Episodic hydrothermal alteration on Middle Permian carbonate reservoirs and its geological significance in southwestern Sichuan Basin,SW China

To analyze the episodic alteration of Middle Permian carbonate reservoirs by complex hydrothermal fluid in southwestern Sichuan Basin,petrology,geochemistry,fluid inclusion and U-Pb dating researches are conducted.The fractures and vugs of Middle Permian Qixia–Maokou formations are filled with multi-stage medium-coarse saddle dolomites and associated hydrothermal minerals,which indicates that the early limestone/dolomite episodic alteration was caused by the large-scale,high-temperature,deep magnesium-rich brine along flowing channels such as basement faults or associated fractures under the tectonic compression and napping during the Indosinian.The time of magnesium-rich hydrothermal activity was from the Middle Triassic to the Late Triassic.The siliceous and calcite fillings were triggered by hydrothermal alteration in the Middle and Late Yanshanian Movement and Himalayan Movement.Hydrothermal dolomitization is controlled by fault,hydrothermal property,flowing channel and surrounding rock lithology,which occur as equilibrium effect of porosity and permeability.The thick massive grainstone/dolomites were mainly altered by modification such as hydrothermal dolomitization/recrystallization,brecciation and fracture-vugs filling.Early thin-medium packstones were mainly altered by dissolution and infilling of fracturing,bedding dolomitization,dissolution and associated mineral fillings.The dissolved vugs and fractures are the main reservoir space under hydrothermal conditions,and the connection of dissolved vugs and network fractures is favorable for forming high-quality dolomite reservoir.Hydrothermal dolomite reservoirs are developed within a range of 1 km near faults,with a thickness of 30–60 m.Hydrothermal dolomite reservoirs with local connected pore/vugs and fractures have exploration potential.

Middle hepatic vein variation provides a safe path for anterior transection of hepatocellular carcinoma in caudate lobe

To the Editor:Hepatocellular carcinoma(HCC)is one of the main causes of cancer related death worldwide,and new cases are expected to continue to increase in future[1].Surgical resection is still the best way to remove the tumor and improve patient’s prognosis.However,resection of caudate lobe often presents a technical challenge,even to accomplished hepatic surgeons.Caudate lobe is located anterior to the inferior vena cava(IVC)and posterior to the bifurcation of the portal vein(PV),generally consists of three regions:the paracaval portion,the left Spiegel lobe and the process portion[2].The anatomy of the paracaval portion includes the liver parenchyma ventral to the hepatic IVC and the area between the Spiegel lobe and the right lobe adjacent to the middle hepatic vein(MHV)ventrally,which was classified by Couinaud as segment IX[3].Here,we presented a case of HCC with successful downstaging therapy,as well as variation of MHV,which provides a safe path for anterior transection of segment IX.

The Middle Miocene lobe-shaped and band-shaped submarine fans in the Lingshui Sag,Qiongdongnan Basin:source-to-sink system,genesis and implication

Deepwater oil and gas exploration is the key to sustainable breakthroughs in petroleum exploration worldwide.The Central Canyon gas field has confirmed the Lingshui Sag is a hydrocarbon-generating sag,and the deepwater reservoirs in the Lingshui Sag still have more fabulous oil and gas exploration potential.Based on drilling data and three-dimensional(3D)seismic data,this paper uses seismic facies analysis,seismic attribute analysis,and coherence slice analysis to identify the types of submarine fans(lobe-shaped and band-shaped submarine fans)that developed in the Lingshui Sag during the Middle Miocene,clarify the source-to-sink system of the submarine fans and discuss the genesis mechanism of the submarine fans.The results show that:(1)the deepwater source-to-sink system of the Lingshui Sag in the Middle Miocene mainly consisted of a“delta(sediment supply)-submarine canyon(sediment transport channel)-submarine fan(deepwater sediment sink)”association;(2)the main factor controlling the formation of the submarine fans developed in the Lingshui Sag was on the relative sea level decline;and(3)the bottom current reworked the lobe-shaped submarine fan that developed in the northern Lingshui Sag and formed the band-shaped submarine fan with a greater sand thickness.This paper aims to provide practical geological knowledge for subsequent petroleum exploration and development in the deepwater area of the Qiongdongnan Basin through a detailed analysis of the Middle Miocene submarine fan sedimentary system developed in the Lingshui Sag.

The Effects of Age and Ejaculatory Abstinence on Semen Quality and Reproductive Hormones in Africa and the Middle East

The aim of this study was to retrospectively evaluate the effects of male age and ejaculatory abstinence on semen parameters and reproductive hormones among men residing in Africa and the Middle East. A total of 70,142 semen analysis results were analysed and grouped according to the age intervals (16 - 20, 21 - 30, 31 - 40, 41 - 50, 51 - 60, >60) and ejaculatory abstinence (<2 days, 2 - 5 days and >5 days). Semen parameters i.e. volume, concentration, progressive motility, total progressively motile count, morphology, total normal sperm count, DNA fragmentation, viability, sORP, normed sORP were specifically evaluated. Additionally, for each age interval, reproductive hormones i.e. estradiol, luteinizing hormone, follicle stimulating hormone, testosterone and prolactin were evaluated. Semen volume, total progressively motile count, sperm morphology and total normal sperm count constantly decrease significantly after the age of 30 years. Sperm concentration started declining significantly after the age of 50 years. There was a constant age- related increase in number of spermatozoa with damaged DNA. sORP constantly increased up to 60 years. Furthermore, constantage-related decreases in FSH, serum testosterone and prolact in were observed from patients aged between 16 years and 60 years. Semen volume, sperm concentration, progressive motility and normal morphology were significantly higher in patients having > 5 days of abstinence. Patients having > 5 days of abstinence had the lowest normed sORP. Male age significantly affects sperm parameters and reproductive hormones in fertile and infertile men residing in Africa and the Middle East. Prolonged abstinence days provides better semen quality.

Abaca Fiber as a Potential Reinforcer for Acoustic Absorption Material at Middle-High Frequencies

Recently,abacafibers have become the focus of specialized research due to their intriguing characteristics,with their outstanding mechanical properties being a particularly notable.In the conducted study,the abacafibers underwent a preliminary treatment process involving an alkaline solution,which was composed of 0.5%sodium hydroxide(NaOH)and 50%acetic acid(CH3COOH).This process entailed immersing eachfiber in the solution for a period of one hour.This treatment led to a 52.36%reduction in lignin content compared to the levels before treatment,resulting in a dramatic decrease in the full width at half maximum(FWHM)in the XRD spectra from 1.13 to 0.13.This change indicates that thefibers became more crystalline following the treatment.The abacafibers were also characterized using BET(Brunauer Emmett Teller)measurements,which revealed that the aver-age pore length ranged from 33–49 nm and the surface area was between 13–28 m^(2)·g^(-1).The morphology of the abacafiber after alkali an hydrolisis treatment(AFAH)appeared rougher and more uniform.DMA measurements revealed a significant rise in the storage modulus of the singlefiber post-treatment,with dependencies on both frequency and temperature.AFAH exhibited an optimal absorption coefficient ofα=0.9 for frequencies above 2500 Hz.The combined effect of alkalization and hydrolyzation treatments,while resulting in an enhancement in the mechanical properties of thefibers,also reduced high-intensity noise produced by sources such as machin-ery,aircraft takeoffs and landings,etc.,across a broader working frequency range.

Characteristics and main controlling factors of intra-platform shoal thin-layer dolomite reservoirs:A case study of Middle Permian Qixia Formation in Gaoshiti-Moxi area of Sichuan Basin,SW China

Based on the study of the distribution of intra-platform shoals and the characteristics of dolomite reservoirs in the Middle Permian Qixia Formation in the Gaoshiti–Moxi area of the Sichuan Basin,SW China,the controlling factors of reservoir development were analyzed,and the formation model of“intra-platform shoal thin-layer dolomite reservoir”was established.The Qixia Formation is a regressive cycle from bottom to top,in which the first member(Qi1 Member)develops low-energy open sea microfacies,and the second member(Qi2 Member)evolves into intra-platform shoal and inter-shoal sea with decreases in sea level.The intra-platform shoal is mainly distributed near the top of two secondary shallowing cycles of the Qi2 Member.The most important reservoir rock of the Qixia Formation is thin-layer fractured-vuggy dolomite,followed by vuggy dolomite.The semi-filled saddle dolomite is common in fracture-vug,and intercrystalline pores and residual dissolution pores combined with fractures to form the effective pore-fracture network.Based on the coupling analysis of sedimentary and diagenesis characteristics,the reservoir formation model of“pre-depositional micro-paleogeomorphology controlling shoal,sedimentary shoal controlling dolomite,penecontemporaneous dolomite benefiting preservation of pores,and late hydrothermal action effectively improving reservoir quality”was systematically established.The“first-order high zone”micro-paleogeomorphology before the deposition of the Qixia Formation controlled the development of large area of intra-platform shoals in Gaoshiti area during the deposition of the Qi2 Member.Shoal facies is the basic condition of early dolomitization,and the distribution range of intra-platform shoal and dolomite reservoir is highly consistent.The grain limestone of shoal facies is transformed by two stages of dolomitization.The penecontemporaneous dolomitization is conducive to the preservation of primary pores and secondary dissolved pores.The burial hydrothermal fluid enters the early dolomite body along the fractures associated with the Emeishan basalt event,makes it recrystallized into medium–coarse crystal dolomite.With the intercrystalline pores and the residual vugs after the hydrothermal dissolution along the fractures,the high-quality intra-platform shoal-type thin-layer dolomite reservoirs are formed.The establishment of this reservoir formation model can provide important theoretical support for the sustainable development of Permian gas reservoirs in the Sichuan Basin.

Digital Twin Modeling and Simulation Optimization of Transmission Front and Middle Case Assembly Line

As the take-off of China’s macro economy,as well as the rapid development of infrastructure construction,real estate industry,and highway logistics transportation industry,the demand for heavy vehicles is increasing rapidly,the competition is becoming increasingly fierce,and the digital transformation of the production line is imminent.As one of themost important components of heavy vehicles,the transmission front andmiddle case assembly lines have a high degree of automation,which can be used as a pilot for the digital transformation of production.To ensure the visualization of digital twins(DT),consistent control logic,and real-time data interaction,this paper proposes an experimental digital twin modeling method for the transmission front and middle case assembly line.Firstly,theDT-based systemarchitecture is designed,and theDT model is created by constructing the visualization model,logic model,and data model of the assembly line.Then,a simulation experiment is carried out in a virtual space to analyze the existing problems in the current assembly line.Eventually,some improvement strategies are proposed and the effectiveness is verified by a new simulation experiment.

Types,composition and diagenetic evolution of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata:A case study of Mao-1 Member of Middle Permian Maokou Formation,eastern Sichuan Basin,SW China

The types,occurrence and composition of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata of the first member of the Middle Permian Maokou Formation(Mao-1 Member)in eastern Sichuan Basin were investigated through outcrop section measurement,core observation,thin section identification,argon ion polishing,X-ray diffraction,scanning electron microscope,energy spectrum analysis and laser ablation-inductively coupled plasma-mass spectrometry.The diagenetic evolution sequence of clay minerals was clarified,and the sedimentary-diagenetic evolution model of clay minerals was established.The results show that authigenic sepiolite minerals were precipitated in the Si4+and Mg2+-rich cool aragonite sea and sepiolite-bearing strata were formed in the Mao-1 Member.During burial diagenesis,authigenic clay minerals undergo two possible evolution sequences.First,from the early diagenetic stage A to the middle diagenetic stage A1,the sepiolite kept stable in the shallow-buried environment lack of Al3+.It began to transform into stevensite in the middle diagenetic stage A2,and then evolved into disordered talc in the middle diagenetic stage B1and finally into talc in the period from the middle diagenetic stage B2to the late diagenetic stage.Thus,the primary diagenetic evolution sequence of authigenic clay minerals,i.e.sepiolite-stevensite-disordered talc-talc,was formed in the Mao-1 Member.Second,in the early diagenetic stage A,as Al3+carried by the storm and upwelling currents was involved in the diagenetic process,trace of sepiolite started to evolve into smectite,and a part of smectite turned into chlorite.From the early diagenetic stage B to the middle diagenesis stage A1,a part of smectite evolved to illite/smectite mixed layer(I/S).The I/S evolved initially into illite from the middle diagenesis stage A2to the middle diagenesis stage B2,and then totally into illite in the late diagenesis stage.Thus,the secondary diagenetic evolution sequence of authigenic clay minerals,i.e.sepiolite-smectite-chlorite/illite,was formed in the Mao-1 Member.The types and evolution of authigenic clay minerals in argillaceous limestone of sepiolite-bearing strata are significant for petroleum geology in two aspects.First,sepiolite can adsorb and accumulate a large amount of organic matters,thereby effectively improving the quality and hydrocarbon generation potential of the source rocks of the Mao-1 Member.Second,the evolution from sepiolite to talc is accompanied by the formation of numerous organic matter pores and clay shrinkage pores/fractures,as well as the releasing of the Mg2+-rich diagenetic fluid,which allows for the dolomitization of limestone within or around the sag.As a result,the new assemblages of self-generation and self-accumulation,and lower/side source and upper/lateral reservoir,are created in the Middle Permian,enhancing the hydrocarbon accumulation efficiency.

Age and geochemical evolution of granite magmatism in Olkhon region from Caledonian syncollisional ore-free granite to the rare metal granite and pegmatite of Middle Paleozoic intraplate setting

The detailed description of two granite complexes in the Olkhon subterrane is given.The Early Paleozoic Sharanur complex was formed by granitization of gneisses of the Olkhon series.It includes migmatites,granite-gneisses,granites and pegmatites of normal alkalinity;they belong to the type of syncollisional granites.The Middle Paleozoic Aya granite complex includes mother Aya massif of amazonite-bearing granites and several types of rare-metal pegmatites.They have elevated alkalinity,low of Ba,Sr,and high LILE and HFSE elements contents.The Aya pegmatites lie in northwest cracks of stretching and associated with the rise of the territory under the influence of the North Asian plume.These cracks and pegmatites mark the beginning of a new intraplate geodynamic setting.Two geochemical types are distinguished among the pegmatites of this complex.These are amazonite pegmatites of Li-F type with Ta mineralization and complex type pegmatite with Be-Rb-Nb-Ta and Li-F mineralization(the Ilixin vein).The Tashkiney pegmatite vein is similar to Ilixin,but lies in the gneisses of the Olkhon series.It shows high concentrations of Be,Nb,Ta,as well as W,Sn,but lacks Li and F,due to a greater depth and higher temperature of the melt crystallization of this pegmatite.

In the Middle of Global Governance Indonesia is actively participating in global governance reform through the MIKTA middle power grouping

In March 2023,Indonesia took over the chairmanship of MIKTA from Turkiye,marking the second time Indonesia has served as the rotating chair of a global governance mechanism,following the Bali G20 Summit in 2022.

First experience in laparoscopic surgery in low and middle income countries: A systematic review

BACKGROUND Laparoscopic surgery has reduced morbidity and mortality rates,shorter post-operative recovery periods and lower complication rates than open surgery.It is routine practice in high-income countries and is becoming increasingly common in countries with limited resources.However,introducing laparoscopic surgery in low-and-middle-income countries(LMIC)can be expensive and requires resour-ces,equipment,and trainers.AIM To report the challenges and benefits of introducing laparoscopic surgery in LMIC as well as to identify solutions to these challenges for countries with limited finances and resources.METHODS MEDLINE,EMBASE and Cochrane databases were searched for studies reporting first experience in laparoscopic surgery in LMIC.Included studies were published between 1996 and 2022 with full text available in English.Exclusion criteria were studies considering only open surgery,ear,nose,and throat,endoscopy,arthro-scopy,hysteroscopy,cystoscopy,transplant,or bariatric surgery.RESULTS Ten studies out of 3409 screened papers,from eight LMIC were eligible for inclusion in the final analysis,totaling 2497 patients.Most reported challenges were related to costs of equipment and training programmes,equipment pro-blems such as faulty equipment,and access to surgical kits.Training-related challenges were reliance on foreign trainers and lack of locally trained surgeons and theatre staff.The benefits of introducing laparoscopic surgery were economic and clinical,including a reduction in hospital stay,complications,and morbidi-ty/mortality.The introduction of laparoscopic surgery also provided training opportunities for junior doctors.CONCLUSION Despite financial and technical challenges,many studies emphasise the overall benefit of introducing laparoscopic surgery in LMICs such as reduced hospital stay and the related lower cost for patients.While many of the clinical centres in LMICs have proposed practical solutions to the challenges reported,more support is critically required,in particular regarding training.

Relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine fetal distress

BACKGROUND By comprehensively analyzing the blood flow parameters of the umbilical and middle cerebral arteries,doctors can more accurately identify fetal intrauterine distress,as well as assess its severity,so that timely interventions can be implemented to safeguard the health and safety of the fetus.AIM To identify the relationship between ultrasound parameters of the umbilical and middle cerebral arteries and intrauterine distress.METHODS Clinical data of pregnant women admitted between January 2021 and January 2023 were collected and divided into the observation and control groups(n=50 each),according to the presence or absence of intrauterine distress.The ultrasound hemodynamic parameters of the uterine artery(UtA),fetal middle cerebral artery(MCA),and umbilical artery(UmA)were compared with neonatal outcomes and occurrence of intrauterine distress in the two groups.RESULTS Comparison of ultrasonic hemodynamic parameters,resistance index(RI),pulsatility index(PI),and systolic maximal blood flow velocity of UmA compared to diastolic blood flow velocity(S/D),revealed higher values of fetal MCA,PI,and S/D of UmA in pregnant women with UtA compared to controls(P<0.05),while there was no difference between the two groups in terms of RI(P<0.05)The incidence of a neonatal Apgar score of 8-10 points was lower in the observation group(66.7%)than in the control group(90.0%),and neonatal weight(2675.5±27.6 g)was lower than in the control group(3117.5±31.2 g).Further,cesarean section rate was higher in the observation group(70.0%)than in the control group(11.7%),and preterm labor rate was higher in the observation group(40.0%)than in the control group(10.0%).The incidence of fetal distress,neonatal growth restriction and neonatal asphyxia were also higher in the observation group(all P<0.05).CONCLUSION Fetal MCA,UmA,and maternal UtA hemodynamic abnormalities all develop in pregnant women with intrauterine distress during late pregnancy,which suggests that clinical attention should be paid to them,and monitoring should be strengthened to provide guidance for clinical intervention.

Effect of nutrition-related infodemics and social media on maternal experience: A nationwide survey in a low/middle income country

BACKGROUND Undernutrition is a crucial cause of morbidity and mortality among children in low-or middle-income countries(LMICs).A better understanding of maternal general healthy nutrition knowledge,as well as misbeliefs,is highly essential,especially in such settings.In the current era of infodemics,it is very strenuous for mothers to select not only the right source for maternal nutrition information but the correct information as well.AIM To assess maternal healthy nutritional knowledge and nutrition-related misbeliefs and misinformation in an LMIC,and to determine the sources of such information and their assessment methods.METHODS This cross-sectional analytical observational study enrolled 5148 randomly selected Egyptian mothers who had one or more children less than 15 years old.The data were collected through online questionnaire forms:One was for the general nutrition knowledge assessment,and the other was for the nutritional myth score.Sources of information and ways of evaluating internet sources using the Currency,Relevance,Authority,Accuracy,and Purpose test were additionally analyzed.RESULTS The mean general nutrition knowledge score was 29±9,with a percent score of 70.8%±12.1%(total score:41).The median myth score was 9(interquartile range:6,12;total score:18).The primary sources of nutrition knowledge for the enrolled mothers were social media platforms(55%).Half of the mothers managed information for currency and authority,except for considering the author's contact information.More than 60%regularly checked information for accuracy and purpose.The mothers with significant nutrition knowledge checked periodically for the author's contact information(P=0.012).The nutrition myth score was significantly lower among mothers who periodically checked the evidence of the information(P=0.016).Mothers dependent on their healthcare providers as the primary source of their general nutritional knowledge were less likely to hold myths by 13%(P=0.044).However,using social media increased the likelihood of having myths among mothers by approximately 1.2(P=0.001).CONCLUSION Social media platforms were found to be the primary source of maternal nutrition information in the current era of infodemics.However,healthcare providers were the only source for decreasing the incidence of maternal myths among the surveyed mothers.

The Critical Role of Middle Leaders in Schools:Cultivating a Culture of Trust and Supporting Educational Reform

This research delves into the often-underappreciated role of middle leaders in educational organizations,highlighting their significance as the linchpins between senior leadership and classroom teachers.Utilizing qualitative research methods,the study investigates the multifaceted responsibilities,challenges,and contributions of middle leaders in schools.Findings indicate that middle leaders foster a culture of trust within the institution by providing mentorship and guidance to new teachers.They undertake substantial tasks,such as team coordination,grade direction,and student supervision,in addition to their teaching duties.Despite their pivotal role,middle leaders often face mounting pressures and heavy workloads.This research underscores the need to recognize and support middle leaders in educational settings,acknowledging their vital role in fostering cohesion and facilitating the implementation of educational reforms.

The Impact of Sports Games on the Psychological Health of Middle School Students

This study conducted a 16-week comparative experiment with 160 students from Jinan No.5 Middle School in Shandong Province as the experimental subjects.During the implementation of the experiment,the subjects were divided into two groups:an experimental group and a control group.The experimental group was subjected to physical exercise interventions using sports game teaching methods during physical education class,while the control group followed traditional physical education teaching methods.The results showed that the psychological health status of the students in the experimental group was significantly better than that of the control group after the experiment.The application of sports games helps to improve the psychological health of middle school students in the course of physical education,promoting a positive and forward direction in student psychology and is an effective means to enhance the psychological health level of middle school students.

Integration of Mathematics History into Junior Middle School Education: A Pedagogical Approach to Enhance Mathematical Literacy

The integration of the history of mathematics into junior middle school mathematics education represents a significant focus of international research in mathematics and education.The mathematics curriculum standards for compulsory education have emphasized the importance of incorporating the history of mathematics,aiming to gradually integrate it into the mathematics classroom.However,in the practical implementation of junior middle school mathematics education,the effective combination of the history of mathematics with teaching methodologies remains largely unexplored.This article explores the integration of junior middle school mathematics education and the history of mathematics,aiming to provide classroom teaching recommendations for teachers and promote the formation of students’mathematical literacy.

A new formula of recovery factor for non-equilibrium transport of graded suspended sediment in the Middle Yangtze River

Suspended sediment concentrations in the Middle Yangtze River(MYR)reduced greatly after the Three Gorges Project operation,causing the composition of bed material to coarsen continuously.However,little is known about the non-equilibrium transport of graded suspended sediment owing to different bed material compositions(BMCs)along the MYR,and it is necessary to determine the magnitude of recovery factor.Using the Markov stochastic process in conjunction with the hiding-exposure effect of non-uniform bed-material,a new formula is proposed for calculating the recovery factor including the effect of different BMCs,and it is incorporated into the non-equilibrium transport equation to simulate the recovery processes of suspended load in both sand-gravel bed and sand bed reaches of the MYR.The results show that:(i)the recovery rate of graded sediment concentrations at Zhicheng was slower than that at Shashi during the period 2003-2007;(ii)the mean recovery factors of the coarse,medium,and fine sediment fractions in the ZhichengShashi reach were 0.152,0.0012,and 0.0005,respectively,and the coarse sediment recovered up to the maximum sediment concentration of 0.138 kg/m3over a distance of 15 km;and(iii)the results of the new formula that can consider the effect of bed material composition are in general agreement with the field observations,and the spatial and temporal delay effects are inversely related to particle size and BMC.Consequently,the BMC effect on the nonequilibrium sediment transport in different reaches of the MYR needs to be considered for higher simulation accuracy.

Paleoenvironment reconstruction of the Middle Ordovician thick carbonate from western Ordos Basin, China

Reconstructing paleoenvironments has long been considered a vital component for understanding the development and evolution of carbonate reservoirs.The Middle Ordovician Period is considered the archetypical greenhouse interval,and also a critical period in biological evolution.The Middle Darriwilian isotope carbon excursion has been observed in many areas of the world and may be related to the biological explosions caused by decreases in the temperature.The thick carbonate rocks in the fifth member of the Middle Ordovician Majiagou Formation in the Dingbei area of the Ordos Basin were chosen as an example,based on the concentration of major,trace and rare earth elements as well as C,O and Sr isotopic analyses,the paleoenvironment was reconstructed.And its impact on natural gas exploration was analyzed.The results show that the seawater paleotemperature was 29℃,suboxicanoxic paleoredox conditions were observed,and the seawater paleosalinity was high.A large number of plankton in the biological explosion caused a rapid increase in the total organic carbon in carbonate rocks,which provided natural gas as supplemental source rocks.Affected by early meteoric water,the dissolution of gypsum laid the foundation for high-quality reservoirs,and the residual gypsum also further preserved natural gas.This study provides new data for the paleoenvironment and a theoretical basis for further natural gas exploration.

Urban Spatial Carrying Capacity and Sustainable Urbanization in the Middle-east Section of North Slope of Kunlun Mountains in Xinjiang,China

Urban spatial carrying capacity is the comprehensive support capacity of natural resources for urban development,which is of great significance in guaranteeing the sustainable urbanization.The middle-east section of North Slope of Kunlun Mountains in Xinjiang,China,is characterized by harsh climate and sparse population,whereas it is important for the initiative of the new Silk Road Belt because of its important location.Cities in this area have begun to take shape,and the implementation of the Silk Road Belt Initiative will inevitably stimulate the urbanization in this area.The extent to which the cities in this area will be supported by natural resources and how to fulfill the requirements of sustainable socioeconomic development needs to be investigated.In view of this,the present study evaluated the urban spatial carrying capacity and discussed feasible approaches that could support the sustainable urbanization in this area.The results show that 97.59%of the study area belongs to the low and relatively low levels of spatial carrying capacity for urban construction,and the area of medium,relatively high and high levels is 1.12×104 km2,accounting for 2.41%of the total study area,mainly distributed in small clusters in the central alluvial fan oasis plains.Resource and environmental factors highly constrain urban construction,and low spatial matching of land and water resources,harsh climatic conditions and high risk of geological disasters are three major shortcomings.In addition,lagging transportation infrastructure construction and the resulting weak internal and external spatial connections also affect urban development.On this basis,the scientific arrangement of urban distribution,steady promotion of regional economic development based on local characteristics,further improvement of transportation infrastructure construction and strengthening the cooperation between the Xinjiang Production and Construction Corps and local governments are suitable approaches for sustainable urbanization in the study area.

An extraordinary multielement apparatus of conodont Nicoraella from the Middle Triassic Luoping Biota,southwest China

Conodont animal is an extinct group of marine animals.The conodont elements and their hard skeletal remains are originally from the head region of this kind of animal,and they are considered to be functioned as“teeth”.The“multielement apparatus”can also be called the“(conodont)apparatus”,“multimembrate(skeletal)apparatus”.