Step-edge-guided nucleation and growth mode transition of α-Ga_(2)O_(3) heteroepitaxy on vicinal sapphire

Controlling the epitaxial growth mode of semiconductor layers is crucial for optimizing material properties and device performance.In this work,the growth mode ofα-Ga_(2)O_(3) heteroepitaxial layers was modulated by tuning miscut angles(θ)from 0°to 7°off the(1010)direction of sapphire(0002)substrate.On flat sapphire surfaces,the growth undergoes a typical three-dimensional(3D)growth mode due to the random nucleation on wide substrate terraces,as evidenced by the hillock morphology and high dislocation densities.As the miscut angle increases toθ=5°,the terrace width of sapphire substrate is comparable to the distance between neighboring nuclei,and consequently,the nucleation is guided by terrace edges,which energetically facilitates the growth mode transition into the desirable two-dimensional(2D)coherent growth.Consequently,the mean surface roughness decreases to only 0.62 nm,accompanied by a significant reduction in screw and edge dislocations to 0.16×10^(7) cm^(-2)and 3.58×10^(9) cm^(-2),respectively.However,the further increment of miscut angles toθ=7°shrink the terrace width less than nucleation distance,and the step-bunching growth mode is dominant.In this circumstance,the misfit strain is released in the initial growth stage,resulting in surface morphology degradation and increased dislocation densities.

Change Point Analysis to Detect the Effect of Pruning Severity on Tree Growth

The effect of pruning severity on tree growth was analyzed by change point detection using segmented regression. The present study applied this analysis to a well-known published data set including diameter growth response, tree age, pruning severity and pretreatment crown size. First, multiple regression analysis was performed to assess the effect of tree age, pruning severity and pretreatment crown size on diameter growth response. Next, segmented regression analysis was performed to assess the effect of pruning severity on diameter growth response. The results of the multiple regression showed that diameter growth response was significantly influenced by pruning severity and pretreatment crown size. The results of the segmented regression showed that in the whole data set, an abrupt change toward a decrease in diameter growth response was detected at 25% of the live crown removed. However, in the group of fully crowned and open-grown, diameter growth response continuously decreased with increasing pruning severity with no significant abrupt change, whereas in the group of 70% - 90% live crown, diameter growth response did not significantly decrease up to the break point (53% crown removed) and then abruptly decreased. This may be the first study to show the numerical evaluation of the effect of pruning severity on tree growth by change point analysis.

Annual growth of Fagus orientalis is limited by spring drought conditions in Iran’s Golestan Province

Due to the lack of a uniform and accurate defi-nition of‘drought’,several indicators have been introduced based on different variables and methods,and the efficiency of each of these is determined according to their relationship with drought.The relationship between two drought indices,SPI(standardized precipitation index)and SPEI(standard-ized precipitation-evapotranspiration index)in different sea-sons was investigated using annual rings of 15 tree samples to determine the effect of drought on the growth of oriental beech(Fagus orientalis Lipsky)in the Hyrcanian forests of northern Iran.The different evapotranspiration calcula-tion methods were evaluated on SPEI efficiency based on Hargreaves-Samani,Thornthwaite,and Penman-Monteith methods using the step-by-step M5 decision tree regression method.The results show that SPEI based on the Penman-Monteith in a three-month time scale(spring)had similar temporal changes and a better relationship with annual tree rings(R^(2)=0.81)at a 0.05 significant level.Abrupt change and a decreasing trend in the time series of annual tree rings are similar to the variation in the SPEI based on the Penman-Monteith method.Factors affecting evapotranspiration,temperature,wind speed,and sunshine hours(used in the Penman-Monteith method),increased but precipitation decreased.Using non-linear modeling methods,SPEI based on Penman-Monteith best illustrated climate changes affecting tree growth.

Population growth，economic growth，technology changes in relation to environmental changes──A theoretical modelling analysis of environmental changes

This paper mainly deals with the impact of three major factors , namely population growth,economic growth and technology changes, on the changes of environmental quality. It presents a curve ofenvironmental changes in relation to demographic transition and process of industrialization. It concludesthat a major way of improving environmental quality is to intensify pollution decreasing technical factorsand that control of population growth will also reduce the pressure on the environment.

The linkage between two ENSO types/modes and the interdecadal changes of ENSO around the year 2000

This study focuses on the interdecadal changes in ENSO properties emerging around the year 2000. Compared to 1980-1999, after 2000, the ENSO amplitude weakened, the occurrence of the central Pacific （CP） Et Nino increased, and the eastern Pacific （EP） El Nino became suppressed. Meanwhile, the dominant period of ENSO shortened from quasi-quadrennial （QQ） to quasi-biennial （QB）. The authors show that these changes in ENSO properties are evidently consistent with the change in the stability of the ENSO mode through connecting the two ENSO types with the two coupled ENSO modes, i.e. the QQ and QB modes. It is suggested that the relative activity or stability of the two ENSO modes changed after the year 2000. The intensity of both the QQ and QB mode weakened. The QQ mode, which is linked to EP ENSO and was significantly strong during 1980-1999, became much weaker after 2000 in terms of the EP type almost disappearing. Compared with the weakness of the QQ mode, the QB mode, as manifested by the CP type, remained active and became dominant in the tropical Pacific after 2000. Analysis shows that the changes in mean states in the tropical Pacific were likely responsible for the interdecadal ENSO changes around the year 2000.

Relationship between the spatial position of the seed and growth mode for single-crystal diamond grown with an enclosed-type holder

The relationship between the spatial position of the diamond seed and growth mode is investigated with an enclosedtype holder for single-crystal diamond growth using the microwave plasma chemical vapor deposition epitaxial method.The results demonstrate that there are three main regions by varying the spatial position of the seed.Due to the plasma concentration occurring at the seed edge,a larger depth is beneficial to transfer the plasma to the holder surface and suppress the polycrystalline diamond rim around the seed edge.However,the plasma density at the edge decreases drastically when the depth is too large,resulting in the growth of a vicinal grain plane and the reduction of surface area.By adopting an appropriate spatial location,the size of single-crystal diamond can be increased from 7 mm×7 mm×0.35 mm to8.6 mm×8.6 mm×2.8 mm without the polycrystalline diamond rim.

Urgency Required in Changing the Growth Mode of China's Foreign Trade

Presently China mainly relies on the low cost of production factors and introducing advanced foreign technology to create an international competitive edge.Thepresent foreign trade growth mode,which is charaterized of quantitative expansion,labor-intensive and low prices,low e ciency,unsustained,is facing lots ofdifficulties.The problems such as the worsening terms of trade,the huge trade surplus,too much dependence on foreign trade,the rising prices of production factors,difficulties in the introduction of high technology,excessive consumption of resources,environmental pressures exacerbated the situations.Therefore,China mustadopt effective measures into a sustained and high efficiency foreign trade growth mode,which is supposed to be described as optimization of export commoditystructure,market diversification,mainly relying on independent innovation and independent brands,promoting trade with science and technology,rationaliztion ofindustrial structure,focusing on high added value.

Development Mode of Mid-small Cities in Northern Jiangsu Based on the Growth Pole Theory

The development mode of mid-small cities in northern Jiangsu is analyzed on the Growth Pole theory.Depending on scales,endowment of resources,geographical positions,and industrial advantages of mil-small cities,we can divide the development mode of those mid-small cities within this context into five types:development through integration into big cities;independent development;resource-dependent development;single industry development;and mixed industry development.

Growth rate of peeling mode in the near separatrix region of diverted tokamak plasma

An analytical expression of the peeling mode in the near separatrix region of diverted tokamak plasma is derived. It is shown that in diverted plasmas both with single and double X points, though the perturbed potential energy of the unstable peeling mode tends to be large, its growth rate becomes very small due to the even larger kinetic energy. Compared to some recent studies that give qualitatively correct results about this growth rate, our result is directly related with the diverted equilibrium quantities suitable for application to realistic experiments.

Changes in embryonic development,juvenile growth and physiological adaptation of the cuttlefish Sepia pharaonis in response to photoperiod manipulation

Photoperiod is a key environmental indicator for re gulating embryonic development,individual growth and physiological processes in aquatic animals.In this study,differences in embryonic development and performance of newly hatched cuttlefish juvenile exposed to five different cycles of light:dark(L:D):constant light,18 L:6D,12 L:12D,6 L:18D cycles,and constant darkness were evaluated.Prolonged exposure to light induced an accelerated rate of embryonic development,particularly after the red-bead stage.Principal component analysis(PCA)revealed that red-bead stage,heartbeat,endoskeleton formation,pigment appear,and six increments of cuttlebone were the main factors contributing to the embryonic development.Meaning that the duration time of these five stages were significantly different when exposed to photoperiod regimes,which may determine the duration of the incubation period of the embryos.Long term light has also affected the incubation parameters with an increased rate in hatching and shortened the incubation and hatching periods in the 12-24-h day length range.However,constant light and darkness environment appeared to have a greater effect on the stress of embryonic development,mainly reflected in the yolk shed ratio and the inking rate in the egg capsule.Moreover,the increase in the day length has contributed to improve the growth and survival of juveniles in the 12-18-h day length range;however,juveniles exposed to constant light and darkness experienced worse re sults in terms of growth,tissue glycogen content,dige stive enzymes of the digestive glands,and metabolic enzymes of the muscles.These finding suggest that prolonged light exposure accelerates the process of embryonic development,maximum feeding time is not necessarily a condition of optimal growth,and inappropriate light cycles can disturb the body’s endogenous controls.Therefore,the optimal photoperiod for the embryos development and juvenile growth of Sepia pharaonis were 12 h and 12-18 h of day length,respectively.These results are useful for increasing the production of this species during embryo incubation and juveniles rearing in aquaculture practice.

Impact of Economic Development Model on the Fitting Effect of the Mathematical Model of Changes in Cultivated Land Resources

The mathematical model is often used for fitting the trend of changes in cultivated land resources in the land use planning,but the fitting effect is different in different study areas. In this paper,we take two geographically adjacent cities with great differences in the economic development model,Xinghua City and Jingjiang City,as the research object. Using logarithmic model( M1),Kuznets model( M2),logistic model( M3) and multivariate linear model( M4),we fit the process of changes in cultivated land resources during the period 1980- 2009,and compare the differences in the fitting effect between different models. In terms of the model fitting effect in Xinghua City,it is in the order of M3 > M4 > M1 > M2,which is related to the fact that the local areas lay great emphasis on agricultural development,and pay close attention to ensuring the cultivated land area; in terms of the model fitting effect in Jingjiang City,it is in the order of M1 > M3 > M4 > M2,and the deep-seated cause is that its development model is dominated by extended trade expansion,and the level of intensive land use is constantly improved. In addition,we discuss the multi-stage characteristics of changes in cultivated land resources,and propose a solution of using the same model to simulate in various phases. The research results in Jingjiang City show that the coefficient of determination in the first phase( R2=0. 958) and the standard error( SE = 0. 261) are both better than those of the original model( R2= 0. 945,SE = 0. 312); the coefficient of determination in the second phase is slightly low( R2= 0. 851),but the standard error is greatly improved( SE = 0. 137). Compared with the research conclusions of other scholars,it can be believed that this method can better solve the problems that the scatter plot of logistic model presents wave-shape and the scatter plot of Kuznets model presents " M"-shape,in order to improve the applicability of mathematical models.

Research on the Influence of Population Structure on Economic Growth: Based on the Provincial Panel Data Model

In recent years, the international environment and conditions of China’s economic development have undergone profound and complex changes, but in the middle and long term, China’s economy has been maintaining a stable medium-high speed development. It is remarkable that population changes bring about changes in economic development;especially the aging of the population has a particularly significant impact on economic growth. Therefore, based on the inter-provincial panel data of 31 provinces and municipalities from 2011 to 2019, this paper mainly studies the impact of population change on economic growth by establishing a solid fixed effect model. The results show that there is a long-term equilibrium relationship between population structure and economic growth, and population structure has a significant positive impact on economic development. In addition, there are regional differences in the positive and significant relationship between the two.

Drivers of spatial structure in thinned forests

Background:As is widely known,an increasing number of forest areas were managed to preserve and enhance the health of forest ecosystems.However,previous research on forest management has often overlooked the importance of structure-based.Aims:Our objectives were to define the direction of structure-based forest management.Subsequently,we investigated the relationships between forest structure and the regeneration,growth,and mortality of trees under different thinning treatments.Ultimately,the drivers of forest structural change were explored.Methods:On the basis of 92 sites selected from northeastern China,with different recovery time (from 1 to 15years) and different thinning intensities (0–59.9%) since the last thinning.Principal component analysis (PCA)identified relationships among factors determining forest spatial structure.The structural equation model (SEM)was used to analyze the driving factors behind the changes in forest spatial structure after thinning.Results:Light thinning (0–20%trees removed) promoted forest regeneration,and heavy thinning (over 35% of trees removed) facilitated forest growth.However,only moderate thinning (20%–35%trees removed) created a reasonable spatial structure.While dead trees were clustered,and they were hardly affected by thinning intensity.Additionally,thinning intensity,recovery time,and altitude indirectly improve the spatial structure of the forest by influencing diameter at breast height (DBH) and canopy area.Conclusion:Creating larger DBH and canopy area through thinning will promote the formation of complex forest structures,which cultivates healthy and stable forests.

Effects of Different Fertilization Modes on Growth of Cymbidium sinense ‘Qihei'

[Objective] This study was conducted to screen the best fertilization mode for potted Cymbidium sinense ＇Qihei＇. [Method] According to the contents of the N, P and K elements in C. sinense ＇Qihei＇ and the main fertilization modes used by producers and related literature information, the effects of 8 kinds of fertilization models on the growth of C. sinense ＇Qihei＇ were studied. Twenty six morphologic and physiological indexes of C. sinense ＇Qihei＇ growth were measured. [Result] Significant differences were shown on 21 indexes. [Conclusion] Based on the 26 in- dexes, the best fertilization mode included the steps of applying 14-14-14 （N-P20^- K20） slow-release fertilizer particles （8 g per bag） once in April, July and October, respectively; drip-applying 800 times of 30-10-10 water-soluble fertilizer once every half a month from April to September; and drip-applying 800 times of 15-5-30 wa- ter-soluble fertilizer （150 ml） once every half a month from October to December.

Divergent responses of Picea crassifolia Kom.in different forest patches to climate change in the northeastern Tibetan Plateau

Global climate changes have significantly affected tree growth and forest structures and functions in some arid and semi-arid regions,which are becoming warmer and wetter.Due to natural factors such as climate and terrain,some tree species may form different forest patches at the edges of their distribution areas.However,how forest patches of various sizes respond to climate change is unclear.In this study,we collected 203 tree cores from six different sizes of forest patches at the edge of the distribution area of Picea crassifolia Kom.in the northeast Tibetan Plateau.And we used the dendrochronology method to study the response of tree growth and resilience in different forest patches to climate change from 1961 to 2020.We simultaneously measured the contents of nonstructural carbohydrates(NSC),total nitrogen and total phosphorus of tree needles.Our results showed that the growth of trees in small-and medium-size forest patches(0.8–18.6 ha)has increased significantly.The early growing season(May–July)minimum temperature was the most important climate factor driving the growth of small-and medium-sized patch trees.The early growing season maximum temperature was the most important climate factor that inhibited the growth of trees in the largest patches(362.8 ha).The growth of individual trees in medium forest patches was better and the correlation with annual minimum temperature,maximum temperature,precipitation,actual evapotranspiration,and palmer drought severity index was stronger.The higher NSC content,stronger photosynthesis,and higher nitrogen utilization efficiency in leaves might be one of the reasons for the better growth of trees in moderate forest patches.In extreme drought years,as the forest patch area increased,the overall trend of tree growth resistance showed a unimodal pattern,with the highest at a forest patch area of 7.1 ha,while the overall trend of tree growth recovery was opposite.Therefore,we should strengthen the management of trees in large forest patches to cope with climate change.

Enhanced soil moisture improves vegetation growth in an arid grassland of Inner Mongolia Autonomous Region, China

Climate change impacts on grasslands that cover a quarter of the global land area, have become unprecedented during the 21~(st) century. One of the important ecological realms, arid grasslands of northern China, which occupy more than 70% of the region's land area. However, the impact of climate change on vegetation growth in these arid grasslands is not consistent and lacks corresponding quantitative research. In this study, NDVI(normalized difference vegetation index) and climate factors including temperature, precipitation, solar radiation, soil moisture, and meteorological drought were analyzed to explore the determinants of changes in grassland greenness in Inner Mongolia Autonomous Region(northern China) during 1982–2016. The results showed that grasslands in Inner Mongolia witnessed an obvious trend of seasonal greening during the study period. Two prominent climatic factors,precipitation and soil moisture accounted for approximately 33% and 27% of grassland NDVI trends in the region based on multiple linear regression and boosted regression tree methods. This finding highlights the impact of water constraints to vegetation growth in Inner Mongolia's grasslands. The dominant role of precipitation in regulating grassland NDVI trends in Inner Mongolia significantly weakened from 1982 to 1996, and the role of soil moisture strengthened after 1996. Our findings emphasize the enhanced importance of soil moisture in driving vegetation growth in arid grasslands of Inner Mongolia, which should be thoroughly investigated in the future.

Investigating the causes of Lake Urmia shrinkage:climate change or anthropogenic factors?

In the current scenario,Lake Urmia,one of the vastest hyper saline lakes on the Earth,has been affected by serious environmental degradation.Using different satellite images and observational data,this study investigated the changes in the lake for the period 1970–2020 based on the effects of climate change and several human-induced processes on Lake Urmia,such as population growth,excessive dam construction,low irrigation water use efficiency,poor water resources management,increased sediment flow into the lake,and lack of political and legal frameworks.The results indicated that between 1970 and 1997,the process of change in Lake Urmia was slow;however;the shrinkage was faster between 1998 and 2018,with about 30.00%of the lake area disappearing.As per the findings,anthropogenic factors had a much greater impact on Lake Urmia than climate change and prolonged drought;the mismanagement of water consumption in the agricultural sector and surface and underground water withdrawals in the basin have resulted in a sharp decrease in the lake's surface.These challenges have serious implications for water resources management in Lake Urmia Basin.Therefore,we provided a comprehensive overview of anthropogenic factors on the changes in Lake Urmia along with existing opportunities for better water resources management in Lake Urmia Basin.This study serves as a guideline framework for climate scientists and hydrologists in order to assess the effects of different factors on lake water resources and for decision-makers to formulate strategies and plans according to the management task.

Regulatory mode selection and legal governance of China's response to climate change risk

The regulation of climate change risk is an important measure for China to achieve the goal of"carbon neutrality and carbon peak".Although China has built a legal regulation system for environmental risk at the macro level,and normative and functionalism have constructed different paths for regulating climate change risk,it is necessary to analysis the two paths at the micro level,in order to examine its adaptability to climate change risk.The normative mode of climate change risk regulation emphasizes the clarity of the legal regulation system,controls the regulatory subject formally,and pays attention to the role of judicial review;The functionalist mode of climate change risk regulation emphasizes the authorization of regulatory subjects,and identifies and manages climate change risks in the way of administrative self-control.In order to regulate climate change risk,in addition to the traditional way of solving the problem of"normalization"and"functionalism",there is also a third regulatory mode,that is,to overcome the inherent shortcomings and defects of both functionalism and normalization,and to integrate the two necessary:not only pay attention to the legal normative requirements of the normative mode,but also mobilize the initiative of administrative regulation under functionalism,and strengthen the judicial prevention function,and then improve the effe ctiveness of China’s participation in global climate change governance.

Using Remote Sensing to Analyse the Role of Urbanization in the Transformation of Land-Use and Land Cover in Likasi Town (Haut-Katanga, DR Congo)

Environmental change is characterized as an alteration in the environment caused primarily by human activities and ecological processes that are natural. Given the fact that the southern part of the province of Haut-Katanga in the Democratic Republic of the Congo (DRC) is part of the African Copperbelt and has been a region of intense mining for decades, humans have affected the physical environment in various ways: such as overpopulation, suburbanization, wastage, deforestation. It is therefore important to track and control the changes in the area’s mining activities. This study aimed to analyze these changes using remote sensing techniques. Landsat satellite images from 2002 and 2022 were processed and classified to quantify changes in built-up area, agricultural land, and vegetation cover over the 20-year period. The classification results revealed sizable differences between the two time points, indicating considerable expansion of built-up land and declines in agricultural land and vegetation cover from 2002 to 2022 in Likasi. These findings provide evidence that urban growth has transformed the landscape in Likasi, likely at the expense of farmland and ecosystems. Further analysis of the remote sensing data could quantify the changes and model future trends to support sustainable land use planning. The land cover and land use analysis were performed with the assistance of the ERDAS 16.6.13 software by mapping LANDSAT data from two different years 2002 and 2022.

Vegetation changes in the agricultural-pastoral areas of northern China from 2001 to 2013

Climate change and human activity have resulted in increasing change of vegetation growth globally. Numerous studies have been conducted on extreme climate events and analyses of ecological environment evolution. However, such studies have placed little emphasis on vegetation change and spatial variation in this type of ecotone. Accordingly, this study analyzed the changes in vegetation type and growth using the 16-d composite MOD13A1 product with 1-km resolution and MOD12Q1 product with 1-km resolution. We used the mean, maximum, standard deviation normalized-difference vegetation index（NDVI） values, and the rate of change（ROC） of NDVI value to explain vegetation changes within the studied ecotone. Our results showed that significant vegetation type and growth changes have occurred in the study area. From 2001 to 2013, for example, with the exception of 2001, 2004 and 2009, a certain extent of grassland area was converted to cropland. Drought severity index（DSI） results indicate that there exists drought in 2001, 2004 and 2009. Such temporal changes in cropland and grassland area confirmed the ecological vulnerability of the ecotone. At the same time, vegetation varied spatially from west to east and from south to north. The mean, maximum and standard deviation NDVI values were all sorted in descending order based on differences in latitude and longitude, as follows： NDVI_（2013）〉NDVI_（2009）〉NDVI_（2004）〉NDVI_（2001）