Structural changes and volatility correlation in nonferrous metal market

The GARCH and DCC-GARCH models are used to study the volatility aggregation and dynamic relevance of China’s three kinds of nonferrous metals （copper, aluminum and zinc） pricesincorporating structural changes. The results show that copper, aluminum and zinc returns have many structure breaks points, and nonferrous metals have the greatvolatilityrisk during financial crisis. From the resultsof GARCH with and without structural changes,it isfoundthat the volatility clustering of single nonferrous metal is overvalued when ignoring the structural mutation, and the return of aluminum isthe most overvalued, indicating that aluminum market is more susceptible to external shock.Furthermore,it is also foundthatdynamic volatility correlation exists in the three prices of nonferrous metals, and the structural changes have no significant effect on the volatility correlation of thethree nonferrous metals.

Impacts of climate change and human activities on vegetation dynamics on the Mongolian Plateau, East Asia from 2000 to 2023

The Mongolian Plateau in East Asia is one of the largest contingent arid and semi-arid areas of the world.Under the impacts of climate change and human activities,desertification is becoming increasingly severe on the Mongolian Plateau.Understanding the vegetation dynamics in this region can better characterize its ecological changes.In this study,based on Moderate Resolution Imaging Spectroradiometer(MODIS)images,we calculated the kernel normalized difference vegetation index(kNDVI)on the Mongolian Plateau from 2000 to 2023,and analyzed the changes in kNDVI using the Theil-Sen median trend analysis and Mann-Kendall significance test.We further investigated the impact of climate change on kNDVI change using partial correlation analysis and composite correlation analysis,and quantified the effects of climate change and human activities on kNDVI change by residual analysis.The results showed that kNDVI on the Mongolian Plateau was increasing overall,and the vegetation recovery area in the southern region was significantly larger than that in the northern region.About 50.99%of the plateau showed dominant climate-driven effects of temperature,precipitation,and wind speed on kNDVI change.Residual analysis showed that climate change and human activities together contributed to 94.79%of the areas with vegetation improvement.Appropriate human activities promoted the recovery of local vegetation,and climate change inhibited vegetation growth in the northern part of the Mongolian Plateau.This study provides scientific data for understanding the regional ecological environment status and future changes and developing effective ecological protection measures on the Mongolian Plateau.

Correlation analysis of human papillomavirus E6/E7 mRNA detection with diagnosis,prognosis and recurrence risk in patients with cervical epithelioma

BACKGROUND Cervical intraepithelial neoplasia(CIN)is an important precursor of cervical cancer.Early detection and treatment can reduce the incidence of cervical cancer.AIM To investigate the detection rate of human papillomavirus(HPV)E6/E7 mRNA in cervical tissue of patients with different types of epithelial cell neoplasia(CIN)and its relationship with CIN progression and diagnosis.METHODS One hundred women with HPV infection detected by cervical exfoliation cytology between January 2022 and January 2023 were retrospectively selected.These patients were graded CIN based on colposcopy and cervical pathology.The positive expression rates of HPV E6/E7 mRNA and HPV[polymerase chain reaction(PCR)-reverse dot crossing]were compared among all groups.Patients with HPV E6/E7 mRNA expression in the grade 1 CIN group were followed up for 1 yr.The relationship between atypical squamous epithelium and high malignant epithelial neoplasia was investigated by univariate and multivariate analysis.RESULTS The diagnostic sensitivity,specificity,and sensitivity of PCR-reverse point hybrid ization technology for secondary CIN were 70.41%,70.66%,and 0.714,respectively.Sensitivity and specificity for secondary CIN were 752%and 7853%,respectively,the area under the curve value was 0.789.Logistic Multifactorial model analysis revealed that the HPV positive rates and the HPV E6/E7 mRNA positive rates were independent risk factors of CIN grade I(P<0.05).In CIN grade I patients with positive for HPV E6/E7 mRNA,in its orientation to grade CIN patients,in its orientation to grade CIN patients,at 69.2%,compared with patients negative for HPV E6/E7 mRNA(30.8%),significant difference(P<0.05).CONCLUSION HPV E6/E7 mRNA and HPV(PCR-reverse dot hybrid)positive expression have a close relationship with CINgrade disease progression and is an independent risk factor for high-grade CIN lesions.

Seismology and Climatology: A Study of Seismological Impacts of Climate Change in Indonesia

Climate change has been a matter of discourse for the last several decades. Much research has been conducted regarding the causes and impacts of climate change around the world. The current research contributes to the knowledge of the influence of climate change on our environment, with emphasis on earthquake occurrences in the region of Indonesia. Using global temperature anomaly as a measure of climate change, and earthquake data in Indonesia for the period 1900-2022, the paper seeks to find a relationship (if any) between the two variables. Statistical methods used include normal distribution analysis, linear regression and correlation test. The results show peculiar patterns in the progression of earthquake occurrences as well as global temperature anomaly occurring in the same time periods. The findings also indicated that the magnitudes of earthquakes remained unaffected by global temperature anomalies over the years. Nonetheless, there appears to be a potential correlation between temperature anomalies and the frequency of earthquake occurrences. As per the results, an increase in temperature anomaly is associated with a higher frequency of earthquakes.

Primary investigation of statistical correlation between changes in ice volume and area of glaciers

This study makes an attempt to investigate through statistical analysis the correlation between changes in ice volume and area of glaciers. Using data from nine sample glaciers in the Tian Shan, the results show that a linear relation exists between changes in ice volume and area, with a correlation coefficient of 0.700. However, the accuracy estimation is difficult due to the limited number of samples. The correlation was not improved after adding eleven glacier samples in other mountains. Two reference glaciers are then analyzed in more detail. The linear correlation coefficient is higher than 0.800 when using the observed changes in ice volume and area during different periods on Urumqi Glacier No. 1, which suggests that the linear relation is valid for one glacier for different periods if its shape does not change noticeably and also for other glaciers of the same shape during the same period. The relation between changes in ice volume and area of Qingbingtan Glacier No. 72 is different during different periods due to change in the shape of the glacier tongue and the influence of the debris cover. Moreover, errors in glacier-change monitoring and-volume estimation have an important influence on the correlation results. Therefore, further study needs to focus not only on the distinction between glacier types and between different periods but also on the accuracy of volume estimation.

The Pursuit of Fallacy in Density Functional Theory: The Quest for Exchange and Correlation, the Rigorous Treatment of Exchange in the Kohn-Sham Formalism and the Continuing Search for Correlation

As pointed out in the paper preceding this one, in the case of functionals whose independent variable must obey conditions of integral normalization, conventional functional differentiation, defined in terms of an arbitrary test function, is generally inapplicable and functional derivatives with respect to the density must be evaluated through the alternative and widely used limiting procedure based on the Dirac delta function. This leads to the determination of the rate of change of the dependent variable with respect to its independent variable at each isolated pair, , that may not be part of a functional (a set of ordered pairs). This extends the concept of functional derivative to expectation values of operators with respect to wave functions leading to a density even if the wave functions (and expectation values) do not form functionals. This new formulation of functional differentiation forms the basis for the study of the mathematical integrity of a number of concepts in density functional theory (DFT) such as the existence of a universal functional of the density, of orbital-free density functional theory, the derivative discontinuity of the exchange and correlation functional and the extension of DFT to open systems characterized by densities with fractional normalization. It is shown that no universal functional exists but, rather, a universal process based only on the density and independent of the possible existence of a potential, leads to unique functionals of the density determined through the minimization procedure of the constrained search. The mathematical integrity of two methodologies proposed for the treatment of the Coulomb interaction, the self-interaction free method and the optimized effective potential method is examined and the methodologies are compared in terms of numerical calculations. As emerges from this analysis, the optimized effective potential method is found to be numerically approximate but formally invalid, contrary to the rigorously exact results of the self-interaction-free method.

Simplified Correlation Equations of Heat Transfer Coefficient during Phase Change for Flow inside Tubes

In this work, the easy to use, simple and direct equations were formulated and tested. These equations can be used to calculate the mean values of the heat transfer coefficients of inside tube flow during phase change. Analytical and experimental methods were used to correlate these equations. Two different forms were used, one for evaporation case and the other for condensation case. Carbon dioxide, CO2, was used as case study. Correlated values of the mean heat transfer coefficients （hcor,.） were compared with the experimental results （he^e） and with other published result, a good agreement was noticed. The resulted correlations can be used to simplify the design and performance studies of both condensers and evaporators.

Spatio-temporal variations in trends of vegetation and drought changes in relation to climate variability from 1982 to 2019 based on remote sensing data from East Asia

Studying the significant impacts on vegetation of drought due to global warming is crucial in order to understand its dynamics and interrelationships with temperature,rainfall,and normalized difference vegetation index(NDVI).These factors are linked to excesses drought frequency and severity on the regional scale,and their effect on vegetation remains an important topic for climate change study.East Asia is very sensitive and susceptible to climate change.In this study,we examined the effect of drought on the seasonal variations of vegetation in relation to climate variability and determined which growing seasons are most vulnerable to drought risk;and then explored the spatio-temporal evolution of the trend in drought changes in East Asia from 1982 to 2019.The data were studied using a series of several drought indexes,and the data were then classified using a heat map,box and whisker plot analysis,and principal component analysis.The various drought indexes from January to August improved rapidly,except for vegetation health index(VHI)and temperature condition index(TCI).While these indices were constant in September,they increased again in October,but in December,they showed a descending trend.The seasonal and monthly analysis of the drought indexes and the heat map confirmed that the East Asian region suffered from extreme droughts in 1984,1993,2007,and 2012among the study years.The distribution of the trend in drought changes indicated that more severe drought occurred in the northwestern region than in the southeastern area of East Asia.The drought tendency slope was used to describe the changes in drought events during 1982–2019 in the study region.The correlations among monthly precipitation anomaly percentage(NAP),NDVI,TCI,vegetation condition index(VCI),temperature vegetation drought index(TVDI),and VHI indicated considerably positive correlations,while considerably negative correlations were found among the three pairs of NDVI and VHI,TVDI and VHI,and NDVI and TCI.This ecological and climatic mechanism provides a good basis for the assessment of vegetation and drought-change variations within the East Asian region.This study is a step forward in monitoring the seasonal variation of vegetation and variations in drought dynamics within the East Asian region,which will serve and contribute to the better management of vegetation,disaster risk,and drought in the East Asian region.

Investigating the Long-Term Relationship between Aerosol Optical Thickness and Land Use/Cover Change in Guangxi Coastal Cities, China

Land Use/Cover Change (LUCC) has an impact on AOD to a certain extent. It is of great significance for ecological environment and public health to pay attention to and explore the response mechanism of AOD to LUCC. Based on remote sensing satellite technology, using landsat8 and MODIS data, this paper analyzes the correlation between different land use types and AOD in Beibu Gulf coastal urban belt under the background of wide-scale region and long time series, and further discusses the difference value and contribution level of each LUCC to AOD. The results show that: 1) there is a positive correlation between PM concentration and cultivated land, urban land, water area and other types of land, and the correlation coefficient increases in turn, R is 0.812, 0.685, 0.627, 0.416, respectively, which indicates that the increase of cultivated land and urban land increases PM concentration to a certain extent;2) there is a significant negative correlation between PM concentration and forest land, R is -0.924, The results show that the decrease of woodland is an important factor for the increase of atmospheric particulate matter concentration in the study area from 2015 to 2019;3) through the contribution analysis method, the contribution of cultivated land to AOD is the largest, followed by urban land, and the water area is the smallest in 2015-2019, which indicates that the land use mode is closely related to AOD. It can be helpful to reasonably plan land use types and scientifically optimize land use structure. It can effectively reduce the concentration of air pollution particles.

Socio-Demographic and Economic Correlates of Climate Change Coping and Adaptation Strategies: A Study on the Farmer Communities in Barisal District, Bangladesh

The major objective of the study is to apply Conservation of Resource (COR) theory for examining the influence of farmers’ socio-demographic and economic correlates upon their adoption of agricultural, economic and emotion-focused coping and adaptation strategies of climate change. An interview schedule developed from the COR theory was utilized for data collection. Using multistage cluster sampling technique, a total of 384 farmers were chosen from Agailjhara Upazila of Barisal District and interviewed through a predesigned structured questionnaire. For triangulation of the quantitative findings, the study employed case study technique to collect qualitative data from the respondents. The findings of the study demonstrate that the most common emotion- focused, agricultural and economic coping and adaptation strategies of climate change were social support seeking (79.69%), planting trees (71.35%), homestead gardening (52.08%), hydroponic farming/floating garden (46.88%), duck rearing (30.73%), saving (20.83%), self-insurance (18.75%), etc. Bivariate results indicate that age, ownership of land, income and ownership of television or mobile phone were found significantly correlated with the three variables, including economic, agricultural and emotion-focused coping and adaptation strategies of COR theory. Again, access to microcredit has relationship with economic and agricultural adaptation strategies. Furthermore, education has significant relationship with agricultural adaptation strategies. The study suggests that continuous researches by policy makers, researchers, GOs and NGOs are very essential to exploring and enhancing farmers’ coping and adaptation strategies which may relegate the adverse impacts and vulnerabilities of climate change in the study area.

Response of Ecosystem Service Value Based on Land Use Changes and Analysis of its Driving Factors in Typical Hilly Region with Red Soil

The contribution rate of ecosystem service value variation was used to analyze the effects of land use changes on the changes of ecosystem service value in Xingguo County during 1996-2005.Grey integrated correlation was employed to explore the contribution level of the indicators such as total population,urbanization level,proportion of primary industry and investment of social fixed assets on ecosystem service value,and the correlation analysis was also carried out.The results showed that the ecosystem service value in Xingguo County during 1996-2005 mainly was woodland,and the decrease of woodland area was the major reason for the sustained reduction of ecosystem service value.With the further increase of market demand and the incentives of local government,the garden area rapidly increased during 2001-2005,and the influence degree of garden towards the changes of ecosystem service value was only second to woodland,ranking No.2.Four socio-economic indicators had different correlation degree with ecosystem service value during the different research periods.Total population,urbanization level and proportion of primary industry had high correlation degree with ecosystem service value,whereas the influence degree of various socio-economic indicators on ecosystem service value was equal with each other day by day.Urbanization level,investment of social fixed assets and total population had significant negative correlation with ecosystem service value,while the proportion of primary industry had positive correlation with ecosystem service value.

Analysis on the Essential Characters and Biological Yield Change of Purple-fleshed Sweetpotato Xuzishu 3

Objective] This study was performed to investigate the trait changes and their correlations as wel as the dynamic changes of biological yield of Xuzishu 3, which wil help to enhance the yield and anthocyanin content of sweetpotato by cul-tivation. [Method] We systematical y measured the agronomic traits, qualitative char-acters and biological yield of Xuzishu 3 during six growing periods to investigate the dynamic changes of its essential characters and yield accumulation. [Result] The characters of Xuzishu 3 appeared most prosperous after the 90th d except for an-thocyanin content. Extremely significant positive correlations were found between ev-ery two of the dry matter rates of above-ground parts （including leaf petioles, leaves and stems）, reducing sugar content and potato weight per plant. Assimilated product distributed more in stems and leaves than in storage roots before the 90th d in growing period. Photosynthetic capacity and net assimilation rate gradual y de-creased after the 90th d, but the assimilated product distributing to storage roots in-creased quickly and maximized in the 135th d. [Conclusion] Xuzishu 3 is a late ma-turing variety requiring more fertilizer, and the accumulation of anthocyanin fluctuates during the growth period of Xuzishu 3. So yield of Xuzishu 3 can be increased by applying more fertilizer and extending the growth period reasonably, meanwhile the anthocyanin content can be increased by means of control ing temperature, light, water and phytohormone within 60 d after planting.

Devonian Frasnian-Famennian Transitional Milankovitch Cycles and High-Resolution Stratigraphic Correlation

Four hierarchical cyclothems, superbundlesets, bundlesets, bundles and laminae, have been identified from the Devonian Frasnian-Famennian carbonate strata in Guangxi, South China. Their hierarchical structures, ratio relationships and sequence in conodont zones are continuous and stable and can be traced across different facies zones and sedimentary basins. Our data show that hierarchically organized superbundlesets, bundlesets, bundles and laminae correspond to the long eccentricity, eccentricity, obliquity or precession and sub-Milankovitch cycles respectively. Their periods were 400,000, 100,000, 33,333, 16,667 and 8,000–17,000 a, respectively. The ratios of long eccentricity to eccentricity, eccentricity to obliquity, and eccentricity to precession in the Devonian are 1:4, 1:3 and 1:6 respectively. Using these hierarchical Milankovitch cyclothems, chronostratigraphical division and correlation can be realized at a resolution of 100 ka or 10 ka at the Frasnian-Famennian transition. The time intervals of the Upper rhenana Zone, linguiformis Zone, and the Lower, Middle and Upper triangularis Zone are 0.6, 0.8, 0.3, 0.3 and 0.3 Ma, respectively. Sea-level changes of the Frasnian-Famennian transition were not coherent and synchronous at the resolution of 100 ka or 10 ka in the basin-slope carbonate sequences of Guangxi, South China.

Spatial features of land use/land cover change in the United States

With the classifi cation data covering American land-use/land-cover (LUCC) with 30 m resolu tion from the project of National Land Cover Data (NLCD), we normalize d them and made their resolution changed into 1 km ×1 km, created the data of American land-use grade and analyzed the spatial distribution and featur es of American LUCC as well as the influence of population and altit ude on the land-use grade in light of methods of sampling analysis a nd correlation study. Based on the analysis, we concluded that forestr y and grassland, accounting for 71.24% of the whole country, has taken the main part of American land cover, and besides, construction and arable land has occupied 19.22% of the total land, the rest of land cover types, including water area, wetland and underdeveloped land, is 9. 54% of the country's total. The developing potential of American land resources is enormous with less destroyed and disturbed ecological environment. Although, in some sense, the population and altitude influence the sp atial variation of American land-use grade respectively, the influence of spatial variation of altitude and population density on that of la nd-use grade is not significanct.

THE IMPACT OF THE CONTEMPORARY CLIMATIC CHANGE ON CHINAS THERMAL RESOURCES

In the global climatic change, China's climatic change will be more compliCated and itS compact on the agroclimatic resources and agricultural production will also be more obvious. Therefore, it is absolutely necessary to take the agroclimatic resources as a comprehensive climatic information syStem for evaluating the impact of climatic change on agriculture and exploring the corresPOndent ways to deal with it. This article studies the compact of climatic change on China's thermal resources and make a correlation analySis of the climatic COndition and the agroclimatic thermal resources in order to establish a regression equation and made simulant computation with Monte Cario Method. In addition, it analyses the change of the thermal resources possibly resulted from climatic change, evaluates its impact on agricultural, and finally sets up the corresPOndent countermeasures.

Monitoring of velocity changes based on seismic ambient noise: A brief review and perspective

Over the past two decades,the development of the ambient noise cross-correlation technology has spawned the exploration of underground structures.In addition,ambient noise-based monitoring has emerged because of the feasibility of reconstructing the continuous Green’s functions.Investigating the physical properties of a subsurface medium by tracking changes in seismic wave velocity that do not depend on the occurrence of earthquakes or the continuity of artificial sources dramatically increases the possibility of researching the evolution of crustal deformation.In this article,we outline some state-of-the-art techniques for noise-based monitoring,including moving-window cross-spectral analysis,the stretching method,dynamic time wrapping,wavelet cross-spectrum analysis,and a combination of these measurement methods,with either a Bayesian least-squares inversion or the Bayesian Markov chain Monte Carlo method.We briefly state the principles underlying the different methods and their pros and cons.By elaborating on some typical noisebased monitoring applications,we show how this technique can be widely applied in different scenarios and adapted to multiples scales.We list classical applications,such as following earthquake-related co-and postseismic velocity changes,forecasting volcanic eruptions,and tracking external environmental forcing-generated transient changes.By monitoring cases having different targets at different scales,we point out the applicability of this technology for disaster prediction and early warning of small-scale reservoirs,landslides,and so forth.Finally,we conclude with some possible developments of noise-based monitoring at present and summarize some prospective research directions.To improve the temporal and spatial resolution of passive-source noise monitoring,we propose integrating different methods and seismic sources.Further interdisciplinary collaboration is indispensable for comprehensively interpreting the observed changes.

Application and comparison of coaxial correlation diagram and hydrological model for reconstructing flood series under human disturbance

Intense human activities have greatly changed the flood generation conditions in most areas of the world, and have destroyed the consistency in the annual flood peak and volume series. For design flood estimation, coaxial correlation diagram and conceptual hydrological model are two frequently used tools to adjust and reconstruct the flood series under human disturbance. This study took a typical mountain catchment of the Haihe River Basin as an example to investigate the effects of human activities on flood regime and to compare and assess the two adjustment methods. The main purpose is to construct a conceptual hydrological model which can incorporate the effects of human activities. The results show that the coaxial correlation diagram is simple and widely-used, but can only adjust the time series of total flood volumes. Therefore, it is only applicable under certain conditions(e.g. There is a strong link between the flood peaks and volumes and the link is not significantly affected by human activities). The conceptual model is a powerful tool to adjust the time series of both flood peak flows and flood volumes over different durations provided that it is closely related to the catchment hydrological characteristics, specifically accounting for the effects of human activities, and incorporating expert knowledge when estimating or calibrating parameters. It is suggested that the two methods should be used together to cross check each other.

A path analysis of the cultivated land change in Hubei Province,China

Hubei Province is one of the critical grain production regions in China with the quantitative cultivated landand good natural condition; it plays an important role in grain security in China. However, owing to rapid economicgrowth, population pressures, anthropogenic activities, and natural disasters, the quality of the cultivated land hassignificantly decreased in recent years and environmental resources are under increasing stress. In order to research onthe mechanism of the change of the cultivated land, this paper analyzes qualitatively the influencing factors of thecultivated land change in Hubei Province from 1978 to 2004, and distinguishes the direct factors from indirect influentones by means of the approach of the path analysis. The result shows that the area of the rent land in the total non-agricultural land, the total population growth and the fixed asset investment are the main factors deciding the change ofthe cultivated land. Meanwhile, the density of the transportation network, the proportion of per capita income of ruralcitizens to that of urban citizens, non-agricultural gross domestic production’s share of the total GDP has a less directeffect but a more indirect influence on the decrease of the cultivated land in Hubei Province. The result means that whilesome factors have less direct influence on the change of the cultivated land, its indirect influence are significant, viceversa. Thus it’s necessary to adopt a comprehensive measurement to protect the cultivated land.

Influence of Multi-component Failure on Mechanical Product Design Change

Design change is one of the most common activities in design and development of mechanical products, and the change will affected by the design and maintenance of the products. It is not uncommon that multiple components might run out of order simultaneously during the use of a product, which would have significant influences on the product performance. Such kind of multi-component failure must be considered early in the product design stage, therefore it is necessary to study multiple design changes incurred by multi-component failure. Existing studies on the design change only focus on single change and ignore multiple simultaneous changes. To address this problem, a change influence network model is establishes, and the propagation path of multiple changes on the change influence network is described according to the change propagation characteristics of mechanical products. By analyzing the degree of dependence between the nodes and the absorption situations of nodes to change propagation, the possible paths of change propagation on the change influence network are determined, and based on which, calculation of the change influence is carried out, which provides decision-making support for product designers. Finally, the feasibility of the proposed methodology is demonstrated by taking a household juicer for case study.

Runoff variation and its response to climate change in Huolin River catchment,Northeast China

The Huolin River catchment(HRC)is located in the semi-arid region of Northeast China,which is very sensitive to climate change.The runoff in HRC is closely related to the recovery of local vegetation in the Greater Khingan Mountains and the survival of downstream wetlands.Dramatic runoff fluctuations and increasing no-flow days confirmed the water crisis in this area.Hence,it is extremely urgent to study the current situation and characteristics of runoff.In this study,hydrological and meteorological data of HRC during 1956-2018 were analyzed to elucidate the processes,characteristics,trends of the river runoff and revealed its response to climate change.The Mann-Kendall test and linear regression method showed that runoff in the HRC demonstrated a downward trend over the study period with a marked annual variation.The runoff in the high flow years was 100 times that of the low flow years,showing a typical continental climatic river characteristic.There are two runoff peak flows in the intra-annual runoff distribution in March and July,whereas two runoff valleys occurred around May and September to February.The runoff positively correlates with precipitation in summer and temperature in early spring.Snowmelt influenced by rising temperatures in April and precipitation in July is the main driving factor for the two peaks flow.Evaporation rose with precipitation decline and temperature increased,which may influence the runoff decrease.The annual runoff is well synchronized with the annual precipitation,and precipitation change is the main driving factor of variation and abrupt change points of annual runoff in the catchment.This study would be beneficial for water resource management in developing adaptation strategies to offset the negative impact of climate change in HRC.