检索结果-南通市图书馆

Field experimental study on the effect of thawed depth of frozen alpine meadow soil on rill erosion by snowmelt waterflow

引用

International Soil and Water Conservation Research 2024年第1期12卷 54-63页

作者： Ying Zheng xiaonan Shi Fan Zhang Tingwu Lei Chen zeng Xiong Xiao Li Wang Guanxing Wang State Key Laboratory of Tibetan Plateau Earth System Resources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing100101China University of Chinese Academy of Sciences Beijing100101China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai UniversityNanjing210098China College of Water Resources and Civil Engineering China Agricultural UniversityBeijing100083China College of Geographic Science Hunan Normal UniversityChangsha410081China

Soil erosion by snow or ice melt waterflow is an important type of soil erosion in many high-altitude and high-latitude regions and is further aggravated by climate warming.The snowmelt waterflow erosion process is affected by soil freeze-thaws and is highly dynamically variable.In this study,a methodology was developed to conduct in situ field experiments to investigate the effects of the thawed depth of the frozen soil profile on snowmelt waterflow erosion.The method was implemented on an alpine meadow soil slope at an altitude of 3700 m on the northeastern Tibetan Plateau.The erosion experiments involved five thawed soil depths of 0,10,30(35),50,and 80(100)mm under two snowmelt waterflow rates(3 and 5 L/min).When the topsoil was fully frozen or shallow-thawed(≤10 mm),its hydrothermal and structural properties caused a significant lag in the initiation of runoff and delayed soil erosion in the initial stage.The runoff and sediment concentration curves for fully frozen and shallow-thawed soil showed two-stage patterns characteristic of a sediment supply limited in the early stage and subject to hydrodynamic-controlled processes in the later stage.However,this effect did not exist where the thawed soil depth was greater than 30 mm.The deep-thawed cases(≥30 mm)showed normal hydrograph and sedigraph patterns similar to those of the unfrozen soil.The findings of this study are important for understanding the erosion rates of partially thawed soil and for improving erosion simulations in cold regions.

关键词： Snowmelt waterflow erosion Hillslope erosion process Soil freeze and thaw Runoff generation In situ experimental method

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

Replacing dietary sodium selenite with biogenic selenium nanoparticles improves the growth performance and gut health of early-weaned piglets

引用

Animal Nutrition 2023年第4期15卷 99-113页

作者： Lei Qiao Xina Dou Xiaofan Song Jiajing Chang xiaonan zeng Lixu Zhu Hongbo Yi Chunlan Xu School of Life Sciences Northwestern Polytechnical UniversityXi'anShaanxi 710072China State Key Laboratory of Livestock and Poultry Breeding Ministry of Agriculture Key Laboratory of Animal Nutrition and Feed Science in South ChinaGuangdong Provincial Key Laboratory of Animal Breeding and NutritionInstitute of Animal Science of Guangdong Academy of Agricultural SciencesGuangzhouGuangdong 510640China

Selenium nanoparticles(SeNPs)are proposed as a safer and more effective selenium delivery system than sodium selenite(Na_(2)SeO_(3)).Here,we investigated the effects of replacing dietary Na_(2)SeO_(3)with SeNPs synthesized by Lactobacillus casei ATCC 393 on the growth performance and gut health of earlyweaned piglets.Seventy-two piglets(Duroc×Landrace×Large Yorkshire)weaned at 21 d of age were divided into the control group(basal diet containing 0.3 mg Se/kg from Na_(2)SeO_(3))and SeNPs group(basal diet containing 0.3 mg Se/kg from SeNPs)during a 14-d feeding period.The results revealed that SeNPs supplementation increased the average daily gain(P=0.022)and average daily feed intake(P=0.033),reduced(P=0.056)the diarrhea incidence,and improved(P=0.013)the feed conversion ratio compared with Na_(2)SeO_(3).Additionally,SeNPs increased jejunal microvilli height(P=0.006)and alleviated the intestinal barrier dysfunction by upregulating(P<0.05)the expression levels of mucin 2 and tight junction proteins,increasing(P<0.05)Se availability,and maintaining mitochondrial structure and function,thereby improving antioxidant capacity and immunity.Furthermore,metabolomics showed that SeNPs can regulate lipid metabolism and participate in the synthesis,secretion and action of parathyroid hormone,proximal tubule bicarbonate reclamation and tricarboxylic acid cycle.Moreover,SeNPs increased(P<0.05)the abundance of Holdemanella and the levels of acetate and propionate.Correlation analysis suggested that Holdemanella was closely associated with the regulatory effects of SeNPs on early-weaned piglets through participating in lipid metabolism.Overall,replacing dietary Na_(2)SeO_(3)with biogenic SeNPs could be a potential nutritional intervention strategy to prevent earlyweaning syndrome in piglets.

关键词： Selenium nanoparticle Early-weaned piglet Gut homeostasis Gut microbiota

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

Cluster analysis reveals a homogeneous subgroup of PCOS women with metabolic disturbance associated with adverse reproductive outcomes

引用

Chinese Medical Journal 2024年第5期137卷 604-612页

作者： Hanxiao Chen Rujun zeng Xun zeng Lang Qin The Reproductive Medical Center Department of Obstetrics and GynecologyWest China Second University HospitalSichuan UniversityChengduSichuan 610041China Key Laboratory of Birth Defects and Related of Women and Children of Ministry of Education West China Second University HospitalSichuan UniversityChengduSichuan 610041China

Background:Polycystic ovarian syndrome(PCOS)is a heterogeneous and complex reproductive endocrinological disease that could lead to infertility.There were many attempts to classify PCOS but it remains unclear whether there is a specific subgroup of PCOS that is associated with the best or worst reproductive outcomes of assisted reproductive techniques(ART).Methods:Infertile PCOS patients who underwent their first cycle of in vitro fertilization(IVF)in West China Second University Hospital,Sichuan University from January 2019 to December 2021 were included.Basic clinical and laboratory information of each individual were extracted.Unsupervised cluster analysis was performed.Controlled ovarian stimulation parameters and reproductive outcomes were collected and compared between the different clusters of PCOS.Results:Our analysis clustered women with PCOS into"reproductive","metabolic",and"balanced"clusters based on nine traits.Reproductive group was characterized by high levels of testosterone(T),sex hormone-binding globulin(SHBG),follicular stimulation hormone(FSH),luteinizing hormone(LH),and anti-Müllerian hormone(AMH).Metabolic group was characterized by high levels of body mass index(BMI),fasting insulin,and fasting glucose.Balanced group was characterized by low levels of the aforementioned reproductive and metabolic parameters,except for SHBG.Compared with PCOS patients in reproductive and balanced clusters,those in metabolic cluster had lower rates of good quality day 3 embryo and blastocyst formation.Moreover,PCOS patients in the reproductive cluster had greater fresh embryo transfer(ET)cancelation rate and clinical pregnancy rate after fresh ET than metabolic cluster(odds ratio[OR]=3.37,95%confidence interval[CI]:1.77-6.44,and OR=6.19,95%CI:1.58-24.24,respectively).And compared with PCOS of metabolic cluster,PCOS of balanced cluster also had higher chance for fresh ET cancelation(OR=2.83,95%CI:1.26-6.35).Conclusion:Our study suggested that PCOS patients in metabolic cluster may be associated with adverse re

关键词： Polycystic ovarian syndrome Assisted reproductive techniques Clustering analysis Metabolic disturbance Clinical pregnancy

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

Silicon Mitigates Aluminum Toxicity of Tartary Buckwheat by Regulating Antioxidant Systems

引用

Phyton-International Journal of Experimental Botany 2024年第1期93卷 1-13页

作者： Anyin Qi xiaonan Yan Yuqing Liu Qingchen zeng Hang Yuan Huange Huang Chenggang Liang Dabing Xiang Liang Zou Lianxin Peng Gang Zhao Jingwei Huang Yan Wan Key Laboratory of Coarse Cereal Processing Ministry of Agriculture and Rural AffairsSichuan Engineering&Technology Research Center of Coarse Cereal IndustrializationCollege of Food and Biological EngineeringChengdu UniversityChengdu610106China Research Center of Buckwheat Industry Technology School of Life SciencesGuizhou Normal UniversityGuiyang550001China

Aluminum (Al) toxicity is a considerable factor limiting crop yield and biomass in acidic soil. Tartary buckwheatgrowing in acidic soil may suffer from Al poisoning. Here, we investigated the influence of Al stress on the growthof tartary buckwheat seedling roots, and the alleviation of Al stress by silicon (Si), as has been demonstrated inmany crops. Under Al stress, root growth (total root length, primary root length, root tips, root surface area, androot volume) was significantly inhibited, and Al and malondialdehyde (MDA) accumulated in the root tips. At thesame time, catalase (CAT) and ascorbate peroxidase activities, polyphenols, flavonoids, and 1,1-diphenyl-2-picrylhydrazyl(DPPH) and 2,2′-azinobis-(3-ethylbenzthiazoline-6-sulphonate) (ABTS) free-radical scavenging abilitywere significantly decreased. After the application of Si, root growth, Al accumulation, and oxidative damage wereimproved. Compared to Al-treated seedlings, the contents of ·O2− and MDA decreased by 29.39% and 25.22%,respectively. This was associated with Si-induced increases in peroxidase and CAT enzyme activity, flavonoidcompounds, and free-radical scavenging (DPPH and ABTS). The application of Si therefore has positive effectson Al toxicity in tartary buckwheat roots by reducing Al accumulation in the roots and maintaining oxidationhomeostasis.

关键词： Tartary buckwheat aluminum stress silicon root growth oxidative stress

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

Comparative Study on Different Methods for Prediction of Thermal Insulation Performance of Thermal Barrier Coating Used on Turbine Blades

引用

Journal of Thermal Science 2024年第1期33卷 172-189页

作者： ZHANG Zhixin zeng Wu ZHANG Xiaodong zeng Yuntao Advanced Gas Turbine Laboratory Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China Key Laboratory of Advanced Energy and Power Institute of Engineering ThermophysicsChinese Academy of SciencesBeijing 100190China Innovation Academy for Light-duty Gas Turbine Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China

As turbine inlet temperature gets higher and higher,thermal barrier coating(TBC) is more and more widely used in turbine blades.For turbine blades with TBC,it is of great significance to evaluate the temperature distribution of its substrate metal quickly and accurately,especially during the design stage.With different degrees of simplification such as whether to consider the change of the geometric size of the fluid domain by TBC and whether to consider the planar heat conduction in TBC,three different methods used in conjugate heat transfer(CHT) simulation to model the TBC of the turbine blades have been developed and widely used by researchers.However,little research has been conducted to investigate the influence of the three methods on the temperature distribution of turbine blade.To fill this gap,three geometric models were designed.They are a solid conduction model with a substrate metal layer and a TBC layer,a transonic turbine vane with internal cooling and TBC,and a plate cylindrical film hole cooling model with TBC.Different methods were used in these geometric models and their differences were carefully analyzed and discussed.The result shows that for the conduction model used in this paper,with the same TBC surface temperature distribution,the difference between the three methods is very small and can be ignored.For a transonic turbine vane with internal cooling,regarding the local maximum temperature of the substrate-TBC interface,the largest difference between the method in which TBC is considered as a thermal resistance or a virtual layer of cells and the method in which three-dimensional heat conduction equation of TBC is solved occurs at the trailing edge.The difference near the leading edge is below 2K.When employed to the film cooling model,the difference of the laterally averaged temperature of the substrate-TBC interface can be 8 K which is mainly due to the change of the length to diameter ratio of the film cooling hole by TBC.If the substrate thickness is reduced by the thickness of TBC wh

关键词： turbine blade thermal barrier coating conjugate heat transfer film cooling hole

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

Gut virome:The next frontier in the treatment of necrotizing enterocolitis

引用

Chinese Medical Journal 2024年第5期137卷 562-564页

作者： Shuqin zeng Li zeng Panyu Yang Qu Zheng Shaopu Wang Department of Pediatrics Key Laboratory of Birth Defects and Related Diseases of Women and Children(Sichuan University)Ministry of EducationWest China Second University HospitalSichuan UniversityChengduSichuan 610041China Sichuan Jinxin Xinan Women&Children Hospital ChengduSichuan 610000China

Necrotizing enterocolitis(NEC)is a devastating gastrointestinal disease over decades,which,however,remains the leading cause of morbidity and mortality in preterm infants.^([1])Although multiple factors,including gastrointestinal tract bacterial colonization,immaturity,and formula feeding,are reported to be involved in the pathogenesis of NEC,the precise mechanisms are not well understood.Owing to the advances in metagenomic sequencing,ample evidences have illustrated the presence of gut dysbacteriosis in infants with NEC,which is characterized by an elevated abundance of Proteobacteria,reduced abundance of Firmicutes phyla,and an overall decrease in bacterial diversity,providing novel insights into NEC progression.^([1,2])Additionally,the bacterial replication rates,particularly those of Enterobacteriaceae,rapidly increase two days prior to NEC diagnosis.^([2])

关键词： elevated frontier treatment

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

Analysis of gravity wave activity during stratospheric sudden warmings in the northern hemisphere

引用

Earth and Planetary Physics 2024年第2期8卷 415-422页

作者： XuanYun zeng Guang Zhong School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410000China Key Laboratory of Geospace Environment Chinese Academy of SciencesUniversity of Science&Technology of ChinaHefei 230026China

Due to the significant changes they bring to high latitude stratospheric temperature and wind,stratospheric sudden warmings(SSWs)can have an impact on the propagation and energy distribution of gravity waves(GWs).The variation characteristics of GWs during SSWs have always been an important issue.Using temperature data from January to March in 2014−2016,provided by the Constellation Observing System for Meteorology,Ionosphere and Climate(COSMIC)mission,we have analyzed global GW activity at 15−40 km in the Northern Hemisphere during SSW events.During the SSWs that we studied,the stratospheric temperature rose in one or two longitudinal regions in the Northern Hemisphere;the areas affected extended to the east of 90°W.During these SSWs,the potential energy density(E_(p)of GWs expanded and covered a larger range of longitude and altitude,exhibiting an eastward and downward extension.The E_(p)usually increased,while partially filtered by the eastward zonal winds.When zonal winds weakened or turned westward,E_(p)began to strengthen.After SSWs,the E_(p)usually decreased.These observations can serve as a reference for analyzing the interaction mechanism between SSWs and GWs in future work.

关键词： stratospheric sudden warming gravity wave wind filter

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

Nested Saturated Control of Uncertain Complex Cascade Systems Using Mixed Saturation Levels

引用

IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1163-1174页

作者： Meng Li Zhigang zeng Wuhan National Laboratory for Optoelectronics Wuhan 430074 School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074China School of Artificial Intelligence and Automation Huazhong University of Science and TechnologyWuhan 430074 Key Laboratory of Image Processing and Intelligent Control of Education Ministry of China Wuhan 430074China

This study addresses the problem of global asymptotic stability for uncertain complex cascade systems composed of multiple integrator systems and non-strict feedforward nonlinear systems. To tackle the complexity inherent in such structures, a novel nested saturated control design is proposed that incorporates both constant saturation levels and state-dependent saturation levels. Specifically, a modified differentiable saturation function is proposed to facilitate the saturation reduction analysis of the uncertain complex cascade systems under the presence of mixed saturation levels. In addition, the design of modified differentiable saturation function will help to construct a hierarchical global convergence strategy to improve the robustness of control design scheme. Through calculation of relevant inequalities, time derivative of boundary surface and simple Lyapunov function,saturation reduction analysis and convergence analysis are carried out, and then a set of explicit parameter conditions are provided to ensure global asymptotic stability in the closed-loop systems. Finally, a simplified system of the mechanical model is presented to validate the effectiveness of the proposed method.

关键词： method saturation differentiable

来源：

维普期刊数据库

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Discovery of Partial Differential Equations from Highly Noisy and Sparse Data with Physics-Informed Information Criterion

引用

Research 2024年第1期2023卷 247-259页

作者： Hao Xu Junsheng zeng Dongxiao Zhang BIC-ESAT EREand SKLTCSCollege of EngineeringPeking UniversityBeijing 100871P.R.China Institute of Applied Physics and Computational Mathematics Beijing 100088P.R.China Eastern Institute for Advanced Study Eastern Institute of TechnologyNingbo 315200ZhejiangP.R.China National Center for Applied Mathematics Shenzhen(NCAMS) Southern University of Science and TechnologyShenzhen 518055GuangdongP.R.China Department of Mathematics and Theories Peng Cheng LaboratoryShenzhen 518000GuangdongP.R.China

Data-driven discovery of partial differential equations(PDEs)has recently made tremendous progress,and many canonical PDEs have been discovered successfully for proof of concept.However,determining the most proper PDE without prior references remains challenging in terms of practical applications.In this work,a physics-informed information criterion(PIC)is proposed to measure the parsimony and precision of the discovered PDE synthetically.The proposed PIC achieves satisfactory robustness to highly noisy and sparse data on 7 canonical PDEs from different physical scenes,which confirms its ability to handle difficult situations.The PIC is also employed to discover unrevealed macroscale governing equations from microscopic simulation data in an actual physical scene.The results show that the discovered macroscale PDE is precise and parsimonious and satisfies underlying symmetries,which facilitates understanding and simulation of the physical process.The proposition of the PIC enables practical applications of PDE discovery in discovering unrevealed governing equations in broader physical scenes.

关键词： process canonical proof

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

Aggregation-regulated bioreduction process of graphene oxide by Shewanella bacteria

引用

Chinese Journal of Chemical Engineering 2024年第5期69卷 56-62页

作者： Kaixin Han Yibo zeng Yinghua Lu Ping zeng Liang Shen Department of Chemical and Biochemical Engineering College of Chemistry and Chemical EngineeringXiamen UniversityXiamen 361005China Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China Chinese Research Academy of Environmental Sciences Beijing 100012China

The bioreduction of graphene oxide(GO)using environmentally functional bacteria such as Shewanella represents a green approach to produce reduced graphene oxide(rGO).This process differs from the chemical reduction that involves instantaneous molecular reactions.In bioreduction,the contact of bacterial cells and GO is considered the rate-limiting step.To reveal how the bacteria-GO integration regulates rGO production,the comparative experiments of GO and three Shewanella strains were carried out.Fourier-transform infrared spectroscopy,X-ray photoelectron spectroscopy,Raman spectroscopy,and atomic force microscopy were used to characterize the reduction degree and the aggregation degree.The results showed that a spontaneous aggregation of GO and Shewanella into the condensed entity occurred within 36 h.A positive linear correlation was established,linking three indexes of the aggregation potential,the bacterial reduction ability,and the reduction degree(ID/IG)comprehensively.

关键词： Graphene oxide Reduced graphene oxide Bioreduction Aggregation Shewanella

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：