检索结果-内蒙古大学图书馆

Utilization of nanohydroxyapatite-kaolin composites as a slow-release materials of urea

Materials Chemistry and Physics 2025年 342卷

作者： Noviyanti, Atiek Rostika Fajrina, Yulia Eddy, Diana Rakhmawaty Irkham Hartati, Yeni Wahyuni Rupaedah, Bedah Suryana Permana, Muhamad Diki Karnjanakom, Surachai Guan, Guoqing Kurnia, Irwan Department of Chemistry Faculty of Mathematics and Natural Sciences Universitas Padjadjaran Jl. Raya Bandung-Sumedang Km 21 Jatinangor West Java Sumedang45363 Indonesia Research Center for Applied Microbiology National Research and Innovation Agency Jl. Raya Jakarta-Bogor Km. 46 Cibinong West Java Bogor16911 Indonesia Department of Biology Faculty of Mathematics and Natural Sciences Universitas Padjadjaran Jl. Raya Bandung-Sumedang Km 21 Jatinangor West Java Sumedang45363 Indonesia Special Educational Program for Green Energy Conversion Science and Technology Integrated Graduate School of Medicine Engineering and Agricultural Sciences University of Yamanashi Kofu400-8511 Japan Center for Crystal Science and Technology University of Yamanashi Kofu400-8511 Japan Department of Chemistry Faculty of Science Rangsit University 52/347 Phahonyothin Road Pathum Thani 12000 Thailand Institute of Regional Innovation Hirosaki University 3-Bunkyocho Hirosaki036-8561 Japan

Urea is widely used as a nitrogen-source fertilizer in agriculture, but its leaching due to rainwater leads to eutrophication and environmental pollution. To address this, urea was incorporated into nanohydroxyapatite (nHA)–kaolin (KA) composites (HKs) that were synthesized via a two-step hydrothermal method as a slow-release materials (SRMs). Among the composites, HK1 (nHA:KA 75:25) is the most promising slow-release material with a urea release rate of 57.0 μgurea min−1 (20.3 % for 240 min), which is 4.6 times slower than urea release rate of nHA-urea for 262.9 μgurea min−1 (93.5 %, 240 min). This enhanced slow-release behavior is attributed to synergistic interactions between nHA and KA, as reflected on their zeta potentials. These findings suggest that HKs are promising slow-release materials for improving fertilizer efficiency and mitigating environmental impact in agricultural applications. © 2025 Elsevier B.V.

关键词： Urea fertilizers

来源：评论

学校读者我要写书评

暂无评论

Principal Curvatures Estimation with Applications to Single Cell Data

arXiv

引用

arXiv 2025年

作者： Zhang, Yanlei Mezrag, Lydia Sun, Xingzhi Xu, Charles Macdonald, Kincaid Bhaskar, Dhananjay Krishnaswamy, Smita Wolf, Guy Rieck, Bastian Université de Montréal Dept. of Math. & Stat. QC Montréal Canada Mila – Quebec AI Institute MontréalQC Canada Yale University Dept. of Comp. Sci. New HavenCT United States Dept. of Genetics New HavenCT United States Applied Mathematics Program New HavenCT United States Université de Fribourg Department of Informatics Fribourg Switzerland Helmholtz Zentrum München Institute of AI for Health Munich Germany

The rapidly growing field of single-cell transcriptomic sequencing (scRNAseq) presents challenges for data analysis due to its massive datasets. A common method in manifold learning consists in hypothesizing that datasets lie on a lower dimensional manifold. This allows to study the geometry of point clouds by extracting meaningful descriptors like curvature. In this work, we will present Adaptive Local PCA (AdaL-PCA), a data-driven method for accurately estimating various notions of intrinsic curvature on data manifolds, in particular principal curvatures for surfaces. The model relies on local PCA to estimate the tangent spaces. The evaluation of AdaL-PCA on sampled surfaces shows state-of-the-art results. Combined with a PHATE embedding, the model applied to single-cell RNA sequencing data allows us to identify key variations in the cellular differentiation. © 2025, CC BY.

关键词： Spatio-temporal data

来源：评论

学校读者我要写书评

暂无评论

GRAPHICAL EKELAND’S PRINCIPLE FOR EQUILIBRIUM PROBLEMS

引用

Proceedings of the American Mathematical Society, Series B 2022年第4期9卷 33-40页

作者： Alfuraidan, Monther Rashed Khamsi, Mohamed Amine Department of Mathematics Interdisciplinary Center of Smart Mobility and Logistics King Fahd University of Petroleum and Minerals Dhahran 31261 Saudi Arabia Department of Applied Mathematics and Sciences Khalifa University Abu Dhabi United Arab Emirates

In this paper, we give a graphical version of the Ekeland’s variational principle (EVP) for equilibrium problems on weighted graphs. This version generalizes and includes other equilibrium types of EVP such as optimization, saddle point, fixed point and variational inequality ones. We also weaken the conditions on the class of bifunctions for which the variational principle holds by replacing the strong triangle inequality property by a below approximation of the bifunctions. © 2022 by the authors under Creative Commons Attribution-Noncommercial 3.0 License (CC BY NC 3.0).

关键词： Ekeland variational principle equilibrium problem fixed point weighted graph

来源：评论

学校读者我要写书评

暂无评论

Inferring domain-domain interactions using an extended parsimony model

Inferring domain-domain interactions using an extended parsi...

引用

5th IEEE International Conference on Systems Biology, ISB 2011

作者： Chen, Chen Zhao, Jun-Fei Huang, Qiang Wang, Rui-Sheng Zhang, Xiang-Sun National Center for Mathematics and Interdisciplinary Sciences Institute of Applied Mathematics Academy of Mathematics and Systems Science Beijing 100190 China Department of Physics Pennsylvania State University University Park PA 16802 United States

ISBN: (纸本)9781457716669

High-throughput technologies have produced a large number of protein-protein interactions (PPIs) for different species. As protein domains are functional and structural units of proteins, many computational efforts have been made to identify domain-domain interactions (DDIs) from PPIs. Parsimony assumption is widely used in computational biology as the evolution of the nature is considered as a continuous optimization process. In the context of identifying DDIs, parsimony methods try to find a minimal set of DDIs that can explain the observed PPIs. This category of methods are promising since they can be formulated and solved easily. Besides, researches have shown that they could detect specific DDIs, which is often hard for many probabilistic methods. In this paper, we revisit the parsimony model by presenting two important extensions. First, complex networks as an emerging concept is incorporated as prior knowledge into the parsimony model. With this improvement, the prediction accuracy increases, which to some extent enhances the biological meaning of the common property of complex networks. Second, two randomization tests are designed to show the parsimony nature of the DDIs in mediating PPIs, which corroborates the model validation. © 2011 IEEE.

关键词： Complex networks

来源：评论

学校读者我要写书评

暂无评论

On sensitivity analysis for problems with numerical noise

On sensitivity analysis for problems with numerical noise

引用

9th AIAA/ISSMO Symposium on Multidisciplinary Analysis and Optimization 2002

作者： Borggaard, J. Pelletier, D. Vugrin, K. Interdisciplinary Center for Applied Mathematics Department of Mathematics Virginia Tech Blacksburg VA 24061 United States H3C 3A7 Canada

ISBN: (纸本)9781624101205

For optimal design problems, approximating differential equation constraints can lead to numerical noise in the objective function to be minimized. Since the continuous sensitivity equation approach performs difierentiation before any approximation is performed, it can lead to more accurate gradient information. We investigate this using a variety of numerical examples with constraints ranging from simple ordinary difierential equations to ow optimization problems with constraints given by Navier- Stokes and Euler equations. © 2002 by the author(s).

关键词： Navier Stokes equations

来源：评论

学校读者我要写书评

暂无评论

Parallel spectral-element-Fourier simulation of turbulent flow over riblet-mounted surfaces

引用

Theoretical and Computational Fluid Dynamics 1992年第4期3卷 219-229页

作者： Chu, Douglas Henderson, Ron Karniadakis, George Em Department of Mechanical and Aerospace Engineering and Program in Applied and Computational Mathematics Princeton University Princeton 08544 NJ United States

The flow in a channel with its lower wall mounted with streamwise V-shaped riblets is simulated using a highly efficient spectral-element-Fourier method. The range of Reynolds numbers investigated is 500 to 4000, which corresponds to laminar, transitional, and turbulent flow states. Our results suggest that in the laminar regime there is no drag reduction, while in the transitional and turbulent regimes drag reduction up to 10% exists for the riblet-mounted wall in comparison with the smooth wall of the channel. For the first time, we present detailed turbulent statistics in a complex geometry. These results are in good agreement with available experimental data and provide a quantitative picture of the drag-reduction mechanism of the riblets. © 1992 Springer-Verlag.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Qualità dei Dati 1

引用

丛书名： UNITEXT

1000年

作者： Carlo Batini Monica Scannapieco

来源：评论

学校读者我要写书评

暂无评论

NUMERICAL STUDY OF A 2-POINT CORRELATION-FUNCTION AND LIOUVILLE FIELD PROPERTIES IN 2-DIMENSIONAL QUANTUM-GRAVITY

引用

MODERN PHYSICS LETTERS A 1991年第12期6卷 1115-1131页

作者： AGISHTEIN, ME BENAV, R MIGDAL, AA SOLOMON, S Program in Applied and Computational Mathematics Fine Hall Princeton University Princeton NJ 08544–1000 USA Nuclear Physics Department Weizmann Institute of Science Rehovot 76100 Israel Physics Department and Program in Applied and Computational Mathematics Fine Hall Princeton University Princeton NJ 08544–1000 USA Physics Department Hebrew University Jerusalem Israel

Two-point Green's function is measured on the manifolds of a 2-dimensional quantum gravity. The recursive sampling technique is used to generate the triangulations, lattice sizes being up to hundred thousand triangles. The grid Laplacian was inverted by means of the algebraic multi-grid solver. The free field model of the Quantum Gravity assumes the Gaussian behavior of Liouville field and curvature. We measured histograms as well as six momenta of these fields. Our results support the Gaussian assumption.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Algoritmi 1

引用

丛书名： UNITEXT

1000年

作者： David Harel Yishai Feldman

来源：评论

学校读者我要写书评

暂无评论

Algorithmik 1

引用

1000年

作者： David Harel Yishai Feldman

来源：评论

学校读者我要写书评

暂无评论

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

请选择保存的检索档案：

请选择收藏分类：

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

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

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：