检索结果-南通市图书馆

Effect of Simulated Acid Rain on Potential Carbon and Nitrogen Mineralization in Forest Soils

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2008年第4期18卷 503-514页

作者： OUYANG Xue-jun ZHOU Guo-Yi HUANG Zhong-Liang liu ju-xiu ZHANG De-Qiang LI Jiong South China Botanic Garden Chinese Academy of Sciences Guangzhou 510650 （China） Graduate School of the Chinese Academy of Sciences Beijing 100049 （China）

Acid rain is a serious environmental problem worldwide. In this study, a pot experiment using forest soils planted with the seedlings of four woody species was performed with weekly treatments of pH 4.40, 4.00, 3.52, and 3.05 simulated acid rain (SAR) for 42 months compared to a control of pH 5.00 lake water. The cumulative amounts of C and N mineralization in the five treated soils were determined after incubation at 25 ℃ for 65 d to examine the effects of SAR treatments. For all five treatments, cumulative CO2-C production ranged from 20.24 to 27.81 mg kg-1 dry soil, net production of available N from 17.37 to 48.95 mg kg-1 dry soil, and net production of NO-3 -N from 9.09 to 46.23 mg kg-1 dry soil. SAR treatments generally enhanced the emission of CO2-C from the soils; however, SAR with pH 3.05 inhibited the emission. SAR treatments decreased the net production of available N and NO3-N. The cumulative CH4 and N2O productions from the soils increased with increasing amount of simulated acid rain. The cumulative CO2-C production and the net production of available N of the soil under Acmena acuminatissima were significantly higher (P ≤ 0.05) than those under Schima superba and Cryptocarya concinna. The mineralization of soil organic C was related to the contents of soil organic C and N, but was not related to soil pH. However, the overall effect of acid rain on the storage of soil organic matter and the cycling of important nutrients depended on the amount of acid deposition and the types of forests.

关键词： forest soils mineralization organic C organic N simulated acid rain

Responses of Soil Acid Phosphomonoesterase Activity to Simulated Nitrogen Deposition in Three Forests of Subtropical China

在线全文

学校读者我要写书评

暂无评论

Pedosphere 2012年第5期22卷 698-706页

作者： HUANG Wen-juan ZHANG De-Qiang LI Yue-Lin LU XianKai ZHANG Wei HUANG juan D.OTIENO Z.H.XU liu ju-xiu liu Shi-Zhong CHU Guo-Wei Key laboratory of Vegetation Restoration and Management of Degrade Ecosystems South China Botanical GardenChinese Academy of SciencesGuangzhou 510650(China) Graduate University of Chinese Academy of Sciences Beijing 100049(China) Department of Plant Ecology University of BayreuthBayreuth 95440(Germany) Environmental Futures Centre&School of Biomoleeular and Physical Sciences Griffith UniversityNathan QLD 4111(Australia)

Soil acid phosphomonoesterase activity (APA) plays a vital role in controlling phosphorus (P) cycling and reflecting the current degree of P limitation. Responses of soil APA to elevating nitrogen (N) deposition are important because of their potential applications in addressing the relationship between N and P in forest ecosystems. A study of responses of soil APA to simulated N deposition was conducted in three succession forests of subtropical China. The three forests include a Masson pine (Pinus massoniana) forest (MPF)-pioneer community, a coniferous and broad-leaved mixed forest (MF)-transition community and a monsoon evergreen broad-leaved forest (MEBF)-climax community. Four N treatments were designed for MEBF: control (without N added), low-N (50 kg N ha-1 year-1), and medium-N (100 kg N ha-1 year-1) and high-N (150 kg N ha-1 year-1), and only three N treatments (i.e., control, low-N, medium-N) were established for MPF and MF. Results showed that soil APA was highest in MEBF, followed by MPF and MF. Soil APAs in both MPF and MF were not influenced by low-N treatments but depressed in medium-N treatments. However, soil APA in MEBF exhibited negative responses to high N additions, indicating that the environment of enhanced N depositions would reduce P supply for the mature forest ecosystem. Soil APA and its responses to N additions in subtropical forests were closely related to the succession stages in the forests.

关键词： Dinghushan Biosphere Reserve forest ecosystems forest succession phosphorus limitation subtropical region

Global status and trends of metabolomics in diabetes: A literature visualization knowledge graph study

在线全文

学校读者我要写书评

暂无评论

World Journal of Diabetes 2024年第5期15卷 1021-1044页

作者： Hong Li liu Li Qiu-Qing Huang Si-Yao Yang jun-ju Zou Fan Xiao Qin Xiang xiu liu Rong Yu College of Chinese Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina College of International Education Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Department of Science and Technology Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina Hunan Key Laboratory of TCM Prescription and Syndromes Translational Medicine Hunan University of Chinese MedicineChangsha 410208Hunan ProvinceChina College of Graduate Hunan University of Chinese MedicineHunan ChangshaHunan ProvinceChina

BACKGROUND Diabetes is a metabolic disease characterized by hyperglycemia,which has increased the global medical burden and is also the main cause of death in most *** To understand the knowledge structure of global development status,research focus,and future trend of the relationship between diabetes and metabolomics in the past 20 *** The articles about the relationship between diabetes and metabolomics in the Web of Science Core Collection were retrieved from 2002 to October 23,2023,and the relevant information was analyzed using CiteSpace6.2.2R(CiteSpace),VOSviewer6.1.18(VOSviewer),and Bibliometrix software under R *** A total of 3123 publications were included from 2002 to *** the past two decades,the number of publications and citations in this field has continued to *** United States,China,Germany,the United Kingdom,and other relevant funds,institutions,and authors have significantly contributed to this *** Reports and PLoS One are the journals with the most publications and the most *** keyword co-occurrence and cluster analysis,the closely related keywords are"insulin resistance","risk","obesity","oxidative stress","metabolomics","metabolites"and"biomarkers".Keyword clustering included cardiovascular disease,gut microbiota,metabonomics,diabetic nephropathy,molecular docking,gestational diabetes mellitus,oxidative stress,and insulin *** detection analysis of keyword depicted that"Gene","microbiota","validation","kidney disease","antioxidant activity","untargeted metabolomics","management",and"accumulation"are knowledge frontiers in recent *** The relationship between metabolomics and diabetes is receiving extensive *** nephropathy,diabetic cardiovascular disease,and kidney disease are key diseases for future research in this *** microbiota,molecular docking,and untargeted metabolomics are key research directions in the *** a

关键词： Diabetes Metabolomics Bibliometric CiteSpace VOSviewer

土壤累积酸化对鼎湖山马尾松林物质元素迁移规律的影响

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

浙江大学学报（农业与生命科学版） 2005年第4期31卷 381-391页

作者：刘菊秀周国逸中国科学院华南植物园广东广州510650

自然酸沉降环境下,土壤酸化是一个逐步累积的过程.在土壤被累积酸化影响下,鼎湖山马尾松林土壤物质元素K、Na、Ca、Mg、P、Fe、Mn、Cu和Al的迁移变化规律与对照相比发生改变.土壤中,交换性K+、有效Fe、有效Cu含量持续上升;总P、活性Al... 详细信息

自然酸沉降环境下,土壤酸化是一个逐步累积的过程.在土壤被累积酸化影响下,鼎湖山马尾松林土壤物质元素K、Na、Ca、Mg、P、Fe、Mn、Cu和Al的迁移变化规律与对照相比发生改变.土壤中,交换性K+、有效Fe、有效Cu含量持续上升;总P、活性Al含量下降;交换性Ca2+、Mg2+含量开始时明显下降,后又稍有上升;有效Mn变化不大.土壤淋洗液中,K+、Na+含量持续下降;Ca2+、Mg2+含量开始时下降,后趋于缓和;总P、Fe、Cu、Mn和Al含量持续上升.酸沉降对土壤有效Fe、Mn和活性Al以及土壤淋洗液中Mg2+、Mn和Al含量有显著影响.在雨季,马尾松叶片中Ca、Mg元素随处理的酸雨酸度的增加,含量下降,马尾松生长应该注意是否缺Mg和出现Al毒.在酸沉降累积影响下,鼎湖山马尾松林最终将容易出现因土壤养分Mg、P、Cu缺乏和微量元素Fe及有毒元素Al的活化而导致的养分失衡状况的发生.

关键词：土壤酸化鼎湖山马尾松林元素迁移影响

Changes in the Non-targeted Metabolomic Profile of Three-year-old Toddlers with Elevated Exposure to Polycyclic Aromatic Hydrocarbons

在线全文

学校读者我要写书评

暂无评论

Biomedical and Environmental Sciences 2024年第5期37卷 479-493页

作者： LI Yang LIN Dan ZHANG xiu Qin ju Guang xiu SU Ya ZHANG Qian DUAN Hai Ping YU Wei Sen WANG Bing Ling PANG Shu Tao Department of Epidemiology and Health Statistics School of Public HealthQingdao UniversityQingdao 266021ShandongChina Department of Environmental Health Qingdao Municipal Center for Disease Control and PreventionQingdao Institute of Preventive MedicineQingdao 266033ShandongChina Physicochemical Laboratory Qingdao Municipal Center for Disease Control and PreventionQingdao Institute of Preventive MedicineQingdao 266033ShandongChina Section of Child Health Care Huangdao Maternity and Child Health Care Hospital of QingdaoQingdao 266499ShandongChina Qingdao Blood Center Qingdao 266071ShandongChina

Objective To investigate changes in the urinary metabolite profiles of children exposed to polycyclic aromatic hydrocarbons(PAHs)during critical brain development and explore their potential link with the intestinal *** Liquid chromatography-tandem mass spectrometry was used to determine ten hydroxyl metabolites of PAHs(OH-PAHs)in 36-month-old ***,37 children were categorized into low-and high-exposure groups based on the sum of the ten ***-high-performance liquid chromatography coupled with quadrupole time-of-flight mass spectrometry was used to identify non-targeted metabolites in the urine ***,fecal flora abundance was assessed by 16S rRNA gene sequencing using Illumina *** The concentrations of 21 metabolites were significantly higher in the high exposure group than in the low exposure group(variable importance for projection>1,P<0.05).Most of these metabolites were positively correlated with the hydroxyl metabolites of naphthalene,fluorine,and phenanthrene(r=0.336–0.531).The identified differential metabolites primarily belonged to pathways associated with inflammation or proinflammatory states,including amino acid,lipid,and nucleotide ***,these distinct metabolites were significantly associated with specific intestinal flora abundances(r=0.34–0.55),which were mainly involved in *** Higher PAH exposure in young children affected metabolic homeostasis,particularly that of certain gut microbiota-derived *** investigation is needed to explore the potential influence of PAHs on the gut microbiota and their possible association with neurodevelopmental outcomes.

关键词： Child Gut microbiota Non-targeted metabolomics Polycyclic aromatic hydrocarbons Urinary metabolite profile

Hepatic ectopic pregnancy with hemorrhage secondary diaphragmatic adhesion:A case report

在线全文

学校读者我要写书评

暂无评论

World Journal of Hepatology 2024年第9期16卷 1289-1296页

作者： xiu-Ci Yang Miao Fang Yi-Gen Peng Liang Wang Rong ju Department of Emergency The Affiliated Jiangning Hospital of Nanjing Medical UniversityNanjing 211100Jiangsu ProvinceChina Department of Gynecology and Obstetrics Nanjing Medical UniversityNanjing 211100Jiangsu ProvinceChina Department of Hepatological Surgery The Affiliated Jiangning Hospital of Nanjing Medical UniversityNanjing 211100Jiangsu ProvinceChina Department of Gynecology The Affiliated Jiangning Hospital of Nanjing Medical UniversityNanjing 211100Jiangsu ProvinceChina

BACKGROUND Primary abdominal pregnancy is an extremely rare form of ectopic *** pregnancies that occur in the liver and diaphragm are even rarer,limited case reports are available in the *** SUMMARY A woman of childbearing age was transferred to the emergency department due to lumbar and abdominal pain radiating to the back toward the lower *** a series of physical and auxiliary examinations,she was clinically diagnosed with hepatic ectopic *** surgery was performed to remove the pregnancy tissue and achieve *** a period of follow-up,the patient was successfully *** Paying attention to the patient's signs and utilizing imaging examination methods can help avoid missed diagnoses of liver pregnancy.

关键词： Ectopic pregnancy Liver Diaphragm Diagnosis Case report

Atomic-Scale Insights into Damage Mechanisms of GGr15 Bearing Steel Under Cyclic Shear Fatigue

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

Acta Metallurgica Sinica(English Letters) 2024年第7期37卷 1265-1278页

作者： Qiao-Sheng Xia Dong-Peng Hua Qing Zhou Ye-Ran Shi Xiang-Tao Deng Kai-ju Lu Hai-Feng Wang xiu-Bing Liang Zhao-Dong Wang State Key Laboratory of Solidification Processing Center of Advanced Lubrication and Seal MaterialsNorthwestern Polytechnical UniversityXi’an710072China State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819China Defense Innovation Institute Academy of Military ScienceBeijing100071China

Alternating shear stress is a critical factor in the accumulation of damage during rolling contact fatigue,severely limiting the service life of ***,the specific mechanisms responsible for the cyclic shear fatigue damage in bearing steel have not been fully *** the mechanical response and microstructural evolution of a model GGr15 bearing steel under cyclic shear loading are investigated through the implementation of molecular dynamics *** samples undergo 30 cycles under three different loading conditions with strains of 6.2%,9.2%,and 12.2%,*** findings indicate that severe cyclic shear deformation results in early cyclic softening and significant accumulation of plastic damage in the bearing ***,samples subjected to higher strain-controlled loading exhibit higher plastic strain energy and shorter fatigue ***,strain localization is identified as the predominant damage mechanism in cyclic shear fatigue of the bearing steel,which accumulates and ultimately results in fatigue ***,simulation results also revealed the microstructural reasons for the strain localization(e.g.,BCC phase transformation into FCC and HCP phase),which well explained the formation of white etching *** study provides fresh atomic-scale insights into the mechanisms of cyclic shear fatigue damage in bearing steels.

关键词： Cyclic shear fatigue Molecular dynamic simulation Bearing steels Plastic damage accumulation