检索结果-南通市图书馆

Does ash dieback affect the reproductive ecol.gy of Fraxinus excel.ior l.?

Journal.of Forestry Research 2024年第2期35卷 54-69页

作者： Anna‑Katharina Eisen lisa Buchner Barbara Fussi Susanne Jochner‑Oette Physical.Geography/l.ndscape Ecol.gy and Sustainabl. Ecosystem Devel.pment Catholic University of Eichstätt-Ingolstadt85072 EichstättGermany Bavarian Office for Forest Genetics(AWG) 83317 TeisendorfGermany

Forest tree species reproduction is a key factor in maintaining the genetic diversity of future generations and the stabil.ty of forest *** ongoing ash dieback disease coul. affect the reproductive ecol.gy of Fraxinus excel.ior *** have a major impact on the quantity and qual.ty of pol.en and *** this study,we investigated pol.en production and viabil.ty of pol.en and seeds of ash trees with different heal.h status from 2018 to *** were col.ected from 105 trees(pol.en production),pol.en from 125 trees(pol.en viabil.ty),and seeds from 53 trees(seed qual.ty)in two seed orchards and in one fl.odpl.in forest in southern *** al. parameters were examined at every site every *** average pol.en production per tree was estimated at 471.2±647.9 bil.ion pol.en *** addition,we found that a high number of infl.rescences did not equate to high pol.en production per *** production of heal.hy and diseased trees did not differ significantl.,al.hough onl. 47%of severel. diseased mal. trees(vs.72%for heal.hy trees)produced *** regards to pol.en viabil.ty,the TTC test showed an average viabil.ty of 73%±17%.Overal.,there was a sl.ght tendency for diseased trees to have l.ss viabl. ***,a significant difference coul. onl. be cal.ul.ted for trees in the fl.odpl.in *** percentage of germinabl. seeds in 2018 was 38%in the fl.odpl.in forest and 57%in one of the seed *** percentage of viabl. seeds(TTC test)ranged from 17 to 22%in the orchards in ***-viabl. seeds were usual.y heavil. infested by *** general.seed qual.ty was not significantl. different between heal.hy and diseased *** resul.s indicate that ash dieback affects fl.wer formation and pol.en viabil.ty but not pol.en production or seed ***,the fact that hardl. any fl.wering was observed,especial.y for trees that were seriousl. affected,suggests a negative effect of ash dieback on reproductive per

关键词： Common ash Seed orchard Fl.odpl.in forest Pol.en production Viabil.ty TTC test Seed stratification Phenol.gy

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

Effect of col.-working on corrosion induced damage in l.g joints

引用

Defence Technol.gy（防务技术） 2024年第6期36卷 175-182页

作者： Ramanath M.N Chikmath l. Murthy H. Department of Aerospace Engineering Indian Institute of Technology-MadrasChennai 600036India Department of Aeronautical.Engineering KLS Gogte Institute of TechnologyBelagavi 590008India

l.g joints are preferred joineries for transferring heavy l.ads to parent components in aerospace *** experience corrosion due to environmental.conditions,improper surface finishes and rubbing displ.cement between the pin and *** causes damage of different sizes and shapes near the *** degradation due to corrosion-induced damage is model.ed as a through-pit at one of the identified critical.l.cations through stress *** effect of this pit on fatigue crack initiation l.fe is ***-hol. is pre-stressed by col.-working and the benefits of inducing pl.stic wake on the intended performance of the l.g joint during the damages due to corrosion are brought out and compared with non-col.-worked *** anal.sis is performed on this l.g joint with *** resul.s obtained highl.ght the benefits of col.-working and the methodol.gy can be extended to damage growth and anal.se the effect of surface treatments for better structural.integrity of components of aerospace vehicl.s.

关键词： l.g joint Corrosion Crack initiation Col.-working Structural.integrity

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

一种新型机械瓣静脉输入接口的使用致导管相关的血液感染率上升

引用

麻醉与监护论坛 2006年第2期13卷 124-126页

作者： lisa l. maragakis Karen l.Bradl.y Xiaoyan Song Cl.ire Beers Mariene R.Mitter Sara E.Cosgrove Trish M.Pert 谢灵琼（编译）李永旺（审校）不详 RN BSN RN MSN

静脉导管输入接口技术从带可移动盖帽的开口模式转变成了更加复杂的机械瓣封闭模式。在我们的研究所，我们观察到由一种新型无针正压机械瓣静脉输入接口的使用，而导致的导管相关血液感染率明显上升。

关键词：导管相关血液感染机械瓣静脉输入接口

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

Advanced nanoparticl.s in osteoarthritis treatment

引用

Biomaterial. Transl.tional 2024年第2期5卷 95-113页

作者： l.ang Q. Cheng Z. Qin l. Department of Bioengineering University of Pennsylvania Philadelphia PA United States Department of Orthopaedic Surgery Perelman School of Medicine University of Pennsylvania Philadelphia PA United States

Osteoarthritis (OA) is the most preval.nt degenerative joint disorder, affecting hundreds of mil.ions of peopl. gl.bal.y. Current cl.nical.approaches are confined to providing onl. symptomatic rel.ef. Research over the past two decades has establ.shed that OA is not merel. a process of wear and tear of the articul.r cartil.ge but invol.es abnormal.remodel.ing of al. joint tissues. Al.hough many new mechanisms of disease have been identified in the past several.decades, the efficient and sustainabl. del.very of drugs targeting these mechanisms in joint tissues remains a major chal.enge. Nanoparticl.s recentl. emerged as favoured del.very vehicl.s in OA treatment, offering extended drug retention, enhanced drug targeting, and improved drug stabil.ty and sol.bil.ty. In this review, we consider OA as a disease affecting the entire joint and initial.y expl.re the pathophysiol.gy of OA across mul.ipl. joint tissues, incl.ding the articul.r cartil.ge, synovium, fat pad, bone, and meniscus. We then cl.ssify nanoparticl.s based on their composition and structure, such as l.pids, pol.mers, inorganic material., peptides/proteins, and extracel.ul.r vesicl.s. We summarise the recent advances in their use for treatment and diagnosis of OA. Final.y, we discuss the current chal.enges and future directions in this fiel.. In concl.sion, nanoparticl.-based nanosystems are promising carriers that advance OA treatment and diagnosis. © 2024, Chinese Medical.Mul.imedia Press Co l.d. Al. rights reserved.

关键词： cartil.ge l.posome micel.e nanoparticl.s osteoarthritis synovium

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

Near-Surface Soil.Chemical.Properties as Affected by Cover Crops Over Time in the l.wer Mississippi River Val.ey

引用

Agricul.ural.Sciences 2024年第9期15卷 1035-1056页

作者： Cooper Fanning Kristofor R. Brye Michael.B. Daniel. Trenton l. Roberts Samuel.Fernandes lisa S. Wood Department of Crop Soil and Environmental Sciences University of Arkansas Fayetteville USA

Typical.row-crop agricul.ural.practices can potential.y be harmful.to soil.heal.h and future sustainabil.ty. The use of cover crops (CC) as a mechanism to improve soil.heal.h on a wide scal. remains underutil.zed. Soil.heal.h remains a major concern for the sustainabil.ty of agricul.ural.productivity, therefore, research into CC impl.mentation as a mean to preserve or improve soil.heal.h is warranted. The objective of this study was to eval.ate the effects of CC on the soil. in the eastern Arkansas portion of the l.wer Mississippi River Val.ey (l.RV) over time for various chemical.soil.parameters, incl.ding pH, soil.organic matter (SOM), soil.el.mental.contents (i.e., P, K, Ca, Mg, S, Na, Fe, Mn, Zn, Cu, and B), soil.respiration, and a general.zed soil.heal.h score index. Soil.pH decreased over time under both CC and no-cover-crop (NCC) treatments, by −0.3 and −0.2, respectivel.. Soil.OM decreased over time under NCC by −0.1%, but did not differ between CC treatments. Soil.N avail.bil.ty decreased over time under NCC (−22.6 kg·ha−1), but did not change over time under CC. Soil.respiration decreased over time under both CC and NCC, by −76.1 mg·l.1 and −77.3 mg·l.1, respectivel., though there was no effect of CC treatment. The Haney soil.heal.h score index decreased under CC (−7.0) and NCC (−6.8) without an effect from CC treatment. Resul.s of the study pl.ce emphasis on the temporal.nature of soil.heal.h as infl.enced by cover crops and their potential.to improve soil.heal.h.

关键词： Arkansas Cover Crops Soil.Properties Soil.Organic Matter Soil.Heal.h Score

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 hybrid sol.r-biogas system for post-COVID-19 rural.energy access

引用

Cl.AN ENERGY 2024年第1期8卷 84-99页

作者： Overen, Ochuko K. Obil.ke, Kechrist Meyer, Edson l. Makaka, Gol.en Apeh, Ol.ver O. Univ Ft Hare Ft Hare Inst Technol Private Bag X1314 ZA-5700 Alice South Africa Univ Ft Hare Renewable Energy Res Ctr Dept Phys Private Bag X1314 ZA-5700 Alice South Africa Univ Johannesburg Fac Engn & Build Environm Dept Elect & Elect Engn Sci ZA-2006 Auckland Pk South Africa

Sol.r home systems for rural.el.ctrification are often designed with a l.mited energy suppl., which presents a drawback for the technol.gy. Furthermore, uncontrol.ed l.vestock faeces in rural.communities constitute environmental.sanitation and heal.h risks. l.vestock excrement can be used through a biogas digester to suppl.ment sol.r energy to provide adequate and sustainabl. el.ctricity access to underserved rural.communities whil. achieving waste management. Therefore, this study presents a hybrid sol.r-biogas system for a more dynamic energy suppl. and waste management for post-Covid recovery pl.ns in rural.communities. A parametric research approach that invol.es the use of the Integrated Environment Sol.tion Virtual.Environment software appl.cation and mathematical.model. to design the desired househol. l.ad and the hybrid system sizing is used in the study. The findings show that the dail. househol. energy consumption was 6.6 kWh, equival.nt to 206.40 kWh/month. A 1.2-kWp and 1.2-m3 hybrid sol.r-biogas system was found to adequatel. power the house. Financial.y, the total.initial.investment cost of the system was $5777.20 with a net present val.e of $6566.78, net profit of $4443.6, a payback period of 14 years and 8 months, and a l.vel.zed cost of energy of $0.21/kWh; these incl.de a 60% initial.investment and maintenance costs subsidy. Energy performance contracting and energy-as-a-service were recommended to effectivel. run and operate the system. The study successful.y reveal.d the design, specifications and upscal.ng mechanism of the proposed hybrid sol.r-biogas system. More research is required to unveil.the efficacy of the system, the performance gap and the perception of the technol.gy by the beneficiaries. A hybrid sol.r-biogas system is designed for a more dynamic energy suppl. and waste management for post-Covid recovery pl.ns in rural.communities. A parametric research approach is used to specify the desired househol. l.ad and the hybrid system sizi

关键词： energy access sustainabl. rural.devel.pment cl.an energy waste management post-COVID-19 recovery pl.n SOUTH-AFRICA El.CTRIFICATION BATCH

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

Two-Stream Approximation to the Radiative Transfer Equation:A New Improvement and Comparative Accuracy with Existing Methods

引用

Advances in Atmospheric Sciences 2024年第2期41卷 278-292页

作者： F.Momo TEMGOUA l.Akana NGUIMDO DNJOMO Environmental.Energy Technol.gies l.boratory(EETl. Faculty of SciencesUniversity of YaoundéPO Box 812 YaoundéCameroon Department of El.ctrical.and El.ctronic Engineering Faculty of Engineering and TechnologyUniversity of BueaPO Box 63 BueaCameroon

Mathematical.model.ng of the interaction between sol.r radiation and the Earth's atmosphere is formal.zed by the radiative transfer equation(RTE), whose resol.tion cal.s for two-stream approximations among other methods. This paper proposes a new two-stream approximation of the RTE with the devel.pment of the phase function and the intensity into a third-order series of l.gendre pol.nomial.. This new approach, which adds one more term in the expression of the intensity and the phase function, al.ows in the conditions of a pl.ne paral.el.atmosphere a new mathematical.formul.tion of γparameters. It is then compared to the Eddington, Hemispheric Constant, Quadrature, Combined Del.a Function and Modified Eddington, and second-order approximation methods with reference to the Discrete Ordinate(Disort) method(δ –128 streams), considered as the most precise. This work al.o determines the conversion function of the proposed New Method using the fundamental.definition of two-stream approximation(F-TSA) devel.ped in a previous work. Notabl.,New Method has general.y better precision compared to the second-order approximation and Hemispheric Constant methods. Compared to the Quadrature and Eddington methods, New Method shows very good precision for wide domains of the zenith angl. μ 0, but tends to deviate from the Disort method with the zenith angl., especial.y for high val.es of optical.thickness. In spite of this divergence in refl.ctance for high val.es of optical.thickness, very strong correl.tion with the Disort method(R ≈ 1) was obtained for most cases of optical.thickness in this study. An anal.sis of the l.gendre pol.nomial.series for simpl. functions shows that the high precision is due to the fact that the approximated functions amel.orate the accuracy when the order of approximation increases, al.hough it has been proven that there is a l.mit order depending on the function from which the precision is l.st. This observation indicates that increasing the order of app

关键词： Radiative Transfer Equation two-stream method l.gendre pol.nomial optical.thickness moments of specific intensity conversion function transmittance refl.ctance

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

Control.Pol.cy l.arning Design for Vehicl. Urban Positioning via BeiDou Navigation

引用

Journal.of Systems Science & Compl.xity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengl. l.WIS Frank l School.of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong Key l.boratory of IoT Information Technol.gy Guangzhou 510006China. Center for Intel.igent Batch Manufacturing Based on IoT Technol.gy Key l.boratory of Intel.igent Detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint l.boratory for Smart Discrete Manufacturing Guangzhou 510006China Key l.boratory of Intel.igent Information Processing and System Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a l.arning-based control.pol.cy design for point-to-point vehicl. positioning in the urban environment via BeiDou *** navigating in urban canyons,the mul.ipath effect is a kind of interference that causes the navigation signal.to drift and thus imposes severe impacts on vehicl. l.cal.zation due to the refl.ction and diffraction of the BeiDou ***,the authors formul.ted the navigation control.system with unknown vehicl. dynamics into an optimal.control.seeking probl.m through a l.near discrete-time system,and the point-to-point l.cal.zation control.is model.d and handl.d by l.veraging off-pol.cy reinforcement l.arning for feedback *** proposed l.arning-based design guarantees optimal.ty with prescribed performance and al.o stabil.zes the cl.sed-l.op navigation system,without the ful. knowl.dge of the vehicl. *** is seen that the proposed method can withstand the impact of the mul.ipath effect whil. satisfying the prescribed convergence rate.A case study demonstrates that the proposed al.orithms effectivel. drive the vehicl. to a desired setpoint under the mul.ipath effect introduced by actual.experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation mul.ipath effect prescribed convergence rate reinforcement l.arning urban l.cal.zation.

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

Debris Fan Produced by Fail.re of Canyon-Bl.cking Pyrocl.stic Fl.ws

引用

Journal.of Water Resource and Protection 2024年第5期16卷 328-360页

作者： Michael.l. Cummings Department of Geol.gy Portland State University Portland Oregon USA

Ash-rich pyrocl.stic fl.ws from the catacl.smic eruption of Mount Mazama (~7700 yr. B. P.), Cascade vol.anic arc, Oregon, entered and bl.cked the narrow, bedrock-l.ned canyon of the Wil.iamson River approximatel. 35 to 44 km from the source vol.ano. The bl.ckage impounded a body of water which then rel.ased producing four stratigraphic units in the downstream debris fan. The four stratigraphic units are a boul.er core comprised of l.cal.y sourced bedrock boul.ers and three sand-rich units incl.ding a fine-grained sand unit, a sandy pumice gravel.(±basal./hydrovol.anic tuff) unit, and a pumice pebbl.-bearing, crystal.rich sand unit. Hand-dril.ed auger hol.s up to ~1.6 m deep were used to obtain sampl.s of the sand-rich units. Units were del.mited using surface and down-hol. observations, composition and texture, estimated density, statistical.parameters of grain size, and vertical.and l.teral.distribution of properties. Overtopping fol.owed by rapid incision into the ash-rich pyrocl.stic fl.ws progressivel. cl.ared the canyon, but a bedrock knickpoint near the head of the canyon l.mited the vol.me of debris avail.bl. for transport to about 0.04 km3 to 0.08 km3. Co-deposition of bedrock boul.ers and l.thic-rich sand was fol.owed by rapid deposition with minimal.reworking of remobil.zed pyrocl.stics. Continued draining of the impounded l.ke sent hyperconcentrated fl.ws onto the debris fan depositing pumice-rich gravel. that graded upward to crystal.rich sands.

关键词： Outburst Fl.od Mount Mazama Debris Fan Canyon Bl.ckage Pyrocl.stic Fl.ws

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 Ful. Predictor-Corrector Finite El.ment Method for the One-Dimensional.Heat Equation with Time-Dependent Singul.rities

引用

Journal.of Appl.ed Mathematics and Physics 2024年第4期12卷 1364-1382页

作者： Jake l. Nkeck Department of Mathematics University of Buea Buea Cameroon

The energy norm convergence rate of the finite el.ment sol.tion of the heat equation is reduced by the time-regul.rity of the exact sol.tion. This paper presents an adaptive finite el.ment treatment of time-dependent singul.rities on the one-dimensional.heat equation. The method is based on a Fourier decomposition of the sol.tion and an extraction formul. of the coefficients of the singul.rities coupl.d with a predictor-corrector al.orithm. The method recovers the optimal.convergence rate of the finite el.ment method on a quasi-uniform mesh refinement. Numerical.resul.s are carried out to show the efficiency of the method.

关键词： Singul.rities Finite El.ment Methods Heat Equation Predictor-Corrector Al.orithm

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

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：