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Cross-Lagged Relationship between Physical Activity Time,Openness and Depression Symptoms among Adolescents:Evidence from China 被引量:4
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作者 Xiaojie Cao Qinyu Zhang Xinqiao Liu 《International Journal of Mental Health Promotion》 2023年第9期1009-1018,共10页
The relationship between physical activity time,openness and depression symptoms among adolescents is a cutting-edge research direction in the field,yet it remains unclear.This study is based on a sample of 7924 stude... The relationship between physical activity time,openness and depression symptoms among adolescents is a cutting-edge research direction in the field,yet it remains unclear.This study is based on a sample of 7924 students from a nationally representative China Education Panel Survey database and examines the bidirectional relationships between physical activity time,openness and depression symptoms among Chinese adolescents.Descriptive analysis showed that during the 7th and 8th grades,the average physical activity time decreased to less than one hour per day,accompanied by a decreasing trend in openness and a slight worsening in depression symptoms.Correlation analysis showed a significant negative correlation between physical activity time and depression symptoms,a significant positive correlation between physical activity time and openness,and a significant negative correlation between depression symptoms and openness.The results from cross-lagged models indicated a bidirectional relationship between physical activity time and openness,with physical activity time significantly positively predicting openness in the following year and openness significantly positively predicting physical activity time in the following year.In addition,depression symptoms had a unidirectional negative predictive effect on openness.The conclusions provide empirical evidence for education administration and schools to promote the physical and mental health development of adolescents worldwide. 展开更多
关键词 Physical activity time DEPRESSION OPENNESS adolescents
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The measurement of time spent outdoors in child myopia research: a systematic review 被引量:7
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作者 Jing Wang Xian-Gui He Xun Xu 《International Journal of Ophthalmology(English edition)》 SCIE CAS 2018年第6期1045-1052,共8页
The purpose of this article is to summarize the methods most commonly used to measure time spent outdoors and provide a comprehensive review of time and activity recording methods with the aim of encouraging the devel... The purpose of this article is to summarize the methods most commonly used to measure time spent outdoors and provide a comprehensive review of time and activity recording methods with the aim of encouraging the development of new methods. PubMed, Embase and the Cochrane Library were searched from Jan. 1st, 1990 to Aug. 31th, 2017. Studies including the following specific terms: “outdoor”, “outside”, “outdoor activity”, “outside activity”, “outdoor time”, “outside time”, and “outdoor AND measurement of time spent outdoors” were considered for this review. In total, three kinds of outdoor time measurements were discussed. Questionnaires have the longest history and are the most thoroughly revised instruments for assessing time spent outdoors, but recall bias is their most substantial drawback. Global positioning system (GPS) tracking can distinguish between indoor and outdoor locations, but its utility is limited due to several factors such as subject compatibility. Light exposure measurement devices are newly emerging, but all of these devices require good subject cooperation. Further efforts and exploration are needed to develop better methods and new tools to record exposure to the outdoors in real time. Moreover, inventing a new device by combining two or more types of devices mentioned above and using the latest technology of en ergy supplementation and autoswitching may make the best use of the advantages and bypass the disadvantages of each tool. 展开更多
关键词 MYOPIA outdoor (activity) time QUESTIONNAIRE global positioning system light exposure
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A Case-Control Study on Leisure Time Physical Activity (LTPA) during the Last Three Months of Pregnancy and Foetal Outcomes in Italy 被引量:1
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作者 Guglielmina Fantuzzi Elena Righi Gabriella Aggazzotti 《Health》 CAS 2016年第2期133-143,共11页
The association between Leisure Time Physical Activity (LTPA) during pregnancy and foetal outcomes has been extensively investigated. However, epidemiological studies specifically referred to LPTA in the last months o... The association between Leisure Time Physical Activity (LTPA) during pregnancy and foetal outcomes has been extensively investigated. However, epidemiological studies specifically referred to LPTA in the last months of pregnancy are scarce. We evaluated the association between LPTA and the risk of both preterm delivery and small for gestational age (SGA) during the last three months of pregnancy in Italy. A nationwide case-control study was performed in nine Italian cities. A total of 299 preterm delivery, 364 SGA and 855 controls were enrolled in the study. A self-administered questionnaire was used to assess socio-demographic variables, medical and reproductive history, life-style habits and LTPA referred to the last three months of pregnancy. Univariate and multivariate regression analyses were performed in order to estimate Odds ratios and 95% CI. LTPA during the last three months of pregnancy decreases the risk of preterm delivery (adjusted OR = 0.56;95% CI 0.39 - 0.79). Among the different types of physical activity, walking, the most frequently referred activity, appears significantly protective against preterm delivery (adjusted OR = 0.53;95% CI 0.36 - 0.81). Moreover, a small protective effect of walking was evidenced against SGA (adjusted OR = 0.72;95% CI 0.51 - 1.00). In conclusion, a mild physical activity such as walking in the last three months of pregnancy seems to reduce the risk of preterm delivery and, at a lesser extent, of SGA, confirming the beneficial effects of physical activity along the whole pregnancy. 展开更多
关键词 Leisure time Physical Activity (LTPA) Preterm Delivery Small for Gestational Age Last Three Months of Pregnancy Case Control Study
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Lower activity time constraint on the ore-controlling Erdaogou fault in the Qingchengzi orefield of the Liaodong Peninsula,NE China
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作者 Yan Zhao Yuewen Feng +4 位作者 Peng Zhang Linlin Kou Zhongzhu Yang Shenghui Li Wei Wang 《Acta Geochimica》 EI CAS CSCD 2022年第2期267-274,共8页
The Erdaogou fault,also known as the 101 fault,comprises the most important NE strike component in the ore-controlling system in the Qingchengzi orefield,Liaodong Peninsula.Due to the poor outcrop conditions in the fi... The Erdaogou fault,also known as the 101 fault,comprises the most important NE strike component in the ore-controlling system in the Qingchengzi orefield,Liaodong Peninsula.Due to the poor outcrop conditions in the field,the Erdaogou fault lacks activity time constraint.We demonstrate the constraint activity time of the fault since we observe a lamprophyre that was cut through by the Erdaogou fault in the Taoyuan area,central to the Qingchengzi orefield.Zircon grains from the lamprophyre dyke exhibit typical oscillatory zoning and yield weighted mean U–Pb age of 223.8±1.1 Ma(MSWD=1.5).The lower activity time limit of the Erdaogou fault is thus first constrained as 224 Ma or so and is correlated with the crystallization age of the Xinling and Shuangdinggou plutons within the orefield.Taking previous mineralization studies into consideration,a Triassic tectonic-magmatism-mineralization model is approved in the Qingchengzi orefield. 展开更多
关键词 The Erdaogou fault LA-ICP-MS U-Pb dating Activity time The Qingchengzi orefield Liaodong Peninsula
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FURTHER DISCUSSION ON STATISTICAL PROPERTIES OF ACTIVITY FLOW TIME IN PERT
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作者 Wang XinghuaDept.of Math.,Zhejiang Univ.,Hangzhou 310028. 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2002年第1期1-6,共6页
In this paper attempts are made at answering the problems on the statistical properties of activity flow time in PERT raised by the late famous mathematician Hua Loo-keng.
关键词 PERT activity flow time the problem of Hua Loo-Keng.
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Effects of Chloroquine and Naphthoquinone on Prothrombin Time and Activated Partial Thromboplastin Time of Swiss Mice
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作者 Nkereuwem S. Etukudoh Ntuhun D. Bala +2 位作者 Obeta M. Uchejeso Hadiza A. Idi Ocheola Oki E. Joyce 《Journal of Biosciences and Medicines》 2020年第12期86-94,共9页
Concerns on the coagulation variables, Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) which are part of coagulation parameters used in assessing haemostatsis in haematology, led to the study of... Concerns on the coagulation variables, Prothrombin Time (PT) and Activated Partial Thromboplastin Time (APTT) which are part of coagulation parameters used in assessing haemostatsis in haematology, led to the study of the effects of naphthoquinone and chloroquine on the PT and APTT of mice infected with <em>Plasmodium berghei</em>, and treated with graded concentrations of chloroquine and naphthoquinone. Using brain thromboplastin with calcium and rabbit brain cephalosporin ad kaolin respectively the experiment aimed at demonstrating the effect of chloroquine with purity of 99.79% and naphthoquinone with purity of 97.00%, upon a three-day intraperitoneal administration at concentrations of 0.1 mg/kg, 0.5 mg/kg, 1.0 mg/kg and 2.0 mg/kg. Result showed that the APTT and PT of naphthoquinone at 2.0 mg/kg, were 196.67 seconds, and 67.63 seconds respectively, while the APTT and PT of chloroquine were 3.63 seconds and 1.40 seconds respectively for the same concentration. Also, naphthoquinone showed lower APTT but sustained PT at concentrations below 1.50 mg/kg whereas both APTT and PT increased from concentrations above 1.50 mg/kg. On the other hand chloroquine showed a lowered APTT between 0.00 to 0.15 mg/kg while PT was sustained, but both APTT and PT increased from concentration of 0.15 mg/kg gradually. This study conclusively showed that chloroquine has a shorter APTT and PT than naphthoquinones, even though they elicited similar actions. Apart from this, naphthoquinone and chloroquine belonging to the same family, naphthoquinone could be more toxic than chloroquine at the dosages equivalent to 1.50 mg/kg, therefore, any administration of naphthoquinone above this dosage should be closely monitored to avoid any form of danger to the patient. 展开更多
关键词 CHLOROQUINE NAPHTHOQUINONE Prothrombin time Activated Partial Thromboplastin time
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Discussion of the Horizontal Intensity of Late Quaternary Fault Activity Along the Tianjingshan Fault Zone in Different Time Intervals and Fault Segments 被引量:1
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作者 Chai Chizhang,Zhang Weiqi,and Jiao DechengSeismological Bureau of Ningxia Hui Autonomous Region,Yinchuan 750001,China 《Earthquake Research in China》 1997年第3期25-32,共8页
By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are disc... By computing and classifying the data of gully offset obtained from field surveys along the Tianjingshan fault zone and estimating the ages of three types of gullies,the strike-slip rates along the fault zone are discussed in different time intervals and fault segments.The results suggest that the intensity of activity along the fault zone is not strong,but the differences between different time intervals and fault segments since the late Pleistocene have been obvious.The average rates range from 0.23 mm/a to 1.62 mm/a.The largest average rate is 1.40 mm/a,which occurred in the early and middle of late Pleistocene along the western segment of the fault zone.Since the late stage of the late Pleistocene,the center of faulting activity of the fault zone has shifted to the middle segment,and the average slip rates range have changed from 1.30 mm/a to 1.63 mm/a. 展开更多
关键词 Discussion of the Horizontal Intensity of Late Quaternary Fault Activity Along the Tianjingshan Fault Zone in Different time Intervals and Fault Segments Activity
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Coagulation abnormalities and their relationship with bleeding manifestations in patients with dengue-A single center observational study 被引量:2
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作者 Govind R.Patel Indu Thanvi +1 位作者 Mohammad Nadeem Rahul Kanwaria 《Asian Pacific Journal of Tropical Medicine》 SCIE CAS 2023年第2期65-71,共7页
Objective:To evaluate coagulation abnormalities and their relationship with bleeding manifestations among patients with dengue.Methods:This observational study was conducted on 292 adult dengue patients who were admit... Objective:To evaluate coagulation abnormalities and their relationship with bleeding manifestations among patients with dengue.Methods:This observational study was conducted on 292 adult dengue patients who were admitted to a tertiary care hospital of Western India from July 2021 to June 2022.Coagulation tests including prothrombin time(PT),international normalized ratio(INR),activated partial thromboplastin time(aPTT),fibrinogen,and D-dimer were performed.Patients were monitored for bleeding manifestations.Results:Coagulation abnormalities were reported in 42.8%of the patients.Overall,prolonged aPTT was the most common coagulation abnormality(40.8%),followed by low fibrinogen(38.7%),raised D-dimer(31.2%),raised INR(26.0%)and prolonged PT(19.2%).Bleeding manifestations were present in 19.9%patients.PT,INR,aPTT and D-dimer levels were significantly higher(P<0.01)and fibrinogen level was significantly lower(P<0.001)in patients with bleeding compared to patients without bleeding.Patients with bleeding had a significantly higher rate of all coagulation abnormalities than patients without bleeding(P<0.01).Conclusions:Patients with bleeding showed a significantly higher frequency of coagulation abnormalities compared to patients without bleeding.Patients with dengue should be assessed for coagulation abnormalities. 展开更多
关键词 DENGUE Coagulation abnormalities Coagulation parameters Prothrombin time Activated partial thromboplastin time Bleeding manifestations
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Clinical association between coagulation indicators and bone metastasis in patients with gastric cancer
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作者 Xuan Wang Jing-Ya Wang +2 位作者 Min Chen Juan Ren Xin Zhang 《World Journal of Gastrointestinal Oncology》 SCIE 2023年第7期1253-1261,共9页
BACKGROUND Bones are one of the most common target organs for cancer metastasis.Early evaluation of bone metastasis(BM)status is clinically significant.Cancer patients often experience a hypercoagulable state.AIM To e... BACKGROUND Bones are one of the most common target organs for cancer metastasis.Early evaluation of bone metastasis(BM)status is clinically significant.Cancer patients often experience a hypercoagulable state.AIM To evaluate the correlation between coagulation indicators and the burden of BM in gastric cancer(GC).METHODS We conducted a single-center retrospective study and enrolled 454 patients.Clinical information including routine blood examination and coagulation markers were collected before any treatment.Patients were grouped according to the status of BM.Receiver operating characteristic curves were used to assess diagnostic performance and determine the optimal cutoff values of the above indicators.Cutoff values,sensitivity and specificity were based on the maximum Youden index.Univariate and multivariate logistic regression analyses were used to evaluate the relationships between biomarkers and BM.RESULTS Of the 454 enrolled patients,191 patients were diagnosed with BM.The receiver operating characteristic curve analysis suggested that prothrombin time(PT)Wang X et al.Coagulation indicators predict bone metastasis WJGO https://www.wjgnet.com 1254 July 15,2023 Volume 15 Issue 7[cutoff:13.25;sensitivity:0.651;specificity:0.709;area under receiver operating characteristic curve(AUC)=0.738],activated partial thromboplastin time(aPTT)(cutoff:35.15;sensitivity:0.640;specificity:0.640;AUC=0.678)and fibrin degradation products(FDP)(cutoff:2.75;sensitivity:0.668;specificity:0.801;AUC=0.768)act as novel predictors for BM.Based on multivariate logistic regression analysis,the results showed the independent correlation between PT[odds ratio(OR):3.16;95%confidence interval(CI):1.612-6.194;P=0.001],aPTT(OR:2.234;95%CI:1.157-4.313;P=0.017)and FDP(OR:3.17;95%CI:1.637-6.139;P=0.001)and BM in patients with GC.Moreover,age,carcinoembryonic antigen,erythrocyte and globulin were found to be significantly associated with BM.CONCLUSION Coagulation markers,namely PT,aPTT and FDP,might be potential predictors for screening BM in patients with GC. 展开更多
关键词 Gastric cancer Bone metastasis Coagulation markers Risk factor Activated partial thromboplastin time Prothrombin time Fibrin degradation products
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Relevant detection indicator of prethrombotic state in patients with primary hypertension
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作者 Jie Luo Tuo Yang +3 位作者 Lan Ding Jian-Hui Xiong Teng Ying Fen Xu 《World Journal of Clinical Cases》 SCIE 2023年第24期5678-5691,共14页
BACKGROUND Hypertension is a common chronic disease that affects many people worldwide.Only a few reports related to the exploration of relevant indicators of the prethrombotic state in patients with primary hypertens... BACKGROUND Hypertension is a common chronic disease that affects many people worldwide.Only a few reports related to the exploration of relevant indicators of the prethrombotic state in patients with primary hypertension(PH)in clinical settings were available.AIM To detect prethrombotic state-related indicators in patients with PH and analyze their differences in different patient populations to provide a laboratory basis for the clinical prevention and control of hypertensive thrombotic diseases.METHODS The general data of patients with PH who attended the Department of Cardiovascular Medicine,The First Affiliated Hospital of Jiangxi Medical College,from January 2022 to December 2022 were collected retrospectively.The patients were divided into three groups of 40 patients each according to the Grade of PH:Grade 1,Grade 2,and Grade 3 hypertension experimental group.The baseline data of 40 volunteers,who underwent physical examination in our hospital but were not diagnosed with PH during the same period,were included in the control group.The relevant indicators of prethrombotic state of the participants were compared,and mainly included inflammation-related indicators,hemorheology-related indicators,and coagulation function related indicators.The relationship between the aforementioned indicators and the progression of PH was analyzed.RESULTS No significant differences were observed in age,sex,diabetes mellitus,smoking history,drinking history,body mass index,New York Heart Association functional classification,or the course of hypertension among the four groups(P>0.05).The expressions of high-sensitivity C-reactive protein(hs-CRP),thrombomodulin(TM),hematocrit(Hct),erythrocyte sedimentation rate(ESR),P-selectin on platelet surface(CD62P),and fibrinogen(FIB)in the control group were<Grade 1 hypertension group<Grade 2 hypertension group<Grade 3 hypertension group,and the expressions of platelet(PLT),activated partial thromboplastin time(APTT),prothrombin(PT),and plasma thrombin time(TT)in the control group was>Grade 1 hypertension group>Grade 2 hypertension group>Grade 3 hypertension group,and the difference was statistically significant(P<0.05).The results of the multivariate logistic regression model showed that the expression of hs-CRP,TM,Hct,ESR,CD62P,PLT,APTT,PT,TT,and FIB in the included participants was related to the progression of PH.Among these,high expression of hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT,and low expression of PLT and FIB were risk factors for PH(OR>1,P<0.05).The results of the receiver operating characteristic curve analysis showed that the area under the curve of hs-CRP,TM,ESR,CD62P,APTT,PT,TT,and FIB for the prediction of PH were>0.80,and the prediction value was ideal.Linear correlation analysis with bivariate Spearman showed that hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT were positively correlated with each other(r>0,P<0.05);PLT and FIB were negatively correlated with hs-CRP,TM,Hct,ESR,CD62P,APTT,PT,and TT(r<0,P<0.05);and PLT and FIB were positively correlated(r>0,P<0.05).Linear correlation analysis using bivariate Spearman showed that hs-CRP,TM,Hct,ESR,CD62P,and FIB were positively correlated with each other(r>0,P<0.05),whereas PLT,APTT,PT,and TT were negatively correlated with hs-CRP,TM,Hct,ESR,CD62P,and FIB(r<0,P<0.05).There was a positive correlation between PLT,APTT,PT,and TT(r>0,P<0.05).CONCLUSION The relevant indicators of the prethrombotic state in patients with PH,such as hs-CRP,TM,Hct,ESR,CD62P,PLT,APTT,PT,TT,and FIB,showed differences.High expression of hs-CRP,TM,Hct,ESR,CD62P,and FIB,and low expression of PLT,APTT,PT,and TT are the keys to the occurrence,progression,and thrombotic state of PH.Based on the above serum indicators’expression in patients,targeted interventions can be administered to patients with abnormal expression levels to control the progression of their disease and reduce the risk of developing a prethrombotic state. 展开更多
关键词 Primary hypertension Prethrombotic state HEMATOCRIT P-selectin on platelet surface Activated partial thromboplastin time Erythrocyte sedimentation rate
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Production and Evaluation of Synthetic Carbonated Sand as an Adsorbent Media for Batch Adsorption Process
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作者 Rafa Hashim A1-Suhaili Diheyaa Waj id Abbood Haider Ali Mehdi 《Journal of Environmental Science and Engineering(A)》 2013年第7期453-463,共11页
An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsi... An attempt was made to improve the adsorption capability of the normal sand to be used as adsorbent for phenol and cadmium This has been done by producing a coated sand media. The coating process was done using emulsion asphalt to convert the normal sand to carbonated sand by using chemical treatment with sulfuric acid. The production process involves mixing of the sand with asphalt and an acid, then subjecting the mix to a heating process. Different mixing ratios, heating temperatures and times (activation times) were tried to obtain the optimum conditions at which the highest removal efficiency is obtained. Three types of acids were tried acetic acid, phosphoric acid and sulfuric acid. It was found that the sulfuric acid requires the lowest activation time, hence selected for the production. The removal efficiency of the produced media was significantly affected by the temperature, mixing ratio and activation heating time. The results show that, the optimum conditions for the production process are 350 , (1:2:3) (Asphalt/acid/sand) and 52 min for temperature, mixing ratio and activation heating time respectively. The final product was tested and found effective as an adsorbent media for phenol and cadmium. The removal efficiencies of these two pollutants in a batch adsorber were found 82.42% and 86.67%, respectively. The X-R diffraction and FTIR spectra tests had proved this media as an adsorbent. 展开更多
关键词 Carbonated sand adsorbent media organic and inorganic emulsion asphalt optimum conditions mixing ratio activation time removal efficiency.
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Mineralogical and Active Mechanical Excitation Characteristics of Filled Fly Ash Cementitious Materials 被引量:7
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作者 杜雨婷 WANG Hongfu +2 位作者 WANG Zhongchang WANG Zechuan XIA Hongchun 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2017年第2期413-416,共4页
To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of var... To reveal the influence of mechanical activation on the performance of fly ash, the microanalysis(the energy spectroscopy, XRD and SEM), the distribution size of particle of fly ash and cement paste intensity of various age for different grinding time were studied. The relationships of the activity and the composition of fly ash, microstructure and the distribution of particle size by mechanical activation of fly ash were obtained. The internal glass beads with activity were released by grinding fly ash for a certain time. The particle specific surface area was improved and the hydration reaction of the interface and the surface active center was increased by grinding. The granularity distributing of fly-ash trended towards optimization. The polar molecules or ions were easier to intrude into the internal cavity of the vitreous body. The active silica and alumina of fly ash were rapidly depolymerized. Each performance index of fly ash was increased before grinding for 20 min. Cement paste intensity of various age increased along with the grinding time, and the early strength increase range was big, but the later period intensity increase range hastened slightly. The internal part of vitreous of fly ash was destroyed if the fly ash continued to be ground and the activity of fly ash was reduced. It is suggested that Guozhuang's fly ash should be ground for 20 min. 展开更多
关键词 fly ash mineral composition the distribution of particle size milling time activity
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Spatio-temporal patterns of satellite-derived grassland vegetation phenology from 1998 to 2012 in Inner Mongolia, China 被引量:13
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作者 SHA Zongyao ZHONG Jialin +2 位作者 BAI Yongfei TAN Xicheng Jonathan LI 《Journal of Arid Land》 SCIE CSCD 2016年第3期462-477,共16页
Spatio-temporal variations of vegetation phenology, e.g. start of green-up season(SOS) and end of vegetation season(EOS), serve as important indicators of ecosystems. Routinely processed products from remotely sen... Spatio-temporal variations of vegetation phenology, e.g. start of green-up season(SOS) and end of vegetation season(EOS), serve as important indicators of ecosystems. Routinely processed products from remotely sensed imagery, such as the normalized difference vegetation index(NDVI), can be used to map such variations. A remote sensing approach to tracing vegetation phenology was demonstrated here in application to the Inner Mongolia grassland, China. SOS and EOS mapping at regional and vegetation type(meadow steppe, typical steppe, desert steppe and steppe desert) levels using SPOT-VGT NDVI series allows new insights into the grassland ecosystem. The spatial and temporal variability of SOS and EOS during 1998–2012 was highlighted and presented, as were SOS and EOS responses to the monthly climatic fluctuations. Results indicated that SOS and EOS did not exhibit consistent shifts at either regional or vegetation type level; the one exception was the steppe desert, the least productive vegetation cover, which exhibited a progressive earlier SOS and later EOS. Monthly average temperature and precipitation in preseason(February, March and April) imposed most remarkable and negative effects on SOS(except for the non-significant impact of precipitation on that of the meadow steppe), while the climate impact on EOS was found to vary considerably between the vegetation types. Results showed that the spatio-temporal variability of the vegetation phenology of the meadow steppe, typical steppe and desert steppe could be reflected by the monthly thermal and hydrological factors but the progressive earlier SOS and later EOS of the highly degraded steppe desert might be accounted for by non-climate factors only, suggesting that the vegetation growing period in the highly degraded areas of the grassland could be extended possibly by human interventions. 展开更多
关键词 phenological timing degradation harmonic analysis human activity climate restoration
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Rediscussion on the seismic regime network
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作者 王泽皋 孙佩卿 +3 位作者 高景春 李淑莲 张雪 郭妍 《Acta Seismologica Sinica(English Edition)》 CSCD 1994年第3期369-377,共9页
On the basis of the past research and utilization on the windows and belts of seismic regime, the seismic regime network which has been supposed and proved in the past is set up by using the monthly frequency data of ... On the basis of the past research and utilization on the windows and belts of seismic regime, the seismic regime network which has been supposed and proved in the past is set up by using the monthly frequency data of small earthquakes from 1970 to 1991 over the whole country. Through checking its function in practice, it is found that the spatial distribution of precursor information is not an isolate window or belt, but a broad precursor information field before the Ms≥7. 0 earthquakes in China and its nearby regions. According to the windows and belts in the field, synchronism and generality of initial time and place of prediction, the comprehensive prediction of activity time periods of groups of strong earthquakes and the detail method of correspondence of groups are proposed. After restrict mathematical test, 10 prediction methods for references are set forth, in which two best methods are selected as references for the whole case prediction in one to three years. Some related problems are discussed at the end of this paper. 展开更多
关键词 seismic regime network seismic precursor information field comprehensive prediction period of activity time
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Timing and Classication of Patellofemoral Osteoarthritis Patients Using Fast Large Margin Classifier
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作者 Mai Ramadan Ibraheem Jilan Adel +3 位作者 Alaa Eldin Balbaa Shaker El-Sappagh Tamer Abuhmed Mohammed Elmogy 《Computers, Materials & Continua》 SCIE EI 2021年第4期393-409,共17页
:Surface electromyogram(sEMG)processing and classication can assist neurophysiological standardization and evaluation and provide habitational detection.The timing of muscle activation is critical in determining vario... :Surface electromyogram(sEMG)processing and classication can assist neurophysiological standardization and evaluation and provide habitational detection.The timing of muscle activation is critical in determining various medical conditions when looking at sEMG signals.Understanding muscle activation timing allows identication of muscle locations and feature validation for precise modeling.This work aims to develop a predictive model to investigate and interpret Patellofemoral(PF)osteoarthritis based on features extracted from the sEMG signal using pattern classication.To this end,sEMG signals were acquired from ve core muscles over about 200 reads from healthy adult patients while they were going upstairs.Onset,offset,and time duration for the Transversus Abdominus(TrA),Vastus Medialis Obliquus(VMO),Gluteus Medius(GM),Vastus Lateralis(VL),and Multidus Muscles(ML)were acquired to construct a classication model.The proposed classication model investigates function mapping from real-time space to a PF osteoarthritis discriminative feature space.The activation feature space of muscle timing is used to train several large margin classiers to modulate muscle activations and account for such activation measurements.The fast large margin classier achieved higher performance and faster convergence than support vector machines(SVMs)and other state-of-the-art classiers.The proposed sEMG classication framework achieved an average accuracy of 98.8%after 7 s training time,improving other classication techniques in previous literature. 展开更多
关键词 literature.Keywords:Muscle activation onset time LS-SVM surface electromyogram patellofemoral osteoarthritis the timing of core muscles
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Behavioural and energetic consequences of competition among three overwintering swan(Cygnus spp.)species
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作者 Kevin A.Wood Julia L.Newth +1 位作者 Geoff M.Hilton Eileen C.Rees 《Avian Research》 SCIE CSCD 2021年第4期707-721,共15页
Background:Winter numbers of the northwest European population of Bewick's Swans(Cygnus columbianus bewickii)declined recently by c.40%.During the same period,numbers of two sympatric and ecologically-similar cong... Background:Winter numbers of the northwest European population of Bewick's Swans(Cygnus columbianus bewickii)declined recently by c.40%.During the same period,numbers of two sympatric and ecologically-similar congeners,the Mute Swan(Cygnus olor)and Whooper Swan(Cygnus cygnus)showed increases or stability.It has been suggested that these opposing population trends could have a causal relationship,as Mute and Whooper Swans are larger and competitively dominant to Bewick's Swans in foraging situations.If so,effects of competition of Mute and Whooper Swans on Bewick's Swans should be detectable as measurable impacts on behaviour and energetics.Methods:Here,we studied the diurnal behaviour and energetics of 1083 focal adults and first-winter juveniles("cygnets")of the three swan species on their winter grounds in eastern England.We analysed video recordings to derive time-activity budgets and these,together with estimates of energy gain and expenditure,were analysed to determine whether individual Bewick's Swans altered the time spent on key behaviours when sharing feeding habitat with other swan species,and any consequences for their energy expenditure and net energy gain.Results:All three swan species spent a small proportion of their total time(0.011)on aggressive interactions,and these were predominantly intraspecific(≥0.714).Mixed-effects models indicated that sharing feeding habitat with higher densities of Mute and Whooper Swans increased the likelihood of engaging in aggression for cygnet Bewick's Swans,but not for adults.Higher levels of interspecific competition decreased the time spent by Bewick's Swan cygnets on foraging,whilst adults showed the opposite pattern.When among low densities of conspecifics(<c.200 individuals/km^(2)),individual Bewick's Swans spent more time on vigilance in the presence of higher densities of Mute and Whooper Swans,whilst individuals within higher density Bewick's Swan flocks showed the opposite pattern.Crucially,we found no evidence that greater numbers of interspecific competitors affected the net energy gain of either adult or cygnet Bewick's Swans.Conclusions:We found no evidence that Bewick's Swan net energy gain was affected by sharing agricultural feeding habitat with larger congeners during winter.This was despite some impacts on the aggression,foraging and vigilance behaviours of Bewick's Swans,especially among cygnets.It is unlikely therefore that competition between Bewick's Swans and either Mute or Whooper Swans at arable sites in winter has contributed to the observed decline in Bewick's Swan numbers.Further research is needed,however,to test for competition in other parts of the flyway,including migratory stopover sites and breeding areas. 展开更多
关键词 Avian behaviour Energy expenditure ETHOLOGY Interference competition Interspecific interactions time activity budgets Video observations
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Melting Properties of Loose and Granulated Glass Batch
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作者 王静 DENG Zhenglu +3 位作者 谢俊 CHENG Jinshu HAN Jianjun ZHOU Xuedong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2014年第6期1161-1164,共4页
The physical properties, the pre-reacting performance and melting properties of the loose glass batch and the granulated glass batch were investigated, respectively. The experimental results showed that compacted glas... The physical properties, the pre-reacting performance and melting properties of the loose glass batch and the granulated glass batch were investigated, respectively. The experimental results showed that compacted glass batch could reduce dust, use ultra-fine powder, and improve heat transfer efficiency. When loose glass batch was compressed into granular, the thermal conductivity was increased from 0.273 W/m·℃ to 0.430 W/m·℃, the activation energy Ea of pre-reacting decreased from 178.77 k J/mol to 143.30 k J/mol. Using the pre-reacted granular glass batch can significantly reduce the melting time, increase the batch melting rate, and decrease the heat consumption of 1kg molten glass from 3591.24 to 3277.03 kJ/kg. 展开更多
关键词 pre-reacting activation energy melting time
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Long-term optical flux and colour variability in quasars
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作者 N.Sukanya C.S.Stalin +3 位作者 S.Jeyakumar D.Praveen Amab Dhani R.Damle 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第2期63-68,共6页
We have used optical V and R band observations from the Massive Compact Halo Object (MACHO) project on a sample of 59 quasars behind the Magellanic clouds to study their long term optical flux and colour variations.... We have used optical V and R band observations from the Massive Compact Halo Object (MACHO) project on a sample of 59 quasars behind the Magellanic clouds to study their long term optical flux and colour variations. These quasars, lying in the redshift range of 0.2 〈 z 〈 2.8 and having apparent V band magnitudes between 16.6 and 20.1 mag, have observations ranging from 49 to 1353 epochs span- ning over 7.5 yr with frequency of sampling between 2 to 10 days. All the quasars show variability during the observing period. The normalised excess variance (Fvar) in V and R bands are in the range 0.2% 〈 F^r 〈 1.6% and 0.1% 〈 Fnr 〈 1.5% respectively. In a large fraction of the sources, Fvar is larger in the V band compared to the R band. From the z-transformed discrete cross-correlation function analysis, we find that there is no lag between the V and R band variations. Adopting the Markov Chain Monte Carlo (MCMC) approach, and properly taking into account the correlation between the errors in colours and mag- nitudes, it is found that the majority of sources show a bluer when brighter trend, while a minor fraction of quasars show the opposite behaviour. This is similar to the results obtained from another two independent algorithms, namely the weighted linear least squares fit (FITEXY) and the bivariate correlated errors and intrinsic scatter regression (BCES). However, the ordinary least squares (OLS) fit, normally used in the colour variability studies of quasars, indicates that all the quasars studied here show a bluer when brighter trend. It is therefore very clear that the OLS algorithm cannot be used for the study of colour variability in quasars. 展开更多
关键词 time lag -- periodicity -- active galaxies -- quasars
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Active suspension with optimal control based on a full vehicle model
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作者 张军伟 陈思忠 赵玉壮 《Journal of Beijing Institute of Technology》 EI CAS 2016年第1期81-90,共10页
The 7-DOF model of a full vehicle with an active suspension is developed in this paper.The model is written into the state equation style.Actuator forces are treated as inputs in the state equations.Based on the basic... The 7-DOF model of a full vehicle with an active suspension is developed in this paper.The model is written into the state equation style.Actuator forces are treated as inputs in the state equations.Based on the basic optimal control theory,the optimal gains for the control system are figured out.So an optimal controller is developed and implemented using Matlab/Simulink,where the Riccati equation with coupling terms is deduced using the Hamilton equation.The all state feedback is chosen for the controller.The gains for all vehicle variables are traded off so that majority of indexes were up to optimal.The active suspension with optimal control is simulated in frequency domain and time domain separately,and compared with a passive suspension.Throughout all the simulation results,the optimal controller developed in this paper works well in the majority of instances.In all,the comfort and ride performance of the vehicle are improved under the active suspension with optimal control. 展开更多
关键词 active suspension full vehicle model optimal control frequencydomain time domain
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Thermal Transfer During the Activation Process in LiSi/FeS2 Thermal Batteries 被引量:7
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作者 KANG Bo ZHANG Wenli +3 位作者 LIN Haibo XING Yonghui ZHAO Jinfeng WANG Yan 《Chemical Research in Chinese Universities》 SCIE CAS CSCD 2016年第4期665-668,共4页
Thermal batteries(TBs) as primary power sources are widely applied in defense and military affairs, and used in electronic packages and nuclear weapons. The activation time(AT) of TBs restricts the reactive speed ... Thermal batteries(TBs) as primary power sources are widely applied in defense and military affairs, and used in electronic packages and nuclear weapons. The activation time(AT) of TBs restricts the reactive speed of them. Therefore, it is a remarkably important parameter and needs to be studied in detail. In our previous study, the thermal transfer model has already been found during the activation process in TBs. In this work, the experimental TBs were fabricated and tested for validating the model. The error between the average value of test and calculation value from this model is less than 1%. As a result, the thermal transfer function for the activation process in the given TBs[FeSJLiC1-KCI(MgO)/LiSi containing Fe/KC104 heat pellet] is suggested. 展开更多
关键词 Thermal battery activation time Thermal transfer model Thermal transfer function
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