Dynamic Characteristics of Functionally Graded Timoshenko Beams by Improved Differential Quadrature Method

This study proposes an effective method to enhance the accuracy of the Differential Quadrature Method(DQM)for calculating the dynamic characteristics of functionally graded beams by improving the form of discrete node distribution.Firstly,based on the first-order shear deformation theory,the governing equation of free vibration of a functionally graded beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam axial displacement,transverse displacement,and cross-sectional rotation angle by considering the effects of shear deformation and rotational inertia of the beam cross-section.Then,ignoring the shear deformation of the beam section and only considering the effect of the rotational inertia of the section,the governing equation of the beam is transformed into the eigenvalue problem of ordinary differential equations with respect to beam transverse displacement.Based on the differential quadrature method theory,the eigenvalue problem of ordinary differential equations is transformed into the eigenvalue problem of standard generalized algebraic equations.Finally,the first several natural frequencies of the beam can be calculated.The feasibility and accuracy of the improved DQM are verified using the finite element method(FEM)and combined with the results of relevant literature.

Research on Spatial-Temporal Characteristics and Driving Factor of Agricultural Carbon Emissions in China

Macroscopic grasp of agricultural carbon emissions status, spatial-temporal characteristics as well as driving factors are the basic premise in further research on China’s agricultural carbon emissions. Based on 23 kinds of major carbon emission sources including agricultural materials inputs, paddy ifeld, soil and livestock breeding, this paper ifrstly calculated agricultural carbon emissions from 1995 to 2010, as well as 31 provinces and cities in 2010 in China. We then made a decomposed analysis to the driving factors of carbon emissions with logarithmic mean Divisia index （LMDI） model. The results show：（1） The amount of agricultural carbon emissions is 291.1691 million t in 2010. Compared with 249.5239 million t in 1995, it increased by 16.69%, in which, agricultural materials inputs, paddy ifeld, soil, enteric fermentation, and manure management accounted for 33.59, 22.03, 7.46, 17.53 and 19.39%of total agricultural carbon emissions, respectively. Although the amount exist ups and downs, it shows an overall trend of cyclical rise; （2） There is an obvious difference among regions：the amount of agricultural carbon emissions from top ten zones account for 56.68%, while 9.84%from last 10 zones. The traditional agricultural provinces, especially the major crop production areas are the main source regions. Based on the differences of carbon emission rations, 31 provinces and cities are divided into ifve types, namely agricultural materials dominant type, paddy ifeld dominant type, enteric fermentation dominant type, composite factors dominant type and balanced type. The agricultural carbon emissions intensity in west of China is the highest, followed by the central region, and the east zone is the lowest; （3） Compared with 1995, efifciency, labor and structure factors cut down carbon emissions by 65.78, 27.51 and 3.19%, respectively;while economy factor increase carbon emissions by 113.16%.

In vitro growth, differentiation and biological characteristics of neural stem cells

OBJECTIVE： To summarize the biological characteristics of neural stem cells, and the separation, purification. differentiation and source of neural stem cells. DATA SOURCES ： An online search of Pubmed database was undertaken to identify English articles about the growth of neural stem cells in vitro published from January 2000 to October 2006 by using the keywords of ＂neural stem cells, bone marrow mesenchymal stem cells （BMSCs）, umbilical cord blood stem cells, embryonic stem cells （ESC）, separation methods, neural growth factor＂. And relevant articles published in IEEE/IEE Electronic Library （IEL） database, Springer Link database and Kluwer Online Journals were also searched, Chinese relevant articles published between January 2000 to October 2006 were searched with the same keywords in Chinese in Chinese journal full-text database. STUDY SELECTION ： The articles were primarily screened, and then the full-texts were searched. Inclusive criteria： （1） Articles relevant to the biological characteristics and classification of neural stem cells; （2） Articles about the source, separation and differentiation of the ESCs, BMSCs and umbilical cord blood stem cells. The repetitive studies and reviews were excluded. DATA EXTRACTION ： Thirty articles were selected from 203 relevant articles according to the inclusive criteria Articles were excluded because of repetition and reviews. DATA SYNTHESES ： Neural stem cells have the ability of self-renewing and high differentiation, and they are obtained from ESCs, nerve tissue, nerve system, BMSCs and umbilical cord blood stem cells. ESCs can be separated by means of mechanical dissociation is better than that of the trypsin digestion, BMSCs by density gradient centrifuge separation, hemolysis, whole-blood culture, etc., and umbilical cord blood stem ceils by Ficoil density gradient centrifugation, hydroxyethyl starch （HES） centrifugation sedimentation, etc. Neural growth factor （NGF） and other factors play an important role in the growth of NSCs, such as transforming growth factor （TGF） is an important player in repairing organs, NGF accelerates the process of growth, insulin-like growth factor serves importantly in the differentiation of stem cells into neuron-like cells. CONCLUSION ： As unipotent stem cells, NSCs have the abilities of self-renewal and potential of high differentiation. The method of mechanical dissociation is better than trypsin digestion in e separating ESCs. However, density gradient centrifuge separation is better than other methods in the separation of the BMSCs. NGF and other factors play an important role in the growth of NSCs.

A SPATIAL-TEMPORAL DISTRIBUTION CHARACTERISTICS STUDY ON THE ATMOSPHERIC CARBON DIOXIDE OBSERVED BY GOSAT SATELLITE REMOTE SENSING

The variation of the atmospheric Carbon Dioxide （CO2） concentration plays an important role in global cli- mate and agriculture. We analyzed the spatial-temporal characteristics of CO2 in the China region and around the globe with the CO2 column mixing ratios observed by the Japanese GOSAT satellite （Greenhouse Gases Observing Satellite）. In order to make sure that the accuracy of the CO2 data retrieved by the satellite meets the needs of the climate charac- teristics analyses, we ran a validation on the CO2 column mixing ratios retrieved by the satellite against the ground-based TCCON （Total Carbon Column Observing Network） observation data. The result shows that the two sets of data have a correlation coefficient of higher than 0.7, and a bias of within 2.2 ppmv. Therefore, the GOSAT CO2 da- ta can be used for the climate characteristics analysis of global CO2. Our analysis on the spatial-temporal characteristics of the CO2 column mixing ratios observed during the period of June 2009 through January 2014 proved that, with the impact of the natural emission of near ground CO2 and human activities, the global CO2 concentration has a significant latitudinal characteristics with its highest level averaging 390 oomv in the 0-40？N latitudinal zone in the Northern Hemisphere, and 387 ppmv in the Southern Hemisphere. China has a relatively higher CO2 concentration with the highest level exceeding 398 ppmv, and the eastern area higher than the western area. The variation of global CO2 concentration shows a seasonal pattern, i.e. the CO2 concen- tration reaches its highest in spring in the Northern Hemisphere averaging more than 392 ppmv, second highest in win- ter, and lowest in summer averaging less than 387 ppmv. It fluctuates the most in the Northern Hemisphere with an av- erage concentration of 392.5 ppmv in April, and 385.5 ppmv in July. While in the Southern Hemisphere, the seasonal fluctuation is smaller with the highest concentration occurring in July. Over the recent years, the global CO2 concentra- tion has shown an elevating trend with an average annual increase rate of 1.58 ppmv per year. It is a challenge that the human kind has to face to slow down the increase of the CO2 concentration.

Spatial-temporal characteristics and influencing factors of relative humidity in arid region of Northwest China during 1966–2017

Playing an important role in global warming and plant growth,relative humidity(RH)has profound impacts on production and living,and can be used as an integrated indicator for evaluating the wet-dry conditions in the arid and semi-arid area.However,information on the spatial-temporal variation and the influencing factors of RH in these regions is still limited.This study attempted to use daily meteorological data during 1966–2017 to reveal the spatial-temporal characteristics of RH in the arid region of Northwest China through rotated empirical orthogonal function and statistical analysis method,and the path analysis was used to clarify the impact of temperature(T),precipitation(P),actual evapotranspiration(ETa),wind speed(W)and sunshine duration(S)on RH.The results demonstrated that climatic conditions in North Xinjiang(NXJ)was more humid than those in Hexi Corridor(HXC)and South Xinjiang(SXJ).RH had a less significant downtrend in NXJ than that in HXC,but an increasingly rising trend was observed in SXJ during the last five decades,implying that HXC and NXJ were under the process of droughts,while SXJ was getting wetter.There was a turning point for the trend of RH in Xinjiang,which occurred in 2000.Path analysis indicated that RH was negatively correlated to T,ETa,W and S,but it increased with increase of P.S,T and W had the greatest direct effects on RH in HXC,NXJ and SXJ,respectively.ETa was the factor which had the greatest indirect effect on RH in HXC and NXJ,while T was the dominant factor in SXJ.

Regional characteristics and spatiotemporal differentiation of the prevalence of hand, foot, and mouth disease in Xinjiang, China

In recent years,the number of hand,foot,and mouth disease(HFMD)cases in China has continued to grow,and the disease has become a serious public health issue.Xinjiang Uygur Autonomous Region is located in the arid areas of Northwest China,where the epidemiological trend of HFMD is gradually increasing and characterized by geographical heterogeneity.In this study,based on the HFMD case data in all counties and cities in Xinjiang,we employed statistical and GIS spatial analyses,and geographic probe models to characterize the spatiotemporal differentiation of HFMD epidemics in Xinjiang during the period of 2009–2018,and quantitatively analyzed the factors influencing the spatial differentiation of HFMD epidemics.The results showed that HFMD incidence rate in Xinjiang had non-stationary temporal characteristics on the interannual and monthly scales,and the monthly variation characteristics of HFMD epidemic were quite different in southern and northern Xinjiang.The spatial distribution characteristics of HFMD epidemics showed a north–south spatial differentiation pattern with the Tianshan Mountains as the boundary;cold spot and hot spot of HFMD epidemics in Xinjiang have shifted from scattered to concentrated,and the spatial differentiation pattern had gradually stabilized.Moreover,the dominant factors influencing the spatial differentiation of HFMD epidemics in Xinjiang were socioeconomic factors,such as per capita GDP and urbanization rate,while the basic factors affecting its spatial differentiation were natural environmental factors.The spatial differentiation and evolution patterns of HFMD epidemics differed between northern and southern Xinjiang.Specifically,the leading role of socioeconomic factors is more obvious in southern Xinjiang than in northern Xinjiang,while natural environmental factors(e.g.,dryness and relative humidity)contribute to the prevalence of HFMD epidemics in northern Xinjiang,and the perturbing effect of these factors was more prominent than other factors.The results of this study can provide a scientific basis for the prevention of HFMD epidemics and early warning of HFMD epidemics in Xinjiang.

Clinicopathological characteristics and prognosis of 232 patients with poorly differentiated gastric neuroendocrine neoplasms

BACKGROUND Poorly differentiated gastric neuroendocrine neoplasms(PDGNENs)include gastric neuroendocrine carcinoma(NEC)and mixed adenoneuroendocrine carcinoma,which are highly malignant and rare tumors,and their incidence has increased over the past few decades.However,the clinicopathological features and outcomes of patients with PDGNENs have not been completely elucidated.AIM To investigate the clinicopathological characteristics and prognostic factors of patients with PDGNENs.METHODS The data from seven centers in China from March 2007 to November 2019 were analyzed retrospectively.RESULTS Among the 232 patients with PDGNENs,191(82.3%)were male,with an average age of 62.83±9.11 years.One hundred and thirteen(49.34%)of 229 patients had a stage III disease and 86(37.55%)had stage IV disease.Three(1.58%)of 190 patients had no clinical symptoms,while 187(98.42%)patients presented clinical symptoms.The tumors were mainly(89.17%)solitary and located in the upper third of the stomach(cardia and fundus of stomach:115/215,53.49%).Most lesions were ulcers(157/232,67.67%),with an average diameter of 4.66±2.77 cm.In terms of tumor invasion,the majority of tumors invaded the serosa(116/198,58.58%).The median survival time of the 232 patients was 13.50 mo(7,31 mo),and the overall 1-year,3-year,and 5-year survival rates were 49%,19%,and 5%,respectively.According to univariate analysis,tumor number,tumor diameter,gastric invasion status,American Joint Committee on Cancer(AJCC)stage,and distant metastasis status were prognostic factors for patients with PDGNENs.Multivariate analysis showed that tumor number,tumor diameter,AJCC stage,and distant metastasis status were independent prognostic factors for patients with PDGNENs.CONCLUSION The overall prognosis of patients with PDGNENs is poor.The outcomes of patients with a tumor diameter>5 cm,multiple tumors,and stage IV tumors are worse than those of other patients.

Characteristics of highly differentiated granite and metallization of tungsten-tin, rare and rare earth metal in the eastern Nanling region, China

1 Introduction Massive tungsten-tin,rare and rare earth metals ore deposits were formed with the widespread granite magmatic activity in early Yanshanian period in the eastern Nanling region.Recent studies indicate that the Yanshanian highly differentiated-granite formation is closely related to the deposits of tungsten and tin,rare and rare earth metals mineralization in the region(Xiao

Spatial differentiation and dynamic mechanism of micro-geomorphology based on acoustic spectrum data of the Huanghe(Yellow)River Delta

Submarine micro-geomorphology is a geo-morphological type occurring in shallow and surface areas of seabed.The combined relationships and distribution of the micro-geomorphology indirectly reflect coupling relationships among the sediment deposition,dynamic environment,and geomorphologic evolution.Spatial differentiation and dynamic changes in micro-geomorphology were studied based on acoustic data interpretation from a wide range(3200 km^(2))of the Huanghe(Yellow)River delta(HRD).The combination of the sub-bottom profiler and the side-scan sonar methods allowed for the identification of submarine shallow micro-geomorphologic types,as well as their scale and spatial distributions.There were seven typical micro-geomorphologic features in the shallow and surface areas of the HRD,including buried ancient channels,stratigraphic disturbances,scour troughs,sand waves,pits,erosional remnants,and sand spots.The coupling and superposition of the sediment,sediment characteristics,seabed scouring and silting,and hydrodynamic conditions of the Huanghe River had combined effects on the patterns of micro-geomorphologic types,characteristics,and ranges.From the perspective of acoustic profile interpretations,the scale,range,and spatial locations of the microgeomorphology in the HRD revealed seasonal variation characteristics,and the spatial distributions displayed significant regional differentiation characteristics.In addition,strong stratigraphic disturbances and areas with densely distributed buried ancient channels reflected the activity and instability of the submarine shallow strata.Through the interpretation of the sub-bottom profile detection data,the diversion processes of the flow paths in the lower reaches of the Huanghe River were obtained for a certain historical period in the coastal waters of the HRD.This study further clarified the relationships between the micro-geomorphologic features and spatial combinations,which is important for research on micro-geomorphologic features and their dynamic mechanisms.

Expression patterns of cluster of differentiation 147 impact the prognosis of hepatocellular carcinoma

BACKGROUND Hepatocellular carcinoma(HCC)has very low overall survival.According to global cancer statistics,approximately 905677 new cases were reported in 2020,with at least 830180 of them being fatal.Cluster of differentiation 147(CD147)is a novel,transmembrane glycoprotein that is expressed in a wide variety of tumor cells and plays an important role in various stages of tumor development.Based on the reports described previously,we theorize that CD147 may be used as a novel biological indicator to predict the prognosis of HCC.To study this possibility,expression profiles of CD147 and corresponding clinical data from The Cancer Genome Atlas(TCGA)and Gene Expression Omnibus(GEO)databases were analyzed,and a hazard ratio(HR)was established.AIM To explore the pattern of CD147 expression and its applicability in the prognosis of HCC.To establish HRs and probability points for predicting the prognosis of HCC by correlating CD147 expression with clinical characteristics.To determine if CD147 can be a reliable biomarker in HCC prognosis.METHODS The CD147 expression profile in HCC and corresponding clinical data were obtained from TCGA database.The expression patterns of CD147 were then validated by analyzing data from the GEO database.In addition,CD147 immunohistochemistry in HCC was obtained from the Human Protein Atlas.CD147 expression patterns and clinical characteristics in the prognosis of HCC were analyzed by accessing the UALCAN web resource.Accuracy,sensitivity,and specificity of the CD147 expression profile in predictive prognosis were determined by the time-dependent receiver operating characteristic(ROC)curves.Kaplan-Meier curves were plotted to estimate the HR of survival in HCC.Univariate and multivariate Cox regression proportional hazards analyses of CD147 expression levels and clinical characteristics as prognostic factors of HCC were performed.Nomograms were used to establish probability points and predict prognosis.RESULTS Data from TCGA and GEO databases revealed that CD147 was significantly overexpressed in HCC(P=1.624×10^(-12) and P=1.2×10^(-5),respectively).The expression of CD147 and prognosis of HCC were significantly correlated with the clinical characteristics of HCC as per the data from the UALCAN web resource(P<0.05).Kaplan-Meier analysis of CD147 expression in HCC revealed that the high expression groups showed poor prognosis and an HR of survival>1[log-rank test,P=0.000542,HR(in high expression group):1.856,95%confidence interval(CI):1.308 to 2.636].ROC curves were plotted to analyze the 1-year,3-year,and 5-year survival rates.The area under the ROC curve values were 0.675(95%CI:0.611 to 0.740),0.623(95%CI:0.555 to 0.692),and 0.664(95%CI:0.582 to 9.745),respectively.Univariate Cox analysis of CD147 expression and clinical characteristics of HCC and multivariate Cox analysis of CD147 patterns and pathological tumor-node-metastasis stage showed significant differences(univariate Cox,P=0.00013,HR:1.424,95%CI:1.884 to 1.707 and P=0.00066,HR:1.376,95%CI:1.145 to 1.654,respectively;multivariate Cox,P=0.00578,HR:1.507,95%CI:1.126 to 2.018 and P=0.00336,HR:1.443,95%CI:1.129 to 1.844,respectively).Nomograms were plotted to establish the probability points and predict prognosis.The total points ranged from 0 to 180,and the C-index value was 0.673(95%CI:0.600 to 1.000,P<0.01).CONCLUSION Overexpression of CD147 was correlated with poor prognosis in HCC.The CD147 expression profile combined with clinical characteristics can reliably predict the prognosis of HCC.CD147 can serve as a biomarker to predict the prognosis of HCC.

County scale spatial differential characteristics of cultivated land use grade: A case of Binchuan County

Land resource is the material foundation of human survival and economic development, and the cultivated land is the essence of land resources. This paper takes the county scale, by using the method of GIS spatial analysis and statistical analysis unifies, to explore the quality of cultivated land in Binchuan County using level, and explain the utilization level of county cultivated land quality spatial differentiation characteristics. The results showed that:(1) in the quantity of cultivated land quality and utilization level, the average utilization of paddy land was greater than that of dry land, and the comprehensive utilization of cultivated land and so on. Among them, the paddy land ranged from grade 6 to 15, the average utilization was grade 11.6; dry land ranged from grade 2 to 11, the average utilization was grade 5.9; comprehensive range of cultivated land is grade 2 to 15, the average utilization was grade 8.1;(2) the quality of cultivated land utilization spatial differentiation. Paddy field, dry land and cultivated land and large value distribution in the central and southern, inverted V shape distribution; the smaller the value distribution in the East and West, a dumbbell shaped distribution. Among them, they don't use a larger value of paddy land distributed in the central, South and southwest, the maximum value is 14.3, the smaller the value distribution in the West and East, the minimum value is grade 7; the larger the value distribution by the dry land in the South and West, the maximum value is grade 10.2, the smaller the value distribution in the West and East. The minimum value is grade 2.3; the comprehensive utilization of cultivated land don't distributed larger value in the central, South and south-west, the maximum value is grade 12.7, the smaller the value distribution in the West and East, the minimum value is grade 3.5. This paper can provide scientific basis for the dynamic monitoring of cultivated land quality, the transformation of low yield farmland and the early warning of cultivated land pressure.

A Testing Method for Ratio Restraint Characteristics of Differential Relay Protection of Transformers

In this paper, a method to calculate the slope of the ratio restraint characteristic of a transformer differential relay protection is proposed. The method allows using some concise but effective means to get the slope. Modulating the argument of current output from ONLLY testing equipment can make the relay protection device operate, thus, the data used for calculation would be obtained naturally after several trails. In order to make sure how effective that method could be, some experiment data is given as well.

A novel ethanol-based method to induce differentiation of adipose-derived stromal cells into astrocytes

The quantity and survival time of astrocytes,which were differentiated from adult adipose-derived stromal cells after exposure to an inducer containing 3-isobutyl-1-methylxanthine,have thus far been unsatisfactory.The present study investigated the growth and differentiation characteristics of induced astrocytes by observing their growth curves.After induction for 48 hours with an inducer containing 0.5% ethanol,some adult adult adipose-derived stromal cells displayed typical astrocytic morphology.The cell quantity gradually decreased with prolonged induction time.Nestin,glial fibrillary acidic protein,and S-100 expression reached peak levels at 14 days,but neuron-specific enolase was not expressed.These results suggest that the induced astrocytes reached their peak at 14 days.Further optimization of the culture environment may yield mature astrocytes with normal functions,in greater quantity,and prolonged survival time.

Numerical modeling of DPSK pressure signals and their transmission characteristics in mud channels

A numerical model and transmission characteristic analysis of DPSK （differential phase shift keying） pressure signals in mud channels is introduced. With the control logic analysis of the rotary valve mud telemetry, a logical control signal is built from a Gate function sequence according to the binary symbols of transmitted data and a phase-shift function is obtained by integrating the logical control signal. A mathematical model of the DPSK pressure signal is built based on principles of communications by modulating carrier phase with the phase-shift function and a numerical simulation of the pressure wave is implemented with the mathematical model by MATLAB programming. Considering drillpipe pressure and drilling fluid temperature profile along drillpipes, the drillpipe of a vertical well is divided into a number of sections. With water-based drilling fluids, the impacts of travel distance, carrier frequency, drillpipe size, and drilling fluids on the signal transmission were studied by signal transmission characteristic analysis for all the sections. Numerical calculation results indicate that the influences of the viscosity of drilling fluids and volume fraction of gas in drilling fluids on the DPSK signal transmission are more notable than the others and the signal will distort in waveform with differential attenuations of the signal frequent component.

Analysis on the Temporal and Spatial Characteristics and Causes of Cold Wave in Qinhuangdao

[Objective] The aim was to study the temporal and spatial characteristics and causes of cold wave in Qinhuangdao.[Method] Based on temperature data from five surface meteorological stations in Qinhuangdao from 1970 to 2009 and the latest standards issuing cold wave early warning signal,statistical analysis on the temporal and spatial distribution of cold wave was carried out,and the causes were discussed preliminarily.[Result] From 1970 to 2009,the frequencies of blue and yellow cold wave in Qinhuangdao region were 2 334 and 105 times respectively,and cold wave occurred most frequently in Qinglong County and least frequently in Lulong County,which was related to the effects of underlying surface,latitude and altitude.Cold wave might happen from September to next May,and the earliest occurrence date was September 9,while the latest end date was May 26.In addition,the frequency of cold wave was the highest in January and lowest in May.From 1970 to 2009,blue cold wave occurred most frequently in 1972 and 1979 and least frequently in 1984,while the frequency of yellow cold wave was the highest in 1979 and lowest in 9 years.From decadal variation,cold wave appeared most frequently in the 1970s and least frequently in the 1990s.With the increase of temperature,the frequency of cold wave showed decrease trend,and the beginning date tended to postpone,while its end date advanced,and it showed that the changes of cold wave was mainly caused by climate warming.[Conclusion] The study could provide theoretical guidance for the meteorological disaster prevention and reduction and local agricultural service.

Daily SPEI Reveals Long-term Change in Drought Characteristics in Southwest China

Drought is the most widespread and insidious natural hazard, presenting serious challenges to ecosystems and human society. The daily Standardized Precipitation Evapotranspiration Index(SPEI) has been developed to identify the regional spatiotemporal characteristics of drought conditions from 1960 to 2016, revealing the variability in drought characteristics across Southwest China. Daily data from142 meteorological stations across the region were used to calculate the daily SPEI at the annual and seasonal time scale. The Mann-Kendall test and the trend statistics were then applied to quantify the significance of drought trends, with the following results. 1) The regionally averaged intensity and duration of all-drought and severe drought showed increasing trends, while the intensity and duration of extreme drought exhibited decreasing trends. 2) Mixed(increasing/decreasing) trends were detected, in terms of intensity and duration, in the three types of drought events. In general, no evidence of significant trends(P < 0.05) was detected in the drought intensity and duration over the last 55 years at the annual timescale. Seasonally, spring was characterized by a severe drought trend for all drought and severe drought conditions, while extreme drought events in spring and summer were very severe. All drought intensities and durations showed an increasing trend across most regions, except in the northwestern parts of Sichuan Province. However, the areal extent of regions suffering increasing trends in severe and extreme drought became relatively smaller. 3) We identified the following drought hotspots: Guangxi Zhuang Autonomous Region from the 1960 s to the 1990 s, respectively. Guangxi Zhuang Autonomous Region and Guizhou Province in the 1970 s and 1980 s, and Yunnan Province in the 2000 s. Finally, this paper can benefit operational drought characterization with a day-to-day drought monitoring index, enabling a more risk-based drought management strategy in the context of global warming.

Spatial-temporal Variation of Extreme Precipitation Events in Northwest China During 1961-2010

Using the daily precipitation data of 118 meteorological stations in Northwest China from January 1, 1961 to December 31,2010, we analyzed extreme precipitation events from prime precipitation data by applying R-language Climate Index （RClimDex）. The spatial-temporal change characteristics in the past 50 years have been examined using the method of trend analysis, Mann-Kendall and the spatial analysis module of Arcgis9.2. The results show that the spatial distribution of the indices for extreme precipitation in Northwest China is greatly influenced by geographic location, atmospheric circulation and topography, and the spatial difference of extreme precipitation events is very evident, while the indices reduce from the southeast to the northwest except Consecutive Dry Days （CDD）. In Xinjiang region, high values appear in Tianshan Mountains and decrease towards the south and north respectively. In the past 50 years, the temporal variation tendency of the indices for extreme precipitation in Northwest China has a great spatial distinction. It shows that the variation tendency is opposite between the east （decrease） and the west （increase）, and CDD has a decreasing tendency while other indices increase. For each region, it is found that the indices for extreme precipitation in Xinjiang and Qinghai Province shows an increasing trend, and it is remarkable in Tianshan Mountains, the north of Xinjiang and the northeast of Qinghai Province. The temporal variation tendency of the indices for extreme precipitation in Ningxia, Shaanxi and Gansu has a large spatial distinction. The stations which have an increasing tend are mainly found in the north of Ningxia, south of Shaanxi and Hexi Corridor of Gansu. However, the south of Ningxia, north of Shaanxi and Longnan of Gansu Province mainly present a decreasing trend. The temporal variation tendency of the indices for extreme precipitation in Inner Mongolia is not obvious. Overall, the east part of Northwest China has a dry tendency, while the west part has an opposite trend.

Spatial-temporal variance of reclamation soil physical and chemical character in opencast mine region

In order to study the effects of soil compaction, and soil physical and chemicalcharacteristics after land reclamation, selected lands that were reclaimed after 1, 2, 3, 4,and 5 a, respectively, in the Majiata Mine of the Shendong Open Pit; tested the effects ofsoil compaction; and collected soil samples from 5 different depths, which are 0-7.62,7.62-15.24, 15.24-22.86, 22.86-30.48, and 30.48-38.10 cm, respectively. The resultsshow that: Land reclamation leads to soil compaction. The lowest effect of soil compaction is in the top layer and the highest one at the depth of 20-30 cm; The bulk density of reclaimed soil is higher than that of undisturbed soil; this declines with the reclamation and nearly reaches the level of undisturbed soil after 5-year reclamation;The content of reclaimed soil nutrients is lower than that of undisturbed soil. The lowest one is inthe soil dumping site, which reaches the level of undisturbed soil after 5-year reclamation;The pH value of reclaimed soil is lower than that of undisturbed soil. The highest one isin the soil dumping site; this declines with the reclamation.

Spatial-temporal Heterogeneity of Industrial Structure Transformation and Carbon Emission Effects in Xuzhou Metropolitan Area

Employing decoupling index and industrial structure characteristic bias index methods, this study analyzed the spatial-temporal characteristics of industrial structure transformations and their resulting carbon emissions in the Xuzhou Metropolitan Area from 2000 to 2014, with a focus on their relationships and driving factors. Our research indicates that carbon emission intensity from industrial structures in the Xuzhou Metropolitan Area at first showed an increasing trend, which then decreased. Furthermore, the relationship between emissions and industrial economic growth has been trending toward absolute decoupling. From the perspective of the center-periphery, the Xuzhou Metropolitan Area formed a concentric pattern, where both progress towards low emissions and the level of technological advancement gradually diminished from the center to the periphery. In terms of variation across provinces, the ISCB index in the eastern Henan has decreased the slowest, followed by the southern Shandong and the northern Anhui, with the northern Jiangsu ranking last. During this period, resource-and labor-intensive industries were the primary growth industries in the northern Anhui and the eastern Henan, while labor-intensive industries dominated the southern Shandong and capital-intensive industries dominated the northern Jiangsu. In terms of city types, the spatial pattern for industrial structure indicates that recession resource-based cities had higher carbon emission intensities than mature resource-based cities, followed by non-resource-based cities and regenerative resource-based cities. Generally, the industrial structure in the Xuzhou Metropolitan Area has transformed from being resource-intensive to capital-intensive, and has been trending toward technology-intensive as resource availability has been exploited to exhaustion and then been regenerated. Industrial structure has been the leading factor causing heterogeneity of carbon emission intensities between metropolitan cities. Therefore, the key to optimizing the industrial structure and layout of metropolitan areas is to promote industrial structure transformation and improve the system controlling collaborative industrial development between cities.

Numerical Study on Heat Transfer and Flow Characteristics for Laminar Flow in a Circular Tube with Swirl Generators

This study investigated the heat transfer and flow characteristics of one kind of swirlgenerator in a circular heat exchanger tube through a numericalsimulation. The swirlflow induced by this type of swirlgenerator can obtain a high heat transfer rate with minimalpressure drop penalty. The simulations were carried out to understand the physicalbehavior of this kind of mesoscale heat enhancement component. By visualizing the heat transfer and flow characteristics, it is found that the swirlflow is induced by swirlgenerator in the circular tube couples with the impinging jet effect. After passing through the swirlgenerator, the localfriction factor of liquid can quickly return to lower levelmore quickly, while the localNusselt number maintains higher values for a distance; thus, the evaluation criterion of localperformance is improved. Single-factor optimization is used for three geometric parameters, i.e., the angle of swirlgenerator(25o, 45o, and 60o), the length of swirlgenerator(0.005, 0.01, and 0.02 m), and the center rod radius(1, 2, and 3 mm). The optimum parameters of the swirlgenerator for laminar flow of air in a circular tube are obtained, which should be 60o, 0.005 m, and 3 mm, respectively.