检索结果-南通市图书馆

Investigation of sediment transport pattern and beach morphology in the vicinity of submerged groyne （case study： Dahane Sar Sefidrood）

引用

Frontiers of Structural and Civil Engineering 2015年第1期9卷 82-90页

作者： h. Afsoos BIRIA M. A. Lashteh NEShAEI A. GhABRAEI M. A. MEhRDAD Marine structure engineer University of Guilan Rasht Iran Department of Civil Engineering University of Guilan Rasht Iran

Marine structures, such as Groynes, Sea walls and Detached Breakwaters, are constructed in coast of area to improve coast stability against bed erosions due to changing wave and current pattern. Marine mechanisms and interaction with the hydraulic structures need to be intensively studied. Groynes are one of the most prominent structures that are used in shore protection and littoral sediment. The main hydraulic function of the groyne is to control the long shore current and littoral sediment transport. This structure can be submerged and provide the necessary beach protection without negative aesthetic impact. however, for submerged structures adopted for beach protection, the shoreline response to these structures is not well understood. The objective of this study is to predict sediment transport in the vicinity of submerged groyne and comparison with non-submerged groyne focusing on a part of the coast at Dahane Sar Sefidrood, Guilan Province, Iran, where serious coast erosion has been occurred. The simulations were designed using a one-line model which can be used as a first approximation of shoreline prediction in the vicinity of groyne. The results of the proposed model are compared with experimental data to determine the shape of the coast. The results of predicted beach deformation show that when submerged groyne construct in the beach, sediment accumulation will be slightly less than the non-submerged groyne; because transfer coefficient for the submerged groyne is more than non-submerged groyne. This result will cause more sediment passing on submerged groyne. Finally, the result of the present study show that using submerged groyne is an efficient way to control the sediment and beach erosion without causing severe environmental effect on the coast.

关键词： submerged groyne non-submerged groyne beach morphology Dahane Sar Sefidrood sediment transport

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

Some Physiological Responses of chinese Iris to Salt Stress

引用

Pedosphere 2008年第4期18卷 454-463页

作者： BAI Wen-Bo LI Pin-Fang LI Bao-Guo h. FUJIYAMA FAN Fen-cheng College of Resources and Environmental Sciences China Agricultural University Key Laboratory of Plant-Soil Interactions Ministry of Education Beijing 100094 （China） Faculty of Agriculture Tottori University Tottori 680-8553 （Japan） Beijing Oasis Technology Development Co. Ltd. Beijing 100094 （China）

chinese iris （Iris lactea Pall. var. chinensis （Fisch） Koidz.）, a robust iridaceous plant, is widespread in arid and semiarid regions with high salinity. however, the mechanism of its salt tolerance is not well understood. In this study, plant growth, water status, content and distribution of inorganic ions, cell membrane permeability, and proline content of I. laetea under salt stress were investigated using nutrient solutions with six NaCl concentrations ranging from 0 to 350 mmol L^-1. The results indicated that the biomass, height, fresh weight, K^＋ content, and K^＋/Na^＋ and Ca^2＋/Na^＋ ratios decreased with increasing NaCl stress, whereas plant water deficit and contents of Na^＋ and Cl- increased with increasing NaCl stress. In all salt treatments, water deficit of shoots was found to be higher than that of roots and had a positive correlation with salt concentration. When the NaCl concentration was less than 280 mmol L^-1, the ion absorption selectivity ratio and the transportation selectivity ratio sharply increased with increasing NaCl stress. Under medium salt stress, I. lactea exhibited a strong K^＋ selective absorption and the transportation of K^＋ from roots to shoots increased, whereas Na^＋ was not transported and was mostly retained in roots. The plants were able to maintain osmotic adjustment through the accumulation of Na^＋, Cl-, and proline. On the basis of its biomass production under salt stress, I. lactea could be considered as a facultative halophyte.

关键词： inorganic ion Iris lactea Pall. var. chinensis (Fisch) Koidz. NaCl stress osmotic adjustment

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

Diesel oil infiltration in soils with selected antecedent water content and bulk density

引用

Journal of Central South University 2016年第8期23卷 1924-1930页

作者：马艳飞李永霞 S.h.Anderson 郑西来冯雪冬高佩玲 Department of Resource and Environmental Engineering Shandong University of Technology Department of Soil Environmental and Atmospheric Sciences University of Missouri Shandong Academy of Environmental Science Key Laboratory of Ocean Environment and Ecology Ministry of Education Ocean University of China

The effects of soil texture, initial water content and bulk density on diesel oil infiltration in fine sand and silty clay loam materials were evaluated. Three physical and two empirical equations express diesel oil infiltration through soils with time, with coefficients of determination greater than 0.99. Diesel oil infiltrates more quickly in the fine sand than in the silty clay loam material. Diesel oil infiltration rates are found to decrease with increasing initial water content and bulk density for the silty clay loam material. The infiltration rate of diesel oil in the fine sand material increases slightly with increasing initial water content. The diesel oil saturated conductivity(Kdiesel) decreases with increasing bulk density for the silty clay loam column. Diesel oil sorptivity(S) decreases linearly with increased initial water content and bulk density of the silty clay loam material. changes in empirical parameters relative to initial water content and bulk density are similar to the parameter S.

关键词： infiltration diesel oil soil physical and empirical models initial water content bulk density

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

Formation of intermetallic phases in unrefined and refined AA6082 Al alloys investigated by using SEM-based ultramicrotomy tomography

引用

Journal of Materials Science & Technology 2022年第25期120卷 118-128页

作者： J.M.Yu T.hashimoto h.T.Li N.Wanderka Z.Zhang C.Cai X.L.Zhong J.Qin Q.P.Dong h.Nagaumi X.N.Wang Shagang School of Iron and Steel and high-Performance Metal Structural Materials Research Institute Soochow UniversitySuzhou 215137China School of Materials The University of ManchesterSackville StreetManchester M139PLUK chinalco Materials Application Research Institute Co.Ltd. Beijing 102200China helmholtz-Zentrum Berlin Für Materialien und Energie Hahn-Meitner-Platz 1Berlin 14109Germany Key Laboratory of Electromagnetic Processing of Materials Ministry of EducationNortheastern UniversityShenyang 110819China

The spatial arrangement,distribution and morphology of Fe-bearing intermetallics in AA6082 alloys depends on the manufacturing process of the alloy and thus influences the macroscopic ***,the microstructure of a near industrial scale casting AA6082 Al alloy fabricated by:(a)direct chill casting,(b)Al-5 Ti-1 B grain refiner addition and(c)intensive melt shearing has been investigated by threedimensional visualization using SEM-based serial ultra microtomy *** formation sequence of phases in AA6082 alloys is generally categorized into four stages:formation ofα-Al grains,Fe-bearing intermetallics,Mg_(2)Si phase,and eutectic *** of three-dimensional visualization of the microstructure indicated that TiBparticles not only could nucleate Fe-bearingβ-intermetallics,but also could provide substrate for the formation of Fe-bearingα-intermetallics and Mg_(2)Si.A further deep analysis reveals that the essential condition for the formation of secondary phases such as Fe-bearing intermetallics and Mg_(2)Si phase is the build-up of a supersaturated solute front at theα-Al solid-liquid interface irrespective of the specific nucleation *** addition,the results indicate that grain refinement processing causes the severe interconnectivity of Fe-bearingα-***,the intensive melt shearing is a better manufacturing process because the intermetallics are more evenly distributed and refined than with the addition of the grain refiner,thereby improving the properties of the alloy.

关键词： Al-Si-Mg alloy Grain refinement Al-Fe-Si intermetallic phase Tomography Ultramicrotomy Mg2Si

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

Systemic treatment for inoperable pancreatic adenocarcinoma: review and update

引用

chinese Journal of Cancer 2014年第6期33卷 267-276页

作者： Stephen L.chan Sin T.chan Eric h.chan Zhe-Xi he State Key Laboratory in Oncology in South china Sir YK Pao Center for Cancer Department of Clinical Oncology and Hong Kong Cancer Institute and Prince of Wales Hospital The Chinese University of Hong Kong The Faculty of Medicine The Chinese University of Hong Kong

There have been many clinical trials conducted to evaluate novel systemic regimens for unresectable pancreatic cancer. however, most of the trial results were negative, and gemcitabine monotherapy has remained the standard systemic treatment for years. A number of molecular targeted agents, including those against epidermal growth factor receptor and vascular endothelial growth factor receptors, have also been tested. In recent years, there have been some breakthroughs in the deadlock: three regimens, namely gemcitabine-erlotinib, FOLFIRINOX, and gemcitabine-nab-paclitaxel, have been shown to prolong the overall survival of patients when compared with gemcitabine monotherapy. In addition, emerging data suggested that the membrane protein human equilibrative nucleotide transporter 1 is a potential biomarker with which to predict the efficacy of gemcitabine. here we review the literature on the development of systemic agents for pancreatic cancer, discuss the current choices of treatment, and provide future directions on the development of novel agents.

关键词：全身治疗胰腺癌审查血管内皮生长因子受体表皮生长因子受体手术临床试验靶向药物

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 long time span relativistic precession model of the Earth

引用

Research in Astronomy and Astrophysics 2015年第4期15卷 583-596页

作者： Kai Tang Michael h.Soffel Jin-he Tao Wen-Biao han Zheng-hong Tang Shanghai Astronomical Observatory Chinese Academy of Sciences University of chinese Academy of Sciences Lohrmann Observatory Dresden Technical University

A numerical solution to the Earth＇s precession in a relativistic framework for a long time span is presented here. We obtain the motion of the solar system in the Barycentric Celestial Reference System by numerical integration with a symplectic in- tegrator. Special Newtonian corrections accounting for tidal dissipation are included in the force model. The part representing Earth＇s rotation is calculated in the Geocentric Celestial Reference System by integrating the post-Newtonian equations of motion published by Klioner et al. All the main relativistic effects are included following Klioner et al. In particular, we consider several relativistic reference systems with cor- responding time scales, scaled constants and parameters. Approximate expressions for Earth＇s precession in the interval ~1 Myr around J2000.0 are provided. In the interval 4-2000 years around J2000.0, the difference compared to the P03 precession theory is only several arcseconds and the results are consistent with other long-term precession theories.

关键词： astrometry -- ephemeris -- post-Newtonian

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

Eighteen-Element Antenna for Metal-Rimmed Smartphone Sub-6 Ghz LTE42 Band Applications

引用

Computers, Materials & Continua 2022年第11期73卷 3181-3198页

作者： Saqer S.Alja’Afreh Mallak h.Alshamaileh Eqab Almajali Jawad Yousaf Amir Altaf Electrical Engineering Department Mutah UniversityAl-karak61710Jordan Electrical Engineering Department University of SharjahSharjahUAE Department of Electrical Computer&Biomedical EngineeringAbu Dhabi UniversityAbu DhabiUAE Department of Electrical and Computer Engineering Sungkyunkwan UniversityKorea

Due to the limited space and large mutual coupling levels,the design of sub-6 Ghz massive Multi-Input Multi-Output(m-MIMO)smartphone antenna system attracts antennas’designers and engineers ***,this paper presents 18-element m-MIMO antenna system that covers the long-term evolution 42(LTE42)frequency band(3.4–3.6 Ghz)for the fifth generation(5G)applications in metallic frame *** proposed array system is etched on the long sides of a metal rim of the mobile chassis symmetrically,which is electrically connected to the system ground plane with zero ground clearance.A low-profile frame of height 7 mm(λ/12.3)is symmetrically placed below&above the ground system *** two frame parts(above/below the ground level)are utilized separately for the implantation of the antenna elements to achieve good space exploitation and perfect pattern diversity between *** feeds are used to further increase the level of the isolation where each antenna element above the ground level is fed by a 50-ohm microstrip line,and each antenna element below the ground level is fed by a 50-ohm coplanar waveguide(CPW).The proposed antenna structure is a capacitive coupled-fed open-slot antenna with a small footprint area of 12×3.5 mm2(λ/7.2×λ/24.5,whereλrepresents the free space wavelength at 3.5 Ghz).A small coupling L-shaped strip provides a capacitive coupling for the proposed 5G antenna *** establish the contribution of the proposed 18-element m-MIMO,the prototype of the proposed system was manufactured and successfully *** measured and simulated results are shown to be in good *** proves that the proposed antenna provides coverage for the LTE42 band(3.4–3.6 Ghz)with acceptable isolation and ***,the performance of the proposed m-MIMO were further verified via channel capacity calculation and the envelope correlation coefficient(ECC)*** on that,the proposed m-MIMO is shown to provide a desira

关键词： Metal-rim smartphone antennas massive MIMO 5G band

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

The corpus cavernosum after treatment with dutasteride or finasteride： a histomorphometric study in a benign prostatic hyperplasia rodent model

引用

Asian Journal of Andrology 2018年第5期20卷 505-510页

作者： Marcello h A Da Silva Waldemar S Costa Francisco J B Sampaio Diogo B De Souza Urogenital Research Unit Rio de Janeiro State University Rio de Janeiro RJ 20551-030 Brazil

Erectile dysfunction is a common side effect of finasteride and dutasteride treatments. The objective of this study was to investigate the structural changes in the penis using a benign prostatic hyperplasia （BPh） rodent model treated with dutasteride or finasteride. Sixty male rats were divided into the following groups： C, untreated control rats; C ＋ D, control rats receiving dutasteride; C ＋ F, control rats receiving finasteride; h, untreated spontaneously hypertensive rats （ShRs）; h ＋ D, ShRs treated with dutasteride; and h ＋ F, ShRs treated with finasteride. Treatments were performed for 40 days, and penises were collected immediately thereafter. The organs were analyzed using histomorphometric methods to determine the cross-sectional penile area, as well as the surface density （Sv） of smooth muscle fibers, connective tissue, elastic system fibers, and sinusoidal spaces of the corpus cavernosum. The results were compared using a one-way ANOVA with Bonferroni＇s posttest. Groups C ＋ D and C ＋ F had a significantly smaller penile cross-sectional area, but more elastic system fiber Sv compared to Group C. Group C ＋ D showed less smooth muscle Sv, and Group h showed more connective tissue but a smaller sinusoidal space Sv in the corpus cavernosum compared to Group C. Groups h ＋ D and h ＋ F had less smooth muscle Sv than Group h. Group h ＋ D also had more connective tissue and elastic system fiber Sv than Group h. Both dutasteride and finasteride promoted penile modifications in the control rat penis, although this affect was ~reater in Group h animals. In this rodent model, dutasteride was the drug that most affected the corpus cavernosum.

关键词： animal models benign prostatic hyperplasia dutasteride erectile dysfunction finasteride penis

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

Wildland fires and moist deciduous forests of chhattisgarh, India: divergent component assessment

引用

Journal of Forestry Research 2014年第4期25卷 857-866页

作者： B.h.Kittur S.L.Swamy S.S.Bargali Manoj Kumar Jhariya Department of Silviculture & Agroforestry College of Forestry Kerala Agriculture University Vellanikara Thrissure Kerala India Department of Forestry College of Agriculture Indira Gandhi Krishi Vishwavidyalaya Raipur (C.G.) 492006 India Department of Botany DSB Campus Kumaun University Nainital–263001 (Uttarakhand) India

We studied moist deciduous forests of chhattisgarh, India （1） to assess the effect of four levels of historic wildland fire frequency （high, medium, low, and no-fire） on regeneration of seedlings in fire affected areas during pre and post-fire seasons, （2） to evaluate vegetation struc- ture and diversity by layer in the four fire frequency zones, （3） to evalu- ate the impact of fire frequency on the structure of economically impor- tant tree species of the region, and （4） to quantify fuel loads by fire fre- quency level. We classified fire-affected areas into high, medium, low, and no-fire frequency classes based on government records. Tree species were unevenly distributed across fire frequency categories. Shrub density was maximum in zones of high fire frequency and minimum in low- frequency and no-fire zones. Lower tree density after fires indicated that regeneration of seedlings was reduced by fire. The population structure in the high-frequency zone was comprised of seedlings of size class （A） and saplings of size class （B）, represented by Diospyros melanoxylon, Dalbergia sissoo, Shorea robusta and Tectona grandis. Younger and older trees were more abundant for Tectona grandis and Dalbargia sis- soo after fire, whereas intermediate-aged trees were more abundant pre- fire, indicating that the latter age-class was thinned by the catastrophic effect of fire. The major contributing components of fuel load included duff litter and small woody branches and twigs on the forest floor. Total fuel load on the forest floor ranged from 2.2 to 3.38 Mg/ha. The netchange in fuel load was positive in high- and medium-frequency fire zones and negative under low- and no-fire zones. Repeated fires, how- ever, slowly reduced stand stability. An ecological approach is needed for fire management to restore the no-fire spatial and temporal structure of moist deciduous forests, their species composition and fuel loads. The management approach should incorporate participatory forest ma

关键词： forest fire diversity fuel load vegetation structure

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

Solar wind transport into magnetosphere caused by magnetic reconnection at high latitude magnetopause during northward IMF: Cluster-DSP conjunction observations

引用

Science china(Technological Sciences) 2008年第10期51卷 1677-1684页

作者： M. DUNLOP E. LUCEK h. RME C. M. CARR Rutherford Appleton Laboratory Didcot United Kingdom Imperial College of Science Technology and Medicine London United Kingdom CESR BP4346 31028 Toulouse Cedex 4 France

An event of Cluster-Double Star conjunction observations of magnetic reconnec-tion at high latitude magnetopause nightside of both cusps and solar wind trans-port into magnetosphere caused by such reconnection process has been investi-gated. During northward IMF, Cluster/SC1 observed accelerated flows and ion heating associated with magnetic reconnection at high latitude magnetopause nightside of southern cusp. And Double Star observed cold dense solar wind plasma transported into dayside magnetosphere. The analysis on such conjunction observations shows that: (1) during northward IMF, magnetic reconnection occurs at high latitude nightside of southern cusp, accompanied by accelerated flows that are observed by Cluster/SC1; (2) the direction of the accelerated flows, with its sunward component Vx, dawnward component Vy, northward component Vz, is quite consistent with the theoretical anticipation under the condition of northward IMF with dawnward component By; (3) reconnection can heat plasma more in par-allel direction than in perpendicular direction, to a level of about 4 keV; (4) with reconnection taking place at high latitude magnetopause nightside of the southern cusp, TC-1 observed cold and dense plasma transported into magnetosphere; (5) by reconnection at high latitude magnetopause nightside of both cusps, solar wind flux tube can be captured by magnetosphere and pulled into dayside magneto-sphere. This event presents further observational evidence for magnetic reconnec-tion at high latitude magnetopause nightside of both cusps as an important mech-anism of sol-ar w-ind transport into magnetosphere.

关键词： transport process magnetic reconnection solar wind-magnetosphere interactions

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：