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边际农地分级研究的新进展 被引量:1
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作者 g.A.larson g.Roloff +1 位作者 W.E.larson 夏农 《水土保持科技情报》 1989年第2期12-16,51,共6页
1986年开始实施了州资助的土地退耕计划(明尼苏达州再投资规划),这将有助于控制土壤侵蚀,改善水质和改进野生动植物生长环境。这些特殊目的和有限的面积目标指出,需要一个划分边际土地等级的新方法。由“土壤保持为国家资源总录”和“... 1986年开始实施了州资助的土地退耕计划(明尼苏达州再投资规划),这将有助于控制土壤侵蚀,改善水质和改进野生动植物生长环境。这些特殊目的和有限的面积目标指出,需要一个划分边际土地等级的新方法。由“土壤保持为国家资源总录”和“土壤—5号”数据库建立的土壤生产力(PI)和抗蚀性(RI)参数,可以双向分级的方式来区分四种土地等级。没有生产力和易受侵蚀的土地可由这种方法鉴别出来,这类土地是规划中登记的主要对象。当地水土保持部门根据本地土壤和地形状况,制定出合格土壤制图单元的确定性目录。现有结果说明,由于当地输入配合较好,土壤单元的合格性受控于面积大小和财政条件,因此,这一土地分级体系一直是成功的,并且可以很灵活地补充联邦农业政策。 展开更多
关键词 边际 农地 双向分级 分级 土壤
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美国明尼苏达州水土保持规划中的一个双目标参数
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作者 g.Roloff g.A.larson 李中魁 《水土保持科技情报》 1989年第4期27-30,共4页
本文建立了一个双目标参数,它可以鉴别明尼苏达州投资(RIM)规划中的边际生产性和易受侵蚀的土地。这个参数是以生产力指数(PI)和抗蚀性指数(RI)为基础的,PI值是由决定根生长环境的土壤性质确定的,而RI值则是由一种土壤在生产力方面的易... 本文建立了一个双目标参数,它可以鉴别明尼苏达州投资(RIM)规划中的边际生产性和易受侵蚀的土地。这个参数是以生产力指数(PI)和抗蚀性指数(RI)为基础的,PI值是由决定根生长环境的土壤性质确定的,而RI值则是由一种土壤在生产力方面的易损失性和侵蚀潜力计算出,当这两个参数以双重分级方式相结合时。我们用它鉴别了四个土地等级。根据全州得到的指数分布,这些等级的划分是灵活的,各个县提供的有关临界地形因子的情报有助于确定目标土地的位置。利用此双目标参数和以土壤流失允许值为基础的参数,我们得到了结果,通过比较说明,差异显著的地块是这两项研究中的目标。 展开更多
关键词 水土保持 规划 双目标 参数 美国
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Evolving technologies for growing,imaging and analyzing 3D root system architecture of crop plants 被引量:2
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作者 Miguel A.Pieros Brandon g.larson +13 位作者 Jon E.Shaff David J.Schneider Alexandre Xavier Falcao Lixing Yuan Randy T.Clark Eric J.Craft Tyler W.Davis Pierre-Luc Pradier Nathanael M.Shaw Ithipong Assaranurak Susan R.Mc Couch Craig Sturrock Malcolm Bennett Leon V.Kochian 《Journal of Integrative Plant Biology》 SCIE CAS CSCD 2016年第3期230-241,共12页
A plant's ability to maintain or improve its yield under limiting conditions,such as nutrient de ficiency or drought,can be strongly in fluenced by root system architecture(RSA),the three-dimensional distribution o... A plant's ability to maintain or improve its yield under limiting conditions,such as nutrient de ficiency or drought,can be strongly in fluenced by root system architecture(RSA),the three-dimensional distribution of the different root types in the soil. The ability to image,track and quantify these root system attributes in a dynamic fashion is a useful tool in assessing desirable genetic and physiological root traits. Recent advances in imaging technology and phenotyping software have resulted in substantive progress in describing and quantifying RSA. We have designed a hydroponic growth system which retains the three-dimensional RSA of the plant root system,while allowing for aeration,solution replenishment and the imposition of nutrient treatments,as well as high-quality imaging of the root system. The simplicity and flexibility of the system allows for modi fications tailored to the RSA of different crop species and improved throughput. This paper details the recent improvements and innovations in our root growth and imaging system which allows for greater image sensitivity(detection of fine roots and other root details),higher ef ficiency,and a broad array of growing conditions for plants that more closely mimic those found under field conditions. 展开更多
关键词 Abiotic stress digital root phenotyping mineral nutrition root system architecture
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A machine learning enabled hybrid optimization framework for efficient coarse-graining of a model polymer
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作者 Zakiya Shireen Hansani Weeratunge +4 位作者 Adrian Menzel Andrew W.Phillips Ronald g.larson Kate Smith-Miles Elnaz Hajizadeh 《npj Computational Materials》 SCIE EI CSCD 2022年第1期2128-2138,共11页
This work presents a framework governing the development of an efficient,accurate,and transferable coarse-grained(CG)model of a polyether material.The framework combines bottom-up and top-down approaches of coarse-gra... This work presents a framework governing the development of an efficient,accurate,and transferable coarse-grained(CG)model of a polyether material.The framework combines bottom-up and top-down approaches of coarse-grained model parameters by integrating machine learning(ML)with optimization algorithms.In the bottom-up approach,bonded interactions of the CG model are optimized using deep neural networks(DNN),where atomistic bonded distributions are matched.In the top-down approach,optimization of nonbonded parameters is accomplished by reproducing the temperature-dependent experimental density.We demonstrate that developed framework addresses the thermodynamic consistency and transferability issues associated with the classical coarse-graining approaches.The efficiency and transferability of the CG model is demonstrated through accurate predictions of chain statistics,the limiting behavior of the glass transition temperature,diffusion,and stress relaxation,where none were included in the parametrization process.The accuracy of the predicted properties are evaluated in context of molecular theories and available experimental data. 展开更多
关键词 optimization GRAIN integrating
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Author Correction: A machine learning enabled hybrid optimization framework for efficient coarse-graining of a model polymer
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作者 Zakiya Shireen Hansani Weeratunge +4 位作者 Adrian Menzel Andrew W.Phillips Ronald g.larson Kate Smith-Miles Elnaz Hajizadeh 《npj Computational Materials》 SCIE EI CSCD 2023年第1期203-203,共1页
Correction to:npj Computational Materials https://doi.org/10.1038/s41524-022-00914-4,published online 04 November 2022 The original version of this Article omitted some contributions in the Author Contributions sectio... Correction to:npj Computational Materials https://doi.org/10.1038/s41524-022-00914-4,published online 04 November 2022 The original version of this Article omitted some contributions in the Author Contributions section and incorrectly read[H.W.:Formal analysis,data visualization,review and editing.]The correct Author Contributions should read:[H.W.:Conceptua-lisation,formal analysis,data visualisation,writing,review and editing;Z.S.and H.W.contributed equally to the conduct of the research and preparation of the manuscript.]This has now been corrected in both the PDF and HTML versions of the Article. 展开更多
关键词 optimization FORMAL GRAIN
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糖尿病代谢轮廓谱及其风险因素研究
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作者 Thomas J.Wang Martin g.larson +1 位作者 Ramachandran S.Vasan 刘丽燕 《营养健康新观察》 2012年第1期36-36,共1页
众所周知,代谢性疾病多为长期慢性病,在多年以后才表现出明显的临床症状。例如,随着胰岛素缺乏时间的延长,患者才能被诊断为2型糖尿病或高胰岛素血症。目前,临床和实验室可通过检测一些指标(如体质指数或空腹血糖)来预测糖尿病发生危险... 众所周知,代谢性疾病多为长期慢性病,在多年以后才表现出明显的临床症状。例如,随着胰岛素缺乏时间的延长,患者才能被诊断为2型糖尿病或高胰岛素血症。目前,临床和实验室可通过检测一些指标(如体质指数或空腹血糖)来预测糖尿病发生危险,但是这些指标只反映疾病的表面状态,无法显示疾病本身的病理生理机制。然而通过对生物样本代谢图谱研究能够更早地发现与糖尿病相关的危险因素,并能够通过早期干预来预防糖尿病的发生和发展。 展开更多
关键词 糖尿病代谢 胰岛素缺乏 空腹血糖 代谢性疾病 高胰岛素血症 病理生理机制 生物样本 胰岛素抵抗 糖尿
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