期刊文献+
共找到1,307篇文章
< 1 2 66 >
每页显示 20 50 100
Mechanisms behind elevated serum levels of plasminogen activator inhibitor-1 in frontotemporal lobar degeneration
1
作者 Francesco Angelucci Jakub Hort 《Neural Regeneration Research》 SCIE CAS 2025年第8期2317-2318,共2页
Frontotemporal lobar degeneration(FTLD)is a form of progressive dementia characterized by degeneration of the frontal and temporal lobes of the brain.This pathology involves a series of cognitive,behavioral,and neurol... Frontotemporal lobar degeneration(FTLD)is a form of progressive dementia characterized by degeneration of the frontal and temporal lobes of the brain.This pathology involves a series of cognitive,behavioral,and neurological symptoms that influence personality,decision-making ability,and language. 展开更多
关键词 DEGENERATION elevateD PATHOLOGY
下载PDF
Response of Rice Cultivars to Elevated Air Temperature and Soil Amendments: Implications towards Climate Change Adaptations and Mitigating Global Warming Potentials
2
作者 Muhammad Aslam Ali S. K. Md. Fazlay Rabbi +8 位作者 Md. Abdul Baten Hafsa Jahan Hiya Shah Tasdika Auyon Md. Shamsur Rahman Deboki Kundu Khairul Amin Sanjit Chandra Barman Tanver Hossain Fariha Binte Nobi 《American Journal of Climate Change》 2024年第3期406-426,共21页
Global mean surface air temperature is expected to increase 1.1˚C - 6.4˚C by the end of 21st century which may affect rice productivity and methane emissions in the future climate. This experiment was conducted to inv... Global mean surface air temperature is expected to increase 1.1˚C - 6.4˚C by the end of 21st century which may affect rice productivity and methane emissions in the future climate. This experiment was conducted to investigate the response of rice cultivars to elevated air temperature (+1.5˚C higher than ambient) and soil amendments in regards to rice yield, yield scaled methane emissions and global warming potentials. The experimental findings revealed that replacement of inorganic fertilizers (20% - 40% of recommended NPKS) with Vermicompost, Azolla biofertilizer, enriched sugarcane pressmud, rice husk biochar and silicate fertilization increased rice yield 13.0% - 23.0%, and 11.0% - 19.0% during wet aman and dry boro season, respectively. However, seasonal cumulative CH4 fluxes were decreased by 9.0% - 25.0% and 5.0% - 19.0% during rainfed wet aman and irrigated dry boro rice cultivation, respectively with selected soil amendments. The maximum reduction in seasonal cumulative CH4 flux (19.0% - 25.0%) was recorded with silicate fertilization and azolla biofertilizer amendments (9.0% - 13.0%), whereas maximum grain yield increment 10.0 % - 14.0% was found with Vermicompost and Sugarcane pressmud amendments compared to chemical fertilization (100% NPKS) treated soils at ambient air temperature. However, rice grain yield decreased drastically 43.0% - 50.0% at elevated air temperature (3˚C higher than ambient air temperature), eventhough accelerated the total cumulative CH4 flux as well as GWPs in all treatments. Maximum seasonal mean GWPs were calculated at 391.0 kg CO2 eq·ha−1 in rice husk biochar followed by sugarcane pressmud (mean GWP 387.0 kg CO2 eq·ha−1), while least GWPs were calculated at 285 - 305 kg CO2 eq·ha−1 with silicate fertilizer and Azolla biofertilizer amendments. Rice cultivar BRRI dhan 87 revealed comparatively higher seasonal cumulative CH4 fluxes, yield scaled CH4 flux and GWPs than BRRI dhan 71 during wet aman rice growing season;while BRRI dhan 89 showed higher cumulative CH4 flux and GWPs than BINA dhan 10 during irrigated boro rice cultivation. Conclusively, inorganic fertilizers may be partially (20% - 40% of the recommended NPKS) replaced with Vermicompost, azolla biofertilizer, silicate fertilizer and enriched sugarcane pressmud compost for sustainable rice production and decreasing GWPs under elevated air temperature condition. 展开更多
关键词 Rice Paddy Soil Amendments CH4 Flux GWPs elevated Air Temperature
下载PDF
Ascending aorta dilatation reduces the influence of elevated pulse pressure on left ventricular hypertrophy:findings from a Chinese elderly hypertensive population
3
作者 Yu-Qi JIANG Huan-Rui ZHANG +3 位作者 Bo-Nan LIU Tian-Wen LI Jun-Feng JIANG Wen TIAN 《Journal of Geriatric Cardiology》 SCIE CAS CSCD 2023年第2期100-108,共9页
OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retros... OBJECTIVE To determine the role of ascending aorta dilatation in the relationship between pulse pressure(PP)and left ventricular(LV)hypertrophy.METHODS A total of 1556 Chinese elderly hypertensive patients were retrospectively studied.Transthoracic echocardiography was used to obtain the aortic and cardiac structure measurements.In addition,brachial blood pressure was measured,and total arterial compliance,systemic vascular resistance,arterial elastance,and end-systolic LV elastance were calculated.The participants were divided into four groups according to the status of ascending aortic diameter and PP.RESULTS LV mass index increased in succession in the four groups,i.e.,the group with the normal aorta and lower PP,with the normal aorta and higher PP,with aortic dilatation and lower PP,and with aortic dilatation and higher PP(Ptrend<0.001).Total arterial compliance−1,arterial elastance,and end-systolic LV elastance were slightly higher in the individuals with normal aorta compared to those with aortic dilatation,regardless of PP being lower or higher(P<0.01).Compared to the group with the normal aorta and lower PP,individuals with aortic dilatation had a significantly increased multivariable adjusted risk of LV hypertrophy,and higher PP further exacerbated this risk[aortic dilatation with lower PP(OR=1.75,95%CI:1.01–3.04)and aortic dilatation with higher PP(OR=3.42,95%CI:2.03–5.77)].In the relation between PP and LV mass index(β=0.095,P<0.001),-41.3%of the total effect was attributable to mediation by ascending aortic diameter(P<0.0001).CONCLUSIONS In Chinese elderly patients with hypertension,ascending aorta dilatation could reduce the influence of elevated PP on LV hypertrophy. 展开更多
关键词 elevateD HYPERTENSIVE HYPERTROPHY
下载PDF
Shock response of cyclotetramethylene tetranitramine(HMX)single crystal at elevated temperatures
4
作者 Kai Ding Xin-Jie Wang +2 位作者 Zhuo-Ping Duan Yan-Qing Wu Feng-Lei Huang 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2023年第3期147-163,共17页
To investigate the shock response of cyclotetramethylene tetranitramine(HMX)single crystals at elevated temperatures(below the phase transition point),plate impact experiments at elevated temperatures were designed an... To investigate the shock response of cyclotetramethylene tetranitramine(HMX)single crystals at elevated temperatures(below the phase transition point),plate impact experiments at elevated temperatures were designed and conducted.The HMX/window interface particle velocities at temperatures of 300 K,373 K,and 423 K were measured by the velocity interferometry system for any reflector(VISAR)technique.To further analyze the related mesoscale deformation mechanisms,a nonlinear thermoelastic-viscoplastic model was developed,which considers thermal activation and phonon drag dislocation slip mechanisms.The proposed model could well reproduce the measured thermal hardening behavior of Hugoniot elastic limit(HEL)of HMX single crystals.At elevated temperatures,the reduced dislocation mobility was observed,which stems from both phonon scattering and radiative damping effects.Comparatively speaking,radiative damping contributes less than phonon scattering to thermal hardening behavior.The calibrated model was further used to predict shock response of HMX single crystals with different thicknesses at different initial temperatures.Both the stress relaxation and elastic precursor decrease with thickness are mainly due to the rapid dislocation generation.These insights shed light on the interplay between dislocation motion and dislocation generation in thermal hardening behavior,stress relaxation,and elastic precursor decay,which serves to reveal the mesoscale deformation mechanisms at elevated temperatures. 展开更多
关键词 DEFORMATION elevateD DISLOCATION
下载PDF
Plant N-acylethanolamines play a crucial role in defense and its variation in response to elevated CO_(2) and temperature in tomato
5
作者 Zhangjian Hu Junying Shi +3 位作者 Shuxian Feng Xiaodan Wu Shujun Shao Kai Shi 《Horticulture Research》 SCIE CSCD 2023年第1期207-219,共13页
The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Her... The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely unclear.Here,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae pv.tomato(Pst)DC3000 in tomato.The knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense response.Using exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense response.Elevated CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and temperature.The results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in tomato.These findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate. 展开更多
关键词 elevateD DEFENSE PLANT
下载PDF
Flow softening and dynamic recrystallization behavior of a Mg-Gd-Y-Nd-Zr alloy under elevated temperature compressions
6
作者 Yiping WU Yuzhen JIA +3 位作者 Sha Zhang Yu Liu Hanqing Xiong Gang Chen 《Journal of Magnesium and Alloys》 SCIE EI CAS CSCD 2023年第8期2891-2900,共10页
Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by opti... Flow softening behavior of a homogenized Mg-7Gd-4Y-1Nd-0.5Zr alloy under compression to a final strain of∼1.8 at elevated temperatures of 450∼550℃ and a constant strain rate of 2s^(−1) has been investigated by optical microscopy,scanning electron microscopy,electron back-scattered diffraction and transmission electron microscopy.The results show that true stress first rises to the peak point and then drops to the bottom value and increases again with further increasing strain at each temperature.Twinning dynamic recrystallization(DRX)and continuous DRX contribute to the formation of new fine grains at temperatures 450∼475℃ when the restoration is caused by both DRX and texture change due to extension twinning,resulting in the larger softening degrees compared with the softening effects owing to continuous DRX and discontinuous DRX at 500∼550℃ when twinning activation is suppressed.500℃ is the transition temperature denoting a significant decline in the contribution of twinning and TDRX to the strain with increasing temperature.The cuboid-shape phase exists in both homogenized and compressed samples,while the compositions are varied. 展开更多
关键词 Mg-Gd-Y alloy elevated temperature compression Flow softening Dynamic recrystallization
下载PDF
The contribution of root respiration of Pinus koraiensis seedlings to total soil respiration under elevated CO_2 concentrations 被引量:14
7
作者 刘颖 韩士杰 +3 位作者 李雪峰 周玉梅 张军辉 贾夏 《Journal of Forestry Research》 SCIE CAS CSCD 2004年第3期187-191,共5页
The impacts of elevated atmospheric CO2 concentrations (500 靘olmol-1and 700 靘olmol-1) on total soil respiration and the contribution of root respiration of Pinus koraiensis seedlings were investigated from May to Oc... The impacts of elevated atmospheric CO2 concentrations (500 靘olmol-1and 700 靘olmol-1) on total soil respiration and the contribution of root respiration of Pinus koraiensis seedlings were investigated from May to October in 2003 at the Research Station of Changbai Mountain Forest Ecosystems, Chinese Academy of Sciences, Jilin Province, China. After four growing seasons in top-open chambers exposed to elevated CO2, the total soil respiration and roots respiration of Pinus koraiensis seedlings were measured by a LI-6400-09 soil CO2 flux chamber. Three PVC cylinders in each chamber were inserted about 30 cm into the soil in-stantaneously to terminate the supply of current photosynthates from the tree canopy to roots for separating the root respiration from total soil respiration. Soil respirations both inside and outside of the cylinders were measured on June 16, August 20 and October 8, respectively. The results indicated that: there was a marked diurnal change in air temperature and soil temperature at depth of 5 cm on June 16, the maximum of soil temperature at depth of 5 cm lagged behind that of air temperature, no differences in temperature between treatments were found (P>0.05). The total soil respiration and soil respiration with roots severed showed strong diurnal and seasonal patterns. There was marked difference in total soil respiration and soil respiration with roots severed between treatments (P<0.01); Mean total soil respiration and contribution of root under different treatments were 3.26, 4.78 and 1.47 靘olm 2s-1, 11.5%, 43.1% and 27.9% on June 16, August 20 and October 8, respectively. 展开更多
关键词 Contribution of root respiration elevated CO2 Pinus koraiensis Root-severed technique Soil respiration
下载PDF
Effects of long-term elevated CO_2 on N_2-fixing,denitrifying and nitrifying enzyme activities in forest soils under Pinus sylvestriformis in Changbai Mountain 被引量:3
8
作者 郑俊强 韩士杰 +2 位作者 任飞荣 周玉梅 张岩 《Journal of Forestry Research》 SCIE CAS CSCD 2008年第4期283-287,共5页
A study was conducted to determine the effects of elevated CO2 on soil N process at Changbai Mountain in Jilin Province, northeastern China (42°24"N, 128°06"E, and 738 m elevation). A randomized complete... A study was conducted to determine the effects of elevated CO2 on soil N process at Changbai Mountain in Jilin Province, northeastern China (42°24"N, 128°06"E, and 738 m elevation). A randomized complete block design of ambient and elevated CO2 was established in an open-top chamber facility in the spring of 1999. Changpai Scotch pine (Pinus sylvestris var. sylvestriformis seeds were sowed in May, 1999 and CO2 fumigation treatments began after seeds germination. In each year, the exposure started at the end of April and stopped at the end of October. Soil samples were collected in June and August 2006 and in June 2007, and soil nitrifying, denitrifying and N2-fixing enzyme activities were measured. Results show that soil nitrifying enzyme activities (NEA) in the 5-10 cm soil layer were significantly increased at elevated CO2 by 30.3% in June 2006, by 30.9% in August 2006 and by 11.3% in June 2007. Soil denitrifying enzyme activities (DEA) were significantly decreased by elevated CO2 treatment in June 2006 (P 〈 0.012) and August 2006 (P 〈 0.005) samplings in our study; no significant difference was detected in June 2007, and no significant changes in N2-fixing enzyme activity were found. This study suggests that elevated CO2 can alter soil nitrifying enzyme and denitrifying enzyme activities. 展开更多
关键词 elevated CO2 forest soil nitrifying enzyme denitrifying enzyme N2-fixing enzyme
下载PDF
Dynamic behavior and fracture mode of TiAl intermetallics with different microstructures at elevated temperatures 被引量:2
9
作者 昝祥 贺跃辉 +1 位作者 汪洋 夏源明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2011年第1期45-51,共7页
Experimental studies were conducted on the tensile behaviors and fracture modes of TiAl(Ti-46.5Al-2Nb-2Cr) alloys with near gamma(NG) equiaxed and near lamellar(NL) microstructures over a temperature range from ... Experimental studies were conducted on the tensile behaviors and fracture modes of TiAl(Ti-46.5Al-2Nb-2Cr) alloys with near gamma(NG) equiaxed and near lamellar(NL) microstructures over a temperature range from room temperature to 840 ℃ and a strain rate range of 0.001-1 350 s-1.The results indicate that the alloys are both temperature and strain rate dependent and they have a similar dependence.The dynamic strength is higher than the quasi-static strength but almost insensitive to high strain rate range of 320-1 350 s-1.The brittle-to-ductile transition temperature(BDTT) increases with increasing strain rates.NG TiAl yields obviously,while NL TiAl does not.Below BDTT,as the temperature increases,the fracture modes of the two alloys change from planar cleavage fracture to a mixture of transgranular and intergranular fractures,and finally to totally intergranular fracture. 展开更多
关键词 TiAl intermetallics high strain rate elevated temperature character tensile properties fracture mode
下载PDF
Response of Photosynthesis, Growth, Carbon Isotope Discrimination and Osmotic Tolerance of Rice to Elevated CO_2 被引量:2
10
作者 彭长连 段俊 +2 位作者 林桂珠 陈贻竹 彭少麟 《Acta Botanica Sinica》 CSCD 2002年第1期76-81,共6页
Four rice ( Oryza sativa L.) cultivars 'IR72', 'Tesanai 2', 'Guichao 2' and 'IIyou 4480' were grown in two plastic house (15 m×3 m) with 35 μmol/mol and 60 μmol/mol CO 2 conc... Four rice ( Oryza sativa L.) cultivars 'IR72', 'Tesanai 2', 'Guichao 2' and 'IIyou 4480' were grown in two plastic house (15 m×3 m) with 35 μmol/mol and 60 μmol/mol CO 2 concentration which was controlled by computer. As compared with rice at ambient 35 μmol/mol CO 2, the changes in photosynthetic rate at elevated CO 2 showed up_regulation ('IR72' and 'Tesanai 2'), stable (unchanged) in 'Guichao 2' and down_regulation type ('IIyou 4480'). Growth rate, panicle weight, integrated water use efficiency (WUE) calculated from Δ 13 C and the capacity of scavenging DPPH · (1,1_diphenyl_2_picrylhydrazyl) free radical were increased at elevated CO 2. An increment in total biomass was observed in three cultivars by elevated CO 2, with the exception of 'IIyou 4480'. Ratios of panicle weight/total biomass were altered to different extents in tested cultivars by elevated CO 2. When leaf segments were subjected to PEG osmotic stress, the electrolyte leakage rate from leaves grown at elevated CO 2 was less than that at 35 μmol/mol CO 2. Those intraspecific variations of rice imply a possibility for selecting cultivars with maximal productivity and high tolerance to stresses adapted to elevated CO 2 in the future. 展开更多
关键词 rice cultivars elevated CO 2 PHOTOSYNTHESIS water use efficiency 13 C discrimination osmotic tolerance
下载PDF
Response of seedlings of different tree species to elevated CO_2 in Changbai Mountain 被引量:1
11
作者 王淼 李秋荣 +1 位作者 代力民 姬兰柱 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期112-116,共5页
Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadlea... Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2. 展开更多
关键词 elevated CO_2 Eco-physiological response Changbai Mountain
下载PDF
Response of seedlings of different tree species to elevated CO2 in Changbai Mountain 被引量:1
12
作者 王淼 李秋荣 +1 位作者 代力民 姬兰柱 《Journal of Forestry Research》 SCIE CAS CSCD 2003年第2期112-116,185,共页
Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadlea... Eco-physiological responses of seedlings of eight species, Pinus koraiensis, Picea koraiensis, Larix olgensis, Populus ussuriensis, Betula platyphylla, Tilia amurensis, Traxinus mandshurica and Acer mono from broadleaved/Korean pine forest, to elevated CO2 were studied by using open-top chambers under natural sunlight in Changbai Mountain, China in two growing seasons (1998-1999). Two concentrations of CO2 were designed: elevated CO2 (700 祄olmol-1) and ambient CO2 (400 祄olmol-1). The study results showed that the height growth of the tree seedlings grown at elevated CO2 increased by about 10%-40% compared to those grown at ambient CO2. And the water using efficiency of seedlings also followed the same tendency. However, the responses of seedlings in transpiration and chlorophyll content to elevated CO2 varied with tree species. The broad-leaf tree species were more sensitive to the elevated CO2 than conifer tree species. All seedlings showed a photosynthetic acclimation to long-term elevated CO2. 展开更多
关键词 elevated CO2 Eco-physiological response Changbai Mountain
全文增补中
Effects of elevated CO_2 concentration and nitrogen supply on biomass and active carbon of freshwater marsh after two growing seasons in Sanjiang Plain, Northeast China 被引量:13
13
作者 ZHAO Guangying LIU Jingshuang +2 位作者 WANG Yang DOU Jingxin DONG Xiaoyong 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2009年第10期1393-1399,共7页
An experiments were carried out with treatments differing in nitrogen supply (0, 5 and 15 g N/m^2) and CO2 levels (350 and 700 μmol/mol) using OTC (open top chamber) equipment to investigate the biomass of Cala... An experiments were carried out with treatments differing in nitrogen supply (0, 5 and 15 g N/m^2) and CO2 levels (350 and 700 μmol/mol) using OTC (open top chamber) equipment to investigate the biomass of Calamagrostis angustifolia and soil active carbon contents after two years. The results showed that elevated CO2 concentration increased the biomass of C. angustifolia and the magnitude of response varied with each growth period. Elevated CO2 concentration has increased aboveground biomass by 16.7% and 17.6% during the jointing and heading periods and only 3.5% and 9.4% during dough and maturity periods. The increases in belowground biomass due to CO2 elevation was 26.5%, 34.0% and 28.7% during the heading, dough and maturity periods, respectively. The responses of biomass to enhanced CO2 concentrations are differed in N levels. Both the increase of aboveground biomass and belowground biomass were greater under high level of N supply (15 g N/m^2). Elevated CO2 concentration also increased the allocation of biomass and carbon in root. Under elevated CO2 concentration, the average values of active carbon tended to increase. The increases of soil active soil contents followed the sequence of microbial biomass carbon (10.6%) 〉 dissolved organic carbon (7.5%) 〉 labile oxidable carbon (6.6%) 〉 carbohydrate carbon (4.1%). Stepwise regressions indicated there were significant correlations between the soil active carbon contents and plant biomass. Particularly, microbial biomass carbon, labile oxidable carbon and carbohydrate carbon were found to be correlated with belowground biomass, while dissolved organic carbon has correlation with aboveground biomass. Therefore, increased biomass was regarded as the main driving force for the increase in soil active organic carbon under elevated CO2 concentration. 展开更多
关键词 elevated CO2 concentration freshwater marsh BIOMASS soil active carbon
下载PDF
Nitrogen Deficiency Limited the Improvement of Photosynthesis in Maize by Elevated CO_2 Under Drought 被引量:9
14
作者 ZONG Yu-zheng SHANGGUAN Zhou-ping 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2014年第1期73-81,共9页
Global environmental change affects plant physiological and ecosystem processes. The interaction of elevated CO2, drought and nitrogen (N) deficiency result in complex responses of C4 species photosynthetic process ... Global environmental change affects plant physiological and ecosystem processes. The interaction of elevated CO2, drought and nitrogen (N) deficiency result in complex responses of C4 species photosynthetic process that challenge our current understanding. An experiment of maize (Zea mays L.) involving CO2 concentrations (380 or 750 μmol mol1, climate chamber), osmotic stresses (10% PEG-6000, -0.32 MPa) and nitrogen constraints (N deficiency treated since the 144th drought hour) was carried out to investigate its photosynthesis capacity and leaf nitrogen use efficiency. Elevated CO2 could alleviate drought-induced photosynthetic limitation through increasing capacity of PEPC carboxylation (Vp~,x) and decreasing stomatal limitations (SL). The N deficiency exacerbated drought-induced photosynthesis limitations in ambient CO2. Elevated CO2 partially alleviated the limitation induced by drought and N deficiency through improving the capacity of Rubisco carboxylation (Vmax) and decreasing SL. Plants with N deficiency transported more N to their leaves at elevated CO2, leading to a high photosynthetic nitrogen-use efficiency but low whole-plant nitrogen-use efficiency. The stress mitigation by elevated CO2 under N deficiency conditions was not enough to improving plant N use efficiency and biomass accumulation. The study demonstrated that elevated CO2 could alleviate drought-induced photosynthesis limitation, but the alleviation varied with N supplies. 展开更多
关键词 DROUGHT elevated CO2 N deficiency PHOTOSYNTHESIS
下载PDF
Study on General Performance of Jack-up Under Elevated Condition 被引量:8
15
作者 李红涛 杨清峡 李晔 《China Ocean Engineering》 SCIE EI 2009年第3期577-584,共8页
Method of checking for jack-up elevated performance including leg structure strength, fixation system or jacking system beating capacity, pre-load requirements, spud can beating capacity and overturning stability is s... Method of checking for jack-up elevated performance including leg structure strength, fixation system or jacking system beating capacity, pre-load requirements, spud can beating capacity and overturning stability is suggested in this paper. As an example, a jack-up with truss legs is analyzed by finite element analysis method. This paper may be helpful to the rig owners, operators and designers. 展开更多
关键词 JACK-UP finite element general performance elevated condition
下载PDF
Processing of AM60 magnesium alloy by hydrostatic cyclic expansion extrusion at elevated temperature as a new severe plastic deformation method 被引量:8
16
作者 Farshad Samadpour Ghader Faraji Armin Siahsarani 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2020年第5期669-677,共9页
Hydrostatic cyclic expansion extrusion(HCEE) process at elevated temperatures is proposed as a method for processing less deformable materials such as magnesium and for producing long ultrafine-grained rods. In the HC... Hydrostatic cyclic expansion extrusion(HCEE) process at elevated temperatures is proposed as a method for processing less deformable materials such as magnesium and for producing long ultrafine-grained rods. In the HCEE process at elevated temperatures, high-pressure molten linear low-density polyethylene(LLDPE) was used as a fluid to eliminate frictional forces. To study the capability of the process,AM60 magnesium rods were processed and the properties were investigated. The mechanical properties were found to improve significantly after the HCEE process. The yield and ultimate strengths increased from initial values of 138 and 221 MPa to 212 and 317 MPa, respectively.Moreover, the elongation was enhanced due to the refined grains and the existence of high hydrostatic pressure. Furthermore, the microhardness was increased from HV 55.0 to HV 72.5. The microstructural analysis revealed that ultrafine-grained structure could be produced by the HCEE process. Moreover, the size of the particles decreased, and these particles thoroughly scattered between the grains. Finite element analysis showed that the HCEE was independent of the length of the sample, which makes the process suitable for industrial applications. 展开更多
关键词 high-pressure fluid elevateD temperature severe plastic deformation HYDROSTATIC CYCLIC EXPANSION EXTRUSION mechanical properties magnesium alloy
下载PDF
CO_2 absorption with ionic liquids at elevated temperatures 被引量:7
17
作者 Lu Bai Dawei Shang +3 位作者 Mengdie Li Zhongde Dai Liyuan Deng Xiangping Zhang 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2017年第5期1001-1006,共6页
COcapture with ionic liquids(ILs) has attracted many attentions, and most works focused on absorption ability at ambient temperatures, while seldom research was concerned at elevated temperatures.This not only limit... COcapture with ionic liquids(ILs) has attracted many attentions, and most works focused on absorption ability at ambient temperatures, while seldom research was concerned at elevated temperatures.This not only limits the COabsorption application at elevated temperature, but also the determination of the operation condition of the COdesorption generally occurring at higher temperature. This work mainly reported COsolubilities in ILs at elevated temperatures and related properties were also provided. 1-alkyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide([CnMIm][TfN]) ILs were selected as physical absorbents for COcapture in this work due to their relative higher COabsorption capacities and good thermal stabilities. The long-term stability tests showed that [CnMIm][TfN] is thermally stable at 393.15 K for long time. COsolubilities in [CnMIm][TfN] were systematically determined at temperatures from 353.15 K to 393.15 K. It demonstrated that COsolubility obviously increases with the increase of pressure while slightly decreases with increase of temperature. As the length of alkyl chain on the cation increases, COsolubility in ILs increases. Additionally, the thermodynamic properties including the Gibbs free energy, enthalpy, and entropy of COwere also calculated. 展开更多
关键词 Ionic liquids CO2 capture elevated temperature Pre-combustion
下载PDF
Increased sink capacity enhances C and N assimilation under drought and elevated CO_2 conditions in maize 被引量:5
18
作者 ZONG Yu-zheng SHANGGUAN Zhou-ping 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第12期2775-2785,共11页
The maintenance of rapid growth under conditions of CO2 enrichment is directly related to the capacity of new leaves to use or store the additional assimilated carbon (C) and nitrogen (N). Under drought conditions... The maintenance of rapid growth under conditions of CO2 enrichment is directly related to the capacity of new leaves to use or store the additional assimilated carbon (C) and nitrogen (N). Under drought conditions, however, less is known about C and N transport in C4 plants and the contributions of these processes to new foliar growth. We measured the patterns of C and N accumulation in maize (Zea mays L.) seedlings using 13C and 15N as tracers in CO2 climate chambers (380 or 750 μmol mol-1) under a mild drought stress induced with 10% PEG-6000. The drought stress under ambient conditions decreased the biomass production of the maize plants; however, this effect was reduced under elevated CO2. Compared with the water-stressed maize plants under atmospheric CO2, the treatment that combined elevated CO2 with water stress increased the accumulation of biomass, partitioned more C and N to new leaves as well as enhanced the carbon resource in ageing leaves and the carbon pool in new leaves. However, the C counterflow capability of the roots decreased. The elevated CO2 increased the time needed for newly acquired N to be present in the roots and increased the proportion of new N in the leaves. The maize plants supported the development of new leaves at elevated CO2 by altering the transport and remobilization of C and N. Under drought conditions, the increased activity of new leaves in relation to the storage of C and N sustained the enhanced growth of these plants under elevated CO2. 展开更多
关键词 DROUGHT elevated CO2 ALLOCATION carbon nitrogen
下载PDF
Proso Millet Protein Elevates Plasma Level of High-Density Lipoprotein:A New Food Function of Proso Millet 被引量:24
19
作者 N. NISHIZAWA S. SHIMANUKI +5 位作者 H. FUJIHASHI H. WATANABE Y. FUDAMOTO AND T. NAGASAWA (Department of Bioscience and Technology, Faculty of Agriculture, Iwate University Morioka, Iwate 020, Japan Research Laboratory,Nitto Best Co., Ltd, Sagae, Yamagata 991 Ka 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 1996年第2期209-212,共4页
We examined the effects of dietary proso-millet protein on plasma levels of high-density lipoprotein (HDL) cholesterol in different rats from animals reported in our previous studies. The results showed also, in this ... We examined the effects of dietary proso-millet protein on plasma levels of high-density lipoprotein (HDL) cholesterol in different rats from animals reported in our previous studies. The results showed also, in this animal, that the ingestion of the millet protein elevates plasma levels of HDL-cholesterol like our earlier works. Taking into account the anti-atherogenic function of HDL, therefore, the millet protein would be useful as a new food ingredient which has the function that regulates cholesterol metabolism 展开更多
关键词 HDL Proso Millet Protein elevates Plasma Level of High-Density Lipoprotein
下载PDF
Response of successive three generations of cotton,bollworm,Helicoverpa armigera (Hübner),fed on cotton bolls under elevated CO_2 被引量:5
20
作者 WU Gang CHEN Fa-jun +1 位作者 SUN Yu-cheng GE Feng 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2007年第11期1318-1325,共8页
The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera (Htibner), fed on cotton bolls grown under elevated CO2 (double-ambient vs. ambient) in open-top cha... The growth, development and consumption of successive three generations of cotton bollworm, Helicoverpa armigera (Htibner), fed on cotton bolls grown under elevated CO2 (double-ambient vs. ambient) in open-top chambers were examined. Significant decreases in protein, total amino acid, water and nitrogen content and increases in free fatty acid were observed in cotton bolls. Changes in quality of cotton bolls affected the growth, development and food utilization of H. armigera. Significantly longer larval development duration in three successive generations and lower pupal weight of the second and third generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower fecundity was also found in successive three generations of H. armigera fed on cotton bolls grown under elevated CO2. The consumption per larva occurred significant increase in successive three generations and frass per larva were also significantly increased during the second and third generations under elevated CO2. Significantly lower relative growth rate, efficiency of conversion of ingested food and significant higher relative consumption rate in successive three generations were observed in cotton bollworm fed on cotton bolls grown under elevated CO2. Significantly lower potential female fecundity, larval numbers and population consumption were found in the second and third generations of cotton bollworm fed on cotton bolls grown under elevated CO2. The integrative effect of higher larval mortality rate and lower adult fecundity resulted in significant decreases in potential population consumption in the latter two generations. The results show that elevated CO2 adversely affects cotton bolls quality, which indicates the potential population dynamics and potential population consumption of cotton bollworm will alleviate the harm to the plants in the future rising CO2 atmosphere. 展开更多
关键词 elevated CO2 Helicoverpa armigera growth development FECUNDITY cotton bolls population consumption successive generation
下载PDF
上一页 1 2 66 下一页 到第
使用帮助 返回顶部