Ⅰ. INTRODUCTION Shaoxing-Jiangshan rift zone is on the boundary of geotectonic units of first order in Zhejiang Province (Fig. 1). The basement complex of 'epicontinental basin', called as Shuangxiwu Group, i...Ⅰ. INTRODUCTION Shaoxing-Jiangshan rift zone is on the boundary of geotectonic units of first order in Zhejiang Province (Fig. 1). The basement complex of 'epicontinental basin', called as Shuangxiwu Group, is composed mainly of the metamorphic rock series on its north side within Zhejiang, and can be correlated to Presinian system in展开更多
Not many 17‑year‑old girls know how to join two pipes together or light the pilot light.These are skills I have learned over the past five years as an assistant to my plumber dad.This summer job demands an attitude of...Not many 17‑year‑old girls know how to join two pipes together or light the pilot light.These are skills I have learned over the past five years as an assistant to my plumber dad.This summer job demands an attitude of perseverance and grace that I frequently struggle to adopt.Each humid morning,my dad and I drag awkward and heavy toolboxes into people's dark and damp basements where I usually get lost in mazes of storage boxes.Nevertheless,I stick to it.I am the plumber's daughter and helper.展开更多
Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of s...Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.展开更多
There is significant debate concerning the tectonic characteristics and evolutionary understanding of the South China Block(SCB)during the Early Mesozoic.One of the key points of contention is the tectonic-magmatic ac...There is significant debate concerning the tectonic characteristics and evolutionary understanding of the South China Block(SCB)during the Early Mesozoic.One of the key points of contention is the tectonic-magmatic activity during the Triassic and its dynamic mechanisms.However,research on the detailed chronology and tectonic settings of granite plutons in key regions remains insuffi-cient,limiting the understanding of the tectonic-magmatic dynamic mechanisms in the interior of SCB during the Triassic.In this contribution,we present whole-rock major and trace elemental data,Sr-Nd isotope data,LA-ICP-MS zircon U-Pb age dating,and Lu-Hf isotope data for granites of Dashenshan pluton in the Xiangzhong,northwest part of SCB.The results indicate that the Dashenshan granite has an emplacement age of 208.4-212.5 Ma,characterized by high SiO_(2),Na_(2)O,and K_(2)O contents and low MgO and CaO.The Dashenshan granite is enriched in light rare-earth elements with a significant negative Eu anomaly(averageδEu=0.42).It is also enriched in Rb,K,and Th and shows pronounced depletion in Nb,Ta,and Ti,classifying it as peraluminous calc-alkaline granite,specifically of the I-type.The zircon ε_(Hf(t)) values range from−8.39 to−4.4,with an average of−5.82,and the Sr-Nd isotopes are relatively enriched[ε_(Nd)(t)=−9.31 to−6.8].Combining these geochemical characteristics,it is revealed that the Dashenshan granite was derived from the partial melting of middle to upper crustal metamorphic basement materials under medium-to low-temperature conditions,with possible minor contributions from mantle-derived materials.Furthermore,it underwent fractional crystallization,including plagioclase differentiation.By integrating the geochemical features and spatial distribution of Triassic granites in SCB,this study suggests that the regional tectonic evolution of SCB during the Triassic was primarily controlled by the collision of the SCB with the Indochina Block and the North China Block.In Xiangzhong,the tectonic setting transitioned from syn-collisional compression to post-collisional extension during the Late Triassic.The Dashenshan pluton formed in a post-collisional extensional setting,resulting from the decompression melting of middle-to-upper crustal rocks.The upwelling of the asthenosphere and upward heat transfer likely played a significant role in the formation of the Dashenshan granitic magma.展开更多
Crack control of basement roof slab is a key technical challenge to ensure building safety and durability.Based on the requirements of“General Specification for Concrete Structures”(GB55008-2021),this paper systemat...Crack control of basement roof slab is a key technical challenge to ensure building safety and durability.Based on the requirements of“General Specification for Concrete Structures”(GB55008-2021),this paper systematically analyses the causes of cracks,and puts forward a whole-process prevention and control system covering design optimization,low-shrinkage material proportioning,fine control of construction technology,and dynamic monitoring and repair.Through structural finite element simulation,wireless sensor network real-time monitoring,and carbon fibre fabric reinforcement test,the effectiveness of the multi-technology synergistic control framework is verified,and the engineering cases show that the crack width after repair is stable within 0.1mm,and the bearing capacity is increased by more than 30%.The study provides theoretical support for crack prevention and control in super-long underground projects,and looks forward to the direction of integration application of BIM technology and intelligent materials.展开更多
With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the...With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the evolution mechanism of tun-nel foundation defects in heavy haul railway tunnels and their impact on structural stiffness degradation through experiments and numerical simulations.A heavy haul train-ballasted track-tunnel basement-surround rock dynamic interaction model(TTTR model)is constructed.Firstly,the study reveals the four-stage evolution process of initial defects in the tunnel base-ment under complex environmental conditions.Experiments were conducted to measure the load-bearing capacity and stiff-ness degradation of the tunnel basement structure under different defect states.It is found that foundation defects,especially under the coupling of loose fill in the basement with the water-rich environment of the surrounding rock,significantly reduce the stiffness of the tunnel bottom structure and increase the risk of structural damage.Then,based on refined simulation of wheel-rail interaction and multi-scale coupled modeling technology,the TTTR dynamic interaction model was successfully constructed,and its validity was proven through numerical validation.A time-varying coupling technique of constrained boundary substructures(CBS technique)was adopted,significantly improving computational efficiency while ensuring calculation accuracy.The study also analyzes the effects of different degrees of void defects on the dynamic behavior of the train and the dynamic characteristics of the tunnel structure.It finds that foundation defects have a significant impact on the train’s operational state,track vibration displacement,and vibration stress of the tunnel lining structure,especially under the coupling effect of basement voids and the water-rich environment,which has the greatest impact.The research results of this paper provide a theoretical basis and technical support for the maintenance and reinforcement of tunnel foundation structures.展开更多
Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods...Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.展开更多
The karst geothermal reservoir in Xiong'an New Area is a representative example of an ancient buried hill geothermal system.However,published heat flow data are predominantly derived from the Cenozoic sedimentary ...The karst geothermal reservoir in Xiong'an New Area is a representative example of an ancient buried hill geothermal system.However,published heat flow data are predominantly derived from the Cenozoic sedimentary cap.Due to the limited depth of borehole exploration,heat flow measurements and analyses of the Archean crystalline base-ment in the study area are rare.Further investigation of the heat flow and temperature field characteristics within the Archean crystalline basement beneath the karst geothermal reservoir is necessary to understand the vertical distribution of heat flow and improve the geothermal genetic mechanism in the area.The D01 deep geothermal scientific drilling param-eter well was implemented in the Niutuozhen geothermal field of Xiong'an New Area.The well exposed the entire Gaoyuzhaung Formation karst geotheremal reservoir of the Jixian system and drilled 1,723.67 m into the Archean crys-talline basement,providing the necessary conditions for determining its heat flow.This study involved borehole tempera-ture measurements and thermophysical property testing of core samples from the D01 well to analyze the vertical distri-bution of heat flow.The findings revealed distinct segmentation in the geothermal gradient and rock thermophysical prop-erties.The geothermal reservoir of Gaoyuzhuang Formation is dominated by convection,with significant temperature inversions corresponding to karst fracture developments.In contrast,the Archean crystalline basement exhibits conduc-tive heat transfer.After 233 days of static equilibrium,the average geothermal gradients of the Gaoyuzhuang Formation and the Archean crystalline basement were determined to be 1.5°C/km and 18.3°C/km,respectively.These values adjusted to-0.8°C/km and 18.2°C/km after 551 days,with the longer static time curve approaching steady-state condi-tions.The average thermal conductivity of dolomite in Gaoyuzhuang Formation was measured as 4.37±0.82 W/(K·m),3 and that of Archean gneiss as 2.41±0.40 W/(K·m).The average radioactive heat generation rate were 0.30±0.32μW/m 3 for dolomite and 1.32±0.69μW/m for gneiss.Using the temperature curve after 551 days and thermal conductivity data,the Archean heat flow at the D01 well was calculated as(43.9±7.0)mW/m2,While the heat flow for the Neogene sedi-mentary cap was estimated at 88.6mW/m2.The heat flow of Neogene sedimentary caprock is significantly higher than 2 that of Archean crystalline basement at the D01 well,with an excess of 44.7 mW/m accounting for approximately 50%of the total heat flow in the Neogene sedimentary caprock.This is primarily attributed to lateral thermal convection within the high-porosity and high-permeability karst dolomite layer,and vertical thermal convection facilitated by the Niudong fault,which collectively contribute to the heat supply of the Neogene sedimentary caprock.Thermal convection in karst fissure and fault zone contribute approximately 50%of the heat flow in the Neogene sedimentary caprock.This study quantitatively revealed the vertical distribution of heat flow,providing empirical evidence for the genetic mechanism of the convection-conduction geothermal system in sedimentary basins.展开更多
The basement was located at the bottom of the building,which not only affected the quality of the whole construction project but also had special requirements for construction technology and construction requirements....The basement was located at the bottom of the building,which not only affected the quality of the whole construction project but also had special requirements for construction technology and construction requirements.In modern times,with the increasing height of the building,the pressure on the ground has grown,and the demands for basements in construction projects have also steadily increased.With the development of modern technology,various construction techniques for basements emerged within the construction industry.Thus,this paper analyses the type of basement floor construction technologies,highlighting the application of these methods,and points out critical issues to consider.By examining frequent basement leakage problems,the paper proposed several measures to improve the quality if basement construction,aiming to better protect the service life of the building and further improve overall quality,and offering valuable insights for future projects.展开更多
We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data coll...We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data collected for more than 50 years, a series of 1：5000000 and 1：1000000 aeromagnetic maps of continental China were compiled using state-of-the-art digital technology, and data processing and transformation. Guided by plate tectonics and continental dynamics, rock physical properties, and magnetic anomalies, we compiled maps of the depth of the magnetic basement of continental China and the major geotectonic units, and presented newly detected geological structures based on the aeromagnefic data.展开更多
The Early Paleozoic evolution of the northern margin of Gondwana is characterized by several episodes of bimodal magmatism intruded or outpoured within thick sedimentary basins. These processes are well recorded in th...The Early Paleozoic evolution of the northern margin of Gondwana is characterized by several episodes of bimodal magmatism intruded or outpoured within thick sedimentary basins. These processes are well recorded in the Variscan blocks incorporated in the Ligurian Alps because they experienced low temperature Alpine metamorphism. During the Paleozoic, these blocks, together with the other Alpine basements, were placed between the Corsica-Sardinia and the Bohemian Massif along the northern margin of Gondwana. In this framework, they host several a variegated lithostratigraphy forming two main complexes(Complexs I and II) that can be distinguished by both the protoliths and their crosscutting relationships, which indicate that the acidic and mafic intrusives of Complex II cut an already folded sequence made of sediments, basalts and granitoids of Complex I. Both complexes were involved in the Variscan orogenic phases as highlighted by the pervasive eclogite-amphibolite facies schistosity(foliation II). However, rare relicts of a metamorphic foliation at amphibolite facies conditions(foliation I)is locally preserved only in the rocks of Complex I. It is debatable if this schistosity was produced during the early folding event e occurred between the emplacement of Complex I and II e rather than during an early stage of the Variscan metamorphic cycle.New SHRIMP and LA ICP-MS Ue Pb zircon dating integrated with literature data, provide emplacement ages of the several volcanic or intrusive bodies of both complexes. The igneous activity of Complex I is dated between 507 ± 15 Ma and 494 ± 5 Ma, while Complex II between 467 ± 12 Ma and 445.5 ± 12 Ma.The folding event recorded only by the Complex I should therefore have occurred between 494 ± 5 Ma and 467 ± 12 Ma. The Variscan eclogite-amphibolite facies metamorphism is instead constrained between ~420 Ma and ~300 Ma. These ages and the geochemical signature of these rocks allow constraining the Early Paleozoic tectono-magmatic evolution of the Ligurian blocks, from a middleeupper Cambrian rifting stage, through the formation of an Early Ordovician volcanic arc during the Rheic Ocean subduction, until a Late Ordovician extension related to the arc collapse and subsequent rifting of the PaleoThetys. Furthermore, the ~420-350 Ma ages from zircon rims testify to thermal perturbations that may be associated with the Silurian rifting-related magmatism, followed by the subduction-collisional phases of the Variscan orogeny.展开更多
Based on the synchronous joint gravity and magnetic inversion of single interface by Pilkington and the need of revealing Cenozoic and crystalline basement thickness in the new round of oil-gas exploration, we propose...Based on the synchronous joint gravity and magnetic inversion of single interface by Pilkington and the need of revealing Cenozoic and crystalline basement thickness in the new round of oil-gas exploration, we propose a joint gravity and magnetic inversion methodfor two-layer models by concentrating on the relationship between the change of thicknessI and position of the middle layer and anomaly and discuss the effects of the key parameters. Model tests and application to field data show the validity of this method.展开更多
Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southe...Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.展开更多
Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilia...Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8–1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47–0.71 and Ba/Ba*=0.16–0.64), with fDM and ENd (1.0 Ga) ranging from 1.87 to 2.26 Ga and from ?8.54 to ?4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to different plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.展开更多
The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneo...The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneous rocks and ophiolites distributed mostly along the Xinjiang-Tibet road and the China-Pakistan road, and have constructed a preliminary tectonic model for this orogenic belt. However, few studies have focused on the so-called Precambrian basement in this area. As a result, the tectonic affinity of the individual terranes of the WKOB and their detailed evolution process are uncertain. Here we report new field observations, zircon and monazite U-Pb ages of the "Precambrian basement" of the South Kunlun terrane(SKT) and the Tianshuihai terrane(TSHT), two major terranes in the WKOB. Based on new zircon U-Pb age data, the amphibolite-facies metamorphosed volcanosedimentary sequence within SKT was deposited during the late Neoproterozoic to Cambrian(600-500 Ma), and the flysch-affinity Tianshuihai Group, as the basement of the TSHT, was deposited during the late Neoproterozoic rather than Mesoproterozoic. The rock association of the volcano-sedimentary sequence within SKT suggests a large early Paleozoic accretionary wedge formed by the long-term lowangle southward subduction of the Proto-Tethys Ocean between Tarim and TSHT. The amphibolitefacies metamorphism in SKT occurred at ca. 440 Ma. This ca. 440 Ma metamorphism is genetically related to the closure of the Proto-Tethys Ocean between Tarim and the Tianshuihai terrane, which led to the assembly of Tarim to Eastern Gondwana and the final formation of the Gondwana. Since the late Paleozoic to early Mesozoic, the northward subduction of the Paleo-Tethys Ocean along the HongshihuQiaoertianshan belt produced the voluminous early Mesozoic arc-signature granites along the southern part of NKT-TSHT. The Paleo-Tethys ocean between TSHT and Karakorum closed at ca. 200 Ma, as demonstrated by the monazite age of the paragneiss in the Kangxiwa Group. Our study does not favor the existence of a Precambrian basement in SKT.展开更多
According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature contin...According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).展开更多
A comprehensive geophysical profile stretching from Qingyijing at the southern edge of the Junggar Basin to Ubara on the northern margin of the Junggar Basin was conducted in an attempt to probe the crustal structure ...A comprehensive geophysical profile stretching from Qingyijing at the southern edge of the Junggar Basin to Ubara on the northern margin of the Junggar Basin was conducted in an attempt to probe the crustal structure of the western Junggar Basin(hereafter referred to simply as ‘the Basin'), and, in particular, the structure and property of the Basin's crystalline basement. A survey using seismically converted waves was conducted along this profile to determine the characteristics of the P-and Swave velocities typical of the crust and uppermost mantle. A joint inversion of gravitation and aeromagnetic data was also performed to acquire the density and magnetization intensity values found beneath the western Basin. This research revealed that the Basin is composed of the so-called Manasi terrain in the south, and the Wulungu terrain in the north. Their boundary is located along the WNW-trending Dishuiquan-Sangequan suture, linking the NE-striking Da'erbute suture(DS) in the west, and the WNWtrending Kalameili suture(KS) in the east. In its northern part, the Wulungu-type terrain has a doublelayered basement, of which the upper layer is a folded basement of Hercynian orogenic origin, and the lower layer is a crystalline basement of Middle–Upper Proterozoic age. The southern part of the Basin, i.e., the Manasi terrain, has a single-layered crystalline basement. The folded basement here is too thin to be clearly distinguished.展开更多
文摘Ⅰ. INTRODUCTION Shaoxing-Jiangshan rift zone is on the boundary of geotectonic units of first order in Zhejiang Province (Fig. 1). The basement complex of 'epicontinental basin', called as Shuangxiwu Group, is composed mainly of the metamorphic rock series on its north side within Zhejiang, and can be correlated to Presinian system in
文摘Not many 17‑year‑old girls know how to join two pipes together or light the pilot light.These are skills I have learned over the past five years as an assistant to my plumber dad.This summer job demands an attitude of perseverance and grace that I frequently struggle to adopt.Each humid morning,my dad and I drag awkward and heavy toolboxes into people's dark and damp basements where I usually get lost in mazes of storage boxes.Nevertheless,I stick to it.I am the plumber's daughter and helper.
基金supported by the‘Korea National Institute of Health’(KNIH)research project(Project No.2022ER130502)the National Research Foundation of Korea(NRF)Grant funded by the Korea Government(MSIT)(No.2021R1A2C20060331222182102840102)。
文摘Bioprinting is a widely used technique for creating three-dimensional,complex,and heterogeneous artificial tissue constructs that are biologically and biophysically similar to natural tissues.The skin is composed of several layers including the epidermis,basement membrane(BM),and dermis.However,the unique undulating structure of basement membranes(i.e.rete ridges)and the function of BM have not been extensively studied in the fabrication of engineered skin substitutes.In this study,a novel engineered skin substitute incorporating an artificially designed rete ridge(i.e.mogul-shape)was developed using bioprinting and bioinks prepared using collagen and fibrinogen.To mimic the structure of the rete ridges of skin tissue,we developed a modified bioprinting technique,controlling rheological property of bioink to create a mogul-shaped layer.In vitro cellular activities,including the expression of specific genes(those encoding vimentin,laminin-5,collagen IV,and cytokeratins),demonstrated that the engineered skin substitute exhibited more potent cellular responses than the normally bioprinted control owing to the favorable biophysical BM structure and the bioink microenvironment.Additionally,the feasibility of utilizing the bioprinted skin-structure was evaluated in a mouse model,and in vivo results demonstrated that the bioprinted skin substitutes effectively promoted wound healing capabilities.Based on these results,we suggest that bioprinted skin tissues and the bioprinting technique for mimicking rete ridges can be used not only as potential lab-chip models for testing cosmetic materials and drugs,but also as complex physiological models for understanding human skin.
基金supported financially by the Research Foundation of the Department of Natural Resources of Hunan Province(20230135DZ)the Provincial Natural Science Foundation of Hunan(2024JJ7080)+1 种基金the Scientific Research Fund of Hunan Provincial Education Department(23C0320)Hunan Provincial College Student Innovation and Entrepreneurship Training Project(S202311527014).
文摘There is significant debate concerning the tectonic characteristics and evolutionary understanding of the South China Block(SCB)during the Early Mesozoic.One of the key points of contention is the tectonic-magmatic activity during the Triassic and its dynamic mechanisms.However,research on the detailed chronology and tectonic settings of granite plutons in key regions remains insuffi-cient,limiting the understanding of the tectonic-magmatic dynamic mechanisms in the interior of SCB during the Triassic.In this contribution,we present whole-rock major and trace elemental data,Sr-Nd isotope data,LA-ICP-MS zircon U-Pb age dating,and Lu-Hf isotope data for granites of Dashenshan pluton in the Xiangzhong,northwest part of SCB.The results indicate that the Dashenshan granite has an emplacement age of 208.4-212.5 Ma,characterized by high SiO_(2),Na_(2)O,and K_(2)O contents and low MgO and CaO.The Dashenshan granite is enriched in light rare-earth elements with a significant negative Eu anomaly(averageδEu=0.42).It is also enriched in Rb,K,and Th and shows pronounced depletion in Nb,Ta,and Ti,classifying it as peraluminous calc-alkaline granite,specifically of the I-type.The zircon ε_(Hf(t)) values range from−8.39 to−4.4,with an average of−5.82,and the Sr-Nd isotopes are relatively enriched[ε_(Nd)(t)=−9.31 to−6.8].Combining these geochemical characteristics,it is revealed that the Dashenshan granite was derived from the partial melting of middle to upper crustal metamorphic basement materials under medium-to low-temperature conditions,with possible minor contributions from mantle-derived materials.Furthermore,it underwent fractional crystallization,including plagioclase differentiation.By integrating the geochemical features and spatial distribution of Triassic granites in SCB,this study suggests that the regional tectonic evolution of SCB during the Triassic was primarily controlled by the collision of the SCB with the Indochina Block and the North China Block.In Xiangzhong,the tectonic setting transitioned from syn-collisional compression to post-collisional extension during the Late Triassic.The Dashenshan pluton formed in a post-collisional extensional setting,resulting from the decompression melting of middle-to-upper crustal rocks.The upwelling of the asthenosphere and upward heat transfer likely played a significant role in the formation of the Dashenshan granitic magma.
文摘Crack control of basement roof slab is a key technical challenge to ensure building safety and durability.Based on the requirements of“General Specification for Concrete Structures”(GB55008-2021),this paper systematically analyses the causes of cracks,and puts forward a whole-process prevention and control system covering design optimization,low-shrinkage material proportioning,fine control of construction technology,and dynamic monitoring and repair.Through structural finite element simulation,wireless sensor network real-time monitoring,and carbon fibre fabric reinforcement test,the effectiveness of the multi-technology synergistic control framework is verified,and the engineering cases show that the crack width after repair is stable within 0.1mm,and the bearing capacity is increased by more than 30%.The study provides theoretical support for crack prevention and control in super-long underground projects,and looks forward to the direction of integration application of BIM technology and intelligent materials.
基金funded by the National Natural Science Foundation of China (Grant No. 52178402 & 52378468)the Open Foundation of MOE Key Laboratory of Engineering Structures of Heavy Haul Railway (Central South University) (Grant No. 2022JZZ01)+1 种基金the National Engineering Research Center for High-Speed Railway Construction Technology for their project supportthe support from the MOE Key Laboratory of Engineering Structure of Heavy Haul Railway (Central South University)
文摘With the rapid development of heavy haul railway transportation technology,tunnel foundation defects and their effects on structural performance have attracted wide attention.This paper systematically investigates the evolution mechanism of tun-nel foundation defects in heavy haul railway tunnels and their impact on structural stiffness degradation through experiments and numerical simulations.A heavy haul train-ballasted track-tunnel basement-surround rock dynamic interaction model(TTTR model)is constructed.Firstly,the study reveals the four-stage evolution process of initial defects in the tunnel base-ment under complex environmental conditions.Experiments were conducted to measure the load-bearing capacity and stiff-ness degradation of the tunnel basement structure under different defect states.It is found that foundation defects,especially under the coupling of loose fill in the basement with the water-rich environment of the surrounding rock,significantly reduce the stiffness of the tunnel bottom structure and increase the risk of structural damage.Then,based on refined simulation of wheel-rail interaction and multi-scale coupled modeling technology,the TTTR dynamic interaction model was successfully constructed,and its validity was proven through numerical validation.A time-varying coupling technique of constrained boundary substructures(CBS technique)was adopted,significantly improving computational efficiency while ensuring calculation accuracy.The study also analyzes the effects of different degrees of void defects on the dynamic behavior of the train and the dynamic characteristics of the tunnel structure.It finds that foundation defects have a significant impact on the train’s operational state,track vibration displacement,and vibration stress of the tunnel lining structure,especially under the coupling effect of basement voids and the water-rich environment,which has the greatest impact.The research results of this paper provide a theoretical basis and technical support for the maintenance and reinforcement of tunnel foundation structures.
基金Supported by the National Natural Science Foundation of China(42472190)Chongqing Natural Science Foundation Innovation and Development Joint Fund Project(CSTB2022NSCQ-LZX0020)Chongqing Talent Innovation and Entrepreneurship Leading Talent Project(0255-19230101042)。
文摘Taking the Wangfu fault depression in the Songliao Basin as an example,on the basis of seismic interpretation and drilling data analysis,the distribution of the basement faults was clarified,the fault activity periods of the coal-bearing formations were determined,and the fault systems were divided.Combined with the coal seam thickness and actual gas indication in logging,the controls of fault systems in the rift basin on the spatial distribution of coal and the occurrence of coal-rock gas were identified.The results show that the Wangfu fault depression is an asymmetrical graben formed under the control of basement reactivated strike-slip T-rupture,and contains coal-bearing formations and five sub-types of fault systems under three types.The horizontal extension strength,vertical activity strength and tectono-sedimentary filling difference of basement faults control vertical stratigraphic sequences,accumulation intensity,and accumulation frequency of coal seam in rift basin.The structural transfer zone formed during the segmented reactivation and growth of the basement faults controls the injection location of steep slope exogenous clasts.The filling effect induced by igneous intrusion accelerates the sediment filling process in the rift lacustrine area.The structural transfer zone and igneous intrusion together determine the preferential accumulation location of coal seams in the plane.The faults reactivated at the basement and newly formed during the rifting phase serve as pathways connecting to the gas source,affecting the enrichment degree of coal-rock gas.The vertical sealing of the faults was evaluated by using shale smear factor(SSF),and the evaluation criterion was established.It is indicated that the SSF is below 1.1 in major coal areas,indicating favorable preservation conditions for coal-rock gas.Based on the influence factors such as fault activity,segmentation and sealing,the coal-rock gas accumulation model of rift basin was established.
基金funded by the National Key Research and Development Program(Grant Nos.2021YFB1507404 and 2018YFC0604305)the Project of China Geological Survey(Grant Nos.DD20221680,DD20189113,and DD20190127).
文摘The karst geothermal reservoir in Xiong'an New Area is a representative example of an ancient buried hill geothermal system.However,published heat flow data are predominantly derived from the Cenozoic sedimentary cap.Due to the limited depth of borehole exploration,heat flow measurements and analyses of the Archean crystalline base-ment in the study area are rare.Further investigation of the heat flow and temperature field characteristics within the Archean crystalline basement beneath the karst geothermal reservoir is necessary to understand the vertical distribution of heat flow and improve the geothermal genetic mechanism in the area.The D01 deep geothermal scientific drilling param-eter well was implemented in the Niutuozhen geothermal field of Xiong'an New Area.The well exposed the entire Gaoyuzhaung Formation karst geotheremal reservoir of the Jixian system and drilled 1,723.67 m into the Archean crys-talline basement,providing the necessary conditions for determining its heat flow.This study involved borehole tempera-ture measurements and thermophysical property testing of core samples from the D01 well to analyze the vertical distri-bution of heat flow.The findings revealed distinct segmentation in the geothermal gradient and rock thermophysical prop-erties.The geothermal reservoir of Gaoyuzhuang Formation is dominated by convection,with significant temperature inversions corresponding to karst fracture developments.In contrast,the Archean crystalline basement exhibits conduc-tive heat transfer.After 233 days of static equilibrium,the average geothermal gradients of the Gaoyuzhuang Formation and the Archean crystalline basement were determined to be 1.5°C/km and 18.3°C/km,respectively.These values adjusted to-0.8°C/km and 18.2°C/km after 551 days,with the longer static time curve approaching steady-state condi-tions.The average thermal conductivity of dolomite in Gaoyuzhuang Formation was measured as 4.37±0.82 W/(K·m),3 and that of Archean gneiss as 2.41±0.40 W/(K·m).The average radioactive heat generation rate were 0.30±0.32μW/m 3 for dolomite and 1.32±0.69μW/m for gneiss.Using the temperature curve after 551 days and thermal conductivity data,the Archean heat flow at the D01 well was calculated as(43.9±7.0)mW/m2,While the heat flow for the Neogene sedi-mentary cap was estimated at 88.6mW/m2.The heat flow of Neogene sedimentary caprock is significantly higher than 2 that of Archean crystalline basement at the D01 well,with an excess of 44.7 mW/m accounting for approximately 50%of the total heat flow in the Neogene sedimentary caprock.This is primarily attributed to lateral thermal convection within the high-porosity and high-permeability karst dolomite layer,and vertical thermal convection facilitated by the Niudong fault,which collectively contribute to the heat supply of the Neogene sedimentary caprock.Thermal convection in karst fissure and fault zone contribute approximately 50%of the heat flow in the Neogene sedimentary caprock.This study quantitatively revealed the vertical distribution of heat flow,providing empirical evidence for the genetic mechanism of the convection-conduction geothermal system in sedimentary basins.
文摘The basement was located at the bottom of the building,which not only affected the quality of the whole construction project but also had special requirements for construction technology and construction requirements.In modern times,with the increasing height of the building,the pressure on the ground has grown,and the demands for basements in construction projects have also steadily increased.With the development of modern technology,various construction techniques for basements emerged within the construction industry.Thus,this paper analyses the type of basement floor construction technologies,highlighting the application of these methods,and points out critical issues to consider.By examining frequent basement leakage problems,the paper proposed several measures to improve the quality if basement construction,aiming to better protect the service life of the building and further improve overall quality,and offering valuable insights for future projects.
基金supported by the China Land Aeromagnetic Characteristics and Tectonic Structures Research(No.1212011087009)part of the national geological and mineral resources investigation projects,and the Comprehensive Exploration of Aero Geophysical&Remote Sensing Survey and Interpretation System Research(No.2013AA063905)part of the planning for national high technology research and development
文摘We review the latest aeromagnetic geological data of continental China. We discuss the latest achievements in geological mapping and the newly detected features based on aeromagnetic data. Using aeromagnetic data collected for more than 50 years, a series of 1：5000000 and 1：1000000 aeromagnetic maps of continental China were compiled using state-of-the-art digital technology, and data processing and transformation. Guided by plate tectonics and continental dynamics, rock physical properties, and magnetic anomalies, we compiled maps of the depth of the magnetic basement of continental China and the major geotectonic units, and presented newly detected geological structures based on the aeromagnefic data.
基金supported by Italian 1:50,000 Geological Mapping (CARGdR egione Liguria Project, University of Pavia grants)
文摘The Early Paleozoic evolution of the northern margin of Gondwana is characterized by several episodes of bimodal magmatism intruded or outpoured within thick sedimentary basins. These processes are well recorded in the Variscan blocks incorporated in the Ligurian Alps because they experienced low temperature Alpine metamorphism. During the Paleozoic, these blocks, together with the other Alpine basements, were placed between the Corsica-Sardinia and the Bohemian Massif along the northern margin of Gondwana. In this framework, they host several a variegated lithostratigraphy forming two main complexes(Complexs I and II) that can be distinguished by both the protoliths and their crosscutting relationships, which indicate that the acidic and mafic intrusives of Complex II cut an already folded sequence made of sediments, basalts and granitoids of Complex I. Both complexes were involved in the Variscan orogenic phases as highlighted by the pervasive eclogite-amphibolite facies schistosity(foliation II). However, rare relicts of a metamorphic foliation at amphibolite facies conditions(foliation I)is locally preserved only in the rocks of Complex I. It is debatable if this schistosity was produced during the early folding event e occurred between the emplacement of Complex I and II e rather than during an early stage of the Variscan metamorphic cycle.New SHRIMP and LA ICP-MS Ue Pb zircon dating integrated with literature data, provide emplacement ages of the several volcanic or intrusive bodies of both complexes. The igneous activity of Complex I is dated between 507 ± 15 Ma and 494 ± 5 Ma, while Complex II between 467 ± 12 Ma and 445.5 ± 12 Ma.The folding event recorded only by the Complex I should therefore have occurred between 494 ± 5 Ma and 467 ± 12 Ma. The Variscan eclogite-amphibolite facies metamorphism is instead constrained between ~420 Ma and ~300 Ma. These ages and the geochemical signature of these rocks allow constraining the Early Paleozoic tectono-magmatic evolution of the Ligurian blocks, from a middleeupper Cambrian rifting stage, through the formation of an Early Ordovician volcanic arc during the Rheic Ocean subduction, until a Late Ordovician extension related to the arc collapse and subsequent rifting of the PaleoThetys. Furthermore, the ~420-350 Ma ages from zircon rims testify to thermal perturbations that may be associated with the Silurian rifting-related magmatism, followed by the subduction-collisional phases of the Variscan orogeny.
基金Supported by the National Natural Science Foundation of China(Grant No.40674063)National Hi-tech Research and Development Program of China(863Program)(Grant No.2006AA09Z311)
文摘Based on the synchronous joint gravity and magnetic inversion of single interface by Pilkington and the need of revealing Cenozoic and crystalline basement thickness in the new round of oil-gas exploration, we propose a joint gravity and magnetic inversion methodfor two-layer models by concentrating on the relationship between the change of thicknessI and position of the middle layer and anomaly and discuss the effects of the key parameters. Model tests and application to field data show the validity of this method.
文摘Based on the data of seismic reflection, seismic refraction and magnetism collected in the research area and geology obtained from adjacent areas, this paper deals with the issue of basement constitution of the southern part of the Okinawa Trough. In the shelf basin of the East China Sea, Taiwan folded belt and Ryukyu Islands folded belt which surround the trough, outcrop Later Paleozoic, Mesozoic and Eogene strata. In the southern trough, multichannel seismic reflection data indicate that the overlying strata are composed of Neogene and Quaternary deposits, and the acoustic basement consists of Eogent and even older strata. Seismic refraction profiles show that there are Eogene and Mesozoic velocity layers with longitudinal velocities of 4.7 - 5.3 km/s and 6.3 km/s respectively beneath the Quaternary-Miocene Layers. Qualitative analysis and forward and reversed calculation of magnetic data show that the magnetic basement is mainly formed by metamorphic rocks, the Yanshanian neutral-acid magmatic rocks and the Himalayan neutral-basic magmatic rocks being the next components, and the magnetic basement is mostly corresponding to the acoustic basement. Comprehensive analyses demonstrate that the basement of the southern Okinawa Trough is mainly formed by Eogene system and Mesozoic and Upper Paleozoic groups metamorphosed in varying degrees, and the basic magmatic rocks of Himalayan epoch have been formed in some parts of the basin.
基金supported by China National Natural Science Foundation Grant 49732070.
文摘Based on geological, chronological, geochemical and Nd isotopic studies of the high-grade basement of the Qilian terrane, the authors have drawn the following main conclusions: (1) the high-grade basement of the Qilian terrane consists mainly of meta-argillo-arenaceous rocks and granites and its bulk part was formed in the period of 0.8–1.0 Ga (the Jinningian period); (2) most of the meta-argillo-arenaceous rocks and granitic rocks have strong negative Eu and Ba anomalies (Eu/Eu*= 0.47–0.71 and Ba/Ba*=0.16–0.64), with fDM and ENd (1.0 Ga) ranging from 1.87 to 2.26 Ga and from ?8.54 to ?4.06 respectively, showing relatively high maturity; and (3) the Jinningian granitic rocks are a typical product of continent-continent collision, being probably related to the formation of the supercontinent Rodinia. These studies, combined with the study of high-grade basement rocks near the Qilian terrane, suggest that before the Jinningian period, the Qilian-Qaidam northern-margin terrane and Dunhuang-Alxa terrane were separated from each other, belonging to different plate systems of the North China craton and Yangtze platform respectively. The Qilian orogenic belt was the same as or similar to the Qiling orogenic belt in terms of the geological evolution history at least before the Jinningian period.
基金funded by the National 305 Project of China (2018A03004-1, 2015BAB05B01-02)the Fundamental Research Fund for Central Universities(B16020127)
文摘The West Kunlun orogenic belt(WKOB) along the northern margin of the Tibetan Plateau is important for understanding the evolution of the Proto-and Paleo-Tethys oceans. Previous investigations have focused on the igneous rocks and ophiolites distributed mostly along the Xinjiang-Tibet road and the China-Pakistan road, and have constructed a preliminary tectonic model for this orogenic belt. However, few studies have focused on the so-called Precambrian basement in this area. As a result, the tectonic affinity of the individual terranes of the WKOB and their detailed evolution process are uncertain. Here we report new field observations, zircon and monazite U-Pb ages of the "Precambrian basement" of the South Kunlun terrane(SKT) and the Tianshuihai terrane(TSHT), two major terranes in the WKOB. Based on new zircon U-Pb age data, the amphibolite-facies metamorphosed volcanosedimentary sequence within SKT was deposited during the late Neoproterozoic to Cambrian(600-500 Ma), and the flysch-affinity Tianshuihai Group, as the basement of the TSHT, was deposited during the late Neoproterozoic rather than Mesoproterozoic. The rock association of the volcano-sedimentary sequence within SKT suggests a large early Paleozoic accretionary wedge formed by the long-term lowangle southward subduction of the Proto-Tethys Ocean between Tarim and TSHT. The amphibolitefacies metamorphism in SKT occurred at ca. 440 Ma. This ca. 440 Ma metamorphism is genetically related to the closure of the Proto-Tethys Ocean between Tarim and the Tianshuihai terrane, which led to the assembly of Tarim to Eastern Gondwana and the final formation of the Gondwana. Since the late Paleozoic to early Mesozoic, the northward subduction of the Paleo-Tethys Ocean along the HongshihuQiaoertianshan belt produced the voluminous early Mesozoic arc-signature granites along the southern part of NKT-TSHT. The Paleo-Tethys ocean between TSHT and Karakorum closed at ca. 200 Ma, as demonstrated by the monazite age of the paragneiss in the Kangxiwa Group. Our study does not favor the existence of a Precambrian basement in SKT.
基金the Major State Basic Research Programs of the People’s Republic of China(No.2001CB409806).
文摘According to the study on the peripheral orogenic belts of the Junggar basin and combined with the interpretation of geophysical data, this paper points out that there is an Early Paleozoic basement of immature continental crust in the Junggar area, which is mainly composed of Neoproterozoic-Ordovician oceanic crust and weakly metamorphosed covering sedimentary rocks. The Late Paleozoic tectonism and mineralization were developed on the basement of the Early Paleozoic immature continental crust. The Junggar metallogenic province is dominated by Cr, Cu, Ni and Au mineralization. Those large and medium-scale deposits are mainly distributed along the deep faults and particularly near the ophiolitic melange zones, and formed in the Late Paleozoic with the peak of mineralization occurring in the Carboniferous-Permian post-collisional stage. The intrusions related to Cu, Ni and Au mineralization generally have low Is, and positive εNd(t) values. The δ34S values of the ore deposits are mostly near zero, and the lead isotopes are mostly of normal lead. All these indicate that the ore-forming material comes either directly from the mantle-derived magma (for chromite and Cu-Ni deposits) or from recirculation of the basement material of the Early Paleozoic immature crust (for most Cu and Au deposits).
基金supported by the Major Program of the National Natural Science Foundation of China (No. 41490611)the Joint Research Projects between the Pakistan Science Foundation and the National Natural Science Foundation of China (No. 41661144026)the Detailed Lithospheric Structure and Deep Processes of the Tibetan Main Collision Zone (No. 2016YFC0600301)
文摘A comprehensive geophysical profile stretching from Qingyijing at the southern edge of the Junggar Basin to Ubara on the northern margin of the Junggar Basin was conducted in an attempt to probe the crustal structure of the western Junggar Basin(hereafter referred to simply as ‘the Basin'), and, in particular, the structure and property of the Basin's crystalline basement. A survey using seismically converted waves was conducted along this profile to determine the characteristics of the P-and Swave velocities typical of the crust and uppermost mantle. A joint inversion of gravitation and aeromagnetic data was also performed to acquire the density and magnetization intensity values found beneath the western Basin. This research revealed that the Basin is composed of the so-called Manasi terrain in the south, and the Wulungu terrain in the north. Their boundary is located along the WNW-trending Dishuiquan-Sangequan suture, linking the NE-striking Da'erbute suture(DS) in the west, and the WNWtrending Kalameili suture(KS) in the east. In its northern part, the Wulungu-type terrain has a doublelayered basement, of which the upper layer is a folded basement of Hercynian orogenic origin, and the lower layer is a crystalline basement of Middle–Upper Proterozoic age. The southern part of the Basin, i.e., the Manasi terrain, has a single-layered crystalline basement. The folded basement here is too thin to be clearly distinguished.
