Primary Control Factor Research Articles

Dynamic coupling responses and sand production behavior of gas hydrate-bearing sediments during depressurization: An experimental study

Gas hydrates that occur in offshore sediments and onshore permafrost represent a vast source of natural gas. However, current gas production trials indicate that sand production, which refers to the migration of sand into boreholes is an obstacle for long-term safe and efficient gas production from gas hydrate reservoirs. Therefore, understanding sand production behaviors during hydrate mining is especially important. In this study, we conducted laboratory-scale tests to investigate the effect of hydrate saturation and overlying stress on the sand production behaviors of hydrate-bearing sediments with a sand screen before, during, and after hydrate dissociation by depressurization. The synthesized methane hydrate saturations and simulated overlying stresses were ~20%, ~30%, ~40%, ~50%, and ~60% and ~11, ~12, ~13, ~14, and ~15 MPa, respectively. The experimental results indicate that sand production before hydrate dissociation is relatively minor and primarily silty. The amount of sand produced increases and silt, fine sand, and medium sand were observed during and after hydrate dissociation. The mass of sand production increases as hydrate saturation increases under constant overlying stress; however, under constant hydrate saturation, it increases then decreases as overlying stress increases. Friction among particles may become the primary control factor once the overlying stress exceeds a critical value. We considered hydrate saturation and overlying stress to establish a sand production prediction model. Our findings help understand sand production behavior using sand screens during gas production from hydrate reservoirs and provide a reference for sand production control design in future hydrate mining.

The Influence of Longitudinal Force on the Internal Force Distribution and Deformation Coordination Mechanism for Segment Lining

A series of local prototype tests are conducted on the Sutong GIL (Gas-Insulated Line) and Shiziyang Tunnel. These tests investigate the redistribution law of segment deformation and the bending moment during construction. The results reveal that the transfer ability of deformation and the bending moment improve with an increase in the longitudinal force. Stage characteristics are observed for the effect of the longitudinal force on the opening of the circumferential joints. Segments are fully contacted for the circumferential joints when the joint opening is not observed. The frictions between the segments are the key factors for the bending moment and segment deformation control. The opening of the circumferential joint with an increase in the joint opening then becomes the primary control factor. The transfer ability becomes stable when the load continues increasing after mortise and tenon contact. Better transfer ability occurs with a general segment with four pairs of mortises and tenons. This was presented as a smaller value of an increasing rate and the stable magnitude of the joint opening. From the perspective of practical engineering, mortises and tenons can be added to the vault to increase the load and deformation transfer ability of the general segment after the loss of the longitudinal force.

Analysis and prediction of the tensile strength of aluminum alloy composite using statistical and artificial neural network technique

In this research work, aluminum alloy (Al-20Fe-5Cr) matrix-based aluminum oxide (Al2O3) reinforced composites were developed through the powder metallurgy (P/M) process. Effect of compaction pressure (200, 250 & 300 MPa) and wt.% of Al2O3 (0, 10, 20 & 30 wt.) on tensile strength and percentage elongation has been analyzed through statistical and artificial neural network techniques (ANN). The mixture of Al-alloy powder particles and Al2O3 particles were synthesized in a centrifugal ball mill for 20 min. Compaction of synthesized powder was carried in the standard tensile die using a uniaxial hydraulic pressing machine. Sintering was performed at temperature 580 ± 20 °C for one hour in an argon gas environment using an electric tubular furnace. It was found that tensile strength enhanced significantly with the addition of Al2O3up to 20 wt.% and then declined sharply for the 30 wt.% of Al2O3at all compaction pressures. The highest tensile strengths were found for each wt.% of Al2O3 at compaction pressure 300 MPa compare to other compaction pressures. Tensile strength increased from 105 to 158 MPa with the addition of 20 wt.% Al2O3 and decreased to 142 MPa for 30 wt.% at 300 MPa compaction pressure. The improvement resulted from better compaction, leading to more plastic deformation, better packing, and high effective contact area. However, the percentage of elongation decreased from 23.2% to 2.2% with an increment of wt.% of Al2O3 for compaction pressure 200 MPa, while for 300 MPa, its value drops from 25.8% to 6.5%. This depreciation can be reasoned for the reduction in ductile matrix content and dilute flowability of the Al matrix, which occurred due to brittle Al2O3. The statistical analysis using ANOVA revealed that the compaction pressure is the primary control factor influencing tensile strength by 90.3%. The feed-forward network with a back-propagating gradient-descent error minimization training approach and mean squared error (MSE) as performance function was employed to model and predict tensile strength. The developed 3-layered multilayer perceptron (MLP) with 2–10–2 network architecture established a correlation between the inputs and outputs with minimum error (MSE) below 1% and maximum correlation coefficient (R) close to 1.

Variable Dimension Fractal-Based Conversion Method between the Nuclear Magnetic Resonance T2 Spectrum and Capillary Pressure Curve

Pore structure is the primary control factor of pore fluid distribution and flow capacity. It is an important content in reservoir evaluation. The capillary pressure curve is a major method to obta...

Influences on Antislide Piles Used for Slope Reinforcement: Numerical Simulation Based on the Soil Arching Effect

This study explores the pile-soil interaction mechanism and the optimal use of antislide piles for slope reinforcement based on finite difference numerical modelling. The force and displacement principles of slopes and antislide piles are analysed. The influences of various factors are investigated, such as postpile filling parameters, pile embedding methods, and pile cross-sectional shapes. Numerical modelling is used to determine the optimal layouts of antislide piles for push and traction landslides. The findings indicate that the cohesive force of the fill has a greater influence on the piles and slope than the friction angle and is the primary control factor. Fully buried antislide piles provide a better antisliding effect than semiburied ones. With fully buried piles, the best controlling effect is obtained when the ratio of the length of the pile’s free section to the height of the sliding body is approximately 4/5. Moreover, stepped-cross-section piles provide better slope reinforcement than those with rectangular, T-shaped, or trapezoidal cross-sections. In practical applications, end-bearing arches can be utilized as the primary control structures, with friction arches used for secondary control to improve the soil arching effect as much as possible, thereby enhancing the stability of the piles and slope. To control landslides of various thrust forms, antislide piles should be set in the active section, the core sliding section, or both, as required. This paper provides guidance for improving the design of antislide piles.

Grapevine Sap Flow in Response to Physio-Environmental Factors under Solar Greenhouse Conditions

Understanding transpiration responses to physiological and environmental factors is essential for efficient water management practices in greenhouse grapevine farms. To determine the driving factors of grapevine sap flow under solar greenhouse conditions in a typical cold climate, the sap flow, greenhouse micro-environmental conditions, and canopy details were measured and analyzed for the 2017–2018 growing season in Northeast China. The results showed that leaf area index controlled the upper boundary of sap flow rate (SFR). Correlations between SFR and meteorological factors obviously varied with time scales. Besides, the correlations at the hourly scale varied across the seasons. Photo-synthetically active radiation (PAR) was the primary control factor of sap flow, irrespective of time scale or season. The start and stop times of sap flow did not change with weather conditions, but SFR had broader peaks with higher peak values during sunny days. The diurnal variation of SFR lagged behind that of PAR, but remained ahead of those of VPD and temperature. Weather condition changed the sizes of the hysteresis loops, but not the rotation direction. The hydrological and physiological processes involved in sap flow are useful for refining transpiration models and improving water use efficiency in the greenhouse environment.

Contrasting policy shifts influence the pattern of vegetation production and C sequestration over pasture systems: A regional-scale comparison in Temperate Eurasian Steppe

Socio-economical conditions profoundly influence terrestrial ecosystems, especially the agroecosystems. However, the effects of large-scale “top-down” socio-economical changes on patterns of vegetation production and C sequestration in pastures remain largely unclear. The contrasting institutional and policy shifts in 1990s over the two sub-region of Temperate Eurasian Steppe (TES), i.e., the Kazakh Steppe (KS) and the Mongol Steppe (MS), provide a unique opportunity to illustrate the human and natural interactions. Combining multiple information from remote sensing, land model, climate and inventory data, this study investigated how the regional trend and inter-annual variability (IAV) of leaf area index (LAI), net primary productivity (NPP), net ecosystem productivity (NEP) were associated with different institutional and policy shifts. From 1997 to 2016, climate is the primary control factor to the IAV of the ecosystem indexes (EIs, i.e., LAI, NPP, NEP) at a regional view. Highly contrasting impacts of human appropriation indexes (HAIs, i.e., livestock number and agricultural GDP) to the EIs were found for the two sub-region. The effect of HAIs on EIs was weak in the MS, but significant negative correlations between HAIs and EIs were found in the KS. Further decomposition into administrative divisions showed that the swift rise of human appropriation in China was accompanied with increases in grassland NPP and NEP, owing to the policy shift to sustainable management. But the institutional shift to market-driven economy and increasing human appropriation generally acted as a negative factor to EIs in various countries over the KS, especially in Uzbekistan and Turkmenistan. Regional evidences revealed the importance of large-scale socio-economic shifts in shaping the pattern of important ecosystem properties of grasslands and emphasized the importance of sustainability development in managing pasture systems.

The influence of the Three Gorges Reservoir regulation on a typical tributary heat budget

Reservoir regulation and local climate both affect the heat budget of tributary bay. It is difficult for traditional methods to identify the influence of different factors on heat budget quantitatively. In this paper, for analysis of the control mechanisms of the heat budget of a large reservoir tributary, the water temperature distribution, and heat budget processes of the Meixi River, a typical tributary to the Three Gorges Reservoir was measured, and a new method was used to calculate the heat content composition of the tributary bay and identify the key factor of the heat balance. The result shows significant variation in the spatial and temporal distributions of water temperatures in the Meixi River, ranging from 12.4 to 28.9 °C on the surface and 12.0 to 24.4 °C at the bottom. The total heat exchange across the air–water interface that ranges from 0.1 to 6% of the budget is not the primary control factor of the annual tributary heat budget. Rather, the change in water depth produced by regulation of the Three Gorges Reservoir is the primary control factor of the tributary heat budget in the whole year, which ranges from 72 to 99% of the budget. The water temperature difference between the main stream and tributary is the not key factor of the heat budget, which ranges from 0.1 to 28% of the heat budget.

Corrosion of Ductile Cast Iron Pipeline in a Water Supply Network Based on the Flow Field Changing

In this work, a computational fluid dynamics (CFD) simulation and electrochemical measurements are performed to study corrosion at different positions of the elbow and its adjacent areas in water supply pipelines using two designed pipe fittings on a dynamic corrosion platform. The corrosion passive film on the ductile cast iron surface is the primary control factor in the corrosion process. Furthermore, although corrosion activity occurs more frequently at the innermost portion of the elbow and the outer portion of the downstream straight sections, corrosion at the top (or bottom) and outer side of the elbow occurs less often.

Horizontal and vertical zoning of carbonate dissolution in China

Natural dissolution and denudation are the essential processes of karstification; however, their intensities depend on geographic and climatic conditions. Field dissolution tests of carbonate tablets were conducted in Hubei Province over a three years period to determine the impact of precipitation, lithology, altitude, vegetation and soil on carbonate dissolution. Results from the study show that carbonate dissolution rates vary from 1.23 to 2.86 mg cm−2 a−1. In addition, a comparative analysis of our results with those from 28 other sites reveal two lateral regional boundaries of karstification, one trending from South to North China, the other from North to Northwest China, with regional precipitation variations appearing to be the primary control factor. Comparison of the dissolution rate of carbonate tablets set up on the surface (150 cm above ground surface and on the ground surface) with those beneath the surface (20 cm and 50 cm beneath the ground surface) at different elevations reveal a vertical karstification boundary in the mountainous areas along the South-North karstification transition zone. The results also show that surface dissolution rates (1.50–2.18 mg cm−2 a−1) are higher than subsurface dissolution rates (0.53–1.61 mg cm−2 a−1) in high altitude areas. Conversely, in low altitude areas, the subsurface dissolution rate (3.94 mg cm−2 a−1) is much higher than surface dissolution rate (1.78 mg cm−2 a−1). Therefore, the horizontal and vertical karstification boundaries in China highlight the main karstification function based on local elevation as well as varying geographical conditions. It was also found that the magnitudes of carbonate dissolution are consistent with recent karstification degree, which is critical for modeling karst landform evolution in the near future.

Controlling factors and accumulation model of hydrocarbon reservoirs in the Upper Cretaceous Yogou Formation, Koulele Area, Termit Basin, Niger

Based on the sedimentary and tectonic background of the Termit Basin, this paper focuses on the Upper Cretaceous Yogou Formation and uses organic geochemistry, logging, oil testing and seismic data to analyze the primary control factors of the hydrocarbon accumulation and establish corresponding model in order to predict favorable exploration target zones of hydrocarbon reservoirs. This study demonstrates that the Upper Cretaceous Yogou Formation is a self-generation and self-accumulation type reservoir. The Yogou Formation hydrocarbon reservoirs in the Koulele area are controlled by four factors: (1) the source rock is controlled by a wide range of YS1-YS2 marine shale, (2) the sandstone reservoir is controlled by the YS3 underwater distributary channel and storm dunes, (3) migration of hydrocarbons is controlled by faults and the regional monocline structure, and (4) the accumulation of hydrocarbons is controlled by lateral seal. The structures in the western Koulele area are primarily reverse fault-blocks with large throws, and the structures in the east are dominantly fault-blocks with small throws (co-rotating and reverse) and a fault-nose. In the western Koulele area, where the facies are dominated by storm dunes on a larger scale, it is easier to form lithologic reservoirs of sandstone lens. In the eastern Koulele area, high-quality channel sandstone reservoirs, fault-blocks with small throws, and the monocline structure benefit for the formation of updip pinch out lithologic traps, fault lithologic reservoirs and fault-nose structural reservoirs. Future exploration targets should be focused in the western storm dunes zone and eastern distributary channel sand zone with small fault-blocks.

Impressive abrasion rates of marked pebbles on a coarse-clastic beach within a 13-month timespan

In this paper the abrasion rate on a coarse-clastic beach was evaluated by calculating the volume loss recorded on indigenous pebbles within a 13-month timespan. The experiment was carried out at Marina di Pisa (Italy) on an artificial beach that was built to counteract the erosion processes affecting this sector of the coast. A total of 240 marble pebbles (120 rounded and 120 angular) were marked using the RFID technology and injected on the beach. The volume loss measured after consecutive recovery campaigns was progressively increasing, reaching the maximum value after 13months (61% overall). The average volume loss is consistent between rounded and angular pebbles at any time (59.3% and 64.2% after 13months respectively), meaning that the roundness is not a primary control factor on abrasion rate. The pebbles that did not reach such abrasion rates after 8 and 10months (volume loss less than 20%) were found at heights equal or greater than 2m above mean sea level, on the crest of the storm berm that formed during the strongest storms. This implies that the highest wearing is achieved in the lower portion of the backshore, which is also the area that underwent major topographic modifications. Here, sea water action might also exert chemical influence on the pebbles, adding to the mechanical abrasion. The main result of this research, indicating an impressive volume loss on beach pebbles in a short timespan, could be of key importance for coastal managers. The optimization of coarse sediment beach nourishments is also relevant, taking into right consideration that the volume loss due to sediment abrasion might exceed 50% of the original fill volume just after 1year in the most dynamic portion of the beach.

Experimental study of entrainment behavior of debris flow over channel inflexion points

On-spot observation and field reconnaissance of debris flows have revealed that inflexion points in the longitudinal profile of a movable channel may easily become unstable points that significantly affect their entrainment behavior. In this study, small-scale flume experiments were performed to investigate the entrainment characteristics of debris flows over two types of inflexion points, namely, a convex point, which has an upslope gradient that is less than the downslope gradient; and a concave point, which has an upslope gradient that is greater than the downslope gradient. It was observed that when debris flowed over a convex point, the entrainment developed gradually and progressively from the convex point in the downstream direction, and the primary control factors were the slope gradient and friction angle. Conversely, when debris flowed over a concave point, the entrainment was characterized by impacting and impinging erosion rather than traditional hydraulic erosion, and the impingement angle of the flow significantly determined the maximum erosion depth and outflow exit angle. An empirical relationship between the topography change and the control factors was obtained from the experimental data.

Contribution of Soil Fauna to Foliar Litter-Mass Loss in Winter in an Ecotone between Dry Valley and Montane Forest in the Upper Reaches of the Minjiang River.

Litter decomposition during winter can provide essential nutrients for plant growth in the subsequent growing season, which plays important role in preventing the expansion of dry areas and maintaining the stability of ecotone ecosystems. However, limited information is currently available on the contributions of soil fauna to litter decomposition during winter in such ecosystems. Therefore, a field experiment that included litterbags with two different mesh sizes (0.04 mm and 3 mm) was conducted to investigate the contribution of soil fauna to the loss of foliar litter mass in winter from November 2013 to April 2014 along the upper reaches of the Minjiang River. Two litter types of the dominant species were selected in each ecosystem: cypress (Cupressus chengiana) and oak (Quercus baronii) in ecotone; cypress (Cupressus chengiana) and clovershrub (Campylotropis macrocarpa) in dry valley; and fir (Abies faxoniana) and birch (Betula albosinensis) in montane forest. Over one winter incubation, foliar litter lost 6.0%-16.1%, 11.4%-26.0%, and 6.4%-8.5% of initial mass in the ecotone, dry valley and montane forest, respectively. Soil fauna showed obvious contributions to the loss of foliar litter mass in all of the ecosystems. The highest contribution (48.5%-56.8%) was observed in the ecotone, and the lowest contribution (0.4%-25.8%) was observed in the montane forest. Compared with other winter periods, thawing period exhibited higher soil fauna contributions to litter mass loss in ecotone and dry valley, but both thawing period and freezing period displayed higher soil fauna contributions in montane forest. Statistical analysis demonstrated that the contribution of soil fauna was significantly correlated with temperature and soil moisture during the winter-long incubation. These results suggest that temperature might be the primary control factor in foliar litter decomposition, but more active soil fauna in the ecotone could contribute more in litter decomposition and its related ecological processes in this region.

Quantitative assessment of groundwater pollution intensity on typical contaminated sites in China using grey relational analysis and numerical simulation

Groundwater vulnerability assessment is an important method for groundwater pollution risk assessment. However, vulnerability assessment results rarely consider groundwater pollution concentration. Few quantitative studies consider groundwater pollutant concentration in different hydrogeological conditions. HYDRUS-1D software can simulate different concentrations of pollutants reaching the shallow aquifer under some vadose zone conditions. However, HYDRUS-1D simulation parameter settings are complicated; thus, it is difficult to simulate groundwater pollution intensity (GPI) on the site with limited information. In this study, the issue of site data constraints for model predictions is solved. Ammonia–nitrogen is selected as an indicator, and a method for quantitative groundwater pollution assessment based on grey relational analysis (GRA) is proposed. According to two factors (inherent, extrinsic) of groundwater vulnerability assessment, and on the basis of the information from 18 contaminated sites, primary GPI control factors, including emission concentration, hydraulic conductivity, soil density and diffusion coefficient, are filtered using GRA. These four factors are utilized as variables to establish a multiple linear regression (MLR) equation, which is used to predict the GPI of polluted sites. Compared with a HYDRUS-1D simulation, the proposed GPI prediction method can effectively predict GPI with simpler input conditions. The established MLR equation satisfies a significance test and small error analysis. Comparative results between simulation values and regression values on the established case show that the regression values are closer to the measured value. Hence, the MLR equation is practical and can be applied for sensible groundwater source management and land use planning.

Does soil moisture overrule temperature dependence of soil respiration in Mediterranean riparian forests?

Abstract. Soil respiration (SR) is a major component of ecosystems' carbon cycles and represents the second largest CO2 flux in the terrestrial biosphere. Soil temperature is considered to be the primary abiotic control on SR, whereas soil moisture is the secondary control factor. However, soil moisture can become the dominant control on SR in very wet or dry conditions. Determining the trigger that makes soil moisture as the primary control factor of SR will provide a deeper understanding on how SR changes under the projected future increase in droughts. Specific objectives of this study were (1) to investigate the seasonal variations and the relationship between SR and both soil temperature and moisture in a Mediterranean riparian forest along a groundwater level gradient; (2) to determine soil moisture thresholds at which SR is controlled by soil moisture rather than by temperature; (3) to compare SR responses under different tree species present in a Mediterranean riparian forest (Alnus glutinosa, Populus nigra and Fraxinus excelsior). Results showed that the heterotrophic soil respiration rate, groundwater level and 30 cm integral soil moisture (SM30) decreased significantly from the riverside moving uphill and showed a pronounced seasonality. SR rates showed significant differences between tree species, with higher SR for P. nigra and lower SR for A. glutinosa. The lower threshold of soil moisture was 20 and 17% for heterotrophic and total SR, respectively. Daily mean SR rate was positively correlated with soil temperature when soil moisture exceeded the threshold, with Q10 values ranging from 1.19 to 2.14; nevertheless, SR became decoupled from soil temperature when soil moisture dropped below these thresholds.

Characteristics of Pulverized Coal during Coalbed Methane Drainage in Hancheng Block, Shaanxi Province, China

Pulverized coal is one of the main controlling factors constraining the capacity of coal-bed methane wells during CBM drainage. The characteristics of pulverized coal can be used to identify the sources of the pulverized coal particles and to develop reasonable means of controlling pulverized coal output. Using light transmission microscopy, laser particle size testing, X-ray diffraction, reflection polarized optical microscopy, and scanning electron microscopy with energy dispersive X, the characteristics of pulverized coal collected during CBM drainage in the Hancheng block were analyzed for concentration, particle size, composition, and morphology. These traits were used to identify the sources of pulverized coal. The results showed that coal body structure (structural damage) was a primary control factor of pulverized coal output. The sizes of the pulverized coal particles tended to be around 100 μm. The main components of pulverized coal were vitrinite and clay minerals. The pulverized coals were divided into groups based on their columnar, flaky, or granular morphology. Columnar pulverized coal may involve the formation of the native structure coal or the fragmented coal that later sustains erosive damage. Flaky pulverized coal may be produced by the flaking of scaled coal or leaf coal. In this way, granular pulverized coal may be produced from granulated coal. Therefore, the morphology of the pulverized coal was found to be related to its coal body structure and to late mechanical destruction.

MCM2 and cancers

Minichromosome maintenance proteins (MCMs) are the primary control factors for eukaryotes DNA replication.MCMs play important roles in the starting place and the extending process of DNA replication.MCM2,one member of MCMs,expresses little in stationary phase while highly in proliferative and transformational phase.MCM2 can accurately reflect the cell proliferation activity and is considered as a specific maker for carcinoma and precancerous lesions.The overexpression of MCM2 is closely correlated with the genesis and development of tumors,and it maybe a good maker for early screening and prognosis assessment in many cancers and used in clinical. Key words: Neoplasms ; Tumor markers, biological ; Minichromosome maintenance protein-2

Evaluating actual evapotranspiration and impacts of groundwater storage change in the North China Plain

AbstractAs a critical water discharge term in basin‐scale water balance, accurate estimation of evapotranspiration (ET) is therefore important for sustainable water resources management. The understanding of the relationship between ET and groundwater storage change can improve our knowledge on the hydrological cycle in such regions with intensive agricultural land usage. Since the 1960s, the North China Plain (NCP) has experienced groundwater depletion because of overexploitation of groundwater for agriculture and urban development. Using meteorological data from 23 stations, the complementary relationship areal evapotranspiration model is evaluated against estimates of ET derived from regional water balance in the NCP during the period 1993–2008. The discrepancies between calculated ET and that derived by basin water balance indicate seasonal and interannual variations in model parameters. The monthly actual ET variations during the period from 1960 to 2008 are investigated by the calibrated model and then are used to derive groundwater storage change. The estimated actual ET is positively correlated with precipitation, and the general higher ET than precipitation indicates the contributions of groundwater irrigation to the total water supply. The long term decreasing trend in the actual ET can be explained by declining in precipitation, sunshine duration and wind speed. Over the past ~50 years, the calculated average annual water storage change, represented by the difference between actual ET and precipitation, was approximately 36 mm, or 4.8 km3; and the cumulative groundwater storage depletion was approximately 1700 mm, or 220 km3 in the NCP. The significantly groundwater storage depletion conversely affects the seasonal and interannual variations of ET. Irrigation especially during spring cause a marked increase in seasonal ET, whereas the rapid increasing of agricultural coverage over the NCP reduces the annual ET and is the primary control factor of the strong linear relationship between actual and potential ET. Copyright © 2013 John Wiley & Sons, Ltd.

Correlation between plate age and layer separation of double seismic zones

Global seismicity catalogs are sufficient for characterizing double seismic zones (DSZs) in subducting slab and facilitate to estimate layer separation without inconsistent uncertainties as local catalogs. Previous studies have shown the correlation between DSZs layer separation and plate age while correlation for those younger than ∼60 Ma is suspicious. The lacking of DSZs with layer separation less than 10 km further makes it difficult to precisely estimate such correlation. Thus, we incorporate eight DSZs data determined through local seismicity into globally-determined dataset and reexamine such correlation. The best fitting results show that both a linear model and a square root of plate age can mathematically fit the layer separation well. However, it is difficult to distinguish these two models when plate age is greater than ∼20 Ma since their difference is less than 2 km. However, if extrapolation is possible, both models should provide physical information that DSZs will not form if there is no subducting lithosphere. As a result, the DSZs cannot be produced until the oceanic lithospheric age becomes greater than 0.9 Ma in the square root model while the linear model gives a misleading result. As such the square root model demonstrates the relationship physically better than the linear one, it still needs further test in the future with more available data, nevertheless, our study might also provide evidence for the suggestion that the plate age is a primary control factor of the DSZs geometry as well as the subducting process which disregards any local tectonic stresses.