检索结果-南通市图书馆

Effects of land use change on the spatiotemporal variability of soil organic carbon in an urban-rural ecotone of Beijing,China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2016年第4期15卷 918-928页

作者： YE Hui-chun huang yuan-fang CHEN Peng-fei huang Wen-jiang ZHANG Shi-wen huangShan-yu HOU Sen Key Laboratory of Digital Earth Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijing 100094P.R.China Hainan Key Laboratory of Earth Observation Sanya 572029P.R.China College of Resources and Environment China Agricultural UniversityBeijing 100193P.R.China State Key Laboratory of Resources and Environment Information System Institute of Geographic Science and Natural Resources ResearchChinese Academy of SciencesBeijing 100101P.R.China College of Earth and Environment Anhui University of Science and TechnologyHuainan 232001P.R.China Institute of Geography University of CologneKoln 50923Germany

Understanding the effects of land use changes on the spatiotemporal variation of soil organic carbon （SOC） can provide guidance for low carbon and sustainable agriculture. In this paper, based on the large-scale datasets of soil surveys in 1982 and 2009 for Pinggu District -- an urban-rural ecotone of Beijing, China, the effects of land use and land use changes on both temporal variation and spatial variation of SOC were analyzed. Results showed that from 1982 to 2009 in Pinggu District, the following land use change mainly occurred： Grain cropland converted to orchard or vegetable land, and grassland converted to forestland. The SOC content decreased in region where the land use type changed to grain cropland （e.g., vegetable land to grain cropland decreased by 0.7 g kg-1; orchard to grain cropland decreased by 0.2 g kg-l）. In contrast, the SOC content increased in region where the land use type changed to either orchard （excluding forestland） or forestland （e.g., grain cropland to orchard and forestland increased by 2.7 and 2.4 g kg-1, respectively; grassland to orchard and forestland increased by 4.8 and 4.9 g kg-1, respectively）. The organic carbon accumulation capacity per unit mass of the soil increased in the following order： grain cropland soil〈vegetable land/grassland soil〈orchard soil〈forestland soil. Therefore, to both secure supply of agricultural products and develop low carbon agriculture in a modern city, orchard has proven to be a good choice for land using.

关键词： land use change soil organic carbon spatiotemporal variability urban-rural ecotone

Spatial Interpolation of Soil Texture Using Compositional Kriging and Regression Kriging with Consideration of the Characteristics of Compositional Data and Environment Variables

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2013年第9期12卷 1673-1683页

作者： ZHANG Shi-wen SHEN Chong-yang CHEN Xiao-yang YE Hui-chun huang yuan-fang LAI Shuang China Agricultural University/Key Laboratory of Arable Land Conservation (North China) Minstry of Agriculture/Key Laboratory of Agricultural Land Quality MonitoringMinistry of Land and Resources School of Earth and Environment Anhui University of Science and Technology Afforestation Management Office Sichuan Forestry Department

The spatial interpolation for soil texture does not necessarily satisfy the constant sum and nonnegativity constraints. Meanwhile, although numeric and categorical variables have been used as auxiliary variables to improve prediction accuracy of soil attributes such as soil organic matter, they （especially the categorical variables） are rarely used in spatial prediction of soil texture. The objective of our study was to comparing the performance of the methods for spatial prediction of soil texture with consideration of the characteristics of compositional data and auxiliary variables. These methods include the ordinary kriging with the symmetry logratio transform, regression kriging with the symmetry logratio transform, and compositional kriging （CK） approaches. The root mean squared error （RMSE）, the relative improvement value of RMSE and Aitchison＇s distance （DA） were all utilized to assess the accuracy of prediction and the mean squared deviation ratio was used to evaluate the goodness of fit of the theoretical estimate of error. The results showed that the prediction methods utilized in this paper could enable interpolation results of soil texture to satisfy the constant sum and nonnegativity constraints. Prediction accuracy and model fitting effect of the CK approach were better, suggesting that the CK method was more appropriate for predicting soil texture. The CK method is directly interpolated on soil texture, which ensures that it is optimal unbiased estimator. If the environment variables are appropriately selected as auxiliary variables, spatial variability of soil texture can be predicted reasonably and accordingly the predicted results will be satisfied.

关键词： compositional kriging auxiliary variables regression kriging symmetry logratio transform

Spatial distribution prediction and benefits assessment of green manure in the Pinggu District,Beijing,based on the CLUE-S model

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2016年第2期15卷 465-474页

作者： ZHANG Li-ping ZHANG Shi-wen ZHOU Zhi-ming HOU Sen huang yuan-fang CAO Wei-dong College of Resources and Environment China Agricultural University/Key Laboratory of Arable Land Conservation(North China)Minstry of Agriculture/Key Laboratory of Agricultural Land Quality MonitoringMinistry of Land and Resources School of Earth and Environment Anhui University of Science and Technology Institute of Agricultural Resources and Regional Planning Chinese Academy of Agricultural Sciences

Green manure use in China has declined rapidly since the 1980 s with the extensive use of chemical *** deterioration of field environments and the demand for green agricultural products have resulted in more attention to green *** intervention and policy-oriented behaviors likely have large impacts on promoting green manure ***,little information is available regarding on where,at what rates,and in which ways（i.e.,intercropping green manure in orchards or rotating green manure in cropland） to develop green manure and what benefits could be gained by incorporating green manure in fields at the county *** paper presents the conversion of land use and its effects at small region extent（CLUE-S） model,which is specifically developed for the simulation of land use changes originally,to predict spatial distribution of green manure in cropland and orchards in 2020 in Pinggu District located in Beijing,*** types of land use for planting or not planting green manure were classified and the future land use dynamics（mainly croplands and orchards） were considered in the *** scenarios were used to predict the spatial distribution of green manure based on data from 2011：The promotion of green manure planting in orchards（scenario 1） and the promotion of simultaneous green manure planting in orchards and croplands（scenario 2）.The predictions were generally accurate based on the receiver operating characteristic（ROC） and Kappa indices,which validated the effectiveness of the CLUE-S model in the *** addition,the spatial distribution of the green manure was acquired,which indicated that green manure mainly located in the orchards of the middle and southern regions of Dahuashan,the western and southern regions of Wangxinzhuang,the middle region of Shandongzhuang,the eastern region of Pinggu and the middle region of Xiagezhuang under scenario *** manure planting under scenario 2 occurred in orchards in the middle re

关键词： CLUE-S model green manure spatial distribution prediction benefits assessment

Toward Analytical Homogenized Relaxation Modulus for Fibrous Composite Material with Reduced Order Homogenization Method

在线全文

学校读者我要写书评

暂无评论

Computers, Materials & Continua 2025年第1期82卷 193-222页

作者： Huilin Jia Shanqiao huang Zifeng yuan HEDPS Center for Applied Physics and Technology(CAPT)Department of Mechanics and Engineering SciencePeking UniversityBeijing100871China State Key Laboratory for Turbulence and Complex Systems Peking UniversityBeijing100871China

In this manuscript,we propose an analytical equivalent linear viscoelastic constitutive model for fiber-reinforced composites,bypassing general computational *** method is based on the reduced-order homogenization(ROH)*** ROH method typically involves solving multiple finite element problems under periodic conditions to evaluate elastic strain and eigenstrain influence functions in an‘off-line’stage,which offers substantial cost savings compared to direct computational homogenization *** to the unique structure of the fibrous unit cell,“off-line”stage calculation can be eliminated by influence functions obtained *** the standard solid model to the ROH method enables the creation of a comprehensive analytical homogeneous viscoelastic constitutive *** method treats fibrous composite materials as homogeneous,anisotropic viscoelastic materials,significantly reducing computational time due to its analytical *** approach also enables precise determination of a homogenized anisotropic relaxation modulus and accurate capture of various viscoelastic responses under different loading *** sets of numerical examples,including unit cell tests,three-point beam bending tests,and torsion tests,are given to demonstrate the predictive performance of the homogenized viscoelastic ***,the model is validated against experimental measurements,confirming its accuracy and reliability.

关键词： Homogenized relaxation modulus viscoelastic standard solid model reduced order homogenization fibrous composite material

Reconstruction characteristics of gut microbiota from patients with type 1 diabetes affect the phenotypic reproducibility of glucose metabolism in mice

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

Science China(Life Sciences) 2025年第1期68卷 176-188页

作者： Zhiyi Wang Mengxue Gong yuanyuan fang Huijuan yuan Chenhong Zhang State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China Department of Endocrinology Henan Provincial People’s HospitalPeople’s Hospital of Zhengzhou UniversityZhengzhou 450003China

The human microbiota-associated(HMA)mice model,especially the germ-free(GF)-humanized mice,has been widely used to probe the causal relationships between gut microbiota and human diseases such as type 1 diabetes(T1D).However,most studies have not clarified the extent to which the reconstruction of the human donor microbiota in recipient mice correlates with corresponding phenotypic *** this study,we transplanted fecal microbiota from five patients with T1D and four healthy people into GF mice,and microbiota from each donor were transplanted into 10 *** with similar microbiota structure to the donor exhibited better phenotypic *** characteristics of the microbial community assembly of donors also influenced the phenotypic reproducibility in mice,and individuals with a higher proportion of stochastic processes showed more severe *** enriched in patients with T1D had a stronger colonization potential in mice with impaired glucose metabolism,and microbiota functional features related to T1D were better reproduced in these *** indicates that assembly traits and colonization efficacy of microbiota influence phenotypic reproducibility in GF-humanized *** findings provide important insights for using HMA mice models to explore links between gut microbiota and human diseases.

关键词： gut microbiome human microbiota-associated animal model type 1 diabetes

High-resolution full waveform seismic imaging: Progresses, challenges, and prospects

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2025年第2期68卷 315-342页

作者： Dinghui YANG Xingpeng DONG Jiandong huang Zhilong fang Xueyuan huang Shaolin LIU Mengxue LIU Weijuan MENG Department of Mathematical Sciences Tsinghua UniversityBeijing 100084China Institute of Geology China Earthquake AdministrationBeijing 100029China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China School of Mathematics and Statistics Beijing Technology and Business UniversityBeijing 100048China National Institute of Natural Hazards Ministry of Emergency Management of ChinaBeijing 100085China

Full waveform inversion(FWI) is a seismic imaging method with a unified mathematical framework based on wave equation constraints. The FWI method can be used to generate a variety of high-resolution seismic parameter models(e.g.,velocity, anisotropy, viscoelasticity, and attenuation), which can facilitate an in-depth understanding of important scientific problems such as the Earth's interior structure and material composition, earthquake preparation and occurrence, and plate motion and dynamic processes. With the development and cross-integration of disciplines such as geophysics, applied mathematics, and computer science, FWI imaging theories and methods not only play a crucial role in revealing the Earth's interior structure, dynamic evolution, and earthquake mechanisms but also show a wide range of application potential in fields such as resource exploration, medical imaging, engineering inspection, carbon dioxide geological sequestration, and earthquake disaster prediction. In this paper, we provide a comprehensive review and analysis of the development of the FWI method,addressing its current challenges, identifying key issues, future directions, and potential research areas in the theory, methodology, and application of high-resolution FWI imaging. We also offer new insights and perspectives to promote advancements of high-resolution FWI research and applications in Earth sciences and other related fields.

关键词： Full waveform inversion High-resolution imaging Interior structure of the Earth Earthquake preparation me-chanism Multidisciplinary integration

The gut microbiome modulate response to immunotherapy in cancer

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2025年第2期68卷 381-396页

作者： Shan-Shan Jiang Zi-Ran Kang Ying-Xuan Chen Jing-yuan fang Division of Gastroenterologyand Hepatology Shanghai Instituteof Digestive DiseaseNHC KeyLaboratoryof Digestive DiseasesState KeyLaboratoryfor Oncogenesand Related GenesRenji HospitalSchool of MedicineShanghai Jiao Tong UniversityShanghai 200001China

Gut microbiota have been reported to play an important role in the occurrence and development of malignant ***,clinical studies have identified specific gut microbiota and its metabolites associated with efficacy of immunotherapy in multiple types of *** investigations have elucidated that gut microbiota modulate the antitumor immunity and affect the efficacy of cancer *** microbiota and its metabolites may favorably remodel the tumor microenvironment by engaging innate and/or adaptive immune *** how the gut microbiome interacts with cancer immunotherapy opens new avenues for improving treatment *** microbial transplants,probiotics,dietary interventions,and other strategies targeting the microbiota have shown promise in preclinical studies to enhance the *** clinical trials are evaluating these *** review presents the recent advancements in understanding the dynamic interplay among the host immunity,the microbiome,and cancer immunotherapy,as well as strategies for modulating the microbiome,with a view to translating into clinical applications.

关键词： cancer immunotherapy gut microbiota intratumoral microbiota microbiota-derived metabolites innate and adaptive immunity

A Three-Dimensional SPH Simulation of Lander Footpad Impact on a Lunar Regolith Bed

在线全文

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2025年第2期142卷 2045-2066页

作者： Wanqing yuan Huiying Xie Can huang Xiaoliang Wang Qingquan Liu Department of Mechanics School of Aerospace EngineeringBeijing Institute of TechnologyBeijing100081China Institute of Computational Aerodynamics China Aerodynamics Research and Development CenterMianyang621000China Institute of Large Structures for Advanced Industrial Equipment Beijing Institute of TechnologyZhuhai519088China

Landing spacecraft experience significant impact forces during landing,resulting in large deformation and failure in the soil surface,which severely affects landing safety and *** paper establishes a smoothed particle hydrodynamics(SPH)model based on the theory of soil elastoplastic constitutive relations to describe the process of a lander’s footpad impacting lunar regolith *** model can provide engineering indices such as impact load and penetration depth,and illustrate the large deformation and crater characteristics of the regolith.A detailed analysis of the response of the footpad and lunar regolith during landing reveals that the process can be broadly divided into two stages of rapid penetration and oscillatory ***,there are significant similarities in the landing process under different landing velocities and footpad *** research investigates the large deformation and crater characteristics of the lunar regolith *** results demonstrate two failure modes in the *** the impact of a footpad with a smaller mass,the final failure surface of the regolith exhibits a bowl-shaped profile with a uniformly open *** contrast,under the impact of a footpad with a larger mass,the final failure surface of the regolith presents an urn-shaped profile with a large abdomen and a small ***,the impact craters in both scenarios show a bowl-like *** cases of high-velocity impacts,the impact crater exhibits obvious blocky spalling on its *** SPH model developed in this study can be applied to predict the large deformation and failure response of lunar soil under the impact of rigid structures as well as the impact load and penetration *** effectively predicts the dynamic response of the landing process,which is expected to provide a reference for engineering design.

关键词： SPH footpad load lunar regolith impact crater

Co-host ncRNA MIR503HG/miR-503-5p antagonistically interfere with the crosstalk between fibroblasts and microvascular endothelial cells by affecting the production of LMW FGF2 in pterygium

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

International Journal of Ophthalmology(English edition) 2025年第2期18卷 199-208页

作者： Yue-Qi yuan Xing-yuan Yan fang Zheng Ming Yan Department of Ophthalmology Zhongnan Hospital of Wuhan UniversityWuhan 430071Hubei ProvinceChina Department of Laboratory Medicine&Center for Gene Diagnosis Zhongnan Hospital of Wuhan UniversityWuhan 430071Hubei ProvinceChina

AIM:To explore the effect of co-host non-coding RNA(ncRNA)MIR503HG/miR-503-5p on the angiogenesis of ***:MIR503HG/miR-503-5p/fibroblast growth factor 2(FGF2)expression levels in pterygium tissues,control conjunctival tissues,and human pterygium fibroblasts(HPF)were examined by reverse transcription-polymerase chain reaction(qRT-PCR)and immunohistochemical *** of MIR503HG/miR-503-5p on low molecular weight FGF2(LWM FGF2),migration and angiogenesis of human retinal microvascular endothelial cells(HRMEC)were determined in an HPF and HRMEC co-culture model using Western blots,wound healing assay,Matrigel-based tube formation assay,and Transwell ***:MIR503HG/miR-503-5p/FGF2 pathway was actively increased in pterygium tissue and there was a negative correlation between the expression of the two ***2 expression level was positively correlated with MIR503HG and negatively correlated with *** MIR503HG/miR-503-5p did not affect the migration and angiogenesis of HRMECs cultured separately,but significantly affected migration and angiogenesis of HRMEC in HPF and HRMEC co-culture *** blotting revealed that MIR503HG/miR-503-5p overexpression significantly increased LMW FGF2 expression in ***:MIR503HG/miR-503-5p inhibits HRMEC migration and angiogenic function by interfering with the interaction between HPF and endothelial cells via reducing LMW FGF2 in HPF.

关键词： pterygium MIR503HG miR-503-5p fibroblast growth factor 2 angiogenesis