Through long-term production and maintenance practice,various types of stacking steel in the 2250mm hot rolling coiler of Ma Steel were tracked and analyzed,and the causes of stacking steel were summarized.Cor-respond...Through long-term production and maintenance practice,various types of stacking steel in the 2250mm hot rolling coiler of Ma Steel were tracked and analyzed,and the causes of stacking steel were summarized.Cor-responding measures were formulated to effectively reduce the probability of stacking steel.展开更多
This paper analyzes the causes of the offshore strength enhancement of Typhoon Tiange (No. 1713) from four aspects: high and low layer divergence, vertical wind shear, southwest monsoon transport, offshore sea tempera...This paper analyzes the causes of the offshore strength enhancement of Typhoon Tiange (No. 1713) from four aspects: high and low layer divergence, vertical wind shear, southwest monsoon transport, offshore sea temperature and weak cold air. The conclusions are as follows: The high-level airflow divergence enhancement and positive vorticity advection in the offshore, strengthen the middle rise movement of the “Tiange”, and the ascending movement enhances the strength of the “Tiange” by strengthening the lower layer convergence;The high offshore sea temperature and sea temperature are changing temperature, which also has a certain effect on the strengthening of “Tiange” in the offshore;The strengthening of the southwest warm and humid airflow provides sufficient water vapor and energy for the development of “Tiange”, which is beneficial to the maintenance of the typhoon warm heart structure;The intrusion of weak cold air, enhanced the radiation cooperation of the lower typhoon disturbance, which is beneficial to the enhancement of “Tiange”.展开更多
The red tide event of 11 ̄28, May in 1987 was caused by Eucampia zoodiacus, a coastal eurythermic phytoplanktou. Results from the field monitoring indicated that during the red tide occurrence the optimal temperature ...The red tide event of 11 ̄28, May in 1987 was caused by Eucampia zoodiacus, a coastal eurythermic phytoplanktou. Results from the field monitoring indicated that during the red tide occurrence the optimal temperature and salinity for the multiplication of the red tide organism were 20 ̄25℃ and 26 ̄28. During the red tide event cell densities in two peak values both reached 3 000×103ind. /din3. Organism number in horizonal distribution increased from the harbour mouth to the inner harbour. Average number of the organism at the monitoring stations in the inner harbour was 2 930×103 md. /dm3 which was 3. 7 and 61 times higher than that at the two control monitoring stations. The organism number in vertical distribution apparently showed stepwise, day and night changes. Daily change of the phytoplankton number with spring and ebb tides exhibited a negative relativity.Major reasons for this red tide event included species competition of red tide organisms, sudden increment in water temperature in short time, sharp decrement in salinity by rainfall, water eutrophication, high contents of stimulating materials such as Fe and Mn, poor water exchange condition and stable synoptic condition, etc.High content of dissolved oxygen and high pH value was resulted from the photosythesis of a great quantity of the red tide organisms.展开更多
Storms that occur at the Bay of Bengal(Bo B) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the...Storms that occur at the Bay of Bengal(Bo B) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the Bo B are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the Bo B storm activity, and the "bimodal period" of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the"bimodal pattern"storm activity in the Bo B. The analysis on sea surface temperature(SST) shows that the SSTs of all the year around in the Bo B area meet the conditions required for the generation of tropical cyclones(TCs). However,the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a "two-peak"storm activity pattern. The genesis potential index(GPI) quantifies and reflects the environmental conditions for the generation of the Bo B storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.展开更多
Root-cause identification plays a vital role in business decision making by providing effective future directions for the organizations.Aspect extraction and sentiment extraction plays a vital role in identifying the ...Root-cause identification plays a vital role in business decision making by providing effective future directions for the organizations.Aspect extraction and sentiment extraction plays a vital role in identifying the rootcauses.This paper proposes the Ensemble based temporal weighting and pareto ranking(ETP)model for Root-cause identification.Aspect extraction is performed based on rules and is followed by opinion identification using the proposed boosted ensemble model.The obtained aspects are validated and ranked using the proposed aspect weighing scheme.Pareto-rule based aspect selection is performed as the final selection mechanism and the results are presented for business decision making.Experiments were performed with the standard five product benchmark dataset.Performances on all five product reviews indicate the effective performance of the proposed model.Comparisons are performed using three standard state-of-the-art models and effectiveness is measured in terms of F-Measure and Detection rates.The results indicate improved performances exhibited by the proposed model with an increase in F-Measure levels at 1%–15%and detection rates at 4%–24%compared to the state-of-the-art models.展开更多
[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information syste...[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information system as data processing platform,statistical methods such as synthesis analysis and correlation analysis were combined to contrast and analyze the flood cause in the Nenjiang Basin between 2013 and1998.[Result]The similarities of two floods in Nenjiang Basin were that rainstorm frequency and summer precipitation were more,and many large and medium-sized reservoirs which undertook the flood control task were running above flood level.In order to protect the safety of reservoir dam,flood discharge volume increased.And the difference was external forcing factor which caused atmospheric circulation abnormality,thus the impact factors of summer more rainfall were not the same.The main reason for more precipitation in Nenjiang Basin in summer of 2013:The northeast cold vortex activity was frequent,and the path was by north;water vapor transport was sufficient at 850 hPa;at 500 hPa,the Eurasian zonal circulation was weak,the West Pacific subtropical high pressure abnormally moved northward,blocking high of the Sea of Okhotsk was obvious,and Heilongjiang region was controlled by negative anomaly in midsummer;East Asian westerly jet location was abnormal at 200 hPa,and East Asian summer monsoon was strong.[Conclusion]The research had very important significance for understanding occurrence rule of flood and improving disaster prevention and mitigation capabilities in Nenjiang Basin.展开更多
[Objective]The research aimed to study climatic change characteristics of sunshine hours in Lianyungang and analyze its formation reason. [Method]Based on monthly sunshine hours,precipitation,cloudiness,haze days and ...[Objective]The research aimed to study climatic change characteristics of sunshine hours in Lianyungang and analyze its formation reason. [Method]Based on monthly sunshine hours,precipitation,cloudiness,haze days and vapor pressure from 7 stations of Lianyungang from 1961 to 2010,monthly,seasonal,annual and interdecadal change trends of the sunshine hours were analyzed by using MK test,linear trend analysis and Morlet wavelet. Meanwhile,the cause of change characteristics was analyzed. [Result] Monthly sunshine hours of Lianyungang showed bimodal distribution,and seasonal and annual sunshine hours had decreasing trend at different degrees. The interdecadal change of sunshine hours showed wave characteristics. The annual sunshine hours had multiple temporal-spatial scale features,and there was an obvious mutation in the late 1980s. Sunshine hours in Lianyungang was closely related to visibility,cloudiness,vapor pressure and haze,and they were important factors causing that sunshine hours significantly declined. [Conclusion]The research could provide reference basis for scientifically developing and using solar energy resource and reasonably adjusting industrial and agricultural structures.展开更多
The analysis of the crack on the HRB400 screw-thread steel surface has been carried out by means of metallographic microscope, scanning electron microscope and EDAX. It is shown that the type of inclusions in the crac...The analysis of the crack on the HRB400 screw-thread steel surface has been carried out by means of metallographic microscope, scanning electron microscope and EDAX. It is shown that the type of inclusions in the crack steel samples is mainly class B oxide, C silicate, and the inclusion size of the majority below 10 μm, and a small number of large inclusions are observed. The content of oxygen in the steel is high, and the carbon segregation is the main reason of the crack formation of HRB400 screw-thread steel. The measures to improve the crack formation of HRB400 screw-thread steel are put forward, which provides a powerful basis for the practical production.展开更多
A lightning strike accident of a residential house in the rural areas of Neijiang is analyzed through on-site investigation,and the causes are discussed. Defensive measures of lightning disasters are proposed to provi...A lightning strike accident of a residential house in the rural areas of Neijiang is analyzed through on-site investigation,and the causes are discussed. Defensive measures of lightning disasters are proposed to provide reference for the prevention of lightning disasters in the construction of new countryside.展开更多
Objective:To explore the status of self-perceived burden(SPB)in primary glaucoma patients and to analyze its influencing factors.Subject and setting:A questionnaire survey was administered to 236 inpatients from a ter...Objective:To explore the status of self-perceived burden(SPB)in primary glaucoma patients and to analyze its influencing factors.Subject and setting:A questionnaire survey was administered to 236 inpatients from a tertiary general hospital and a eye hospital in Tianjin.The investigation was conducted after obtaining informed consent from each participant.Instruments:They were investigated using general data questionnaire,Self-Perceived Burden Scale(SPBS),Medical Coping Modes Questionnaire(MCMQ).Design:A descriptive cross-sectional design was used to gather data in this study.Results:The total SPBS score of primary glaucoma patients was(31.10±9.34)was medium.Regression consults showed that avoidance and surrender coping style,medical burden and right eye vision were the influencing factors of patients’SPB(P<0.05).Conclusion:Patients with primary glaucoma have a relatively heavy SPB,so medical staff should encourage them to actively face it.Tailored strategies in line with the patient’s economic and visual conditions to reduce the SPB.展开更多
Some factors (i.e. lithology, topography, climate, the change of population as well as land use during the past 50 years) that could have great influence on the development of gully in the arid-hot basin of Jinshaji...Some factors (i.e. lithology, topography, climate, the change of population as well as land use during the past 50 years) that could have great influence on the development of gully in the arid-hot basin of Jinshajiang valley were investigated. The results show that the factors leading to the strong gully erosion in this area include: the widely distributed Yuanmou group stratum, which promotes the development of gully erosion; the unique geomorphologic configuration that is prone to rock fall and gully erosion; the strong and time-concentrated rainfall; the arid-humid alternate climate characteristics that prepares the ground for the development of fissures in soils; the arid-hot climate that goes against the growth and recovery of vegetation; and the unreasonable and abusive human activities.展开更多
[Objective] The research aimed to analyze difference of the observation data by transfer station in Nanning National Weather Station. [Method] By using observation data (atmospheric pressure, temperature, relative hum...[Objective] The research aimed to analyze difference of the observation data by transfer station in Nanning National Weather Station. [Method] By using observation data (atmospheric pressure, temperature, relative humidity, wind direction and speed, precipitation, sunshine, etc.) from January to December in 2000 at old and new Nanning National Weather Station, difference of the each meteorological factor was contrasted. Main reason for difference of the each meteorological factor was analyzed from altitude, underlying surface property and station environment. [Result] Atmospheric pressure and temperature at new station were both lower than that at old station, while relative humidity and wind speed were both higher than that at old station. Rainfall and sunshine had big differences at new and old stations, but variation did not have rule. Main reasons for obvious difference of the meteorological factor were that altitude, observation environment, terrain and underlying surface property at new and old stations were different. Influences of the altitude and observation environment were especially significant. [Conclusion] The research provided basis for continuity and homogeneity correction of the data sequence at Nanning National Weather Station.展开更多
Modern industrial systems are usually in large scale,consisting of massive components and variables that form a complex system topology.Owing to the interconnections among devices,a fault may occur and propagate to ex...Modern industrial systems are usually in large scale,consisting of massive components and variables that form a complex system topology.Owing to the interconnections among devices,a fault may occur and propagate to exert widespread influences and lead to a variety of alarms.Obtaining the root causes of alarms is beneficial to the decision supports in making corrective alarm responses.Existing data-driven methods for alarm root cause analysis detect causal relations among alarms mainly based on historical alarm event data.To improve the accuracy,this paper proposes a causal fusion inference method for industrial alarm root cause analysis based on process topology and alarm events.A Granger causality inference method considering process topology is exploited to find out the causal relations among alarms.The topological nodes are used as the inputs of the model,and the alarm causal adjacency matrix between alarm variables is obtained by calculating the likelihood of the topological Hawkes process.The root cause is then obtained from the directed acyclic graph(DAG)among alarm variables.The effectiveness of the proposed method is verified by simulations based on both a numerical example and the Tennessee Eastman process(TEP)model.展开更多
The geological condition and the original structure feature and foundation design of Wuhan Tianheng building are described. The accident appearance of pile foundation in the construction execution of work is illustrat...The geological condition and the original structure feature and foundation design of Wuhan Tianheng building are described. The accident appearance of pile foundation in the construction execution of work is illustrated. The generating source of this pile foundation accident is analyzed in great details.展开更多
[Objective] The aim was to study the reasons for consecutive severe droughts in autumn and winter. [Method] By dint of precipitation in the observatory station and NCEP/NCAR reanalysis data in observatory station, the...[Objective] The aim was to study the reasons for consecutive severe droughts in autumn and winter. [Method] By dint of precipitation in the observatory station and NCEP/NCAR reanalysis data in observatory station, the circulation background, vertical movement, abnormal temperature and changes of water vapor conditions in Xuzhou from October 2008 to January 2009 were expounded to reveal the causes for consecutive drought in autumn and winter. [Result] Xuzhou was under stable situation for a long time in autumn and winter in 2008, being behind east coastal trough, the downward airstream prevailing; the south trough intensity was weak, and in addition to the east subtropical high and weak intensity, the water vapor transportation condition in Indian Ocean and South Sea was unfavorable. The autumn was warm and the cold air was weak; ever since winter, there were several cold air activities. But the influencing body was in the east, and the south warm and wet airstream was insufficient. Thus, they couldn’t met, which resulted into gale and lower temperature and less precipitation when under the influence of cold air. [Conclusion] The study provided theoretical basis for the prevention of drought in the area.展开更多
Based on data of haze days observed by Puyang Meteorological Station of Henan Province from 1971 to 2012, climatic characteristics, causes and prevention countermeasures of haze in Puyang were discussed. The results s...Based on data of haze days observed by Puyang Meteorological Station of Henan Province from 1971 to 2012, climatic characteristics, causes and prevention countermeasures of haze in Puyang were discussed. The results showed that annual average haze days in Puyang tended to increase slightly over the past 42 years on the whole, and the increasing trend became obvious since the 1990s. Meanwhile, haze days in Puyang showed an obvious seasonal variation, that is, haze mainly appeared in autumn (from September to November) and winter (from December to next February), and it was the most frequent in winter. Haze formation was closely related to meteorological and environment elements. Increase of calm wind in horizontal direction, inversion layer in vertical direction, and increase of suspended particulate matter could lead to aggregation of air pollutants, so that haze days increased. Some countermeasures against haze pollution, such as controlling pollution sources, limiting discharge of vehicle exhaust and industrial gases, and increasing green area, should be adopted to reduce haze harm to air quality and human health.展开更多
A distributed information network with complex network structure always has a challenge of locating fault root causes.In this paper,we propose a novel root cause analysis(RCA)method by random walk on the weighted faul...A distributed information network with complex network structure always has a challenge of locating fault root causes.In this paper,we propose a novel root cause analysis(RCA)method by random walk on the weighted fault propagation graph.Different from other RCA methods,it mines effective features information related to root causes from offline alarms.Combined with the information,online alarms and graph relationship of network structure are used to construct a weighted graph.Thus,this approach does not require operational experience and can be widely applied in different distributed networks.The proposed method can be used in multiple fault location cases.The experiment results show the proposed approach achieves much better performance with 6%higher precision at least for root fault location,compared with three baseline methods.Besides,we explain how the optimal parameter’s value in the random walk algorithm influences RCA results.展开更多
In order to comprehensively understand the water quality in Yinma River Basin,and to analyze the spatial-temporal variation characteristics of water quality over the years and the causes of water pollution,15 sections...In order to comprehensively understand the water quality in Yinma River Basin,and to analyze the spatial-temporal variation characteristics of water quality over the years and the causes of water pollution,15 sections were selected in the Yinma River Basin.Based on the water quality monitoring data in the past decade,7 evaluation indexes including dissolved oxygen(DO),5-day biochemical oxygen demand(BOD_(5)),permanganate index(COD_(MN)),chemical oxygen demand(COD),ammonia nitrogen(NH_(4)-N),total phosphorus(TP)and total nitrogen(TN)were determined,according to the Environmental Quality Standard for Surface Water(GB3838-2002)and the historical monitoring data of rivers.The water quality of 15 sections in Yinma River Basin was comprehensively evaluated,and the water quality categories and the evolution of river water quality were analyzed.The pollution sources of Yinma River Basin were analyzed,and the constructive countermeasures were put forward according to the conclusions.展开更多
The paper discusses the framework for a risk-informed root cause analysis process.Such process enables scaling of the analysis performed based on the risk associated with the undesired event or condition,thereby creat...The paper discusses the framework for a risk-informed root cause analysis process.Such process enables scaling of the analysis performed based on the risk associated with the undesired event or condition,thereby creating tiers of analysis where the greater the risk,the more sophisticated the analysis.In a risk-informed root cause analysis process,a situation is normally not analyzed at a level less than what actually occurred.However,a situation may be investigated as though the consequence were greater than actually happened,especially if only slight differences in circumstances could result in a significantly higher consequence.While operational events or safety issues are normally expected to result only with negligible or marginal actual consequences,many of those would actually have certain potential to develop or propagate into catastrophic events.This potential can be expressed qualitatively or quantitatively.Risk-informing of root cause analysis relies on mapping the event or safety issue into a risk matrix which,traditionally,is a two-dimensional probability-consequence matrix.A new concept employed in the risk matrix for root cause analysis is that,while the probability reflects the observed or expected range of values(retaining,thus,its“traditional”meaning),the consequence reflects not only the observed or materialized impact(such as failure of equipment)but,also,its potential to propagate or develop into highly undesirable final state.The paper presents main elements of risk-informed root cause analysis process and discusses qualitative and quantitative aspects and approaches to determination of risk significance of operational events or safety issues.展开更多
Based on the 58 years monthly flow data (from 1956 to 2013) editing by Jingle hydrological station of Fen River and Shangjinyou station, data resources are used to analyze the annual and inter-annual changes from spat...Based on the 58 years monthly flow data (from 1956 to 2013) editing by Jingle hydrological station of Fen River and Shangjinyou station, data resources are used to analyze the annual and inter-annual changes from spatial and temporal scale by statistical methods, mainly annual spatial and temporal distribution, trend of inter-annual changes, cycle and mutation changes. The reasons of runoff into reservoir changes are deeply analyzed by annual precipitation data of catchments above Fenhe Reservoir 1956 to 2013 and the land and water reservation methods which are implemented recently. It shows that there is a significant decrease of the inter-annual run-off with main and second cycle periods, 23a and 13a respectively. Furthermore, it exists mutation point between 1970 and 1971 through runoff series. As for further analysis of the causes of Fenhe Reservoir runoff changes, it illustrates that the change of precipitation is the main reason the facilitate runoff changes. Also, the land and water reservation methods which are implemented in upstream of Fenhe Reservoir increase water storage capacity of soil, showing it non-ignorable effect to runoff changes.展开更多
文摘Through long-term production and maintenance practice,various types of stacking steel in the 2250mm hot rolling coiler of Ma Steel were tracked and analyzed,and the causes of stacking steel were summarized.Cor-responding measures were formulated to effectively reduce the probability of stacking steel.
文摘This paper analyzes the causes of the offshore strength enhancement of Typhoon Tiange (No. 1713) from four aspects: high and low layer divergence, vertical wind shear, southwest monsoon transport, offshore sea temperature and weak cold air. The conclusions are as follows: The high-level airflow divergence enhancement and positive vorticity advection in the offshore, strengthen the middle rise movement of the “Tiange”, and the ascending movement enhances the strength of the “Tiange” by strengthening the lower layer convergence;The high offshore sea temperature and sea temperature are changing temperature, which also has a certain effect on the strengthening of “Tiange” in the offshore;The strengthening of the southwest warm and humid airflow provides sufficient water vapor and energy for the development of “Tiange”, which is beneficial to the maintenance of the typhoon warm heart structure;The intrusion of weak cold air, enhanced the radiation cooperation of the lower typhoon disturbance, which is beneficial to the enhancement of “Tiange”.
文摘The red tide event of 11 ̄28, May in 1987 was caused by Eucampia zoodiacus, a coastal eurythermic phytoplanktou. Results from the field monitoring indicated that during the red tide occurrence the optimal temperature and salinity for the multiplication of the red tide organism were 20 ̄25℃ and 26 ̄28. During the red tide event cell densities in two peak values both reached 3 000×103ind. /din3. Organism number in horizonal distribution increased from the harbour mouth to the inner harbour. Average number of the organism at the monitoring stations in the inner harbour was 2 930×103 md. /dm3 which was 3. 7 and 61 times higher than that at the two control monitoring stations. The organism number in vertical distribution apparently showed stepwise, day and night changes. Daily change of the phytoplankton number with spring and ebb tides exhibited a negative relativity.Major reasons for this red tide event included species competition of red tide organisms, sudden increment in water temperature in short time, sharp decrement in salinity by rainfall, water eutrophication, high contents of stimulating materials such as Fe and Mn, poor water exchange condition and stable synoptic condition, etc.High content of dissolved oxygen and high pH value was resulted from the photosythesis of a great quantity of the red tide organisms.
基金Meteorological Administration Special Public Welfare Research Fund of China(GYHY201106005)National Natural Science Foundation of China(41665004,41205067)
文摘Storms that occur at the Bay of Bengal(Bo B) are of a bimodal pattern, which is different from that of the other sea areas. By using the NCEP, SST and JTWC data, the causes of the bimodal pattern storm activity of the Bo B are diagnosed and analyzed in this paper. The result shows that the seasonal variation of general atmosphere circulation in East Asia has a regulating and controlling impact on the Bo B storm activity, and the "bimodal period" of the storm activity corresponds exactly to the seasonal conversion period of atmospheric circulation. The minor wind speed of shear spring and autumn contributed to the storm, which was a crucial factor for the generation and occurrence of the"bimodal pattern"storm activity in the Bo B. The analysis on sea surface temperature(SST) shows that the SSTs of all the year around in the Bo B area meet the conditions required for the generation of tropical cyclones(TCs). However,the SSTs in the central area of the bay are higher than that of the surrounding areas in spring and autumn, which facilitates the occurrence of a "two-peak"storm activity pattern. The genesis potential index(GPI) quantifies and reflects the environmental conditions for the generation of the Bo B storms. For GPI, the intense low-level vortex disturbance in the troposphere and high-humidity atmosphere are the sufficient conditions for storms, while large maximum wind velocity of the ground vortex radius and small vertical wind shear are the necessary conditions of storms.
文摘Root-cause identification plays a vital role in business decision making by providing effective future directions for the organizations.Aspect extraction and sentiment extraction plays a vital role in identifying the rootcauses.This paper proposes the Ensemble based temporal weighting and pareto ranking(ETP)model for Root-cause identification.Aspect extraction is performed based on rules and is followed by opinion identification using the proposed boosted ensemble model.The obtained aspects are validated and ranked using the proposed aspect weighing scheme.Pareto-rule based aspect selection is performed as the final selection mechanism and the results are presented for business decision making.Experiments were performed with the standard five product benchmark dataset.Performances on all five product reviews indicate the effective performance of the proposed model.Comparisons are performed using three standard state-of-the-art models and effectiveness is measured in terms of F-Measure and Detection rates.The results indicate improved performances exhibited by the proposed model with an increase in F-Measure levels at 1%–15%and detection rates at 4%–24%compared to the state-of-the-art models.
基金Supported by Science and Technology Research Item of Heilongjiang Meteorological Bureau in 2014,China(HQ2014018)
文摘[Objective]The research aimed to analyze and contrast flood cause in Nenjiang Basin between 2013 and 1998.[Method]Based on meteorological and hydrological data in and around Nenjiang Basin,geographic information system as data processing platform,statistical methods such as synthesis analysis and correlation analysis were combined to contrast and analyze the flood cause in the Nenjiang Basin between 2013 and1998.[Result]The similarities of two floods in Nenjiang Basin were that rainstorm frequency and summer precipitation were more,and many large and medium-sized reservoirs which undertook the flood control task were running above flood level.In order to protect the safety of reservoir dam,flood discharge volume increased.And the difference was external forcing factor which caused atmospheric circulation abnormality,thus the impact factors of summer more rainfall were not the same.The main reason for more precipitation in Nenjiang Basin in summer of 2013:The northeast cold vortex activity was frequent,and the path was by north;water vapor transport was sufficient at 850 hPa;at 500 hPa,the Eurasian zonal circulation was weak,the West Pacific subtropical high pressure abnormally moved northward,blocking high of the Sea of Okhotsk was obvious,and Heilongjiang region was controlled by negative anomaly in midsummer;East Asian westerly jet location was abnormal at 200 hPa,and East Asian summer monsoon was strong.[Conclusion]The research had very important significance for understanding occurrence rule of flood and improving disaster prevention and mitigation capabilities in Nenjiang Basin.
基金Supported by Meteorological Youth Fund of Jiangsu Province,China(Q201104)the Project of Science and Technology Bureau in Lianyungang of Jiangsu Province,China(SH1206,SH1013)the Project of Science and Technology Department of Jiangsu Province,China(BE2011720)
文摘[Objective]The research aimed to study climatic change characteristics of sunshine hours in Lianyungang and analyze its formation reason. [Method]Based on monthly sunshine hours,precipitation,cloudiness,haze days and vapor pressure from 7 stations of Lianyungang from 1961 to 2010,monthly,seasonal,annual and interdecadal change trends of the sunshine hours were analyzed by using MK test,linear trend analysis and Morlet wavelet. Meanwhile,the cause of change characteristics was analyzed. [Result] Monthly sunshine hours of Lianyungang showed bimodal distribution,and seasonal and annual sunshine hours had decreasing trend at different degrees. The interdecadal change of sunshine hours showed wave characteristics. The annual sunshine hours had multiple temporal-spatial scale features,and there was an obvious mutation in the late 1980s. Sunshine hours in Lianyungang was closely related to visibility,cloudiness,vapor pressure and haze,and they were important factors causing that sunshine hours significantly declined. [Conclusion]The research could provide reference basis for scientifically developing and using solar energy resource and reasonably adjusting industrial and agricultural structures.
文摘The analysis of the crack on the HRB400 screw-thread steel surface has been carried out by means of metallographic microscope, scanning electron microscope and EDAX. It is shown that the type of inclusions in the crack steel samples is mainly class B oxide, C silicate, and the inclusion size of the majority below 10 μm, and a small number of large inclusions are observed. The content of oxygen in the steel is high, and the carbon segregation is the main reason of the crack formation of HRB400 screw-thread steel. The measures to improve the crack formation of HRB400 screw-thread steel are put forward, which provides a powerful basis for the practical production.
文摘A lightning strike accident of a residential house in the rural areas of Neijiang is analyzed through on-site investigation,and the causes are discussed. Defensive measures of lightning disasters are proposed to provide reference for the prevention of lightning disasters in the construction of new countryside.
文摘Objective:To explore the status of self-perceived burden(SPB)in primary glaucoma patients and to analyze its influencing factors.Subject and setting:A questionnaire survey was administered to 236 inpatients from a tertiary general hospital and a eye hospital in Tianjin.The investigation was conducted after obtaining informed consent from each participant.Instruments:They were investigated using general data questionnaire,Self-Perceived Burden Scale(SPBS),Medical Coping Modes Questionnaire(MCMQ).Design:A descriptive cross-sectional design was used to gather data in this study.Results:The total SPBS score of primary glaucoma patients was(31.10±9.34)was medium.Regression consults showed that avoidance and surrender coping style,medical burden and right eye vision were the influencing factors of patients’SPB(P<0.05).Conclusion:Patients with primary glaucoma have a relatively heavy SPB,so medical staff should encourage them to actively face it.Tailored strategies in line with the patient’s economic and visual conditions to reduce the SPB.
基金the National Key Technologies Research and Development Program in the Eleventh Five-Year Plan of China (2006BAC01A11, 2006BAB04A08)the Open Fund of Key Laboratory of Mountain Hazards and Surface Process, Chinese Academy of Sciences
文摘Some factors (i.e. lithology, topography, climate, the change of population as well as land use during the past 50 years) that could have great influence on the development of gully in the arid-hot basin of Jinshajiang valley were investigated. The results show that the factors leading to the strong gully erosion in this area include: the widely distributed Yuanmou group stratum, which promotes the development of gully erosion; the unique geomorphologic configuration that is prone to rock fall and gully erosion; the strong and time-concentrated rainfall; the arid-humid alternate climate characteristics that prepares the ground for the development of fissures in soils; the arid-hot climate that goes against the growth and recovery of vegetation; and the unreasonable and abusive human activities.
文摘[Objective] The research aimed to analyze difference of the observation data by transfer station in Nanning National Weather Station. [Method] By using observation data (atmospheric pressure, temperature, relative humidity, wind direction and speed, precipitation, sunshine, etc.) from January to December in 2000 at old and new Nanning National Weather Station, difference of the each meteorological factor was contrasted. Main reason for difference of the each meteorological factor was analyzed from altitude, underlying surface property and station environment. [Result] Atmospheric pressure and temperature at new station were both lower than that at old station, while relative humidity and wind speed were both higher than that at old station. Rainfall and sunshine had big differences at new and old stations, but variation did not have rule. Main reasons for obvious difference of the meteorological factor were that altitude, observation environment, terrain and underlying surface property at new and old stations were different. Influences of the altitude and observation environment were especially significant. [Conclusion] The research provided basis for continuity and homogeneity correction of the data sequence at Nanning National Weather Station.
基金supported by the National Natural Science Foundation of China(Nos.61903345 and 61973287)。
文摘Modern industrial systems are usually in large scale,consisting of massive components and variables that form a complex system topology.Owing to the interconnections among devices,a fault may occur and propagate to exert widespread influences and lead to a variety of alarms.Obtaining the root causes of alarms is beneficial to the decision supports in making corrective alarm responses.Existing data-driven methods for alarm root cause analysis detect causal relations among alarms mainly based on historical alarm event data.To improve the accuracy,this paper proposes a causal fusion inference method for industrial alarm root cause analysis based on process topology and alarm events.A Granger causality inference method considering process topology is exploited to find out the causal relations among alarms.The topological nodes are used as the inputs of the model,and the alarm causal adjacency matrix between alarm variables is obtained by calculating the likelihood of the topological Hawkes process.The root cause is then obtained from the directed acyclic graph(DAG)among alarm variables.The effectiveness of the proposed method is verified by simulations based on both a numerical example and the Tennessee Eastman process(TEP)model.
文摘The geological condition and the original structure feature and foundation design of Wuhan Tianheng building are described. The accident appearance of pile foundation in the construction execution of work is illustrated. The generating source of this pile foundation accident is analyzed in great details.
基金Supported by Xuzhou Scientific Program (XM09B023)
文摘[Objective] The aim was to study the reasons for consecutive severe droughts in autumn and winter. [Method] By dint of precipitation in the observatory station and NCEP/NCAR reanalysis data in observatory station, the circulation background, vertical movement, abnormal temperature and changes of water vapor conditions in Xuzhou from October 2008 to January 2009 were expounded to reveal the causes for consecutive drought in autumn and winter. [Result] Xuzhou was under stable situation for a long time in autumn and winter in 2008, being behind east coastal trough, the downward airstream prevailing; the south trough intensity was weak, and in addition to the east subtropical high and weak intensity, the water vapor transportation condition in Indian Ocean and South Sea was unfavorable. The autumn was warm and the cold air was weak; ever since winter, there were several cold air activities. But the influencing body was in the east, and the south warm and wet airstream was insufficient. Thus, they couldn’t met, which resulted into gale and lower temperature and less precipitation when under the influence of cold air. [Conclusion] The study provided theoretical basis for the prevention of drought in the area.
文摘Based on data of haze days observed by Puyang Meteorological Station of Henan Province from 1971 to 2012, climatic characteristics, causes and prevention countermeasures of haze in Puyang were discussed. The results showed that annual average haze days in Puyang tended to increase slightly over the past 42 years on the whole, and the increasing trend became obvious since the 1990s. Meanwhile, haze days in Puyang showed an obvious seasonal variation, that is, haze mainly appeared in autumn (from September to November) and winter (from December to next February), and it was the most frequent in winter. Haze formation was closely related to meteorological and environment elements. Increase of calm wind in horizontal direction, inversion layer in vertical direction, and increase of suspended particulate matter could lead to aggregation of air pollutants, so that haze days increased. Some countermeasures against haze pollution, such as controlling pollution sources, limiting discharge of vehicle exhaust and industrial gases, and increasing green area, should be adopted to reduce haze harm to air quality and human health.
基金supported by ZTE Industry-University-Institute Cooperation Funds under Grant No.HC-CN-20201120009。
文摘A distributed information network with complex network structure always has a challenge of locating fault root causes.In this paper,we propose a novel root cause analysis(RCA)method by random walk on the weighted fault propagation graph.Different from other RCA methods,it mines effective features information related to root causes from offline alarms.Combined with the information,online alarms and graph relationship of network structure are used to construct a weighted graph.Thus,this approach does not require operational experience and can be widely applied in different distributed networks.The proposed method can be used in multiple fault location cases.The experiment results show the proposed approach achieves much better performance with 6%higher precision at least for root fault location,compared with three baseline methods.Besides,we explain how the optimal parameter’s value in the random walk algorithm influences RCA results.
文摘In order to comprehensively understand the water quality in Yinma River Basin,and to analyze the spatial-temporal variation characteristics of water quality over the years and the causes of water pollution,15 sections were selected in the Yinma River Basin.Based on the water quality monitoring data in the past decade,7 evaluation indexes including dissolved oxygen(DO),5-day biochemical oxygen demand(BOD_(5)),permanganate index(COD_(MN)),chemical oxygen demand(COD),ammonia nitrogen(NH_(4)-N),total phosphorus(TP)and total nitrogen(TN)were determined,according to the Environmental Quality Standard for Surface Water(GB3838-2002)and the historical monitoring data of rivers.The water quality of 15 sections in Yinma River Basin was comprehensively evaluated,and the water quality categories and the evolution of river water quality were analyzed.The pollution sources of Yinma River Basin were analyzed,and the constructive countermeasures were put forward according to the conclusions.
文摘The paper discusses the framework for a risk-informed root cause analysis process.Such process enables scaling of the analysis performed based on the risk associated with the undesired event or condition,thereby creating tiers of analysis where the greater the risk,the more sophisticated the analysis.In a risk-informed root cause analysis process,a situation is normally not analyzed at a level less than what actually occurred.However,a situation may be investigated as though the consequence were greater than actually happened,especially if only slight differences in circumstances could result in a significantly higher consequence.While operational events or safety issues are normally expected to result only with negligible or marginal actual consequences,many of those would actually have certain potential to develop or propagate into catastrophic events.This potential can be expressed qualitatively or quantitatively.Risk-informing of root cause analysis relies on mapping the event or safety issue into a risk matrix which,traditionally,is a two-dimensional probability-consequence matrix.A new concept employed in the risk matrix for root cause analysis is that,while the probability reflects the observed or expected range of values(retaining,thus,its“traditional”meaning),the consequence reflects not only the observed or materialized impact(such as failure of equipment)but,also,its potential to propagate or develop into highly undesirable final state.The paper presents main elements of risk-informed root cause analysis process and discusses qualitative and quantitative aspects and approaches to determination of risk significance of operational events or safety issues.
文摘Based on the 58 years monthly flow data (from 1956 to 2013) editing by Jingle hydrological station of Fen River and Shangjinyou station, data resources are used to analyze the annual and inter-annual changes from spatial and temporal scale by statistical methods, mainly annual spatial and temporal distribution, trend of inter-annual changes, cycle and mutation changes. The reasons of runoff into reservoir changes are deeply analyzed by annual precipitation data of catchments above Fenhe Reservoir 1956 to 2013 and the land and water reservation methods which are implemented recently. It shows that there is a significant decrease of the inter-annual run-off with main and second cycle periods, 23a and 13a respectively. Furthermore, it exists mutation point between 1970 and 1971 through runoff series. As for further analysis of the causes of Fenhe Reservoir runoff changes, it illustrates that the change of precipitation is the main reason the facilitate runoff changes. Also, the land and water reservation methods which are implemented in upstream of Fenhe Reservoir increase water storage capacity of soil, showing it non-ignorable effect to runoff changes.