A review of reservoir damage during hydraulic fracturing of deep and ultra-deep reservoirs

Deep and ultra-deep reservoirs have gradually become the primary focus of hydrocarbon exploration as a result of a series of significant discoveries in deep hydrocarbon exploration worldwide.These reservoirs present unique challenges due to their deep burial depth(4500-8882 m),low matrix permeability,complex crustal stress conditions,high temperature and pressure(HTHP,150-200℃,105-155 MPa),coupled with high salinity of formation water.Consequently,the costs associated with their exploitation and development are exceptionally high.In deep and ultra-deep reservoirs,hydraulic fracturing is commonly used to achieve high and stable production.During hydraulic fracturing,a substantial volume of fluid is injected into the reservoir.However,statistical analysis reveals that the flowback rate is typically less than 30%,leaving the majority of the fluid trapped within the reservoir.Therefore,hydraulic fracturing in deep reservoirs not only enhances the reservoir permeability by creating artificial fractures but also damages reservoirs due to the fracturing fluids involved.The challenging“three-high”environment of a deep reservoir,characterized by high temperature,high pressure,and high salinity,exacerbates conventional forms of damage,including water sensitivity,retention of fracturing fluids,rock creep,and proppant breakage.In addition,specific damage mechanisms come into play,such as fracturing fluid decomposition at elevated temperatures and proppant diagenetic reactions at HTHP conditions.Presently,the foremost concern in deep oil and gas development lies in effectively assessing the damage inflicted on these reservoirs by hydraulic fracturing,comprehending the underlying mechanisms,and selecting appropriate solutions.It's noteworthy that the majority of existing studies on reservoir damage primarily focus on conventional reservoirs,with limited attention given to deep reservoirs and a lack of systematic summaries.In light of this,our approach entails initially summarizing the current knowledge pertaining to the types of fracturing fluids employed in deep and ultra-deep reservoirs.Subsequently,we delve into a systematic examination of the damage processes and mechanisms caused by fracturing fluids within the context of hydraulic fracturing in deep reservoirs,taking into account the unique reservoir characteristics of high temperature,high pressure,and high in-situ stress.In addition,we provide an overview of research progress related to high-temperature deep reservoir fracturing fluid and the damage of aqueous fracturing fluids to rock matrix,both artificial and natural fractures,and sand-packed fractures.We conclude by offering a summary of current research advancements and future directions,which hold significant potential for facilitating the efficient development of deep oil and gas reservoirs while effectively mitigating reservoir damage.

Targeting GPR65 alleviates hepatic inflammation and fibrosis by suppressing the JNK and NF-κB pathways

Background:G-protein coupled receptors(GPCRs)are recognized as attractive targets for drug therapy.However,it remains poorly understood how GPCRs,except for a few chemokine receptors,regulate the progression of liver fibrosis.Here,we aimed to reveal the role of GPR65,a proton-sensing receptor,in liver fibrosis and to elucidate the underlying mechanism.Methods:The expression level of GPR65 was evaluated in both human and mouse fibrotic livers.Furthermore,Gpr65-deficient mice were treated with either bile duct ligation(BDL)for 21 d or carbon tetrachloride(CCl4)for 8 weeks to investigate the role of GPR65 in liver fibrosis.A combination of experimental approaches,including Western blotting,quantitative real-time reverse transcription-polymerase chain reaction(qRT-PCR),and enzyme-linked immunosorbent assay(ELISA),confocal microscopy and rescue studies,were used to explore the underlying mechanisms of GPR65’s action in liver fibrosis.Additionally,the therapeutic potential of GPR65 inhibitor in the development of liver fibrosis was investigated.Results:We found that hepatic macrophage(HM)-enriched GPR65 was upregulated in both human and mouse fibrotic livers.Moreover,knockout of Gpr65 significantly alleviated BDL-and CCl4-induced liver inflammation,injury and fibrosis in vivo,and mouse bone marrow transplantation(BMT)experiments further demonstrated that the protective effect of Gpr65knockout is primarily mediated by bone marrow-derived macrophages(BMMs).Additionally,in vitro data demonstrated that Gpr65 silencing and GPR65 antagonist inhibited,while GPR65 overexpression and application of GPR65 endogenous and exogenous agonists enhanced the expression and release of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)and transforming growth factor-β(TGF-β),all of which subsequently promoted the activation of hepatic stellate cells(HSCs)and the damage of hepatocytes(HCs).Mechanistically,GPR65 overexpression,the acidic pH and GPR65 exogenous agonist induced up-regulation of TNF-αand IL-6 via the Gαq-Ca^(2+)-JNK/NF-κB pathways,while promoted the expression of TGF-βthrough the Gαq-Ca^(2+)-MLK3-MKK7-JNK pathway.Notably,pharmacological GPR65 inhibition retarded the development of inflammation,HCs injury and fibrosis invivo.Conclusions:GPR65 is a major regulator that modulates the progression of liver fibrosis.Thus,targeting GPR65 could be an effective therapeutic strategy for the prevention of liver fibrosis.

Bionic lightweight design of limb leg units for hydraulic quadruped robots by additive manufacturing and topology optimization

Galloping cheetahs,climbing mountain goats,and load hauling horses all show desirable locomotion capability,which motivates the development of quadruped robots.Among various quadruped robots,hydraulically driven quadruped robots show great potential in unstructured environments due to their discrete landing positions and large payloads.As the most critical movement unit of a quadruped robot,the limb leg unit(LLU)directly affects movement speed and reliability,and requires a compact and lightweight design.Inspired by the dexterous skeleton–muscle systems of cheetahs and humans,this paper proposes a highly integrated bionic actuator system for a better dynamic performance of an LLU.We propose that a cylinder barrel with multiple element interfaces and internal smooth channels is realized using metal additive manufacturing,and hybrid lattice structures are introduced into the lightweight design of the piston rod.In addition,additive manufacturing and topology optimization are incorporated to reduce the redundant material of the structural parts of the LLU.The mechanical properties of the actuator system are verified by numerical simulation and experiments,and the power density of the actuators is far greater than that of cheetah muscle.The mass of the optimized LLU is reduced by 24.5%,and the optimized LLU shows better response time performance when given a step signal,and presents a good trajectory tracking ability with the increase in motion frequency.

Identification and effective regulation of scarb1 gene involved in pigmentation change in autotetraploid Carassius auratus

The autotetraploid Carassius auratus(4nRR,4n=200,RRRR)is derived from whole-genome duplication of Carassius auratus red var.(RCC,2n=100,RR).In the current study,we demonstrated that chromatophores and pigment changes directly caused the coloration and variation of 4nRR skin(red in RCC,brownish-yellow in4nRR).To further explore the molecular mechanisms underlying coloration formation and variation in 4nRR,we performed transcriptome profiling and molecular functional verification in RCC and 4nRR.Results revealed that scarb1,associated with carotenoid metabolism,underwent significant down-regulation in 4nRR.Efficient editing of this candidate pigment gene provided clear evidence of its significant role in RCC coloration.Subsequently,we identified four divergent scarb1 homeologs in 4nRR:two original scarb1 homeologs from RCC and two duplicated ones.Notably,three of these homeologs possessed two highly conserved alleles,exhibiting biased and allelespecific expression in the skin.Remarkably,after precise editing of both the original and duplicated scarb1homeologs and/or alleles,4nRR individuals,whether singly or multiply mutated,displayed a transition from brownishyellow skin to a cyan-gray phenotype.Concurrently,the proportional areas of the cyan-gray regions displayed a gene-dose correlation.These findings illustrate the subfunctionalization of duplicated scarb1,with all scarb1genes synergistically and equally contributing to the pigmentation of 4nRR.This is the first report concerning the functional differentiation of duplicated homeologs in an autopolyploidfish,substantiallyenrichingour understanding of coloration formation and change within this group of organisms.

Target Detection on Water Surfaces Using Fusion of Camera and LiDAR Based Information

To address the challenges of missed detections in water surface target detection using solely visual algorithms in unmanned surface vehicle(USV)perception,this paper proposes a method based on the fusion of visual and LiDAR point-cloud projection for water surface target detection.Firstly,the visual recognition component employs an improved YOLOv7 algorithmbased on a self-built dataset for the detection of water surface targets.This algorithm modifies the original YOLOv7 architecture to a Slim-Neck structure,addressing the problemof excessive redundant information during feature extraction in the original YOLOv7 network model.Simultaneously,this modification simplifies the computational burden of the detector,reduces inference time,and maintains accuracy.Secondly,to tackle the issue of sample imbalance in the self-built dataset,slide loss function is introduced.Finally,this paper replaces the original Complete Intersection over Union(CIoU)loss function with the Minimum Point Distance Intersection over Union(MPDIoU)loss function in the YOLOv7 algorithm,which accelerates model learning and enhances robustness.To mitigate the problem of missed recognitions caused by complex water surface conditions in purely visual algorithms,this paper further adopts the fusion of LiDAR and camera data,projecting the threedimensional point-cloud data from LiDAR onto a two-dimensional pixel plane.This significantly reduces the rate of missed detections for water surface targets.

Synergy of inside doped metals–Outside coated graphene to enhance hydrogen storage in magnesium-based alloys

Grain growth of magnesium(Mg)and its hydride is one of the main reasons for kinetic and capacity degradation during the hydrogen absorption and desorption cycles.To solve this problem,herein we propose a novel method involving synergistic effect of inside embedded metals and outside coated graphene to limit the growth of Mg and its hydride grains.The graphene coated Mg-Y-Al alloys were selected as a model system for demonstrating this positive effect where the Mg_(91)Y_(3)Al_(6)alloy was first prepared by rapidly solidified method and then high-pressure milled with 5 wt%graphene upon 5 MPa hydrogen gas for obtaining in-situ formed YAl_(2)and YH_(3)embedded in the MgH_(2)matrix with graphene shell(denoted as MgH_(2)-Y-Al@GR).In comparison to pure MgH_(2),the obtained MgH_(2)-Y-Al@GR composites deliver much better kinetics and more stable cyclic performance.For instance,the MgH_(2)-Y-Al@GR can release about 6.1 wt%H_(2)within 30 min at 300℃ but pure MgH_(2)only desorbs∼1.5 wt%H_(2).The activation energy for desorption of MgH_(2)-Y-Al@GR samples is calculated to be 75.3±9.1 kJ/mol that is much lower than approximately 160 kJ/mol for pure MgH_(2).Moreover,its capacity retention is promoted from∼57%of pure MgH_(2)to∼84%after 50th cycles without obvious particle agglomeration and grain growth.The synergistic effect of outside graphene coating with inside embedded metals which could provide a huge number of active sites for catalysis as well as inhibit the grain growth of Mg and its hydride is believed to be responsible for these.

Facies-controlled prediction of dolomite reservoirs in the Middle Permian Qixia Formation in Shuangyushi,northwestern Sichuan Basin

The Middle Permian Qixia Formation in the Shuangyushi area,northwestern Sichuan Basin,develops shoal-facies dolomite reservoirs.To pinpoint promising reservoirs in the Qixia Formation,deep thin shoal-facies dolomite reservoirs were predicted using the techniques of pre-stack Kirchhoff-Q compensation for absorption,inverse Q filtering,low-to high-frequency compensation,forward modeling,and facies-controlled seismic meme inversion.The results are obtained in six aspects.First,the dolomite reservoirs mainly exist in the middle and lower parts of the second member of Qixia Formation(Qi2 Member),which coincide with the zones shoal cores are developed.Second,the forward modeling shows that the trough energy at the top and bottom of shoal core increases with increasing shoal-core thickness,and weak peak reflections are associated in the middle of shoal core.Third,five types of seismic waveform are identified through waveform analysis of seismic facies.Type-Ⅰ and Type-Ⅱ waveforms correspond to promising facies(shoal core microfacies).Fourth,vertically,two packages of thin dolomite reservoirs turn up in the sedimentary cycle of intraplatform shoal in the Qi2 Member,and the lower package is superior to the upper package in dolomite thickness,scale and lateral connectivity.Fifth,in plane,significantly controlled by sedimentary facies,dolomite reservoirs laterally distribute with consistent thickness in shoal cores at topographical highs and extend toward the break.Sixth,the promising prospects are the zones with thick dolomite reservoirs and superimposition of horstegraben structural traps.

锂电池用固态聚合物电解质的制备

碳酸乙烯亚乙酯(VEC)是液体电解质的重要组成部分。但是,电池过热等因素易导致VEC燃烧。文中将马来酸酐(MA)和VEC共聚得到固体聚(马来酸酐-co-碳酸乙烯亚乙酯)(P(MA-co-VEC)),并以该聚合物为导锂离子体、P(VDF-co-HFP)为成膜助剂、双三氟甲基磺酰亚胺为锂源制备锂电池用电解质膜。表征了聚合物及电解质膜的结构和电化学性能。结果表明,当铸膜液中P(MA-co-VEC)和P(VDF-co-HFP)这2种聚合物质量比为3:7时,聚合物电解质的力学和电化学性能达到最佳,该比例膜吸液率为60%,离子电导率在一定范围随温度升高而增大,室温(25℃)离子电导率为0.634×10^(-4) S/cm,75℃达到9.772×10^(-4) S/cm。组装的锂电池经过100循环,电池容量仍保持在124.8 mAh/g,库仑效率99.0%,在锂电池等新能源领域具有较大的应用前景。

Ada-FFL:Adaptive computing fairness federated learning

As the scale of federated learning expands,solving the Non-IID data problem of federated learning has become a key challenge of interest.Most existing solutions generally aim to solve the overall performance improvement of all clients;however,the overall performance improvement often sacrifices the performance of certain clients,such as clients with less data.Ignoring fairness may greatly reduce the willingness of some clients to participate in federated learning.In order to solve the above problem,the authors propose Ada-FFL,an adaptive fairness federated aggregation learning algorithm,which can dynamically adjust the fairness coefficient according to the update of the local models,ensuring the convergence performance of the global model and the fairness between federated learning clients.By integrating coarse-grained and fine-grained equity solutions,the authors evaluate the deviation of local models by considering both global equity and individual equity,then the weight ratio will be dynamically allocated for each client based on the evaluated deviation value,which can ensure that the update differences of local models are fully considered in each round of training.Finally,by combining a regularisation term to limit the local model update to be closer to the global model,the sensitivity of the model to input perturbations can be reduced,and the generalisation ability of the global model can be improved.Through numerous experiments on several federal data sets,the authors show that our method has more advantages in convergence effect and fairness than the existing baselines.

A Fair and Trusted Trading Scheme for Medical Data Based on Smart Contracts

Data is regarded as a valuable asset,and sharing data is a prerequisite for fully exploiting the value of data.However,the current medical data sharing scheme lacks a fair incentive mechanism,and the authenticity of data cannot be guaranteed,resulting in low enthusiasm of participants.A fair and trusted medical data trading scheme based on smart contracts is proposed,which aims to encourage participants to be honest and improve their enthusiasm for participation.The scheme uses zero-knowledge range proof for trusted verification,verifies the authenticity of the patient’s data and the specific attributes of the data before the transaction,and realizes privacy protection.At the same time,the game pricing strategy selects the best revenue strategy for all parties involved and realizes the fairness and incentive of the transaction price.The smart contract is used to complete the verification and game bargaining process,and the blockchain is used as a distributed ledger to record the medical data transaction process to prevent data tampering and transaction denial.Finally,by deploying smart contracts on the Ethereum test network and conducting experiments and theoretical calculations,it is proved that the transaction scheme achieves trusted verification and fair bargaining while ensuring privacy protection in a decentralized environment.The experimental results show that the model improves the credibility and fairness of medical data transactions,maximizes social benefits,encourages more patients and medical institutions to participate in the circulation of medical data,and more fully taps the potential value of medical data.

Clinical review and literature analysis of hepatic epithelioid angiomyolipoma in alcoholic cirrhosis: A case report

BACKGROUND Hepatic epithelioid angiomyolipoma(HEA)has a low incidence and both clinical manifestations and imaging lack specificity.Thus,it is easy to misdiagnose HEA as other tumors of the liver,especially in the presence of liver diseases such as hepatitis cirrhosis.This article reviewed the diagnosis and treatment of a patient with HEA and alcoholic cirrhosis,and analyzed the literature,in order to improve the understanding of this disease.CASE SUMMARY A 67-year-old male patient with a history of alcoholic cirrhosis was admitted due to the discovery of a space-occupying lesion in the liver.Based on the patient’s history,laboratory examinations,and imaging examinations,a malignant liver tumor was considered and laparoscopic partial hepatectomy was performed.Postoperative pathology showed HEA.During outpatient follow-up,the patient showed no sign of recurrence.CONCLUSION HEA is difficult to make a definite diagnosis before surgery.HEA has the poten-tial for malignant degeneration.If conditions permit,surgical treatment is recom-mended.

Circadian rhythm dysfunction and psychopathology in the offspring of parents with bipolar disorder:a highrisk study in the Chinese population

Background Understanding the evolution of circadian rhythm dysfunction and psychopathology in the high-risk population has important implications for the prevention of bipolar disorder.Nevertheless,some of the previous studies on the emergence of psychopathologies and circadian dysfunction among high-risk populations were inconsistent and limited.Aims To examine the prevalence rates of sleep and circadian dysfunctions,mental disorders and their symptoms in the offspring of parents with(O-BD)and without bipolar disorder(O-control).Methods The study included 191 O-BD and 202 O-control subjects aged 6-21 years from the Greater Bay Area,China.The diagnoses and symptoms of sleep/circadian rhythm and mental disorders were assessed by the Diagnostic Interview for Sleep Patterns and Disorders,and the Schedule for Affective Disorders and Schizophrenia for School-Age Children-Present and Lifetime Version,respectively.Generalised estimating equations and shared frailty proportional hazards models of survival analysis were applied to compare the outcomes in the offspring.Results Adjusting for age,sex and region of recruitment,there was a significantly higher risk of delayed sleep phase symptoms(9.55%vs 2.58%,adjusted OR:4.04)in O-BD than in O-control.O-BD had a nearly fivefold higher risk of mood disorders(11.70%vs 3.47%,adjusted OR:4.68)and social anxiety(6.28%vs 1.49%,adjusted OR:4.70),a fourfold higher risk of depressive disorders(11.17%vs 3.47%,adjusted OR:3.99)and a threefold higher risk of mood symptoms(20.74%vs 10.40%,adjusted OR:2.59)than O-control.Subgroup analysis revealed that O-BD children(aged under 12 years)had a nearly 2-fold higher risk of any mental and behavioural symptoms than O-control,while there was a nearly 4-fold higher risk of delayed sleep phase symptoms,a 7.5-fold higher risk of social anxiety and a 3-fold higher risk of mood symptoms in O-BD adolescents(aged 12 years and over).Conclusions There was an increase in delayed sleep phase symptoms in O-BD adolescents compared with their control counterparts,confirming the central role of circadian rhythm dysfunction in bipolar disorder.The findings of the specific age-related and stage-related developmental patterns of psychopathologies and circadian dysfunction in children and adolescent offspring of parents with bipolar disorder paved the way to develop specific and early clinical intervention and prevention strategies.

Cognitive impairment in patients with bipolar disorder alone versus those with bipolar disorder comorbid with borderline personality disorder

BACKGROUND Bipolar disorder(BD)is a severe mental illness.BD often coexists with borderline personality disorders,making the condition more complex.AIM To explore the differences in cognitive impairment between patients with BD and those with BD comorbid with borderline personality disorder.METHODS Eighty patients with BD and comorbid borderline personality disorder and 80 patients with BD alone were included in groups A and B,respectively,and 80 healthy volunteers were included as controls.Cognitive function in each group was evaluated using the Chinese version of the repeatable battery for the assess-ment of neuropsychological status(RBANS),the Stroop color-word test,and the Wechsler intelligence scale-revised(WAIS-RC).RESULTS The indices of the RBANS,Stroop color-word test,and WAIS-RC in groups A and B were significantly lower than those of the control group(P<0.05).Group A had significantly longer Stroop color-word test times for single-character,single-color,double-character,and double-color,lower scores of immediate memory,visual breadth,verbal function dimensions and total score of the RBANS,as well as lower scores of verbal IQ,performance IQ,and overall IQ of the WAIS-RC compared with group B(P<0.05).Compared to group B,group A exhibited significantly longer single-character time,single-color time,double-character time,and double-color time in the Stroop color-word test(P<0.05).CONCLUSION The cognitive function of patients with BD complicated with borderline personality disorder is lower than that of patients with BD.

Primary hepatic leiomyosarcoma masquerading as liver abscess: A case report

BACKGROUND Primary hepatic leiomyosarcoma(PHL)is a rare malignant tumor and has non-specific clinical manifestations and imaging characteristics,making preoperative diagnosis challenging.Here,we report a case of PHL presenting primarily with fever,with computed tomography imaging showing a thick-walled hepatic lesion with low-density areas,resembling liver abscess.CASE SUMMARY The patient was a 34-year-old woman who presented with right upper abdominal pain and fever over 4 days before admission.Based on the patient’s medical history,laboratory examinations,and imaging examinations,liver abscess was suspected.Mesenchymal tumor was diagnosed by percutaneous liverbiopsy and partial hepatectomy was performed.Postoperative pathology revealed PHL.The patient is currently undergoing intravenous chemotherapy with the AD regimen and shows no signs of recurrence.CONCLUSION When there is a thick wall and rich blood supply in the hepatic lesion with a large proportion of uneven low-density areas,PHL should be considered.

Malignant myopericytoma originating from the colon: A case report

BACKGROUND Myopericytoma is a benign tumor that typically occurs within subcutaneous tissue and most often involves the distal extremities,followed by the proximal extremities,neck,thoracic vertebrae and oral cavity.Complete resection is often curative.Malignant myopericytoma is extremely rare and has a poor prognosis.Here,we report for the first time a case of malignant myopericytoma originating from the colon.CASE SUMMARY A 69-year-old male was admitted to our hospital with right upper quadrant pain for five days.Imaging suggested a liver mass with hemorrhage.A malignant hepatic tumor was the initial diagnosis.Surgical resection was performed after a complete preoperative work up.Initial postoperative pathology suggested that the mass was a malignant myoblastoma unrelated to the liver.Four months after the first surgery,an enhanced computed tomography(CT)scan revealed a recurrence of the tumor.The diagnosis of malignant myopericytoma derived from the colon was confirmed on histopathological examination of the specimen from the second surgery.The patient did not return to the hospital regularly for surveillance.The first postoperative abdominal CT examination six months after the second surgery demonstrated multiple liver metastases.Survival time between the diagnosis of the tumor to death was approximately one year.CONCLUSION Malignant myopericytoma is a rare cancer.Preoperative diagnosis may be difficult.Due to a lack of treatment options,prognosis is poor.

Innovation and Practice of Teaching Methods in Digital and Adaptive Learning:Taking Communication Engineering Major as an Example

This paper proposes teaching reforms in communication engineering majors,emphasizing the implementation of digital and adaptive teaching methodologies,integrating emerging technologies,breaking free from the constraints of traditional education,and fostering high-caliber talents.The reform measures encompass fundamental data collection,recognition of individual characteristics,recommendation of adaptive learning resources,process-oriented teaching management,adaptive student guidance and early warning systems,personalized evaluation,and the construction of an integrated service platform.These measures,when combined,form a comprehensive system that is expected to enhance teaching quality and efficiency,and facilitate student development.

Reform and Practice of the Course“Introduction to Computer Science”in Universities Based on the Cultivation of Computational Thinking and Systematic Abilities

Introduction to Computer Science,as one of the fundamental courses in computer-related majors,plays an important role in the cultivation of computer professionals.However,traditional teaching models and content can no longer fully meet the needs of modern information technology development.In response to these issues,this article introduces the concept of computational creative thinking,optimizes course content,adopts exploratory teaching methods,and innovates course assessment methods,aiming to comprehensively enhance students’computational thinking and innovative abilities.By continuously improving and promoting this teaching model,it will undoubtedly promote computer education in universities to a new level.

Transient neurogenesis in ischemic cortex from Sox2^(+)astrocytes

The adult cortex has long been regarded as non-neurogenic.Whether injury can induce neurogenesis in the adult cortex is still controversial.Here,we report that focal ischemia stimulates a transient wave of local neurogenesis.Using 5′-bromo-2′-deoxyuridine labeling,we demonstrated a rapid generation of doublecortin-positive neuroblasts that died quickly in mouse cerebral cortex following ischemia.Nestin-Cre^(ER)-based cell ablation and fate mapping showed a small contribution of neuroblasts by subventricular zone neural stem cells.Using a mini-photothrombotic ischemia mouse model and retrovirus expressing green fluorescent protein labeling,we observed maturation of locally generated new neurons.Furthermore,fate tracing analyses using PDGFRα-,GFAP-,and Sox2-Cre^(ER) mice showed a transient wave of neuroblast generation in mild ischemic cortex and identified that Sox2-positive astrocytes were the major neurogenic cells in adult cortex.In addition,a similar upregulation of Sox2 and appearance of neuroblasts were observed in the focal ischemic cortex of Macaca mulatta.Our findings demonstrated a transient neurogenic response of Sox2-positive astrocytes in ischemic cortex,which suggests the possibility of inducing neuronal regeneration by amplifying this intrinsic response in the future.

电场对废旧锂离子电池中有价金属浸出的影响

提出一种电场强化浸出工艺,用于提高废旧锂离子电池提取Li、Ni、Co以及Mn过程中的浸出效率。通过产品表征和浸出动力学等手段,对浸出工艺参数进行优化并对浸出机制进行研究。在优化浸出条件下,超过98%Li、97%Ni和Co以及93%Mn被浸出进入到溶液中。浸出动力学研究表明,Li、Ni、Co和Mn的浸出过程由基于核缩减模型的化学反应控制,并确定浸出活化能分别为42.4、46.1、46.2和47.3k J/mol。浸出过程中,施加电场为溶液中Fe^(2+)和Cl^(-)的循环利用提供了便利通道,减少了还原剂的添加量,同时保证了高的金属浸出率。

Estimation of Lightning-Generated NO_(x) in the Mainland of China Based on Cloud-to-Ground Lightning Location Data

Lightning-generated nitrogen oxides(LNO_(x))have a major influence on the atmosphere and global climate change.Therefore,it is of great importance to obtain a more accurate estimation of LNO_(x).The aim of this study is to provide a reference for the accurate estimation of the total LNO_(x) in the mainland of China based on cloud-to-ground lightning(CG)location data from 2014 to 2018.The energy of each CG flash was based on the number of return strokes per CG flash,the peak current of each return stroke,and the assumed CG breakdown voltage.The energy of intracloud lightning(IC)was based on the estimated frequencies of IC and the assumed energy of each IC flash.Combining the energy of lightning and the number of nitric oxide(NO)molecules produced by unit energy(ρno),the total LNO_(x) production in the mainland of China was determined.The LNO_(x) in the mainland of China estimated in this study is in the range(0.157-0.321)×10^(9) kg per year[Tg(N)yr-1],which is on the high end of other scholars’works.Negative cloud-to-ground lightning(NCG)flashes produce the most moles of NO_(x),while positive cloud-to-ground lightning(PCG)flashes produce the least total moles of NO_(x).The breakdown voltage of PCG is greater than that of IC or NCG,while the latter has a greater output of LNO_(x).