Analysis of sea level changes in the Caspian Sea related to Cosmo-geophysical processes based on satellite and terrestrial data

Analysis results of the average annual sea levels in the Caspian Sea obtained from ground and satellite observations, corresponding to solar activity characteristics, magnetic field data, and length of day are presented. Spectra of the indicated processes were investigated and their approximation models were also built. Previously assumed statistical relationships between space-geophysical processes and Caspian Sea level(CSL) changes were confirmed. A close connection was revealed between the low-frequency models of the solar and geomagnetic activity parameters and the CSL changes. Predictions extending into the next decades showed a high probability of an increase in the CSL and a decrease of the compared space-geophysical parameters.

Spatial Analysis of Structural Changes and Floristic Distribution of Forest Landscapes in the Centre-West Region of Burkina Faso

Land use and occupation dynamics impact landscape structure, diversity, richness and balance of vegetation cover. The aim of this study is to describe the process of fragmentation of the forest landscape from 1990 to 2020 and its effects on the degradation of the floristic characteristics of the vegetation in the Central West region of Burkina Faso. To achieve this, satellite data were collected and processed as part of a mapping approach to describing the landscape and the different types of landscape fragmentation. Mapping indices of landscape fragmentation (relative richness, change process, patch zones, Shannon diversity index) were also calculated. These indices were programmed in Idrisi Selva’s Landscape Pattern and change process analysis module. Spatio-temporal analysis revealed that in 1990, the landscape was dominated by natural vegetation formations, covering 66.33% of the territory. By 2020, these had been degraded to 44.80% by farmlands. The mapping analysis of indices also showed that the study area is characterized by four types of landscape fragmentation, including attrition, aggregation, creation and dissection. We also observed an abundant homogeneity, diversity and richness of conservation areas with legal and land tenure status. However, the structure is heterogeneous in landscapes outside protected areas and in areas under human occupation. This shows the crucial role played by conservation areas in preserving and balancing the diversity of vegetative cover in the study area.

Process and mechanism of arable land change in Hebei Province during the past 50 years

Hebei Province is one of the regions with most densely population, fastest economic growth and most intensive land use in China. The contradiction of land shortage sharpened by high-speed economic development with population growth has become a serious problem, which has restricted regional sustainable development.This paper revealed the basic process, regional differences of change and the gravity center of arable land area according to the long-series statistical data of arable land during the past 50 years. On the basis of the above mentioned, the major driving forces that influence the changes of the arable land are discussed. The research results indicate that there is a trend of obvious fluctuating decrease in arable land area during the last 50 years. The changes of arable land area undergo the process from increase to sharp decrease to gently decrease. The regional disparity of change in arable land area is very notable and the gravity center of arable land area moves to the northeast 49.22 km. Regarding the decrease in arable land, the direct driving forces include adjustments of agricultural structure and reclamation, and indirect driving forces include advance in technology, economic interest and population growth etc.

Pollution of bed sediments and its changing process of Nansihu Lake

In order to research the changing process of the pollution from the formation of Nansihu Lake, this study determined the isotope age and depositional rate and analyzed the organic geo-chemical quotas and heavy metal quotas of two sedimentary profiles of Weishan and Dushan lakes. Research results showed that from the formation of Nansihu Lake, the change of the pollution could be divided into four phrases. At the early phrase of the formation, the organic matters of the lake mainly derived from the exotic matters and had a close relation to the effect on the water and sands from the Huanghe (Yellow) River. At the middle and late phrases of the development, the endogenous matters of the lake became the main and stable source of the organic matters. The overflow of the Huanghe River, the excavation of the Grand Canal and the cut of trees caused the changes of the historic pollution. In recent 20 years, the modern industrial pollution from the organic matters and heavy metals has an increasingly heavy tendency.

Effects of PHC on Water Quality of Jiaozhou Bay Ⅱ. Changing Process of Pollution Sources

Based on investigation data on PHC content in Jiaozhou Bay, China during 1979 -1983, the horizontal distribution and pollution sources of PHC in Jiaozhou Bay were analyzed. The results showed that from 1979 to 1983, PHC in the water body of Jiaozhou Bay was mainly from rivers such as Haibo River, Licun River and Loushan River, and PHC content ranged from 0.10 to 1.10 mg/L. The pollution sources of PHC were serious during 1979 -1981 and then became slight during 1982 -1983. From 1979 -1981 to 1982 -1983, PHC content, horizontal distribution and degree of pollution sources changed, but the input mode of PHC was constant, that is, PHC was brought into Jiaozhou Bay by rivers.

Secular change in earth processes： Preface

1.Introduction Uniformitarianism is a traditional approach used in many areas of geoscience that assumes the geologic processes observed today operated similarly throughout all of Earth history（Hutton,1788;Windley,1993）,with such an ideology commonly encapsulated by the maxim＂the present is the key to the past＂.This concept is closely associated with the philosophical principle of Occam’s razor.

RATE OF CONVERGENCE FOR MULTIPLE CHANGEPOINTS ESTIMATION OF MOVING-AVERAGE PROCESSES

In this paper, the least square estimator in the problem of multiple change points estimation is studied. Here, the moving-average processes of ALNQD sequence in the mean shifts are discussed. When the number of change points is known, the rate of convergence of change-points estimation is derived. The result is also true for p-mixing, φ-mixing, a-mixing, associated and negatively associated sequences under suitable conditions.

Crystallization Process of Superlattice-Like Sb/SiO_2 Thin Films for Phase Change Memory Application

After compositing with SiO_2 layers, it is shown that superlattice-like Sb/SiO_2 thin films have higher crystallization temperature（~240°C）, larger crystallization activation energy（6.22 e V）, and better data retention ability（189°C for 10 y）. The crystallization of Sb in superlattice-like Sb/SiO_2 thin films is restrained by the multilayer interfaces. The reversible resistance transition can be achieved by an electric pulse as short as 8 ns for the Sb（3 nm）/SiO_2（7 nm）-based phase change memory cell. A lower operation power consumption of 0.09 m W and a good endurance of 3.0 × 10~6 cycles are achieved. In addition, the superlattice-like Sb（3 nm）/SiO_2（7 nm） thin film shows a low thermal conductivity of 0.13 W/（m·K）.

Matched or nonmatched interventions based on the transtheoretical model to promote physical activity.A meta-analysis of randomized controlled trials

Purpose: The aim of this study was to examine whether the efficacy of transtheoretical model(TTM)-based interventions on physical activity(PA)varied according to the following criteria:(1) interventions targeted the actual stages of change(SOCs) or did not;(2) participants were selected according to their SOC or were not; and(3) its theoretical constructs(decisional balance, temptation, self-efficacy, processes of change).Methods: Thirty-three randomized controlled trials assessing TTM-based interventions promoting PA in adults were systematically identified.Results: The between-group heterogeneity statistic(Qb) did not reveal any differential efficacy either in interventions targeting the actual SOC compared with those that did not(Qb = 1.48, p = 0.22) or in interventions selecting participants according to their SOC compared with those that did not(Qb = 0.01, p = 0.91). TTM-based interventions enhanced PA behavior whether they targeted the actual SOC(Cohen's d = 0.36; 95%confidence interval(CI): 0.22–0.49) or not(d = 0.23; 95%CI: 0.09–0.38) and whether they selected their participants according to their SOC(d = 0.33; 95%CI: 0.13–0.53) or not(d = 0.32; 95%CI: 0.19–0.44). The moderators of the efficacy of TTM-based interventions were the number of theoretical constructs used to tailor the intervention(Qb = 8.82, p = 0.003), the use of self-efficacy(Qb = 6.09, p = 0.01), and the processes of change(Qb = 3.51, p = 0.06).Conclusion: TTM-based interventions significantly improved PA behavior, and their efficacy was not moderated by SOC but by the TTM theoretical constructs.

Assessment of heavy metals in sediment in a heavily polluted urban river in the Chaohu Basin, China

The Nanfei River （Anhui Province, China） is a severely polluted urban river that flows into Chaohu Lake. In the present study, sediments were collected from the river and analyzed for their heavy metal contents. Multivariate statistics and the fuzzy comprehensive assessment method were used to determine the sources of pollution, the current pollution status, and spatial and temporal variations in heavy metal pollution in sediments. The concentrations of arsenic （As）, cadmium （Cd）, chromium （Cr）, copper （Cu）, mercury （Hg）, nickel （Ni）, lead （Pb）, and zinc （Zn） in sediments ranged from 5.67-113, 0.08-40.2, 41.6-524, 15.5-460, 0.03-4.84, 13.5-180, 18.8-250, and 47.9-1 996 mg/kg, and the average concentrations of each metal were 1.7, 38.7, 1.8, 5.5, l 8.8, 1.3, 2.5, and 11.1 times greater than the background values, respectively. Multivariate statistical analysis demonstrated that Hg, Cu, Cr, Cd, and Ni may have originated from industrial activities, whereas As and Pb came from agricultural activities. The fuzzy comprehensive assessment method, based on the fuzzy mathematics theory, was used to obtain a detailed assessment of the sediment quality in the Nanfei River watershed. The results indicated that the pollution was moderate in the downstream tributaries of the Nianbu and Dianbu Rivers, but was severe in the main channel of the Nanfei River and in the upstream tributaries of the Sill and Banqiao Rivers. Therefore, sediments in the Nanfei River watershed are heavily polluted and urgent measures should be taken to remedy the status.

Changes in hydrological processes in the headwater area of Yellow River,China during 1956-2019 under the influences of climate change,permafrost thaw and dam

Discharge characteristics are crucial for detecting changes in hydrological processes.Recently,the river hydrology)in the Headwater Area of the Yellow River(HAYR)has exhibited erratic regimes(e.g.,monotonously declining/low/high hydrograph,even with normal precipitation)under the effects of climate change,permafrost thaw and changes in dam operation.This study integrates hydroclimatic variables(air temperature,precipitation,and potential evapotranspiration)with anthropogenic dam operation and permafrost degradation impact data to systematically examine the mechanisms of these hydrological process changes during 1956–2019.The results show the following:1)compared with the pre-dammed gauged flow,dam construction(January 1998–January 2000)and removal of dam(September 2018–August 2019)induced monotonously low(−17.2 m^(3) s^(−1);−61%)and high(+54.6 m^(3) s^(−1);+138%)hydrographs,respectively;2)hydroclimatic variables mainly controlled the summer–autumn hydrological processes in the HAYR;3)the monotonous decline of the hydrograph of Yellow River in the HAYR in some hydrological years(e.g.,1977,1979,1990 and 1995)was closely related with unusually high atmospheric demands of evaporation and low-intense rainfall during summer–autumn seasons;and 4)the lengthening of subsurface hydrological pathways and residence time,permafrost degradation reduced the recession coefficient(−0.002 per year)of winter flow and altered the hydrological regimes of seasonal rivers,which resulted in flattened hydrographs that reduced and delayed the peak flow(of 0.05 mm per year and 1.65 d per year,respectively)as well as boosted the winter baseflow(0.01 mm per year).This study can provide updated and systematic understanding of changing hydrological processes in typical alpine catchments on northeastern Qinghai–Tibet Plateau,China under a warming climate.

Landform Instability and Land-use Dynamics in Tropical High Mountains, Central Mexico

This investigation is an analysis of the influence of landform instability on the distribution of land-use dynamics in a hydrographical basin, located in the Mexican Volcanic Belt mountain range (central Mexico), currently affected by substantial changes in land use and deforestation. A landform map was produced, in addition to seven attribute maps - altimetry, drainage density, slope, relief energy, potential erosion, geology and tectonics - which were considered as factors for determining landform instability through Multi-criteria Evaluation Analysis. Likewise, the direction and rhythm of land-use dynamics were analyzed in four dates - between 1976 and 2000 - and cross tabulations were made between them, in order to analyze the trends and processes of land-use dynamics. Afterwards, the databases obtained were cross tabulated with the landform variables to derive areas, percentages and correlation indices. In the study area, high-instability landforms are associated with most ancient volcanic and sedimentary landforms, where high altitude, drainage density, slope and potential to develop gravitational and fluvial processes are the major factors favouring a land-use pattern, dominated by the conservation of extensive forest land, abandonment of human land use and regeneration of disturbed areas. In contrast, low-instability landforms correspond to alluvial plains and lava hills covered by pyroclasts, where low potential erosion to develop fluvial processes, added to water and soil availability and accessibility, have favoured a land-use pattern dominated by the expansion of agroforestry plantations and human settlements, showing a marked trend towards either intensification or permanence of the current land use and with little abandonment and regeneration.

Drag material change in hot runner injection molding

Quick material change is often encountered for the different colors or kinds of polymer in hot runner injecting molding process. Time costing and incompleteness of material change process often affects the quality and productivity of products. In the practical production, multi injection or white material as the transition material is often adopted for quick material change. Based on the rheological behavior of the new and the previous plastic melt, the researches on the related problems were carried out. The concept of drag material change was originally presented. The physical and mathematical model on the simultaneous flow process of the new and the previous plastic melt in hot runner were built up, which can well explain the influence of the injection speed, pressure, viscosity difference, temperature and mold structure on the drag material change efficiency. When temperature in different position in the mold was increased and adjusted, the viscosity difference between the two kinds of melt can be controlled. Therefore the material change ability can be greatly improved during the whole material change process, getting rid of more and more difficult changing in the late stage.

天路 历程

天路历程余云叶我走近你，走近千年古刹角落。突用，我睁大双眼，心灵被深深地震撼了：一棵粗如碗口的紫藤，悬空地、毫无依托地腾空六七丈，紧紧抓住孤形大树的横斜的枝干，绷成一张巨弓的长长的弓弦。抬头侧视。蓦地，我仿佛看到山民攀山岩、爬绝崖、登上悬崖之颠去采药...

Study on Cultivated Land Resource Situation and Its Macro-Driving Forces in Yantai Area

According to the statistics of cultivated land in Yantai area during the Reform and Opening-up over the past 20 years and with the detailed survey and changing data of land use during the recent live years, this paper reveals the basic characteristics of the resource utilization, the basic process of the changes, regional differences, and current direction of cultivated land In addition, this paper makes a preliminary research on the major driving factors and the influence mechanism for the changes in the cultivated land area. and reaches the following conclasions： （1） There was a trend of obvious fluctuant decrease in cultivated laud area during the past 20 years. The changes of cultivated land have undergone the process - slow decrease,steep decrease, slow decrease. And there were three peak periods of cultivated land loss around 1985. 1987-1996 and 1991-1993 respectively （2） The decreased cultivated land was mainly converted into land for industry and mining, residential area. and all kinds of traffic and orchards. The increase of cultivated land mainly came from exploitation and land and arrangement and reclamation of industry and mining land （3） The economic development. population growth and policy are the dominant macro-driving factors for the decrease of cultivated land area in Yantai. The obvious sudden changes during the change process of cultivated land acreage are relevant to the national macro.policies background The rapid decrease of cnltivated land area is synchronous with the overheated economic growth resulting from the direct investment in fixed assets. Spatial distribution of the decrease in cultivated land is congruous with the differences in speed and the scale of economic growth between the different regions of Yantai area. Furthermore. the decrease in cultivated land caused by population increase cannot be ignored.

Effect of Microstructure on Thermal Expansion Coeffcient of 7A09 Aluminum Alloy

The relationship between microstructure evolution and coefficient of thermal expansion （CTE） of 7A09 aluminum alloy was investigated in this paper. Differential scanning calorimetry （DSC） was combined with transmission electron microscopy （TEM） and high-resolution transmission electron microscopy （HRTEM） to investigate microstructure evolution taking place in 7A09 aluminum alloy during heating and cooling process. The corresponding CTE curves of the 7A0g alloy were recorded by thermal dilatometer. Results indicated that GPII zones and Ur phase were main precipitates in the highest strength tempered （T6） 7A09 alloy. The r/phase was the main participate in 7A09 alloy during the cooling process. The nonlinear dependency existed between CTE and temperature in both changing temperature processes. During the heating process, obvious additional contraction of alloy volume was directly caused by phase transition, such as dissolution of η＇ phase, transition from η＇ to η phase and dissolution of η phase. The additional contraction could slow down the increase of CTE greatly and be expressed in the nonlinearity of CTE curve. Volume and energy changes of alloy system influenced the variation trend of CTE directly, which was caused by the precipitation of U phase during the cooling process. These effects were revealed by the corresponding nonlinear change of CTE.