期刊文献+
共找到89篇文章
< 1 2 5 >
每页显示 20 50 100
Harnessing Eu/Ce-codoped ZnO nanomaterial derived from MOF precursor for high-performance n-butanol sensing under UV activation at ambient temperature
1
作者 Yinzhong Liu Xuechun Yang +7 位作者 Yun Guo Lingchao Wang Xiaofan Li Hui Guo Yiyu Qiao Xiaotao Zhu Lingli Cheng Zheng Jiao 《Journal of Semiconductors》 2026年第2期97-109,共13页
Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low ... Prolonged exposure to n-butanol, a common hazardous volatile organic compound(VOC) in the environment, can lead to a broad range of adverse health effects. Therefore, detecting n-butanol safely and efficiently at low concentrations becomes critical for both environmental monitoring and human health. In this study, a novel Eu/Ce-codoped MOF-ZnO gas sensor was developed for the sensitive detection of n-butanol gas under ultraviolet activation at ambient temperature. A series of Eu/Ce-ZnO nanomaterials were synthesized via a simple co-precipitation route, by carefully designing the varied mass ratios of Eu and Ce incorporated into pristine ZnO derived from MOF precursors. The gas testing results revealed that introducing an appropriate amount of Eu and Ce would enlarge the specific surface area and enrich the oxygen vacancy content compared to pristine MOF-ZnO. Upon UV irradiation, the 0.03 wt% Eu 0.04 wt% Ce-ZnO sensor achieved a superior response of 611 for100 ppm n-butanol at room temperature, 15.28 times higher than that of pristine MOF-ZnO(40). Furthermore, the sensor presented rapid response/recovery times(15 s/28 s) and excellent selectivity. The above contributions pave the way for the promising development of highly sensitive, ultraviolet-enhanced gas sensors for ambient temperature detection of VOCs. 展开更多
关键词 Eu/Ce ZnO N-BUTANOL ULTRAVIOLET ambient temperature
在线阅读 下载PDF
Impact of ambient temperature on postoperative cognitive dysfunction in elderly patients surgery:A seasonal comparison in tropical regions
2
作者 Mi Liu Wen-Li Song +1 位作者 Hai-Jun Shen Yun-Mian Liu 《World Journal of Psychiatry》 2025年第11期335-345,共11页
BACKGROUND To investigate whether seasonal differences in ambient temperature affect the incidence of early postoperative cognitive dysfunction(POCD)among elderly patients undergoing laparoscopic surgery in tropical r... BACKGROUND To investigate whether seasonal differences in ambient temperature affect the incidence of early postoperative cognitive dysfunction(POCD)among elderly patients undergoing laparoscopic surgery in tropical regions.Additionally,it explored the perioperative risk factors associated with early POCD following abdominal laparoscopic surgery.AIM To investigate the influence of seasonal differences in ambient temperature on POCD of elderly patients METHODS A total of 125 patients aged≥65 years from Hainan Province,China,who underwent laparoscopic surgery under general anesthesia with tracheal intubation,were enrolled. All patients completed the Mini-Mental State Examination one day before surgery and onpostoperative days 1, 3, and 7. A decline of ≥ 2 points from baseline was considered indicative of cognitivedysfunction. Serum levels of S100 calcium binding protein B and neuron-specific enolase were measured usingenzyme-linked immunosorbent assay at three time points: Preoperatively, immediately after extubation, and 24hours postoperatively. Perioperative clinical data were collected to identify potential risk factors for POCD.Propensity score matching (PSM) was performed (1:1, caliper = 0.03), resulting in 41 matched patient pairs betweenwinter and summer groups.RESULTSAfter PSM, baseline characteristics including age, gender, body mass index, education level, comorbidities, andsurgical variables were well balanced between groups. There were no significant differences in the incidence ofPOCD on postoperative days 1, 3, and 7 between patients undergoing laparoscopic surgery in winter vs summer.However, multivariable logistic regression revealed that surgical duration (day 1, P value = 0.049), advanced ageand elevated creatinine (day 3, P value = 0.044, P value = 0.008), and hypoalbuminemia (day 3, P value = 0.042;day7, P value = 0.015) were independently associated with early POCD.CONCLUSIONAmbient temperature differences between winter and summer in tropical regions did not significantly affect theincidence of early POCD in elderly patients undergoing laparoscopic surgery. Nonetheless, age, longer surgicalduration, elevated creatinine, and hypoalbuminemia emerged as key risk factors. These findings underscore theimportance of perioperative optimization to reduce the risk of POCD in elderly patients, regardless of seasonaltemperature variations. 展开更多
关键词 Tropical region Seasonal variation ambient temperature Postoperative cognitive dysfunction ELDERLY Laparoscopic surgery Risk factors
暂未订购
Ambient temperature catalyzed air-oxidation of 5-hydroxymethylfurfural via ternary metal and oxygen vacancies
3
作者 Yunlei Zhang Yiran Liu +5 位作者 Qinghua Xia Yao Chen Lingzhao Kong Xingchen Yan Wen Guan Jianming Pan 《Green Energy & Environment》 2025年第7期1568-1582,共15页
Catalytic oxidation of biomass-derived 5-hydroxymethylfurfural(HMF)to 2,5-furandicarboxylic acid(FDCA,an alternative bioplastic monomer to petroleum-derived terephthalic acid),has been identified as an important bioma... Catalytic oxidation of biomass-derived 5-hydroxymethylfurfural(HMF)to 2,5-furandicarboxylic acid(FDCA,an alternative bioplastic monomer to petroleum-derived terephthalic acid),has been identified as an important biomass conversion reaction in bio-based polyester industry.However,it is still challenging to acquire a high FDCA yield from the selective oxidation of HMF at low temperatures.Herein,a ternary metal-based catalyst was prepared by loading AuPdPt noble metal nanoparticles on the oxygen-rich vacancy titanium dioxide layer deposited on natural clay mineral halloysite nanotubes(HNTs),and the catalytic activity was examined for air-oxidation of HMF to FDCA in water at ambient temperature(30℃).By adjusting the Au/Pd/Pt ratio,a 93.6%FDCA yield was achieved with the optimal Au_(0.5)Pd_(0.2)Pt_(0.3)/TiO_(2)@HNTs catalyst,which revealed an impressive FDCA formation rate of 67.58 mmol g^(-1)h^(-1)and an excellent TOF value of 17.54 h^(-1)under normal air pressure at 30℃,surpassing the performance of mono-and bimetallic-based catalysts.Theoretical calculation and catalytic performance study clarified the structure-activity relationship.It was found that the ternary metal and oxygen vacancies revealing synergistic enhancement of ambient temperature catalyzed HMF air-oxidation via electronic structure tuning and adsorption intensification.DFT and kinetics study demonstrated that the presence of ternary metal significantly improved the adsorption capacity of substrate and enhanced the rate-determining step of the key intermediate 5-hydroxymethyl-2-furanocarboxylic acid(HMFCA)oxidation when compared to mono-and bimetal.Additionally,the TiO_(2)@HNTs support with high oxygen vacancy concentration facilitated the adsorption of oxygen,synergistically working with the ternary metal to activate and low the energy barriers for the generation of superoxide radical,thus enhancing the FDCA formation.This work offers a novel strategy for designing ternary metal-based catalysts for low-energy catalytic oxidation reactions. 展开更多
关键词 5-hydroxymethylfurfural air-oxidation 2 5-furandicarboxylic acid ambient temperature Normal pressure Ternary metal
在线阅读 下载PDF
Study on Desulfurization Efficiency and Products of Ce-Doped Nanosized ZnO Desulfurizer at Ambient Temperature 被引量:14
4
作者 李芬 闫波 +4 位作者 张杰 姜安玺 邵纯红 孔祥吉 王新 《Journal of Rare Earths》 SCIE EI CAS CSCD 2007年第3期306-310,共5页
Ce-doped nanosized ZnO desulfurizer was prepared by homogeneous precipitation,and its desulfurization efficiency at ambient temperature was investigated through dynamic experiments.The results showed that the desulfur... Ce-doped nanosized ZnO desulfurizer was prepared by homogeneous precipitation,and its desulfurization efficiency at ambient temperature was investigated through dynamic experiments.The results showed that the desulfurization activity of nanosized Ce-ZnO had improved greatly,compared to nanosized ZnO desulfurizer.Nanosized Ce-ZnO desulfurizer was characterized by XRD,TPD-MS,XPS,and TEM.The research results indicated that doping Ce decreased the particle size of the nanosized ZnO desulfurizer and ZnS was the principal desulfurization product.There were adsorption complexes of HS and S on the surface of desulfurizer as well.Only a small amount of vapor appeared in the tail gas on the condition of meeting the precision of desulfurization. 展开更多
关键词 nanosized ZnO Ce-doped desulfurization at ambient temperature rare earths
在线阅读 下载PDF
Partial Nitrification from Domestic Wastewater by Aeration Control at Ambient Temperature 被引量:11
5
作者 彭永臻 高守有 +1 位作者 王淑莹 白璐 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2007年第1期115-121,共7页
The objective of this paper was to examine the feasibility of partial nitrification from raw domestic wastewater at ambient temperature by aeration control only. Airflow rate was selected as the sole operational param... The objective of this paper was to examine the feasibility of partial nitrification from raw domestic wastewater at ambient temperature by aeration control only. Airflow rate was selected as the sole operational parameter. A 14L sequencing batch reactor was operated at 23℃ for 8 months, with an input of domestic wastewater. There was a prolgrammed decrease of the airflow rate to 28L·h^-1, the corresponding average dissolved oxygen (DO) was 0.32mg·h^-1, and the average nitrite accumulation rate increased to 92.4% in 3 weeks. Subsequently, further increase in the airflow rate to 48L·h^-1 did not destroy the partial nitrification to nitrite, with average DO of 0.60mg·h^-1 and nitrite accumulating rate of 95.6%. The results showed that limited airflow rate to cause oxygen deficiency in the reactor would eventually induce only nitrification to nitrite and not further to nitrate and that this system showed relatively stability at higher airflow rate independent of pH and temperature. About 50% of influent total nitrogen was eliminated coupling with partial nitrification, taking the advantage of low DO during the reaction. 展开更多
关键词 partial nitrification oxygen-limiting condition ambient temperature domestic wastewater
在线阅读 下载PDF
Influence of Normal Load,Sliding Speed and Ambient Temperature on Wear Resistance of ZG42CrMo 被引量:5
6
作者 ZHANG Jian PENG Yan +1 位作者 LIU Hong-min LIU Yun-fei 《Journal of Iron and Steel Research International》 SCIE EI CAS CSCD 2012年第4期69-74,共6页
To investigate the wear resistance of ZG42CrMo in industrial application,the wear behaviors under different normal loads,sliding speeds and ambient temperatures were simulated by an MMU-5G abrasion tester to acquire t... To investigate the wear resistance of ZG42CrMo in industrial application,the wear behaviors under different normal loads,sliding speeds and ambient temperatures were simulated by an MMU-5G abrasion tester to acquire the friction coefficients and wear rates,with the morphology of worn surface observed by scanning electron microscopy(SEM)and chemical composition of worn surface and debris analyzed by X-ray energy dispersive spectroscopy(EDS).Combine with the theory of tribology,finally the regular of environmental factors’influence on material wear behaviors is determined.The results show that the increase of load decreases wear resistance significantly,when the pressure reaches a certain extent,severe spalling occurs on the worn surface;the changes of speed result in the changes of size of abrasive debris,and then effect the wear behaviors,in the increasing process of speed,the wear rate increases firstly and then decreases;the rise of temperature causes changes in wear mechanism,bring forth oxidation film on the worn surface,which leads to significant improvement of the wear resistance of materials under high temperature compared to that under low temperature. 展开更多
关键词 ZG42CrMo wear resistance normal load sliding speed ambient temperature
原文传递
Supplementation with turmeric residue increased survival of the Chinese soft-shelled turtle (Pelodiscus sinensis) under high ambient temperatures 被引量:4
7
作者 Yong CHEN Yi-fan ZHANG +5 位作者 Hao-cheng QIAN Jing-liang WANG Zhe CHEN Jose M.ORDOVAS Chao-qiang LAI Li-rong SHEN 《Journal of Zhejiang University-Science B(Biomedicine & Biotechnology)》 SCIE CAS CSCD 2018年第3期245-252,共8页
Turmeric residue(TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the e... Turmeric residue(TR), containing residual levels of curcumin, is a solid by-product waste generated after the extraction and separation of curcumin from turmeric root. A feeding trial was conducted to evaluate the effects of TR on the survival of Chinese soft-shelled turtles(SSTs), Pelodiscus sinensis, under a high ambient temperature. A total of 320 female SSTs were assigned randomly to two diets: basal diet(the control group, n=160) and an interventional diet supplemented with 10% TR(the TR group, n=160). Our results demonstrated that supplementation of TR increased the SST survival rate by 135.5%, and superoxide dismutase(SOD) activity of SST liver by 112.8%, and decreased the malondialdehyde(MDA) content of SST liver by 36.4%, compared to the control group. The skin of the SST fed TR showed a golden color. High-performance liquid chromatography(HPLC) analysis indicated that the concentrations of curcumin in TR and the skin of the SST fed TR were(1.69±0.30) and(0.14±0.03) μg/g, respectively. Our observation suggests that supplementation of TR increased the survival rate of SST under high ambient temperatures. We speculated that the increased survival rate and tolerance at the high ambient temperature were associated with the anti-oxidation activity of curcumin from TR. Moreover, curcumin in TR could be deposited in SST skin, which made it more favored in the market of China. Our findings provide new knowledge and evidence to effectively reuse TR as a feed additive in animal and aquatic farming. 展开更多
关键词 Turmeric residue (TR) CURCUMIN Chinese soft-shelled turtle (SST) SURVIVAL High ambient temperature Antioxidant
原文传递
Degradation of phenol in an upflow anaerobic sludge blanket(UASB) reactor at ambient temperature 被引量:3
8
作者 KEShui-zhou SHIZhou +1 位作者 ZHANGTong HerbertH.P.FANG 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2004年第3期525-528,共4页
A synthetic wastewater containing phenol as sole substrate was treated in a 2 8 L upflow anaerobic sludge blanket(UASB) reactor at ambient temperature. The operation conditions and phenol removal efficiency were disc... A synthetic wastewater containing phenol as sole substrate was treated in a 2 8 L upflow anaerobic sludge blanket(UASB) reactor at ambient temperature. The operation conditions and phenol removal efficiency were discussed, microbial population in the UASB sludge was identified based on DNA cloning, and pathway of anaerobic phenol degradation was proposed. Phenol in wastewater was degraded in an UASB reactor at loading rate up to 18 gCOD/(L·d), with a 1:1 recycle ratio, at 26±1℃, pH 7 0—7 5. An UASB reactor was able to remove 99% of phenol up to 1226 mg/L in wastewater with 24 h of hydraulic retention time(HRT). For HRT below 24 h, phenol degradation efficiency decreased with HRT, from 95 4% at 16 h to 93 8% at 12 h. It further deteriorated to 88 5% when HRT reached 8 h. When the concentration of influent phenol of the reactor was 1260 mg/L(corresponding COD 3000 mg/L), with the HRT decreasing(from 40 h to 4 h, corresponding COD loading increasing), the biomass yields tended to increase from 0 265 to 3 08 g/(L·d). While at 12 h of HRT, the biomass yield was lower. When HRT was 12 h, the methane yield was 0 308 L/(gCOD removed), which was the highest. Throughout the study, phenol was the sole organic substrate. The effluent contained only residual phenol without any detectable intermediates, such as benzoate, 4 hydrobenzoate or volatile fatty acids(VFAs). Based on DNA cloning analysis, the sludge was composed of five groups of microorganisms. Desulfotomaculum and Clostridium were likely responsible for the conversion of phenol to benzoate, which was further degraded by Syntrophus to acetate and H 2/CO 2. Methanogens lastly converted acetate and H 2/CO 2 to methane. The role of epsilon Proteobacteria was, however, unsure. 展开更多
关键词 ambient temperature anaerobic degradation PHENOL UASB DNA WASTEWATER
在线阅读 下载PDF
Ambient Temperature and Outpatient Visits for Acute Exacerbation of Chronic Bronchitis in Shanghai: A Time Series Analysis 被引量:9
9
作者 HUANG Fang ZHAO Ang +2 位作者 CHEN Ren Jie KAN Hai Dong KUANG Xing Ya 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2015年第1期76-79,共4页
The association between ambient temperature and acute exacerbation of chronic bronchitis (AECB) was still unknown. Therefore, we performed an epidemiological study in a large hospital of Shanghai to explore the rela... The association between ambient temperature and acute exacerbation of chronic bronchitis (AECB) was still unknown. Therefore, we performed an epidemiological study in a large hospital of Shanghai to explore the relationship about temperature and outpatient visit for AECB. We adopted a quasi-Poisson generalized additive models and distributed lag nonlinear models to estimate the accumulative effects of temperature on AECB across multiple days. We found significant non-linear effects of cold temperature on hospital visits for AECB, and the potential effect of cold temperature might last more than 2 weeks. The relative risks of extreme cold (first percentiles of temperature throughout the study period) and cold (10th percentile of temperature) temperature over lags 0-14 d were 2.98 [95% confidence intervals (CI): 1.77, 5.04] and 1.63 (95% Ch 1.21, 2.19), compared with the 25th percentile of temperature. However, we found no positive association between hospital visits and hot weather. This study showed that exposure to both extreme cold and cold temperatures were associated with increased outpatient visits for AECB in a large hospital of Shanghai. 展开更多
关键词 AECB ambient temperature and Outpatient Visits for Acute Exacerbation of Chronic Bronchitis in Shanghai
暂未订购
Novel-structured Mo-Cu-Fe-O composite for catalytic air oxidation of dye-containing wastewater under ambient temperature and pressure 被引量:3
10
作者 Yin Xu Henan Shao +1 位作者 Fei Ge Yun Liu 《Chinese Journal of Catalysis》 CSCD 北大核心 2017年第10期1719-1725,共7页
A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐progr... A novel‐structured Mo‐Cu‐Fe‐O composite was successfully prepared by co‐precipitation and impregnation method.The properties of the as‐prepared samples were determined using X‐ray diffraction,temperature‐programmed reduction by H2,cyclic voltammetry,and temperature‐programmed desorption by O2.The results showed that Mo6+diffused into the Cu‐Fe‐O crystal lattice and then formed a new crystalline phase of CuMoO4.The Mo‐Cu‐Fe‐O catalyst had redox properties,and its surface contained active sites for oxygen adsorption.In addition,the catalytic activity of the Mo‐Cu‐Fe‐O composite was evaluated by the degradation of Cationic Red GTL,Crystal Violet,and Acid Red in catalytic wet air oxidation(CWAO)at ambient temperature and pressure.The Mo‐Cu‐Fe‐O catalyst showed excellent activity at basic conditions for the degradation of Cationic Red GTL.High removal efficiencies of91.5%and92.8%were achieved for Cationic Red GTL and Crystal Violet,respectively,in wastewater,and the efficiency remained high after seven cycles.However,almost no degradation of Acid Red occurred in the CWAO process.Furthermore,hydroxyl radicals were formed in the CWAO process,which induced the decomposition of the two cationic dyes in wastewater,and the toxicity of their effluents was decreased after degradation.The results indicate that the Mo‐Cu‐Fe‐O composite shows excellent catalytic activity for the treatment of wastewater contaminated with cationic dyes. 展开更多
关键词 Mo‐Cu‐Fe‐O catalyst ambient temperature and pressure Dye wastewater Hydroxyl radical Oxidative degradation
在线阅读 下载PDF
Effects of low ambient temperatures and dietary vitamin C supplementation on pulmonary vascular remodeling and hypoxic gene expression of 21-d-old broilers 被引量:1
11
作者 ZENG Qiu-feng YANG Xia +7 位作者 ZHENG Ping ZHANG Ke-ying LUO Yu-heng DING Xue-mei BAI Shi-ping WANG Jian-ping XUAN Yue SU Zhuo-wei 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第1期183-190,共8页
The objective of this study was to evaluate the effects of low ambient temperature (LAT) and dietary vitamin C (VC) sup- plementation on pulmonary vascular remodeling (PVR) and the relative expression of hypoxia... The objective of this study was to evaluate the effects of low ambient temperature (LAT) and dietary vitamin C (VC) sup- plementation on pulmonary vascular remodeling (PVR) and the relative expression of hypoxia inducible factor-la (HIF-la), vascular endothelial growth factor (VEGF) and its receptor 2 (VEGFR-2) mRNA of lungs in 21-d-old broilers. 400 1-d-old male Cobb broilers were assigned randomly to 4 treatments as follows for 21 d: 1 ) LAT and a basal diet; 2) LAT and a basal diet supplemented with 1 000 mg kg-1 VC (LAT+VC); 3) normal ambient temperature (NAT) and a basal diet; 4) NAT and a basal diet supplemented with 1 000 mg kg-1 VC (NAT+VC). Each treatment was composed of 10 replicates of 10 birds per replicate. Samples of lung were collected after the broilers were killed at d 21. LAT increased the ratio of vessel wall area to vessel total area (WA/TA, %) and mean media thickness in pulmonary arterioles (mMTPA, %) (P〈0.05). Dietary VC supplementation decreased mMTPA (P〈0.05), but had no effect on the WA/TA. LAT increased (P〈0.05) the relative mRNA expression of HIF-la, VEGF and VEGFR-2, while adding VC to the diet could decrease (P〈0.05) their relative mRNA expression. A significant positive correlation existed between the level of VEGF mRNA expression and the value of WA/WT (P〈0.05) or mMTPA (P〈0.05). These results suggested LAT resulted in pulmonary vascular remodeling, and the increase of HIF-la, VEGF and VEGFR-2 mRNA expression, and dietary VC supplementation can alleviate pulmonary vascular remodeling in broiler by affecting these gene expression. 展开更多
关键词 BROILER hypoxia inducible factor-la low ambient temperature pulmonary vascular remodeling vitamin C
在线阅读 下载PDF
Influence of ambient temperature on the CO_(2)emitted of light-duty vehicle 被引量:1
12
作者 Dan Tan Yachao Wang +3 位作者 Jianwei Tan Jiachen Li Changyu Wang Yunshan Ge 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第6期59-68,共10页
Because of global warming,people have paid more attention to greenhouse gas emitted by vehicles.To quantify the impact of temperature on vehicle CO_(2)emissions,this study was conducted using the world light vehicle t... Because of global warming,people have paid more attention to greenhouse gas emitted by vehicles.To quantify the impact of temperature on vehicle CO_(2)emissions,this study was conducted using the world light vehicle test cycle on two light-duty E10 gasoline vehicles a ambient temperatures of-10,0,23,and 40℃,and found that CO_(2)emission factors of Vehicle1 in the low-speed phase were 22.07%and 20.22%higher than those of Vehicle 2 at cold star and hot start under-10℃.The reason was vehicle 1 had a larger displacement and more friction pairs than vehicle 2.There was the highest CO_(2)emission at the low-speed phase due to low average speed,frequent acceleration,and deceleration.The CO_(2)temperature factor and the ambient temperature had a strong linear correlation(R2=0.99).According to CO_(2)temperature factors and their relationships,CO_(2)emission factors of other ambien temperatures could be calculated when the CO_(2)emission factor of 23℃was obtained,and the method also could be used to obtain the CO_(2)temperature factors of different vehicles.To separate the effect of load setting and temperature variation on CO_(2)emission quantitatively a method was proposed.And results showed that the load setting was dominant for the CO_(2)emission variation.Compared with 23℃,the CO_(2)emission for vehicle 1 caused by load setting variation were 62.83 and 47.42 g/km,respectively at-10 and 0℃,while those fo vehicle 2 were 45.01 and 35.63 g/km,respectively. 展开更多
关键词 CO_(2)emission ambient temperature E10 gasoline Light-duty vehicle WLTC
原文传递
Sodium fluoride as an efficient catalyst for the synthesis of 2,4-disubstituted-1,3-thiazoles and selenazoles at ambient temperature 被引量:1
13
作者 Janardhan Banothu Krishnaiah Vaarla +1 位作者 Rajitha Bavantula Peter A.Crooks 《Chinese Chemical Letters》 SCIE CAS CSCD 2014年第1期172-175,共4页
Sodium fluoride was found to be a simple, mild and efficient catalyst for the synthesis of 2,4- disuhstituted 1,3-thiazoles and selenazoles utilizing phenacyl bromides/3-(2-bromoacetyl)-2H-chro- men-2-one and thiour... Sodium fluoride was found to be a simple, mild and efficient catalyst for the synthesis of 2,4- disuhstituted 1,3-thiazoles and selenazoles utilizing phenacyl bromides/3-(2-bromoacetyl)-2H-chro- men-2-one and thioureaJphenylthiourea/selenourea in aqueous methanol at ambient temperature. Analytically pure products are formed within 1-3 rain in excellent yields. 展开更多
关键词 Sodium fluoride1 3-Thiazoles Selenazoles Aqueous methanol ambient temperature
原文传递
Low ambient temperature and air pollution are associated with hospitalization incidence of coronary artery disease:Insights from a cross-sectional study in Northeast China 被引量:1
14
作者 Rui Jiang Lingling Xu +4 位作者 Yue Liu Guangna Zhao Chun Xing Youyuan Li Yongchen Wang 《Frigid Zone Medicine》 2023年第4期232-241,I0007-I0013,共17页
Background:Previous studies have established a link between fluctuations in climate and increased mortality due to coronary artery disease(CAD).However,there remains a need to explore and clarify the evidence for asso... Background:Previous studies have established a link between fluctuations in climate and increased mortality due to coronary artery disease(CAD).However,there remains a need to explore and clarify the evidence for associations between meteorological changes and hospitalization incidences related to CAD and its subtypes,especially in cold regions.This study aimed to systematically investigate the relationship between exposure to meteorological changes,air pollutants,and hospitalization for CAD in cold regions.Methods:We conducted a cross-sectional study using hospitalization records of 86,483 CAD patients between January 1,2009,and December 31,2019.Poisson regression analysis,based on generalized additive models,was applied to estimating the influence of hospitalization for CAD.Results:Significant associations were found between low ambient temperature[-10℃,RR=1.65;95%CI:(1.28-2.13)]and the incidence of hospitalization for CAD within a lag of 0-14 days.Furthermore,O_(3)[95.50μg/m^(3),RR=12;95%CI:(1.03-1.21)]and NO_(2)[48.70μg/m^(3),RR=1.0895%CI:(1.01-1.15)]levels were identified as primary air pollutants affecting the incidence of CAD,ST-segment-elevation myocardial infarction(STEMI),and non-STEMI(NSTEMI)within the same lag period.Furthermore,O_(3)[95.50μg/m^(3),RR=1.12;95%CI:(1.03-1.21)]and NO_(2)[48.70μg/m^(3),RR=1.0895%CI:(1.01-1.15)]levels were identified as primary air pollutants affecting the incidence of CAD,ST-segment-elevation myocardial infarction(STEMI),and non-STEMI(NSTEMI)within the same lag period.The effect curve of CAD hospitalization incidence significantly increased at lag days 2 and 4 when NO_(2)and O_(3)concentrations were higher,with a pronounced effect at 7 days,dissipating by lag 14 days.No significant associations were observed between exposure to PM,SO_(2),air pressure,humidity,or wind speed and hospitalization incidences due to CAD and its subtypes.Conclusion:Our findings suggest a positive correlation between short-term exposure to low ambient temperatures or air pollutants(O_(3)and NO_(2))and hospitalizations for CAD,STEMI,and NSTEMI.These results could aid the development of effective preparedness strategies for frequent extreme weather events and support clinical and public health practices aimed at reducing the disease burden associated with current and future abnormal weather events. 展开更多
关键词 meteorological changes ambient temperature air pollution coronary heart disease Poisson regression analysis
原文传递
Effects of high ambient temperature on lipid metabolism in finishing pigs 被引量:2
15
作者 WU Xin LI Ze-yang +4 位作者 JIA An-feng SU Hong-guang HU Chun-hong ZHANG Min-hong FENG Jing-hai 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2016年第2期391-396,共6页
In this study,we investigated the effects of high ambient temperature on lipid metabolism in finishing pigs.Sixteen pigs((79.6±1.2) kg) were randomly assigned to two groups:(1) ambient temperature of 30℃ ... In this study,we investigated the effects of high ambient temperature on lipid metabolism in finishing pigs.Sixteen pigs((79.6±1.2) kg) were randomly assigned to two groups:(1) ambient temperature of 30℃ with ad libitum access to feed(HT;n=8) and(2) ambient temperature of 22℃ and fed the average amount consumed by eight pigs in HT group on the previous day(PF;n=8).After 21 days of constant exposure to different environmental conditions,all the pigs were euthanized,and blood and tissue samples were obtained.High ambient temperature increased the proportion of backfat(P=0.04,+21.6%)and flare fat(P〈0.01,+43.3%).Compared with pair-fed pigs,the activities of fatty acid synthase(FAS) and malic enzyme in backfat and flare fat were lower(P〈0.05) in heat-stressed pigs,as were the amounts of acetyl-CoA-carboxylase and FAS in the longissimus muscle(LM),the amount of FAS in backfat(P〈0.01),and FAS activity in the liver(P〈0.01).Ambient temperature did not affect the amount of hormone-sensitive lipase in different tissues.The amount of lipoprotein lipase in flare fat tended to be higher(P=0.09,+28.3%),and the activities of β-hydroxyacyl coenzyme A dehydrogenase in front and back of LM were lower(P〈0.01,-48.3 and-49.8%,respectively) at 30℃ than at 22℃.The plasma concentration of high-density lipoprotein tended to be lower(P=0.08),but the plasma concentrations of very low-density lipoprotein(VLDL)(P=0.09,+50.0%) and nonestesterified fatty acid(NEFA)(P=0.04,+44.2%) were higher in heat-stressed pigs.We concluded that high ambient temperature depressed de novo fatty acid synthesis in both adipose tissues and the liver.However,β-oxidation of fatty acid in skeletal muscles was also inhibited in the high-temperature environment.As a result,more plasma NEFAs were used to synthesize VLDLs in the liver and were absorbed by adipose tissues.This may be one reason that high ambient temperature enhances the accumulation of backfat and flare fat in finishing pigs. 展开更多
关键词 β-hydroxyacyl coenzyme A dehydrogenase lipoprotein lipase lipogenesis finishing pigs high ambient temperature
在线阅读 下载PDF
Evaluation of the Influence of Ambient Temperature on the Performance of the Trans-Amadi Gas Turbine Plant 被引量:1
16
作者 Emughiphel Nelson Igoma Barinaada Thaddeus Lebele-Alawa John Sodiki 《Journal of Power and Energy Engineering》 2016年第11期19-31,共13页
This paper examines the effects of ambient temperature on the Trans-Amadi gas turbine power station Phase II. The investigation took thirteen (13) months (January 2012 to January 2013) during which plant data were mon... This paper examines the effects of ambient temperature on the Trans-Amadi gas turbine power station Phase II. The investigation took thirteen (13) months (January 2012 to January 2013) during which plant data were monitored and operational Logsheets like turbine logsheets, plant—auxiliaries’ logsheets and generator logsheets were studied. The gas turbine (GT) that was under investigation was GT-2: MS5001 Nuovopignone with designed installed capacity of 25.0 Megawatts (MW). The result of the study shows that a 1℃ rise of the ambient temperature is responsible for the following: 0% - 0.12% decrease in the power output, 0% - 0.12% increase in the power differential, 0% - 1.17% decrease in the thermal efficiency, 0% - 27.18% increase in the heat rate and 0% - 3.57% increase in the specific fuel consumption. An ambient temperature of 30℃ is found to yield minimal fuel consumption. 展开更多
关键词 ambient temperature PERFORMANCE Gas Turbine Power and Thermal Efficiency
在线阅读 下载PDF
Ambient Temperature Living Radical Copolymerization of Styrene and Methyl Methacrylate with Sodium Hypophosphite as Reducing Agent
17
作者 刘晓辉 Hui-na Li +3 位作者 Fei-jun Zhang Shan Xie Zhan-jun Liu 李彦国 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2015年第2期362-370,共9页
A facile, safe and economical reducing agent, sodium hypophosphite(Na H2PO2·H2O), has been successfully employed for ambient temperature living radical copolymerization of styrene(St) and methyl methacrylate... A facile, safe and economical reducing agent, sodium hypophosphite(Na H2PO2·H2O), has been successfully employed for ambient temperature living radical copolymerization of styrene(St) and methyl methacrylate(MMA). Such effective reducing agent significantly improved the reactivity of low reactive St monomers during the copolymerization, where the reactivity ratios of St and MMA were determined to be 0.50 and 0.36 by Finemann-Ross method. Thus the copolymerizations proceeded fast and showed typical living/controlled features, as evidenced by pseudo first-order kinetics of polymerization, linear increase in molecular weight versus monomer conversion, and low polydispersity index values. Effects of the concentration of reducing agent and the monomer feed ratio on the copolymerization were investigated in detail. Furthermore, gel permeation chromatography and 1H-NMR analyses as well as chain extension experiments confirmed the high chain-end functionality of the resultant copolymer. 展开更多
关键词 Controlled/living radical copolymerization Sodium hypophosphite ambient temperature Methyl methacrylate STYRENE
原文传递
Targeting PPARαin low ambient temperature exposure-induced cardiac dysfunction and remodeling
18
作者 Xi-Yao Chen Yang Jiao Fu-Yang Zhang 《Military Medical Research》 SCIE CSCD 2022年第3期382-384,共3页
The present study demonstrates that the down-regulation of peroxisome proliferator-activated receptor-α(PPARα)results in chronic low ambient temperature(LT)exposure-induced cardiac dysfunction and remodeling,emphasi... The present study demonstrates that the down-regulation of peroxisome proliferator-activated receptor-α(PPARα)results in chronic low ambient temperature(LT)exposure-induced cardiac dysfunction and remodeling,emphasizing the therapeutic potential of PPARαactivation strategies(e.g.,fenofibrate treatment)in LT-associated cardiac injury. 展开更多
关键词 Low ambient temperature Cardiac dysfunction REMODELING Peroxisome proliferator-activated receptor-α Fatty acid metabolism
原文传递
Synthesis of hierarchical transition metal oxyhydroxides in aqueous solution at ambient temperature and their application as OER electrocatalysts
19
作者 Zongkun Chen Xingkun Wang +3 位作者 Sascha Keßler Qiqi Fan Minghua Huang Helmut Cölfen 《Journal of Energy Chemistry》 SCIE EI CAS CSCD 2022年第8期89-97,I0003,共10页
First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various advantages.Although investigating the oxidation mechanism and processing such materials into hierarchical architect... First-row(3 d)transition metal oxyhydroxides have attracted increasing attention due to their various advantages.Although investigating the oxidation mechanism and processing such materials into hierarchical architectures are greatly desired for their further development,it remains unclear how the oxidation state change occurs,and efforts to produce hierarchical oxyhydroxides in compliance with high ecological and economic standards have progressed slowly.Here,we describe a facile one-step coprecipitation route for the preparation of hierarchical CoOOH,NiOOH and MnOOH,which involves the diffusion of NH_(3)originating from ammonium hydroxide solution into an aqueous solution containing metal ion salts and K_(2)S_(2)O_(8).Comprehensive characterizations by scanning electron microscope,transmission electron microscopy,X-ray diffraction analysis,X-ray photoelectron spectroscopy,ultraviolet-visible spectroscopy and in situ p H measurement demonstrated that K_(2)S_(2)O_(8)induces the oxidation state change of metal ion species after the start of hydrolysis.Meanwhile,it was found that,benefiting from the OH–concentration gradient created by the NH_(3)diffusion method and the suitable growth environment provided by the presence of K_(2)S_(2)O_(8)(high nucleation rate and secondary nucleation),the formation of hierarchical oxyhydroxide structures can be realized in aqueous solution at ambient temperature without the use of heat energy and additional structure-directing agents.The hierarchical CoOOH structures are performed as the electrocatalysts for the oxygen evolution reaction in alkaline media,which exhibit good activity with an overpotential of 320 m V at 10 m A cm^(-2)and a low Tafel slope of 59.6 m V dec^(–1),outperforming many congeneric electrocatalysts.Overall,our study not only provides important insights to understand the formation mechanism of hierarchical oxyhydroxides,but also opens up new opportunities for the preparation of hierarchical oxyhydroxides via a facile,green and low-cost method. 展开更多
关键词 Formation mechanism Hierarchical transition metal oxyhydroxides Aqueous solution ambient temperature Oxygen evolution reaction
在线阅读 下载PDF
Effect of Ambient Temperature on the Electrochemical Properties of La_4MgNi_(17.5)Co_(1.5) Hydrogen Storage Alloy
20
作者 Xin Cai Fan-Song Wei +1 位作者 Fan-Na Wei Huan-Huan Lu 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2016年第7期614-618,共5页
The effect of different ambient temperatures on the electrochemical properties of La4MgNi17.5C01.5 hydrogen storage alloy was investigated. The X-ray diffraction pattern shows that the alloy consists of LaNis-type pha... The effect of different ambient temperatures on the electrochemical properties of La4MgNi17.5C01.5 hydrogen storage alloy was investigated. The X-ray diffraction pattern shows that the alloy consists of LaNis-type phase and AsB19- type (Ce5C019 + Pr5CO19) phase. With the increase of the ambient temperature, the maximum discharge capacity of the alloy electrodes increases from 353.33 (283 K) to 379.25 mAh/g (308 K), and the cyclic stability (Sloo) of the electrodes decreases from 80.19 (283 K) to 52.04% (308 K) due to the acceleration of pulverization, corrosion and oxidation at higher ambient temperature. Moreover, it is found that the increase of the temperature can accelerate the diffusion rate of hydrogen in the alloy (D) and increase the exchange current density (Io), which are beneficial for improving the activation performance and the high-rate dischargeability (HRD) of the alloy electrodes. The activation cycles of the electrodes decrease from 4 (283 K) to 1 (308 K), and the HRD9oo of the electrodes sharply increases from 66.36 (283 K) to 95.64% (308 K). 展开更多
关键词 Hydrogen storage alloy ambient temperature AsB19 type Electrochemical property
原文传递
上一页 1 2 5 下一页 到第
使用帮助 返回顶部