检索结果-南通市图书馆

Comparison of carbon-stock changes, eddycovariance carbon fluxes and model estimates in coastal Douglas-fir stands in British Columbia

引用

Forest Ecosystems 2015年第2期2卷 104-122页

作者： Colin J Ferster JA (Tony) Trofymow Nicholas C Coops Baozhang Chen thomas andrew black Department of Forest Resources Management University of British Columbia Canadian Forest Service (Pacific Forestry Centre) Natural Resources Canada Department of Biology University of Victoria Faculty of Land and Food Systems University of British Columbia

Background： The global network of eddy-covariance （EC） flux-towers has improved the understanding of the terrestrial carbon （C） cycle, however, the network has a relatively limited spatial extent compared to forest inventory data and plots. Developing methods to use inventory-based and EC flux measurements together with modeling approaches is necessary evaluate forest C dynamics across broad spatial extents. Methods： Changes in C stock change （AC） were computed based on repeated measurements of forest inventory plots and compared with separate measurements of cumulative net ecosystem productivity （~NEP） over four years （2003 - 2006） for Douglas-fir （Pseudotsuga menzies# var menziesil} dominated regeneration （HDF00）, juvenile （HDF88 and HDF90） and near-rotation （DF49） aged stands （6, 18, 20, 57 years old in 2006, respectively） in coastal British Columbia. AC was determined from forest inventory plot data alone, and in a hybrid approach using inventory data along with litter fall data and published decay equations to determine the change in detrital pools. These AC-based estimates were then compared with Y_NEP measured at an eddy-covariance flux-tower （EC-flux） and modelled by the Carbon Budget Model - Canadian Forest Sector （CBM-CFS3） using historic forest inventory and forest disturbance data. Footprint analysis was used with remote sensing, soils and topography data to evaluate how well the inventory plots represented the range of stand conditions within the area of the flux-tower footprint and to spatially scale the plot data to the area of the EC-flux and model based estimates, Results： The closest convergence among methods was for the juvenile stands while the largest divergences were for the regenerating clearcut, followed by the near-rotation stand. At the regenerating clearcut, footprint weighting of CBM-CFS3 TNEP increased convergence with EC flux Z_NEP, but not for AC. While spatial scaling and footprint weighting did not increase convergence for AC, they d

关键词： Forest carbon Micrometeorology Blometry Remote sensing Geographic information systems

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

Larger floods reduce soil CO_(2)efflux during the post-flooding phase in seasonally flooded forests of Western Amazonia

引用

Pedosphere 2021年第2期31卷 342-352页

作者： Emma M.DOCHERTY andrew D.thomas Department of Geography and Earth Sciences Aberystwyth UniversityAberystwyth SY233DB(UK) School of Geography University of LeedsLeeds LS29JT(UK)

Seasonally flooded várzea forests of Western Amazonia are one of the most productive and biodiverse wetland forests in the ***,data on their soil CO_(2)emissions,soil organic matter decomposition rates,and soil C stocks are *** is a concern because hydrological changes are predicted to lead to increases in the height,extent,and duration of seasonal floods,which are likely to have a significant effect on soil C stocks and ***,with no empirical data,the impact of altered flood regimes on várzea soil C cycles remains *** study quantified the effects of maximum annual flood height and soil moisture on soil CO_(2)efflux rate(R_(s))and soil organic matter decomposition rate(k)in the várzea forests of Pacaya Samiria National Reserve,*** study was conducted between May and August *** results showed that R_(s)(10.6–182.7 mg C m^(-2)h^(-1))and k(0.016–0.078)varied between and within sites,and were considerably lower than the values reported for other tropical *** addition,R_(s)was negatively affected by flood height(P<0.01)and soil moisture(P<0.001),and it decreased with decreasing river levels post flooding(P<0.001).In contrast,k was not affected by any of the above-mentioned *** moisture was the dominant factor influencing R_(s),and it was significantly affected by maximum flood height,even after the floods had subsided(P<0.001).Consequently,we concluded that larger floods will likely lead to reduced R_(s),whilst k could remain unchanged but with decomposition processes becoming more anaerobic.

关键词： C cycle climate change greenhouse gas soil CO_(2)emissions soil moisture soil organic matter decomposition rate tropical 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

Impact of medical therapy on patients with Crohn's disease requiring surgical resection

引用

World Journal of Gastroenterology 2014年第33期20卷 11808-11814页

作者： YT Nancy Fu thomas Hong andrew Round Brian Bressler Division of Gastroenterology Department of Medicine University of British Columbia St. Paul’s Hospital Vancouver BC V6Z 1Y6 Canada Faculty of Medicine University of British Columbia Vancouver BC V6T 1Z3 Canada GI Clinic and Gastrointestinal Research Institute Vancouver BC V6Z 2K5 Canada

AIM: To evaluate the impact of medical therapy on Crohn’s disease patients undergoing their first surgical resection.

关键词： Crohn's disease Surgery Medication Phe-notype Biologics Anti-tumor necrosis factor Immuno-modulators Inflammatory bowel disease

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

Impact of Brunswick River Mouth Training Walls on Adjacent Beaches,Brunswick Heads,New South Wales,Australia

引用

海洋工程：英文版 2004年第2期18卷 207-220页

作者：黄海军 andrew D.SHORT thomas ZENG David HANSLOW Institute of Oceanology Coastal Studies Unit Department of Land and Water Conservation

River training walls have been built at scores of locations along the NSW coast and their impacts on shoreline change are still not fully understood. In this study, the Brunswick River entrance and adjacent beaches are selected for examination of the impact of the construction of major training walls. Thirteen sets of aerial photographs taken between 1947 and 1994 are used in a GIS approach to accurately determine the shoreline position, beach contours and sand volumes, and their changes in both time and space, and then to assess the contribution of both the structures and natural hydrodynamic conditions to large scale (years-decades and kilometres) beach changes. The impact of the training walls can be divided into four stages: natural conditions prior to their construction (pre 1959), major downdrift erosion and updrift accretion during and following the construction of the walls in 1959～1962 and 1966, diminishing impact of the walls between 1966 and 1987, and finally no apparent impact between 1987～1994. The impact extends horizontally about 8 km updrift and 17 km downdrift, and temporally up to 25 years.

关键词： human structure beach erosion and accretion beach downdrift/updrift shoreline change GIS

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

Tungsten Promoted Ni/Al_2O_3 Catalysts for Carbon Dioxide Reforming of Methane to Synthesis Gas

引用

Chemical Research in Chinese Universities 2004年第4期20卷 470-477页

作者： thomas Suhartanto andrew P. E. York Malcolm L. H. Green Wolfson Catalysis Centre Inorganic Chemistry Laboratory University of OxfordWolfson Catalysis Centre Inorganic Chemistry Laboratory University of OxfordWolfson Catalysis Centre Inorganic Chemistry Laboratory University of Oxford South Parks Road Oxford OX1 3QR UKSouth Parks Road Oxford OX1 3QR UKSouth Parks Road Oxford OX1 3QR UK

A series of tungsten promoted alumina supported nickel catalysts has been prepared for the carbon dioxide reforming of methane to synthesis gas. The catalysts have been characterized by means of XRD, TEM, and Laser Raman spectroscopy. It is shown that the addition of tungsten to the nickel catalyst can stabilize the catalyst and increase the resistance to carbon deposition. Adding a suitable amount of tungsten can also increase the catalyst activity to be close to that of supported noble metal catalysts. The carburisation of the tungsten modified nickel catalyst decreases the catalyst activity at lower reaction temperatures(<1123K), but has no effect on the catalyst performance at higher reaction temperatures. The alumina supported nickel catalyst modified by 0.67%(mass fraction) WO_3 has the equivalent equilibrium constant of the dry reforming reaction to that of alumina supported 5%(mass fraction) Ru at 873 K, and also has a lower activation energy for dry reforming than the latter.

关键词： Nickel catalyst Tungsten modifier CO_2 reforming Methane Syngas

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

Trajectory sampling and finite-size effects in first-principles stopping power calculations

引用

npj Computational Materials 2023年第1期9卷 238-246页

作者： Alina Kononov thomas W.Hentschel Stephanie B.Hansen andrew D.Baczewski Center for Computing Research Sandia National LaboratoriesAlbuquerqueNMUSA School of Applied&Engineering Physics Cornell UniversityIthacaNYUSA Pulsed Power Sciences Center Sandia National LaboratoriesAlbuquerqueNMUSA

Real-time time-dependent density functional theory(TDDFT)is presently the most accurate available method for computing electronic stopping powers from first ***,obtaining application-relevant results often involves either costly averages over multiple calculations or ad hoc selection of a representative ion *** consider a broadly applicable,quantitative metric for evaluating and optimizing trajectories in this *** methodology enables rigorous analysis of the failure modes of various common trajectory choices in crystalline *** randomly selecting trajectories is common practice in stopping power calculations in solids,we show that nearly 30%of random trajectories in an FCC aluminum crystal will not representatively sample the material over the time and length scales feasibly simulated with TDDFT,and unrepresentative choices incur errors of up to 60%.We also show that finite-size effects depend on ion trajectory via“ouroboros”effects beyond the prevailing plasmon-based interpretation,and we propose a cost-reducing scheme to obtain converged results even when expensive core-electron contributions preclude large *** work helps to mitigate poorly controlled approximations in first-principles stopping power calculations,allowing 1–2 order of magnitude cost reductions for obtaining representatively averaged and converged results.

关键词： size prevailing selecting

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

Empowering progress:unraveling the promising capabilities of Cu_(2)S:ZnS:NiS_(2) trimetal sulphide thin films

引用

Frontiers of Materials Science 2024年第3期18卷 95-111页

作者： Mahwash Mahar Gul Khuram Shahzad Ahmad andrew Guy thomas Mohamed A.Habila Department of Environmental Sciences Fatima Jinnah Women UniversityRawalpindi 46000Pakistan Department of Materials Photon Science InstituteSir Henry Royce InstituteAlan Turing BuildingThe University of ManchesterOxford RoadManchester M139PLUK Department of Chemistry College of ScienceKing Saud UniversityP.O.Box 2455Riyadh 11451Saudi Arabia

This study focuses on the synthesis and characterization of a thin film comprising of trimetallic sulphide,Cu_(2)S:ZnS:NiS_(2).The fabrication process involved the utilization of diethyldithiocarbamate as a sulfur source,employing physical vapor deposition.A range of analytical techniques were employed to elucidate the material's structure,morphology,and optical *** thin film exhibited a well-defined crystalline structure with an average crystallite size of 33 nm.X-ray photoelectron spectroscopy provided distinct core level peaks associated with Cu 2p,Zn 2p,Ni 2p,and S *** electrochemical properties were assessed through voltammetry measurements,which demonstrated an impressive specific capacitive of 797 F·g^(-1).The thin film demonstrated remarkable stability over multiple cycles,establishing it as a highly promising candidate for diverse energy storage *** addition,comprehensive investigations were carried out to assess the photocatalytic performance of the fabricated material,particularly its efficacy in the degradation of diverse environmental *** notable findings emphasize the versatility of trimetal sulphide thin films,expanding their potential beyond energy storage and opening avenues for further research and technological advancements in fields including photocatalysis and beyond.

关键词： supercapacitor energy storage photocatalyst thin film metal sulphide

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

Critical analysis of feeding jejunostomy following resection of upper gastrointestinal malignancies

引用

World Journal of Gastrointestinal Surgery 2017年第2期9卷 53-60页

作者： andrew M Blakely Saad Ajmal Rachel E Sargent thomas T Ng thomas J Miner Department of Surgery Rhode Island HospitalProvidence Warren Alpert Medical School of Brown University Providence

AIM To assess nutritional recovery,particularly regarding feeding jejunostomy tube(FJT)utilization,following upper gastrointestinal resection for malignancy. METHODS A retrospective review was performed of a prospectively-maintained database of adult patients who underwent esophagectomy or gastrectomy(subtotal or total)for cancer with curative intent,from January 2001 to June 2014. Patient demographics,the approach to esophagectomy,the extent of gastrectomy,FJT placement and utilization at discharge,administration of parenteral nutrition(PN),and complications were evaluated. All patients were followed for at least ninety days or until *** The 287 patients underwent upper GI resection,comprised of 182 esophagectomy(n=107 transhiatal,58.7%; n=56 Ivor-Lewis,30.7%)and 105 gastrectomy [n=63 subtotal(SG),60.0%; n=42 total(TG),40.0%]. 181 of 182 esophagectomy patients underwent FJT,compared with 47 of 105 gastrectomy patients(99.5% vs 44.8%,P < 0.0001),of whom most had undergone TG(n=39,92.9% vs n=8 SG,12.9%,P < 0.0001). Median length of stay was similar between esophagectomy and gastrectomy groups(14.7 d vs 17.1 d,P=0.076). Upon discharge,87 esophagectomy patients(48.1%)were taking enteral feeds,with 53(29.3%)fully and 34(18.8%)partially dependent. Meanwhile,20 of 39 TG patients(51.3%)were either fully(n=3,7.7%)or partially(n=17,43.6%)dependent on tube feeds,compared with 5 of 8 SG patients(10.6%),all of whom were partially dependent. Gastrectomy patients were significantly less likely to be fully dependent on tube feeds at discharge compared to esophagectomy patients(6.4% vs 29.3%,P=0.0006). PN was administered despite FJT placement more often following gastrectomy than esophagectomy(n=11,23.4% vs n=7,3.9%,P=0.0001). FJT-specific complications requiring reoperation within 30 d of resection occurred more commonly in the gastrectomy group(n=6),all after TG,compared to 1 esophagectomy patient(12.8% vs 0.6%,P=0.0003). Six of 7 patients(85.7%)who experienced tube-re

关键词： Feeding jejunostomy Esophagectomy Gastrectomy Nutritional recovery Outcomes

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

Review of additive manufactured tissue engineering scaffolds:relationship between geometry and performance

引用

Burns & Trauma 2018年第3期6卷 167-182页

作者： andrew Gleadall Dafydd Visscher Jing Yang Daniel thomas Joel Segal Wolfson School of Mechanical and Manufacturing Engineering Loughborough UniversityLoughboroughLeicestershire LE11 3TUUK Department of Plastic Reconstructive and Hand SurgeryVU University Medical CenterAmsterdam Movement SciencesAmsterdamThe Netherlands Faculty of Science School of PharmacyUniversity of NottinghamUniversity ParkNottingham NG7 2RDUK 3Dynamic Systems Heol Ty Gwyn Industrial EstateBridgend CF34 0BQUK Advanced Manufacturing Technology Research Group Faculty of EngineeringUniversity of NottinghamUniversity ParkNottingham NG7 2RDUK.

Material extrusion additive manufacturing has rapidly grown in use for tissue engineering research since its adoption in the year 2000. It has enabled researchers to produce scaffolds with intricate porous geometries that were not feasible with traditional manufacturing processes. Researchers can control the structural geometry through a wide range of customisable printing parameters and design choices including material, print path, temperature, and many other process parameters. Currently, the impact of these choices is not fully understood. This review focuses on how the position and orientation of extruded filaments, which sometimes referred to as the print path, lay-down pattern, or simply'scaffold design', affect scaffold properties and biological performance. By analysing trends across multiple studies, new understanding was developed on how filament position affects mechanical properties. Biological performance was also found to be affected by filament position, but a lack of consensus between studies indicates a need for further research and understanding. In most research studies, scaffold design was dictated by capabilities of additive manufacturing software rather than free-form design of structural geometry optimised for biological requirements. There is scope for much greater application of engineering innovation to additive manufacture novel geometries. To achieve this, better understanding of biological requirements is needed to enable the effective specification of ideal scaffold geometries.

关键词： Fused deposition modelling Bioprinting 3D printing Scaffold architecture Tissue engineering constructs Regenerative medicine

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

Templating core-shell particles using metal ion-chelating biosurfactants

引用

Particuology 2022年第5期20卷 145-152页

作者： Ching-Min Yeh thomas Jarrett Yuan Gao Chun-Xia Zhao andrew Whittaker Frank Sainsbury Alison L.White Australian Institute of Bioengineering and Nanotechnology The University of QueenslandSt.LuciaQueensland4072Australia ARC Centre of Excellence in Convergent Bio-Nano Science and Technology The University of QueenslandSt Lucia4072Australia CSIRO Probing Biosystems Future Science Platform BrisbaneAustralia Centre for Cell Factories and Biopolymers Griffith Institute for Drug DiscoveryGriffith UniversityBrisbaneQLD4111 Australia

Designer biosurfactants can be used to stabilise and functionalise *** particularly promising use is the stabilisation of oil-in-water emulsions,enabling fine tuning physical,chemical and biological surface *** ability of emulsion systems to carry high payloads makes them attractive for applications in medicine,food and fragrances,and ***,they have limited long-term *** we sought to use the metal ion-chelating ability of the biosurfactant peptide,AM1,to precipitate the formation of a gold metal shell on AM1-stabilised emulsions by electroless *** found that replacing the commonly used zinc(Ⅱ)with palladium(Ⅱ)for coordination by histidine residues of adjacent AM1 peptides produced interfacial films that maintained elasticity at acidic *** NMR suggested a coordination mechanism independent of the imidazole ring of the *** of emulsions at low pH enabled the deposition of a gold shell,albeit by an unexpected *** propose that gold nanoparticles forming in bulk are adsorbed onto the peptide-stabilised interface,accumulating into a particulate *** resulting one-step method for nanoparticle precipitation and shell formation will be useful for the creation of biocompatible core-shell particles for applications where large payloads of hydrophobic active compounds require stability over long time periods.

关键词： Biosurfactants Emulsion Core-shell particles Electroless plating Histidine Interfacial elasticity

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：