions and SystemsFaculty of Engineering and ArchitectureGhent UniversityGent 9000Belgium Department of Bridge and Tunnel Engineering Faculty of Civil EngineeringUniversity of Transport and CommunicationsHo Chi Minh 700000Vietnam Department of Bridge and Tunnel Engineering Faculty of Bridge and RoadNational University of Civil EngineeringHanoiVietnam Department of Civil Engineering Structural MechanicsKatholieke Universiteit LeuvenB-3001 LeuvenBelgium Department of Bridge and Tunnel Engineering Faculty of Civil EngineeringUniversity of Transport and CommunicationsHanoiVietnam Division of Computational Mechanics Ton Due Thang UniversityHo Chi Minh CityVietnam Faculty of Civil Engineering Ton Due Thang UniversityHo Chi Minh CityVietnam

Over recent decades,the artificial neural networks(ANNs)have been applied as an effective approach for detecting damage in construction ***,to achieve a superior result of defect identification,they have to overcome some shortcomings,for instance slow convergence or stagnancy in local ***,optimization algorithms with a global search ability are used to enhance ANNs,*** increase the rate of convergence and to reach a global *** paper introduces a two-stage approach for failure identification in a steel *** the first step,the presence of defects and their positions are identified by modal *** the second step,a feedforward neural network,improved by a hybrid particle swarm optimization and gravitational search algorithm,namely FNN-PSOGSA,is used to quantify the severity of *** element(FE)models of the beam for two damage scenarios are used to certify the accuracy and reliability of the proposed *** comparison,a traditional ANN is also used to estimate the severity of the *** obtained results prove that the proposed approach can be used effectively for damage detection and quantification.

关键词： Feedforward neural network-particle swarm optimization and gravitational search algorithm(FNN-PSOGSA) Modal damage indices Damage detection Hybrid algorithm PSOGSA

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

A time-domain estimation method of rapidly time-varying channels for OFDM-based LTE-R systems

引用

Digital Communications and Networks 2019年第2期5卷 94-101页

作者： Jin-Kyu Choi Van Due nguyen Hai Nam nguyen Van Vinh Duong tien Hoa nguyen Hanbyeog Cho Hyun-Kyun Choi Seong-Gyoon Park Smart Mobility Research Department of ETR1 DaejeonSouth Korea School of Electronics and Telecommunicalions HUSTViet Nam Electronics and Telecommunications Research Institute DaejeonSouth Korea School of Information and Communication in KongJu National University South Korea

This paper addresses the performance of fast doubly selective fading channel estimation combined with InterCarrier Interference (ICI) cancellation for Long Term Evolution (LTE) communication platform in the High Speed Railway (HSR) environment. We consider the Channel Impulse Response (CIR) coefficients with a critical Doppler frequency shift and multi-path fading that were taken from the WINNER II channel model and the D2a propagation scenario, where the conditions of HSR are analyzed. As multi-path fading increases and the channel varies in the order of the symbol period, we first propose a novel approach for designing a pilot symbol structure in the time domain. Then, we describe the deployment of the proposed pilot symbol structure to estimate the channel in the time domain. Channel information corresponding to the data positions is obtained by linear interpolation. In each OFDM symbol, the slope and the initial value for establishing an interpolation function are estimated to adapt to the time variation of the channel. An accurate estimate of channel state information is used for the purpose of ICI cancellation. The simulation results show that the channel estimated by our proposed method can follow the real channel well, even in a very high Doppler frequency. The estimation method in terms of Mean Squared Error (MSE) significantly outperforms the state-of-the-art methods. The combination of our channel estimator with several interference cancelers provides a considerably better system performance than that achieved when frequency channel estimation is used.

关键词： ICI cancellation OFDM Channel estimation LTE-R

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

Detection and localization of the hemoglobin and collagen distribution of the uterine cervix

引用

Journal of Innovative Optical Health Sciences 2019年第4期12卷 116-126页

作者： Tran Van tien nguyen Ngoc Quynh Le Huynh Duc Phan Ngoc Khuong Cat Huynh Quang Linh Department of Applied Physics Faculty of Applied Science Ho Chi Minh City University of Technology700000 Vietnam DCSELAB—National key Laboratory of Digital Control and System Engineering 700000 Vietnam Department of Biomedical Engineering Faculty of Medicine Nguyen Tat Thanh University700000 Vietnam Department of Engineering Physics Faculty of Applied Science Ho Chi Minh City University of Technology700000 Vietnam

Changes of the blood vessels and collagen are associated with the development of abnormal cervical ***,optical coberence tomography and Mueller polarization images were 1used to provide information regarding the presence of collagen fibers in the cervical ***,most of these methods need a lot of time for image recording and are *** addition,the general survey on the absorption and distribution characteristics of collagen and blood in the cervical is still *** this study,we developed a colposcopy combining cross-polarized inage and image procssing algorithm with an fficient analytical model to map the distribution of blood and collagen in the *** this system's proof of concept,we captured and processed the case of cervical ectopy and Nabothian *** results show that the distribution of blood and collagen maps matched with anatomical and physiological when compared with Lugol's iodline *** technology has some advantages,such as low cost,real time,and can replace the 11se of acetic acid or Lugol's iodine in the future.

关键词： Hemoglobin collagen cross polarized image uterine cervix

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

A New Species of Amsassia from the Ordovician of Korea and South China:Paleobiological and Paleogeographical Significance

引用

Acta Geologica Sinica(English Edition) 2016年第3期90卷 796-806页

作者： Mirinae LEE Heeju PARK nguyen Viet tien Suk-Joo CHOH Robert J.ELIAS Dong-Jin LEE Department of Earth and Environmental Sciences Andong National UniversityAndong36729Republic of Korea Institute of Geological Sciences-Vietnam Academy of Science and Technology(IGS-VAST) Hanoi100000Socialist Republic of Vietnam Department of Earth and Environmental Sciences Korea UniversitySeoul02841Republic of Korea Department of Geological Sciences The University of ManitobaWinnipegR3T 2N2Canada

A new species of the probable calcareous alga Amsassia, A. koreanensis, is recognized from the Duwibong Formation （Middle Ordovician, Darriwilian） of the Taebaeksan Basin in mid-eastern Korea. This is the first report of the genus from the Korean Peninsula, expanding its geographical range to the eastern Sino-Korean Block. The new species also occurs in the Xiazhen Formation （Upper Ordovician, Katian） at Zhuzhai in the South China Block. Amsassia koreanensis is the smallest species of this modular genus, having a maximum module diameter of 0.28 ram. Module increase is by bipartite, tripartite and quadripartite types of longitudinal axial fission, but unlike other species of the genus, quadripartite fission is common. The types of fission are comparable to those in some Tetradiida （now Prismostylales, florideophycean rhodophyte algae）, although the processes of fission are different. The distribution of A. koreanensis further strengthens the biogeographical connection between the Sino-Korean and South China blocks, suggesting that these two paleocontinents were located closer together during the Middle to Late Ordovician than previously speculated.

关键词： Amsassia koreanensis sp. nov. Ordovician Sino-Korean Block South China Block paleobiology paleogeography.

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

Anti-inflammatory effects of fatty acids isolated from Chromolaena odorata

引用

Asian Pacific Journal of Tropical Medicine 2011年第10期4卷 760-763页

作者： Tran Thi Hong Hanh Dan Thi Thuy Hang Chau Van Minh nguyen tien Dat Institute of Marine Biochemistry Vietnam Academy of Science and Technology(VAST)

Objective:To identify inhibitors of nitric oxide production and NF-κB activity from Chromolaena odorata（***）.Methods:The compounds isolated from the aerial parts of *** by bioassay-guided fractionation were investigated for their inhibitory effects on the NO production and NF-κB activity in LPS-stimulated RAW264.7 ***:Six fatty acids （S）-coriolic acid（1）,（S）-coriolic acid methyl ester（2）,（5）-15,16-didehydrocoriolic acid（3）,（S）- 15,16-didehydrocoriolic acid methyl ester（4）,linoleamide（5） and linolenamide（6） were isolated. All compounds inhibited the NO production at concentrations consistent with those required for NF-κB *** 2 was the most active with the IC50 values of 5.22 and 5.73μM. The addition of a double bond in the fatty chain decreased the inhibitory effects while the methyl esterification increased the ***:The fatty acid components in *** with NF-κB inhibitory activity could explain the anti-inflammation property of this plant in traditional *** study could also contribute to the better use of *** for human health care.

关键词： Chromolaena odorata Asteraceae Fatty acid NF-κB Nitric oxide

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

Ecoregional variations of aboveground biomass and stand structure in evergreen broadleaved forests

引用

Journal of Forestry Research 2020年第5期31卷 1713-1722页

作者： Tran Van Do Mamoru Yamamoto Osamu Kozan Vo Dai Hai Phung Dinh Trung nguyen Toan Thang Lai Thanh Hai Vu Thanh Nam Trieu Thai Hung Hoang Van Thang Tran Duc Manh Cao Chi Khiem Vu tien Lam nguyen Quang Hung Tran Hoang Quy Pham Quang Tuyen Trinh Ngoc Bon nguyen Thi Thu Phuong Ninh Viet Khuong nguyen Van Tuan Dang Thi Hai Ha Tran Hai Long Dang Van Thuyet Dang Thinh Trieu nguyen Van Thinh Tran Anh Hai Duong Quang Trung nguyen Van Bich Dinh Hai Dang Pham tien dung nguyen Huy Hoang Le Thi Hanh Phan Minh Quang nguyen Thi Thuy Huong Hoang Thanh Son nguyen Thanh Son nguyen Thi Van Anh nguyen Thi Hoai Anh Pham Dinh Sam Hoang Thi Nhung Hoang Van Thanh nguyen Huu Thinh Tran Hong Van Ho Trung Luong Bui Kieu Hung Research Institute for Sustainable Humanosphere Kyoto UniversityUjiKyotoJapan Silviculture Research Institute Vietnamese Academy of Forest SciencesNorth Tu LiemHanoiVietnam Center for Southeast Asian Studies Kyoto UniversityKyotoJapan Vietnamese Academy of Forest Sciences North Tu LiemHanoiVietnam Vietnam Administration of Forestry No.2 Ngoc HaBa DinhHanoiVietnam

Biotic and abiotic factors control aboveground biomass(AGB)and the structure of forest *** study analyses the variation of AGB and stand structure of evergreen broadleaved forests among six ecoregions of Vietnam.A data set of 1731-ha plots from 52 locations in undisturbed old-growth forests was *** results indicate that basal area and AGB are closely correlated with annual precipitation,but not with annual temperature,evaporation or hours of *** area and AGB are positively correlated with trees>30 cm *** areas surveyed(52.6%)in these old-growth forests had AGB of 100–200 Mg ha^-1;5.2%had AGB of 400–500 Mg ha^-1,and 0.6%had AGB of>800 Mg ha^-*** percent of the areas surveyed had stand densities of 300–600 ***^-1,and 64%had basal areas of 20–40 m^2 ha^-*** is an important factor influencing the AGB of old-growth,evergreen broadleaved forests in *** causing the loss of large-diameter trees(e.g.,>100 cm DBH)affects AGB but may not seriously affect stand density.

关键词： Aboveground biomass Carbon storage Climatic variables Ecoregion Edaphic variables Oldgrowth forest

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

Fitting a Probability Distribution to Extreme Precipitation for a Limited Mountain Area in Vietnam

引用

Journal of Geoscience and Environment Protection 2017年第5期5卷 92-107页

作者： nguyen tien Thanh Department of Hydrometeorological Modeling and Forecasting Thuy Loi University Hanoi Vietnam

In this paper, an analysis of adapted 20 extreme precipitation indices is calculated for a limited mountain area in southern Vietnam. The daily precipitation data from four stations in the period of more than 30 years are selected. The statistical characteristics of maximum, minimum, mean, standard deviation, skewness, and kurtoris for each index are also analysed. A variety of distributions such as Normal, Lognormal, Beta, Gamma, Exponential, Loglogistic, and Johnson is used to find the best fit probability distribution for this area on the basic of the highest score. The scores are estimated based on the ranking of statistical goodness of fit test. The goodness of fit tests is the Anderson-Darling and Shapiro-Wilks tests. The best fit distribution for each index of extreme precipitation at each station is found out. Results revealed that the Johnson distribution is the best fit distribution to the data of very heavy precipitation days greater than 50 mm. Over a limited mountain area, it is difficult to fit a probability distribution to the precipitation fraction due to extremely wet days, number of extremely wet days, and number of extremely wet days when precipitation greater than 99 percentage. The lognormal, Johnson, and Loglogistic distribution are the best choices to fit most of the extreme precipitation indices over this area.

关键词： Extreme Precipitation Mountain Distribution Vietnam

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

Association of Allergic Symptoms with Dengue Infection and Severity:A Systematic Review and Meta-analysis

引用

Virologica Sinica 2020年第1期35卷 83-92页

作者： nguyen Dang Kien Amr Ehab El-Qushayri Ali Mahmoud Ahmed Adnan Safi Sarah Abdel Mageed Samar Muhammed Mehyar Mohammad Rashidul Hashan Sedighe Karimzadeh Kenji Hirayama nguyen tien Huy Department of Obstetrics and Gynecology Thai Binh University of Medicine and PharmacyThai Binh 410000Vietnam Online Research Club(http://***/) NagasakiJapan Faculty of Medicine Minia UniversityMinia 61519Egypt Faculty of Medicine Al-Azhar UniversityCairo 11865Egypt Nishtar Medical University Multan 60000Pakistan Faculty of Medicine Tanta UniversityTanta 31511Egypt Istishari Hospital Amman 11953Jordan Infectious Disease Division Respiratory and Enteric Infections DepartmentInternational Center for Diarrheal Disease ResearchDhakaGPO Box 128Dhaka 1000Bangladesh School of Medicine Sabzevar University of Medical SciencesSabzevar ***Iran Department of Immunogenetics Institute of Tropical Medicine(NEKKEN)Leading Graduate School Programand Graduate School of Biomedical SciencesNagasaki University1-12-4 SakamotoNagasaki 852-8523Japan Evidence Based Medicine Research Group Ton Duc Thang UniversityHo Chi Minh City 70000Vietnam Faculty of Applied Sciences Ton Duc Thang UniversityHo Chi Minh City 70000Vietnam

The relationship between the severity of dengue infection and allergy is still obscure. We conducted an electronic search across 12 databases for relevant articles reporting allergic symptoms, dengue infection, and dengue classification. These studies were categorized according to dengue severity and allergy symptoms, and a meta-analysis was performed by pooling the studies in each category. Among the included 57 articles, pruritus was the most common allergic sign followed by non-specified allergy and asthma(28.6%, 13%, and 6.5%, respectively). Despite the reported significant association of dengue with pruritus and total Ig E level(P \ 0.05), in comparison with non-dengue cases and healthy controls, there was no association between the different severe dengue group with pruritus, skin allergy, food allergy or asthma. However,removing the largest study revealed a significant association between asthma with dengue hemorrhagic fever(DHF) rather than dengue fever(DF). In comparison with DF, DHF was associated with Ig E positivity. Furthermore, specific-Ig E level was higher in secondary DF rather than primary DF. There was a possible association between allergy symptoms and dengue severity progression. Further studies are needed to clarify this association.

关键词： Dengue Allergy Severity IgE Asthma Association

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：