期刊文献+
共找到20,369篇文章
< 1 2 250 >
每页显示 20 50 100
Moso bamboo expansion decreased soil heterotrophic respiration but increased arbuscular mycorrhizal mycelial respiration in a subtropical broadleaved forest 被引量:1
1
作者 Wenhao Jin Jiaying Tu +7 位作者 Qifeng Wu Liyuan Peng Jiajia Xing Chenfei Liang Shuai Shao Junhui Chen Qiufang Xu Hua Qin 《Forest Ecosystems》 SCIE CSCD 2023年第3期337-347,共11页
Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant... Moso bamboo(Phyllostachys Pubescens)expansion into adjacent forests has been widely reported to affect plant diversity and its association with mycorrhizal fungi in subtropical China,which will likely have significant impacts on soil respiration.However,there is still limited information on how Moso bamboo expansion changes soil respiration components and their linkage with microbial community composition and activity.Based on a mesh exclusion method,soil respirations derived from roots,arbuscular mycorrhizal(AM)mycelium,and free-living microbes were investigated in a pure Moso bamboo forest(expanded),an adjacent broadleaved forest(nonexpanded),and a mixed bamboo-broadleaved forest(expanding).Our results showed that bamboo expansion decreased the cumulative CO_(2)effluxes from total soil respiration,root respiration and soil heterotrophic respiration(by 19.01%,30.34%,and 29.92%on average),whereas increased those from AM mycelium(by 78.67%in comparison with the broadleaved forests).Bamboo expansion significantly decreased soil organic carbon(C)content,bacterial and fungal abundances,and enzyme activities involved in C,N and P cycling whereas enhanced the interactive relationships among bacterial communities.In contrast,the ingrowth of AM mycelium increased the activities ofβ-glucosidase and N-acetyl-β-glucosaminidase and decreased the interactive relationships among bacterial communities.Changes in soil heterotrophic respiration and AM mycelium respiration had positive correlations with soil enzyme activities and fungal abundances.In summary,our findings suggest that bamboo expansion decreased soil heterotrophic respiration by decreasing soil microbial activity but increased the contribution of AM mycelial respiration to soil C efflux,which may potentially increase soil C loss from AM mycelial pathway. 展开更多
关键词 Bamboo expansion Soil respiration Soil organic carbon Plant C allocation Arbuscular mycorrhizal fungi
下载PDF
Response of soil respiration to short-term changes in precipitation and nitrogen addition in a desert steppe
2
作者 MA Jinpeng PANG Danbo +4 位作者 HE Wenqiang ZHANG Yaqi WU Mengyao LI Xuebin CHEN Lin 《Journal of Arid Land》 SCIE CSCD 2023年第9期1084-1106,共23页
Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the ef... Changes in precipitation and nitrogen(N)addition may significantly affect the processes of soil carbon(C)cycle in terrestrial ecosystems,such as soil respiration.However,relatively few studies have investigated the effects of changes in precipitation and N addition on soil respiration in the upper soil layer in desert steppes.In this study,we conducted a control experiment that involved a field simulation from July 2020 to December 2021 in a desert steppe in Yanchi County,China.Specifically,we measured soil parameters including soil temperature,soil moisture,total nitrogen(TN),soil organic carbon(SOC),soil microbial biomass carbon(SMBC),soil microbial biomass nitrogen(SMBN),and contents of soil microorganisms including bacteria,fungi,actinomyces,and protozoa,and determined the components of soil respiration including soil respiration with litter(RS+L),soil respiration without litter(RS),and litter respiration(RL)under short-term changes in precipitation(control,increased precipitation by 30%,and decreased precipitation by 30%)and N addition(0.0 and 10.0 g/(m^(2)·a))treatments.Our results indicated that short-term changes in precipitation and N addition had substantial positive effects on the contents of TN,SOC,and SMBC,as well as the contents of soil actinomyces and protozoa.In addition,N addition significantly enhanced the rates of RS+L and RS by 4.8%and 8.0%(P<0.05),respectively.The increase in precipitation markedly increased the rates of RS+L and RS by 2.3%(P<0.05)and 5.7%(P<0.001),respectively.The decrease in precipitation significantly increased the rates of RS+L and RS by 12.9%(P<0.05)and 23.4%(P<0.001),respectively.In contrast,short-term changes in precipitation and N addition had no significant effects on RL rate(P>0.05).The mean RL/RS+L value observed under all treatments was 27.63%,which suggested that RL is an important component of soil respiration in the desert steppe ecosystems.The results also showed that short-term changes in precipitation and N addition had significant interactive effects on the rates of RS+L,RS,and RL(P<0.001).In addition,soil temperature was the most important abiotic factor that affected the rates of RS+L,RS,and RL.Results of the correlation analysis demonstrated that the rates of RS+L,RS,and RL were closely related to soil temperature,soil moisture,TN,SOC,and the contents of soil microorganisms,and the structural equation model revealed that SOC and SMBC are the key factors influencing the rates of RS+L,RS,and RL.This study provides further insights into the characteristics of soil C emissions in desert steppe ecosystems in the context of climate change,which can be used as a reference for future related studies. 展开更多
关键词 soil respiration litter respiration nitrogen deposition soil carbon soil microorganisms climate change desert steppe ecosystems
下载PDF
Transcriptome Analysis Reveals New Insights into the Respiration Metabolism Mechanism of Different Feeding Rations of Sea Cucumber(Apostichopus japonicus)
3
作者 MEI Yaoping HOU Zhishuai +3 位作者 GAO Qinfeng DONG Shuanglin LI Xueqi XU Yuling 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第6期1621-1634,共14页
Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variatio... Sea cucumber(Apostichopus japonicus)is an excellent model for investigating effects of bottom-dwellers on carbon mig-ration and transformation.However,the molecular mechanism of respiratory metabolism process variation caused by feeding rations is poorly understood.In this study,treatment groups set as 1%(about 0.63g),3%,and 7%of total body weight(named F1,F3 and F7 groups respectively).The potential molecular mechanisms behind the functions of respiratory tree and body wall were investigated by RNA-Seq.A total of 52411 expressed genes were identified from 89342 expressed transcripts.The results showed 759,254 and 334 genes were up-regulated,and 334,445 and 992 genes were down-regulated in respiratory tree of F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Meanwhile,2070,1601 and 896 genes were up-regulated,and 1303,1337 and 1144 genes were down-regulated in body wall between F1 vs.F3,F1 vs.F7 and F3 vs.F7,respectively.Differentially expressed genes were enriched in salivary secretion and ECM-receptor interaction pathways in respiratory tree,and in various types of N-glycan biosynthesis,ribosome and sphingolipid metabolism pathways in body wall.These results suggested respiratory tree and body wall were involved in activation of respiratory metabolisms in response to different feeding rations.Our research provided valuable knowledge for physiological differences in res-piratory metabolism. 展开更多
关键词 TRANSCRIPTOMICS Apostichopus japonicus feeding ration respiration metabolism
下载PDF
Effects of Biowaste-Derived Hydrochar on Anaerobic Digestion:Insights into Hydrochar Characteristics
4
作者 Hongqiong Zhang Xu Wang +3 位作者 Zhaojing Qian Buchun Si Kai Jin Tengfei Wang 《Journal of Renewable Materials》 EI 2023年第10期3647-3657,共11页
Hydrochar prepared with four typical biowastes,pine wood,food waste,digested sewage sludge,and Chlorella were applied for the promotion of anaerobic digestion.The gas production and substrate composition were analyzed... Hydrochar prepared with four typical biowastes,pine wood,food waste,digested sewage sludge,and Chlorella were applied for the promotion of anaerobic digestion.The gas production and substrate composition were analyzed associated with the hydrochar characteristics.The results suggested that Chlorella hydrochar(C-C)showed the highest cumulative yield of methane(approximately 345 mL)with high total organic carbon(TOC)removal efficiency and low volatile fatty acids(VAFs)concentration.Especially,food waste hydrochar(F-C)showed a poor effect on anaerobic digestion and aroused 1.4–1.6 g/L accumulation of VAFs,in which the toxic components may account for the low efficiency.The C-C and sludge hydrochar(S-C)may develop direct interspecific electron transport(DIET)to facilitate the generation of methane by both surface groups and conductivity of the body structure,unlike pinewood hydrochar(P-C),which mainly depended on the aromatic matrix structure of hydrochar body.This work suggested that C-C can be the best candidate for the facilitation of anaerobic digestion,and N-containing biowaste like algae and lignocellulose like pine wood may establish different DIET pathways based on the physicochemical characteristics of hydrochar. 展开更多
关键词 BIOWASTE hydrochar DIET anaerobic digestion METHANE
下载PDF
Accuracy of Mean Value of Central Venous Pressure from Monitor Digital Display: Influence of Amplitude of Central Venous Pressure during Respiration
5
作者 Meng-Ru Xu Wang-Lin Liu +4 位作者 Huai-Wu He Xiao-Li Lai Mei-Ling Zhao Da-Wei Liu Yun Long 《Chinese Medical Sciences Journal》 CAS CSCD 2023年第2期117-124,共8页
Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measureme... Background A simple measurement of central venous pressure(CVP)-mean by the digital monitor display has become increasingly popular.However,the agreement between CVP-mean and CVP-end(a standard method of CVP measurement by analyzing the waveform at end-expiration)is not well determined.This study was designed to identify the relationship between CVP-mean and CVP-end in critically ill patients and to introduce a new parameter of CVP amplitude(ΔCVP=CVPmax-CVPmin)during the respiratory period to identify the agreement/disagreement between CVP-mean and CVP-end.Methods In total,291 patients were included in the study.CVP-mean and CVP-end were obtained simultaneously from each patient.CVP measurement difference(|CVP-mean-CVP-end|)was defined as the difference between CVP-mean and CVP-end.TheΔCVP was calculated as the difference between the peak(CVPmax)and the nadir value(CVPmin)during the respiratory cycle,which was automatically recorded on the monitor screen.Subjects with|CVP-mean-CVP-end|≥2 mm Hg were divided into the inconsistent group,while subjects with|CVP-mean-CVP-end|2 mm Hg were divided into the consistent group.ResultsΔCVP was significantly higher in the inconsistent group[7.17(2.77)vs.5.24(2.18),P0.001]than that in the consistent group.There was a significantly positive relationship betweenΔCVP and|CVP-mean-CVP-end|(r=0.283,P 0.0001).Bland-Altman plot showed the bias was-0.61 mm Hg with a wide 95%limit of agreement(-3.34,2.10)of CVP-end and CVP-mean.The area under the receiver operating characteristic curves(AUC)ofΔCVP for predicting|CVP-mean-CVP-end|≥2 mm Hg was 0.709.With a high diagnostic specificity,usingΔCVP3 to detect|CVP-mean-CVP-end|lower than 2mm Hg(consistent measurement)resulted in a sensitivity of 22.37%and a specificity of 93.06%.UsingΔCVP8 to detect|CVP-mean-CVPend|8 mm Hg(inconsistent measurement)resulted in a sensitivity of 31.94%and a specificity of 91.32%.Conclusions CVP-end and CVP-mean have statistical discrepancies in specific clinical scenarios.ΔCVP during the respiratory period is related to the variation of the two CVP methods.A highΔCVP indicates a poor agreement between these two methods,whereas a lowΔCVP indicates a good agreement between these two methods. 展开更多
关键词 central venous pressure monitor digital display monitor cursor-line display respiration
下载PDF
Improvement of Methane Production from Corn Stalk for Whole Slurry Anaerobic Co-digestion Under Hydrothermal Wastewater Pretreatment
6
作者 Sun Yong Wang Ze-hao +3 位作者 Qu Jing-bo Cao Guang-li Zheng Guo-xiang Sun Jia-zheng 《Journal of Northeast Agricultural University(English Edition)》 CAS 2023年第1期44-55,共12页
Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,... Corn stalk hydrothermal wastewater(CSHW)was used as a pretreatment for whole-slurry anaerobic co-digestion instead of conventional acid pretreatment.CSHW pretreatment was conducted at 20℃,35℃and 50℃for 3,6 and 9 h,after which all experimental groups were digested at 35℃for 24 days.This pretreatment method efficiently broke the lignocellulose structure of the corn stalk.Different from the volatile fatty acids(VFAs)content,the pH and RS contents were relatively higher than those of the control during the pretreatment process.Furthermore,the highest methane production[185.03 mL•g-1 VS(volatile solid)]was achieved at 55.46%under 35℃in 6 h,which was higher than that of the normal corn stalk anaerobic digestion.The VFAs contents and pH increased compared to CK upon the addition of NaOH to adjust pH,and the RS content also increased slightly due to the degradability of lignocellulose during the whole-slurry anaerobic co-digestion.This work provided a potential method to sustainably treat wastewater and improve fermentation performance. 展开更多
关键词 PRETREATMENT anaerobic co-digestion corn stalk hydrothermal wastewater corn stalk
下载PDF
Density Functional Theory Study of Marine Polybrominated Diphenyl Ethers in Anaerobic Degradation
7
作者 XU Xiang MAN Miaomiao +3 位作者 SUN Qinxing LIU Qingzhi WU Kechen YANG Dengfeng 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第5期1353-1360,共8页
Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway... Polybrominated diphenyl ethers(PBDEs)are a kind of serious pollutants in the ocean.Biodegradation is considered as an economical and safe way for PBDEs removal and reductive debromination dominates the initial pathway of anaerobic degradation.On the basis of experimental study,Octa-BDE 197,Hepta-BDE 183,Hexa-BDE 153,Penta-BDE 99 and Tetra-BDE 47 were selected as the initial degradation objects,and their debromination degradation were studied using density functional theory.The structures were optimized by Gaussian 09 program.Furthermore,the molecular orbitals and charge distribution were analyzed.All C-Br bond dissociation energies at different positions including ortho,meta and para bromine atoms were calculated and the sequence of debromination was obtained.There is a close relationship between molecular structure,charge,molecular orbital and C-Br bond.All PBDEs exhibited similar debromination pathways with preferential removal of meta and para bromines. 展开更多
关键词 polybrominated diphenyl ethers reductive debromination anaerobic degradation density functional theory bond dissociation energies
下载PDF
Effects of Potassium Ferrate and Low-Temperature Thermal Hydrolysis Co-Pretreatment on the Hydrolysis and Anaerobic Digestion Process of Waste Activated Sludge
8
作者 MA Yingpeng HAO Di +3 位作者 YAO Shuo ZHANG Dahai LI Xianguo FENG Lijuan 《Journal of Ocean University of China》 SCIE CAS CSCD 2023年第6期1583-1591,共9页
This study evaluated the effect of potassium ferrate(PF)and low-temperature thermal hydrolysis co-pretreatment on the promotion of sludge hydrolysis process and the impact on acid production in the subsequent anaerobi... This study evaluated the effect of potassium ferrate(PF)and low-temperature thermal hydrolysis co-pretreatment on the promotion of sludge hydrolysis process and the impact on acid production in the subsequent anaerobic digestion process.The analytical investigations showed that co-pretreatment significantly facilitated the hydrolysis process of the sludge and contributed to the accumulation of short-chain fatty acids(SCFAs).The pretreatment conditions under the optimal leaching of organic matter from sludge were hydrothermal temperature of 75℃,hydrothermal treatment time of 12 h,and PF dosage of 0.25 g g^(−1)TSS(total suspended solids),according to the results of orthogonal experiments.By pretreatment under proper conditions,the removal rate of soluble chemical oxygen demand(SCOD)achieved 71.8%at the end of fermentation and the removal rate of total phosphorus(TP)was 69.1%.The maximum yield of SCFAs was 750.3 mg L^(−1),7.45 times greater than that of the blank group.Based on the analysis of the anaerobic digestion mechanism,it was indicated that the co-pretreatment could destroy the floc structure on the sludge surface and improve organic matter dissolving,resulting in more soluble organic substances for the acidification process.Furthermore,microbial community research revealed that the main cause of enhanced SCFAs generation was an increase in acidogenic bacteria and a reduction of methanogenic bacteria. 展开更多
关键词 waste activated sludge potassium ferrate low-temperature thermal hydrolysis anaerobic digestion short-chain fatty acids
下载PDF
Heartbeat and Respiration Rate Prediction Using Combined Photoplethysmography and Ballisto Cardiography
9
作者 Valarmathi Ramasamy Dhandapani Samiappan RRamesh 《Intelligent Automation & Soft Computing》 SCIE 2023年第5期1365-1380,共16页
Owing to the recent trends in remote health monitoring,real-time appli-cations for measuring Heartbeat Rate and Respiration Rate(HARR)from video signals are growing rapidly.Photo Plethysmo Graphy(PPG)is a method that ... Owing to the recent trends in remote health monitoring,real-time appli-cations for measuring Heartbeat Rate and Respiration Rate(HARR)from video signals are growing rapidly.Photo Plethysmo Graphy(PPG)is a method that is operated by estimating the infinitesimal change in color of the human face,rigid motion of facial skin and head parts,etc.Ballisto Cardiography(BCG)is a non-surgical tool for obtaining a graphical depiction of the human body’s heartbeat by inducing repetitive movements found in the heart pulses.The resilience against motion artifacts induced by luminancefluctuation and the patient’s mobility var-iation is the major difficulty faced while processing the real-time video signals.In this research,a video-based HARR measuring framework is proposed based on combined PPG and BCG.Here,the noise from the input video signals is removed by using an Adaptive Kalmanfilter(AKF).Three different algorithms are used for estimating the HARR from the noise-free input signals.Initially,the noise-free sig-nals are subjected to Modified Adaptive Fourier Decomposition(MAFD)and then to Enhanced Hilbert vibration Decomposition(EHVD)andfinally to Improved Var-iation mode Decomposition(IVMD)for attaining three various results of HARR.The obtained values are compared with each other and found that the EHVD is showing better results when compared with all the other methods. 展开更多
关键词 Heartbeat rate and respiration rate PHOTOPLETHYSMOGRAPHY BALLISTOCARDIOGRAPHY adaptive kalmanfilter
下载PDF
Relation between anthropometric variations and resting energy expenditure,VO_(2) max and anaerobic capacity of young,healthy individuals-an update
10
作者 Savarna Kumari Madhusudan Tiwari 《TMR Non-Drug Therapy》 2023年第1期40-46,共7页
Anthropometric variations can affect resting energy expenditure,VO_(2) max and anaerobic capacity of young,healthy individuals.Studies have shown that body fat percentage,weight,and height can all affect the three mea... Anthropometric variations can affect resting energy expenditure,VO_(2) max and anaerobic capacity of young,healthy individuals.Studies have shown that body fat percentage,weight,and height can all affect the three measures.The study aimed to study VO_(2) max and 24-hour thermogenesis measures in predominantly sedentary individuals and weight changes afterwards.VO_(2) max-associated research shows that taller individuals tend to have higher VO_(2) max levels compared to shorter individuals.This could be because taller individuals have a larger lung capacity and greater oxygen delivery to the muscles.Weight can also affect VO_(2) max,as heavier individuals tend to have higher VO_(2) max levels than lighter individuals.Weight is also associated with resting energy expenditure,as heavier individuals tend to have a higher resting energy expenditure than lighter individuals.The purpose of this study was to conduct a systematic review of the existing literature related to resting energy expenditure and metabolic effects of VO_(2) max,and anaerobic capacity in sedentary active adults of anthropometric variations.Several studies have recently examined the possibility of improving aerobic and metabolic functions ensuring cardiorespiratory fitness within the population of anthropometric variations.Everyday physical activity and heredity ability influenced mainly the gold standard measuring tool for cardiorespiratory fitness,VO_(2) max,predicting mortality and morbidity.Weight gain has also been shown to be associated with lower cardiorespiratory fitness,regardless of physical activity levels.The VO_(2) max may have a different effect on energy balance apart from physical activity’s energy expenditure(EE),possibly by affecting the resting metabolic rate(RMR)or triggering a common mechanism associated with diet-induced thermogenesis.Weight change is predicted by sedentary energy expenditure,but directly measured VO_(2) max does not appear to be correlated with weight change.The relationship between resting energy expenditure,VO_(2) max,and anaerobic capacity in individuals is complex.Resting energy expenditure is directly related to anaerobic capacity,as it is an indicator of the body’s ability to work anaerobically.VO_(2) max is also related to anaerobic capacity,as it reflects the body’s maximal aerobic power.However,the strength of this relationship is not known.Overall,both resting energy expenditure and VO_(2) max are important determinants of anaerobic capacity in individuals and are worth considering when evaluating an individual’s anaerobic potential. 展开更多
关键词 BMI body mass index VO_(2)max anaerobic capacity
下载PDF
柔性可穿戴湿敏传感器制备及呼吸检测实验
11
作者 张冬至 周兰娟 +2 位作者 徐振原 朱华建 刘希臣 《实验技术与管理》 CAS 北大核心 2024年第3期192-196,共5页
该文以壳聚糖/导电炭黑复合薄膜作为敏感层,构建了高性能湿度传感器,并研究了传感器件微结构薄膜对呼吸检测敏感的机理。该文展开实验测试了传感器的湿度及呼吸响应特性,使用灵敏度、响应恢复特性、重复性等参数评价传感器性能,同时基于... 该文以壳聚糖/导电炭黑复合薄膜作为敏感层,构建了高性能湿度传感器,并研究了传感器件微结构薄膜对呼吸检测敏感的机理。该文展开实验测试了传感器的湿度及呼吸响应特性,使用灵敏度、响应恢复特性、重复性等参数评价传感器性能,同时基于LabVIEW技术实现了湿敏/呼吸信号的实时读取与处理、单片机与电脑终端通信、呼吸波形显示等功能。该检测平台成本低、易操作,为传感器检测技术的实际应用提供了借鉴,同时可促进学生对柔性可穿戴传感器检测实验与应用的深度理解,有效提升课堂教学效果和学生的学习积极性。 展开更多
关键词 呼吸检测 可穿戴 单片机 湿度传感器 显示界面
下载PDF
凋落物处理对华山松人工林土壤呼吸的影响
12
作者 崔鸿侠 胡文杰 +3 位作者 潘磊 唐万鹏 黄金莲 胡琛 《中南林业科技大学学报》 CAS CSCD 北大核心 2024年第2期91-97,共7页
【目的】通过探讨凋落物添加和去除处理对土壤呼吸速率的影响,为人工林土壤碳库管理提供理论依据。【方法】以神农架林区华山松人工林为研究对象,2021年4月—2022年3月通过设置对照(CK)、凋落物去除(LR)和凋落物添加(LA)3种处理,采用Li-... 【目的】通过探讨凋落物添加和去除处理对土壤呼吸速率的影响,为人工林土壤碳库管理提供理论依据。【方法】以神农架林区华山松人工林为研究对象,2021年4月—2022年3月通过设置对照(CK)、凋落物去除(LR)和凋落物添加(LA)3种处理,采用Li-8100A土壤碳通量测量系统测定土壤呼吸速率和土壤温湿度,研究土壤呼吸速率对凋落物处理的响应规律。【结果】1)3种处理间的土壤温度和土壤含水量均无显著差异(P>0.05),土壤呼吸速率与土壤温度的变化趋势一致,最大值均出现在7月,最小值均出现在2月;2)3种处理下土壤呼吸速率的年平均值为LA(2.17μmol·m^(-2)·S^(-1))>CK(1.69μmol·m^(-2)·S^(-1))>LR(1.25μmol·m^(-2)·S^(-1)),与对照相比,凋落物去除使土壤呼吸速率年均降低了26.02%,凋落物添加使土壤呼吸速率年均提高了29.48%;3)不同凋落物处理的土壤呼吸速率与土壤温度均呈极显著正相关(P<0.01),土壤温度分别解释了3种处理下土壤呼吸速率97.31%、99.18%和95.37%的变异。而土壤呼吸速率与土壤含水量相关性不显著(P>0.05),华山松人工林土壤呼吸速率的主要影响因子是土壤温度;4)土壤呼吸温度敏感性指数(Q10)为CK(2.98)>LR(2.91)>LA(2.88),凋落物去除和添加处理均降低了土壤呼吸温度敏感性。【结论】凋落物输入量的改变对土壤呼吸速率具有重要影响,且不同处理方式对土壤呼吸影响程度不一致。 展开更多
关键词 华山松人工林 凋落物 土壤呼吸 土壤温度 土壤含水量
下载PDF
水分及秸秆覆盖对夏玉米土壤呼吸及碳平衡的影响
13
作者 张笑培 常晓 +2 位作者 杨慎骄 王和洲 周新国 《灌溉排水学报》 CAS CSCD 2024年第1期1-8,共8页
【目的】充分发挥秸秆覆盖与适宜灌溉对作物增产及土壤固碳减排的各自优势及二者协同效应,建立减排增产节水的高效农田管理模式。【方法】以豫东地区夏玉米为研究对象,设置覆盖方式(秸秆覆盖(S)和无覆盖(N))和灌水控制下限(田间持水率(... 【目的】充分发挥秸秆覆盖与适宜灌溉对作物增产及土壤固碳减排的各自优势及二者协同效应,建立减排增产节水的高效农田管理模式。【方法】以豫东地区夏玉米为研究对象,设置覆盖方式(秸秆覆盖(S)和无覆盖(N))和灌水控制下限(田间持水率(FC)的50%(W1)、60%(W2)、70%(W3)、80%(W4))两因素试验,系统研究水分及秸秆覆盖对土壤碳排放总量、土壤微生物异氧呼吸碳释放量和农田净初级生产力固碳量影响。【结果】秸秆覆盖和灌水增加了土壤呼吸、农田净初级生产力固碳量和土壤微生物异氧呼吸碳释放量,其中SW4处理均最高,与SW3、NW4处理差异不显著。SW3处理净生态系统生产力(NEP)和碳排放效率均最高,分别较其他处理高3.99%~245.74%和2.35%~138.80%。与SW4处理相比,SW3处理在节约灌水的前提下,农田净生态系统生产力提高2.99%,碳排放效率提高2.35%。【结论】综合考虑农田净生态系统生产力和碳排放效率,SW3处理(灌水控制下限为70%FC+秸秆覆盖)可以作为节水、减排、增产的农田管理模式。 展开更多
关键词 秸秆覆盖 土壤水分 夏玉米 土壤呼吸 碳平衡
下载PDF
多导睡眠图辅助药物诱导睡眠内镜正压呼吸机压力滴定的操作要点
14
作者 刘丹 万南生 +4 位作者 王杰 句仁华 谢巍 田羽 冯靖 《天津医药》 CAS 2024年第3期324-326,共3页
识别阻塞性睡眠呼吸暂停(OSA)患者上气道阻塞和狭窄情况对于决定后续治疗方案至关重要。药物诱导睡眠内镜(DISE)是可提供OSA患者麻醉后“睡眠”状态时上呼吸道解剖学结构的三维可视化评估技术,通过内镜安全而快速地观察上呼吸道阻塞及... 识别阻塞性睡眠呼吸暂停(OSA)患者上气道阻塞和狭窄情况对于决定后续治疗方案至关重要。药物诱导睡眠内镜(DISE)是可提供OSA患者麻醉后“睡眠”状态时上呼吸道解剖学结构的三维可视化评估技术,通过内镜安全而快速地观察上呼吸道阻塞及塌陷的动态情况,为制定手术方案、进行气道正压(PAP)干预治疗等提供重要参考。在多导睡眠图(PSG)辅助下,DISE对优化OSA个体化治疗方案发挥重要作用。该文介绍了多导睡眠图辅助药物诱导睡眠内镜正压呼吸机压力滴定的操作要点。 展开更多
关键词 睡眠呼吸暂停综合征 正压呼吸 多道睡眠描记术 药物诱导睡眠内镜
下载PDF
生草对贵州高海拔区苹果园土壤呼吸及水热环境的影响
15
作者 冯建文 韩秀梅 +3 位作者 蒙小玉 杨华 李顺雨 吴亚维 《贵州农业科学》 CAS 2024年第4期81-89,共9页
【目的】探明西南冷凉高地苹果产区果园不同草种覆盖条件土壤呼吸特征及其与土壤水热的关系,为筛选苹果园适宜生草类型提供参考依据。【方法】设置鼠茅草(Vulpia myuros)、鸭茅(Dactylis glomerata)、黑麦草(Lolium perenne)、白三叶(Tr... 【目的】探明西南冷凉高地苹果产区果园不同草种覆盖条件土壤呼吸特征及其与土壤水热的关系,为筛选苹果园适宜生草类型提供参考依据。【方法】设置鼠茅草(Vulpia myuros)、鸭茅(Dactylis glomerata)、黑麦草(Lolium perenne)、白三叶(Trifolium repens)、光叶紫花苕(Vicia villosa)、鼠茅草+鸭茅+白三叶混播、黑麦草+白三叶+鸭茅混播、鼠茅草+黑麦草+白三叶混播8个苹果园生草处理,以清耕作对照(CK),利用LI-6400XT便携式光合测定系统配套使用土壤呼吸气室(6400-09)测定果园土壤呼吸速率,采用非线性回归和指数模型,分析不同生草处理对土壤呼吸与土壤水热环境的影响。【结果】生草显著提高果园土壤呼吸速率,较清耕提高0.07%~256.39%,其中,黑麦草+白三叶+鸭茅混播处理提高幅度最高。生草覆盖显著提高土壤水分保持能力,对0~20 cm土层的影响最明显,相同月份不同生草处理间土壤水分差异明显,生草混播处理提高土壤水分能力优于生草单播处理。生草覆盖后显著降低夏季(5—7月)表层土壤(0~5 cm)温度。不同生草覆盖处理土壤水分含量与土壤呼吸以二次函数拟合效果最佳,决定系数R 2在0.242~0.989,拟合度较高。各生草处理土壤温度与土壤呼吸速率呈指数函数关系,0~5 cm和5~10 cm土层拟合模型决定系数R 2平均值高于10~15 cm和15~20 cm土层。土壤温度、水分及二者的交互作用对土壤呼吸的协同影响高于土壤单因子的影响。【结论】苹果园生草处理可显著提高土壤呼吸速率,显著增加0~20 cm土层土壤的水分保持能力,降低果园夏季表层土壤(0~5 cm)温度,有效改善苹果根系生长环境,有利于树体发育。不同生草模式中以黑麦草+白三叶+鸭茅混播处理效果最优。 展开更多
关键词 苹果园 生草 土壤呼吸 水热环境 高海拔区 贵州
下载PDF
AIM2炎性小体与胸腔镜下肺叶切除术肿瘤患者单肺通气相关肺损伤的关系及预测价值
16
作者 宗宇红 王磊 +4 位作者 杜小兵 尹翔宇 许紫舸 王曼 朱蕾 《西部医学》 2024年第1期72-78,共7页
目的 评价肺组织AIM2炎性小体与胸腔镜下肺叶切除术肿瘤患者单肺通气相关肺损伤的关系及预测价值。方法 选取2019年9月—2021年12月在保定市第一中心医院和河北大学附属医院择期全麻下拟行胸腔镜下行肺叶切除术的肺癌手术全麻患者750例... 目的 评价肺组织AIM2炎性小体与胸腔镜下肺叶切除术肿瘤患者单肺通气相关肺损伤的关系及预测价值。方法 选取2019年9月—2021年12月在保定市第一中心医院和河北大学附属医院择期全麻下拟行胸腔镜下行肺叶切除术的肺癌手术全麻患者750例,术中切除肺叶时取远离病变处>8 cm以上肺组织。采用Western blot法检测肺组织黑色素瘤缺如因子2(AIM2),凋亡相关微粒蛋白(ASC)和半胱天冬酶-1前体(pro-Caspase1)的表达。采用急性肺损伤/急性呼吸窘迫综合征诊断和治疗指南提出的诊断标准判断是否发生单肺通气相关肺损伤。采用Logistic回归分析筛选单肺通气相关肺损伤的危险因素。采用ROC曲线和精确率召回率曲线(PR曲线)预测相关危险因素诊断单肺通气相关肺损伤的准确程度。结果 最终纳入678例胸腔镜下肺癌手术患者。根据患者是否发生术后单肺通气相关肺损伤,将患者分为单肺通气肺损伤组(I组,115例)和单肺通气非肺损伤组(NI组,563例)。术后单肺通气肺损伤发生率是16.9%。I组和NI组相比较,年龄、FEV_(1)/FVC、单肺通气时间、手术时间、AIM2、ASC和pro-Caspase1的差异有统计学意义(P<0.05)。多因素Logistic回归分析结果显示:年龄、FEV_(1)/FVC、单肺通气时间、AIM2、ASC和pro-Caspase1是单肺通气肺损伤的危险因素,并且通过二次敏感性分析结果发现,AIM2、ASC和pro-Caspase1蛋白表达仍是发生术后单肺通气肺损伤独立危险因素。ROC曲线和PR曲线分析显示,AIM2炎性小体预测单肺通气相关肺损伤的发生有较高的准确性。结论 肺组织AIM2炎性小体升高是胸腔镜下肺叶切除术肺癌患者单肺通气相关肺损伤的独立危险因素,且肺组织AIM2炎性小体可准确预测单肺通气相关肺损伤。 展开更多
关键词 呼吸/人工 呼吸窘迫综合征/成人 黑色素瘤缺如因子2 凋亡相关颗粒样蛋白 半胱氨酸天冬氨酸蛋白酶1
下载PDF
减氮施炭对温室膜下滴灌黄瓜土壤呼吸和氮素气态损失的影响
17
作者 陈涛涛 刘晓晗 +2 位作者 孟凡超 张妮子 迟道才 《沈阳农业大学学报》 CAS CSCD 北大核心 2024年第1期9-20,共12页
为降低温室蔬菜过量施氮的不利影响,明确减氮施炭条件下温室膜下滴灌黄瓜土壤呼吸和氮素气态排放特征,以不覆膜不施炭(CK)为对照,设置覆膜(M)、覆膜施炭(MB)、覆膜施炭减氮(MBN_(80%))共4个处理,对覆膜条件下减氮施炭处理对黄瓜产量、... 为降低温室蔬菜过量施氮的不利影响,明确减氮施炭条件下温室膜下滴灌黄瓜土壤呼吸和氮素气态排放特征,以不覆膜不施炭(CK)为对照,设置覆膜(M)、覆膜施炭(MB)、覆膜施炭减氮(MBN_(80%))共4个处理,对覆膜条件下减氮施炭处理对黄瓜产量、耗水量、土壤养分动态、土壤呼吸、N_(2)O排放和氨挥发的影响进行探讨。结果表明:与CK相比,M可降低温室膜下滴灌黄瓜全生育期耗水量20.95%,提高水分利用效率41.03%,降低0~20 cm表层土铵态氮48.12%,降低全生育期氨挥发32.35%、N_(2)O排放量14.34%和CO_(2)排放量12.68%(<0.05)。施炭后,与CK相比,MB可降低耗水量28.37%,提高水分利用效率55.60%,降低表层土铵态氮30.0%,提升硝态氮12.37%,有机质56.28%,降低氨挥发36.68%、N_(2)O排放18.64%,但却显著增大了CO_(2)排放4.66%(p<0.05)。同M对比,MB可在M基础上,进一步提升表层土有机质和铵态氮含量,降低氨挥发,但促进了CO_(2)排放。覆膜施炭减氮20%后,与CK相比,MBN_(80%)可增产25.47%,降低耗水量32.43%,提升水分生产率72.67%,降低表层土铵态氮56.33%,增加有机质51.72%,降低氨挥发40.48%、N_(2)O排放20.79%(p<0.05)。CK全生育期全球增温潜势(global warming potential,GWP)和活性氮排放分别为13.57 t·CO_(2)-eq·hm^(-2)和6.54 kg·hm^(-2),M可显著降低GWP(14.15%)和活性氮排放(27.37%);在M基础上施炭,将进一步降低活性氮排放,但导致GWP显著增大;而在MB基础上减氮20%,可同时显著降低GWP和活性氮排放(p<0.05)。与CK相比,MBN80%在通过施炭20 t·hm^(-2),减氮20%条件下,实现增产25.47%,降低耗水量32.43%,增加有机质51.72%,增加收入17.52%,降低活性氮排放35.32%和GWP 2.28%,也可在MB的基础上,进一步实现增产,降低氨挥发,并破解M和MB处理CO_(2)排放增大的问题(p<0.05)。研究揭示了减氮施炭条件下温室膜下滴灌黄瓜土壤呼吸和氮素气态排放特征,为实现温室蔬菜节水增产固碳减排提供理论依据和技术支撑。 展开更多
关键词 温室 生物炭 氨挥发 氧化亚氮 土壤呼吸 膜下滴灌
下载PDF
基于文献计量学分析的剩余污泥厌氧消化预处理研究进展
18
作者 杨杨阳 朱震霆 +4 位作者 杨翠萍 李世豪 张舒 范秀磊 万蕾 《广西师范大学学报(自然科学版)》 CAS 北大核心 2024年第2期16-29,共14页
污水处理过程中会产生大量剩余污泥,对剩余污泥进行厌氧消化处理既能减少环境污染,又能回收能源。本文基于文献计量学方法和可视化工具,对中国知网(CNKI)数据库和Web of Science核心数据库2003—2023年间收录的相关文章进行梳理,对当前... 污水处理过程中会产生大量剩余污泥,对剩余污泥进行厌氧消化处理既能减少环境污染,又能回收能源。本文基于文献计量学方法和可视化工具,对中国知网(CNKI)数据库和Web of Science核心数据库2003—2023年间收录的相关文章进行梳理,对当前剩余污泥厌氧消化处理的研究热点领域进行比较分析,并对剩余污泥成分、理化特性和厌氧消化预处理方法进行文献综述。研究表明,剩余污泥厌氧消化产生甲烷是该处理技术的重要目的,预处理技术与剩余污泥处理存在重要关联性;物理、化学和生物酶等不同预处理技术对产沼气量有较大影响,针对污泥本身的理化性质而采用更加合适的预处理技术,能够在节约成本的同时进一步提高剩余污泥资源化利用程度。 展开更多
关键词 剩余污泥 厌氧消化 甲烷 预处理 资源化利用
下载PDF
无创机械通气联合呼吸训练在AECOPD合并呼吸衰竭患者中的应用评价
19
作者 叶宁 罗淼 +1 位作者 秦燕 唐丽娟 《中国医学创新》 CAS 2024年第6期27-31,共5页
目的:探讨无创机械通气联合呼吸训练对慢性阻塞性肺疾病急性加重期(AECOPD)合并呼吸衰竭患者的效果。方法:前瞻性纳入2019年2月—2022年2月桂林医学院附属医院急诊科收治的AECOPD合并呼吸衰竭患者共67例,采用随机数字表法将患者分为两... 目的:探讨无创机械通气联合呼吸训练对慢性阻塞性肺疾病急性加重期(AECOPD)合并呼吸衰竭患者的效果。方法:前瞻性纳入2019年2月—2022年2月桂林医学院附属医院急诊科收治的AECOPD合并呼吸衰竭患者共67例,采用随机数字表法将患者分为两组。对照组(n=33)接受间断无创机械通气治疗,观察组(n=34)在对照组基础上增加主动呼吸训练(包括上肢弹力带阻抗训练、缩唇腹式呼吸、呼吸训练器使用)。记录两组2 d内撤机成功率、不良反应发生率,比较两组氧合指数(OI)、动脉血二氧化碳分压(PaCO_(2))、改良版英国医学研究委员会(mMRC)呼吸困难问卷分级、呼吸频率(RR)、自主呼吸潮气量。结果:对照组2 d内撤机成功率为60.6%,观察组为82.4%,观察组的撤机成功率高于对照组(P<0.05);观察组咳痰乏力、呼吸疲劳发生率均低于对照组(P<0.05);与治疗前相比,两组患者治疗2 d后的OI和PaCO_(2)均有显著改善,差异均有统计学意义(P<0.05);治疗2 d后,观察组PaCO_(2)低于对照组(P<0.05),但两组OI比较,差异无统计学意义(P>0.05);与治疗前相比,两组患者治疗2 d后的mMRC呼吸困难问卷分级和RR均有明显下降,自主呼吸潮气量均有明显提升,差异均有统计学意义(P<0.05);治疗2 d后,两组mMRC呼吸困难问卷分级和RR比较,差异均无统计学意义(P>0.05),但观察组患者自主呼吸潮气量明显高于对照组(P<0.05)。结论:AECOPD合并呼吸衰竭患者进行无创机械通气联合呼吸训练,能有效改善呼吸肌疲劳,增加肺通气,提高撤机成功率。 展开更多
关键词 无创机械通气 呼吸训练 慢性阻塞性肺疾病急性加重期 呼吸衰竭
下载PDF
减氮配施生物炭对北疆小麦产量品质及固碳减排的影响
20
作者 杨卫君 杨梅 +4 位作者 郭颂 宋世龙 陈雨欣 王森 赵红梅 《农业工程学报》 EI CAS CSCD 北大核心 2024年第4期104-111,共8页
为研究生物炭在北疆灌区农田应用的稳产增产及固碳减排综合潜力,探索农田氮肥优化施用途径,该研究于2021年4月—2022年7月在新疆奇台设置常规施氮(N1:300 kg/hm^(2))、氮肥减量15%(N2:255 kg/hm^(2))、氮肥减量30%(N3:210 kg/hm^(2))、... 为研究生物炭在北疆灌区农田应用的稳产增产及固碳减排综合潜力,探索农田氮肥优化施用途径,该研究于2021年4月—2022年7月在新疆奇台设置常规施氮(N1:300 kg/hm^(2))、氮肥减量15%(N2:255 kg/hm^(2))、氮肥减量30%(N3:210 kg/hm^(2))、单施生物炭(B:20 t/hm^(2))、常规施氮+生物炭(N1B)、氮肥减量15%+生物炭(N2B)、氮肥减量30%+生物炭(N3B)7个处理,分析两季小麦(春小麦、冬小麦)种植期间不同处理下麦田土壤有机碳含量、土壤呼吸速率、小麦品质及产量变化。结果表明,与单施常规氮肥相比,施用生物炭后土壤总有机碳(soil total organic carbon,SOC)、活性有机碳(active organic carbon,AOC)、碳库管理指数(carbon pool management index,CPMI)和小麦产量、籽粒水分及蛋白(干基)含量均呈提高趋势。综合表现以氮肥减量15%配施生物炭(N2B)处理最优,较氮肥常规单施(N1)相比,AOC、SOC均有显著提高,2 a产量分别显著提高22.12%、36.17%(P<0.05)。与常规施氮相比,氮肥减量15%配施生物炭(N2B)处理下,2022年冬小麦蛋白(干基)、面筋(湿基)、Zeleny沉降值均有提高,而2021年各处理间差异不显著(P>0.05)。同时,除单施生物炭(B)处理(2021年)和除单施生物炭(B)及减氮15%(N2)处理外(2022年),其他处理下土壤CO_(2)累积排放量较单施常规氮肥均有所升高。综上,氮肥减量15%(255 kg/hm^(2))配施20 t/hm^(2)生物炭时其农田土壤固碳减排效果及小麦产量品质综合表现较好,建议作为北疆灌区麦田氮肥优化配施生物炭的理想施肥方案。 展开更多
关键词 生物炭 土壤 呼吸 有机碳 小麦 产量 品质
下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部