Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheime...Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer’s disease.Hence,promoting neuroplasticity may represent an effective strategy with which Alzheimer’s disease can be alleviated.Due to their significant ability to self-renew,differentiate,and migrate,neural stem cells play an essential role in reversing synaptic and neuronal damage,reducing the pathology of Alzheimer’s disease,including amyloid-β,tau protein,and neuroinflammation,and secreting neurotrophic factors and growth factors that are related to plasticity.These events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian brain.Consequently,neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer’s disease and other neurodegenerative diseases.In this review,we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer’s disease in the clinic.展开更多
Handover authentication in high mobility scenarios is characterized by frequent and shortterm parallel execution.Moreover,the penetration loss and Doppler frequency shift caused by high speed also lead to the deterior...Handover authentication in high mobility scenarios is characterized by frequent and shortterm parallel execution.Moreover,the penetration loss and Doppler frequency shift caused by high speed also lead to the deterioration of network link quality.Therefore,high mobility scenarios require handover schemes with less handover overhead.However,some existing schemes that meet this requirement cannot provide strong security guarantees,while some schemes that can provide strong security guarantees have large handover overheads.To solve this dilemma,we propose a privacy-preserving handover authentication scheme that can provide strong security guarantees with less computational cost.Based on Orthogonal Time Frequency Space(OTFS)link and Key Encapsulation Mechanism(KEM),we establish the shared key between protocol entities in the initial authentication phase,thereby reducing the overhead in the handover phase.Our proposed scheme can achieve mutual authentication and key agreement among the user equipment,relay node,and authentication server.We demonstrate that our proposed scheme can achieve user anonymity,unlinkability,perfect forward secrecy,and resistance to various attacks through security analysis including the Tamarin.The performance evaluation results show that our scheme has a small computational cost compared with other schemes and can also provide a strong guarantee of security properties.展开更多
Through caching popular contents at the network edge,wireless edge caching can greatly reduce both the content request latency at mobile devices and the traffic burden at the core network.However,popularity-based cach...Through caching popular contents at the network edge,wireless edge caching can greatly reduce both the content request latency at mobile devices and the traffic burden at the core network.However,popularity-based caching strategies are vulnerable to Cache Pollution Attacks(CPAs)due to the weak security protection at both edge nodes and mobile devices.In CPAs,through initiating a large number of requests for unpopular contents,malicious users can pollute the edge caching space and degrade the caching efficiency.This paper firstly integrates the dynamic nature of content request and mobile devices into the edge caching framework,and introduces an eavesdroppingbased CPA strategy.Then,an edge caching mechanism,which contains a Request Pattern Change-based Cache Pollution Detection(RPC2PD)algorithm and an Attack-aware Cache Defense(ACD)algorithm,is proposed to defend against CPAs.Simulation results show that the proposed mechanism could effectively suppress the effects of CPAs on the caching performance and improve the cache hit ratio.展开更多
This study summarized the main achievements of farmers’training and rural informatization construction in the past few years,and explored the needs of rural informatization in western Liaoning Province.The current st...This study summarized the main achievements of farmers’training and rural informatization construction in the past few years,and explored the needs of rural informatization in western Liaoning Province.The current status of agricultural development in western Liaoning and farmers’needs for education and training and rural education informatization were surveyed.The construction of an education and technical support service platform for scientific and technological farmers in western Liaoning was proposed,aiming to use information technology to train modern professional farmers.Through independent and self-learning education and training methods,it is expected to promote great improvement in the scientific and technological quality and moral level of farmers in western Liaoning and cultivate professional farmers who are educated and understand both agricultural techniques and business management.展开更多
In order to develop the conversion of heavy oil with a high yield of propylene in the catalytic cracking process, ZSM-5 zeolite was modified by tungsten and phosphorus, which was proved to be an effective method. Char...In order to develop the conversion of heavy oil with a high yield of propylene in the catalytic cracking process, ZSM-5 zeolite was modified by tungsten and phosphorus, which was proved to be an effective method. Characterization results show that the improvement of catalytic performance could be correlated to the interaction of phosphorus and tungsten species on ZSM-5. P inhibited the aggregation of tungsten species on ZSM-5 and was conductive to convert the tungsten species with octahedral coordination into tetrahedral coordination. And this ultimately led to that more acid sites were reserved after hydrothermal treatment in the tungsten and phosphorus co-modified ZSM-5 catalyst. Phosphorus species played an important role to restrain the dehydrogenation activity of tungsten. In addition, a model reflecting the interaction between tungsten species and ZSM-5 framework was proposed.展开更多
Objective： Previous studies have investigated the role of cytotoxic T-lymphocyte antigen-4 （CTLA-4） and tumor necrosis factor-alpha （TNF-a） in carcinogenesis of osteosarcoma, but their results were inconsistent. ...Objective： Previous studies have investigated the role of cytotoxic T-lymphocyte antigen-4 （CTLA-4） and tumor necrosis factor-alpha （TNF-a） in carcinogenesis of osteosarcoma, but their results were inconsistent. We aimed to clarify the associations between CTLA-4, TNF-a polymorphism and osteosarcoma risk by using meta-analysis. Methods： We searched relevant studies without language restriction in PubMed, EMbase, Cochrane Library, Google Scholar databases, Chinese National Knowledge Infrastructure （CNKI） and conference literature in humans published prior to March 2013. The strengths of the associations between genetic variants and osteosarcoma risk were estimated by odds ratio （OR） with 95% confidence interval （95% CI）. Results： A total of seven studies with 1,198 osteosarcoma patients and 1,493 controls were selected. Four studies were eligible for CTLA-4 （1,003 osteosarcoma and 1,162 controls）, and three studies for TNF-a （195 osteosarcoma and 331 controls）. Pooled results showed that rs231775 polymorphism of CTLA-4 was associated with osteosarcoma risk （GG vs. AA： OR=1.63, 95% CI=1.24-2.13; GG ＋ GA vs. AA： OR=1.56, 95% CI=1.21-2.01; AA ＋ GA vs. GG： OR=0.83, 95% CI=0.71-0.97; G vs. A： OR=1.21, 95% CI=1.08-1.36）. No significant heterogeneity was observed across the studies. No significant associations were found between rs5742909 polymorphism of CTLA-4 or rs1800629 polymorphism of TNF-a and osteosarcoma risk. Conclusions： These results suggest that the rs231775 polymorphism of CTLA-4 may play an important role in carcinogenesis of osteosarcoma.展开更多
Previous works mainly focused on estimating direct relationship strength in social networks. If two users are not directly connected in a social network, there is no direct relationship. In order to estimate the relat...Previous works mainly focused on estimating direct relationship strength in social networks. If two users are not directly connected in a social network, there is no direct relationship. In order to estimate the relationship strength between two indirectly connected users as well as directly connected users, this paper proposes an estimation method for relationship strength in weighted social network graphs, which is based on the trust propagation strategy and the estimation of direct relationship strength. Our method considers the length of a relationship path, the number of relationship paths and the edge weights (direct relationship strength) along with a relationship path to estimate the strength of indirect relationship. Then it synthesizes the direct and indirect relationship strength to represent the strength of relationship between two users in social net- works. Thus our method can fully estimate the relationship strength between any two users in a social network no matter whether they are directly connected or not.展开更多
In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for gen...In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for general scenario,we propose a new quantum homomorphic signature scheme with repeatable verification by introducing serial verification model and parallel verification model.Serial verification model solves the problem of signature verification by combining key distribution and Bell measurement.Parallel verification model solves the problem of signature duplication by logically treating one particle of an EPR pair as a quantum signature and physically preparing a new EPR pair.These models will be beneficial to the signature verification of general scenarios.Scheme analysis shows that both intermediate verifiers and terminal verifiers can successfully verify signatures in the same operation with fewer resource consumption,and especially the verified signature in entangled states can be used repeatedly.展开更多
Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement dis...Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.展开更多
The catalytic performance of Cs-substituted phosphomolybdic salts was studied for selective oxidation of isobutane. The results of activity tests revealed that 360 °C was the optimal reaction temperature. It was ...The catalytic performance of Cs-substituted phosphomolybdic salts was studied for selective oxidation of isobutane. The results of activity tests revealed that 360 °C was the optimal reaction temperature. It was demonstrated that oxidizing sites not only took dominating part in the activation of isobutane, but also influenced the product distribution. Besides, appropriate Cs addition led to moderate acidity of catalysts, favoring the selectivity to desired products. Furthermore, to obtain partially reduced catalysts, different calcination atmospheres were investigated and certain proportion of Mo^（5＋） produced during calcination was crucial for the redox reaction. The catalyst calcined in N2 showed the highest yield of MAA（7.0%）. Fe-substitution enhanced the activity of catalysts by rapid reoxidation of Mo^（5＋）.展开更多
BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensiv...BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensive methylprednisolone dosing improves neurological recovery in SCI patients. However, it remains uncertain whether high-dose methylprednisolone inhibits bacterial translocation and endotoxin release following acute SCI. OBJECTIVE： To investigate the inhibitory effect of methylprednisolone on bacterial translocation and endotoxin release from the gut in paraplegic rats. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Orthopedic Lab, First Affiliated Hospital, Nanchang University, China, from April to December 2008. MATERIALS： Methylprednisolone （Pfizer, USA）, automatic microbial identification instrument ATB Expression and reagent ID 32 system （BioMerieux, France）, Limulus test kit （ACC, USA）, and optical microscope （Olympus, Japan） were used in this study. METHODS： A paraplegia model was established following SCI in 48 Wistar rats, aged 7 weeks. The rats were equally and randomly assigned to saline and methylprednisolone groups. Immediately post-injury, the methylprednisolone group was administered 30 mg/kg methylprednisolone via caudal intravenous infusion, followed by a 23-hour infusion of 5.4 mg/kg per hour. The saline group received an equal volume of saline as placebo. MAIN OUTCOME MEASURES： At 24 hours, 72 hours, and 1 week after SCI, blood samples were collected for bacterial cultures, and bacteria and endotoxin were identified using ATB Expression and Limulus test kits. In addition, mesenteric lymph node, spleen, and liver samples were collected for bacterial cultures. Histological examinations of mesenteric lymph node, spleen, liver, jejunum, and ileum were performed 1 week post-injury. Locomotor function in the hind limb was evaluated using the Basso, Beattie, and Bresnahan score at pre-injury time point, as well as 24 hours, 72 hours, and 1 week post-injury. RESULTS： Endotoxemia and bacterial growth were identified at 24 hours post-injury in both groups. However, plasma endotoxin levels were significantly decreased in the methylprednisolone group compared with the saline group at 72 hours and 1 week post-injury （P 〈 0.05）. Translocated bacteria mainly comprised Bacillus coli, Enterobacter cloacae, Escherichia coli, Proteus vulgaris, and Enterococcus faecalis following SCI combined with paraplegia. Histological changes were not as severe in the methylprednisolone group compared with the saline group 1 week after injury. Basso, Beattie, and Bresnahan scores were significantly better in the methylprednisolone group compared with the saline group 1 week after injury （P 〈 0.05）. CONCLUSION： High-dose methylprednisolone inhibited bacterial translocation from the gut and endotoxin release in rats with SCI.展开更多
With the rapid development of the genomic sequencing technology,the cost of obtaining personal genomic data and effectively analyzing it has been gradually reduced.The analysis and utilization of genomic dam gradually...With the rapid development of the genomic sequencing technology,the cost of obtaining personal genomic data and effectively analyzing it has been gradually reduced.The analysis and utilization of genomic dam gradually entered the public view,and the leakage of genomic dam privacy has attracted the attention of researchers.The security of genomic data is not only related to the protection of personal privacy,but also related to the biological information security of the country.However,there is still no.effective genomic dam privacy protection scheme using Shangyong Mima(SM)algorithms.In this paper,we analyze the widely used genomic dam file formats and design a large genomic dam files encryption scheme based on the SM algorithms.Firstly,we design a key agreement protocol based on the SM2 asymmetric cryptography and use the SM3 hash function to guarantee the correctness of the key.Secondly,we used the SM4 symmetric cryptography to encrypt the genomic data by optimizing the packet processing of files,and improve the usability by assisting the computing platform with key management.Software implementation demonstrates that the scheme can be applied to securely transmit the genomic data in the network environment and provide an encryption method based on SM algorithms for protecting the privacy of genomic data.展开更多
BACKGROUND： Studies addressing the correlation between prion protein gene codon 129 polymorphism, Alzheimer＇s disease, and cognitive disorders have mainly focused on Caucasians. However, prion protein gene codon 1...BACKGROUND： Studies addressing the correlation between prion protein gene codon 129 polymorphism, Alzheimer＇s disease, and cognitive disorders have mainly focused on Caucasians. However, prion protein gene codon 129 polymorphism is thought to also affect the Chinese Han and Wei populations. OBJECTIVE： To analyze the differences of prion protein gene codon 129 distribution among the elderly Chinese Han, East Asian, and Caucasian populations, and to study the correlation between prion protein gene codon 129 distribution and late-onset Alzheimer＇s disease. DESIGN, TIME AND SETTING： A gene polymorphism analysis was performed in the Institute of Geriatrics, General Hospital of Chinese PLA between January 2006 and January 2007. PARTICIPANTS： A total of 152 elderly Chinese Han people were selected from the Beijing Troop Cadre＇s Sanitarium. Among them, 60 patients with late-onset Alzheimer＇s disease, with a mean age of （82 ± 7） years （range 67-94 years） and disease course of （5.9 ± 4.4） years, comprising 44 males with a mean age of （83 ± 7） years and 16 females with a mean age of （78 ±7） years, were selected for the case group. An additional 92 healthy elderly subjects, with a mean of （76 ± 9） years （range 60-94 years）, comprising 76 males with a mean age of （77 ± 9） years and 16 females with a mean age of （70 ± 8） years, were selected for the control group. There were no significant differences in age and gender between the two groups （P〉 0.05）. METHODS： DNA was extracted from peripheral blood leukocytes using routine phenol/chloroform methodology. Prion protein gene codon 129 potymorphism and ApoE polymorphism were measured using PCR-restriction fragment length polymorphism. The ApoEε allele was considered the standard for analyzing correlations between prion protein gene codon 129 polymorphism and late-onset Alzheimer＇s disease. MAIN OUTCOME MEASURES： Prion protein gene codon 129 distribution; correlation between genotypic frequency and allele frequency of prion protein gene codon 129 with Alzheimer＇s disease; relationship between methionine/methionine genotype of priori protein gene, ApoEε4 allele, gender, and age of Alzheimer＇s disease patients. RESULTS： Methionine/methionine genotypic frequency of prion protein gene codon 129 was 94.08% in the Chinese elderly population, and the methionine/valine genotypic frequency was 5.92%. However, valine/valine homozygotes were not determined. There was no significant difference in prion protein gene codon 129 polymorphism between the Chinese elderly and East Asian populations （P〉 0.05）. However, there was a significant difference between the Chinese elderly and the Caucasian population （P 〈 0.05）. The methionine/methionine genotype for the positive and negative ApoEε4 alleles was a risk factor for increased incidence of Alzheimer＇s disease, but there was no significant difference between the positives and the negatives （odds ratio = 1.33, 95% confidence interval = 0.32-6.49, P〉 0.05）. CONCLUSION： Prion protein gene codon 129 distribution in the Chinese elderly was different from the Caucasian population, which suggested that the methionine/methionine genotype of prion protein gene codon 129 negatively correlated with late-onset Alzheimer＇s disease.展开更多
In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts...In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts the efficiency of quantum communication. Inspired by sharing idea of quantum secret sharing (QSS), which is based on three collaborative nodes with pre-shared GHZ (Greenberger-Horne-Zeilinger) states, we propose a quantum secret broadcast scheme to improve network performance. In a cluster net-work cored on three parties of QSS, three cluster heads with pre-shared GHZ states are senders, while cluster members are receivers. One cluster head encodes secret messages on auxiliary particles by performing certain operations on them with GHZ particles, then three cluster heads measure their own par-ticles and broadcast measurement results honestly. Based on the specific correlation of measurement results and secret messages, all receivers can re-cover the secret messages. Furthermore, to prevent eavesdropping, cluster heads can update an encoding key periodically. Analysis shows the proposed scheme is more efficient than previous schemes in wireless quantum net-works, especially when the number of receivers is larger. Besides, in the proposed scheme, attacks on quantum channel based on GHZ state can be detected, and eavesdroppers cannot recover messages correctly for lack of suitable decoding key.展开更多
Aprotic rechargeable lithium-air batteries(LABs)with an ultrahigh theoretical energy density(3,500 Wh kg^(-1))are known as the‘holy grail’of energy storage systems and could replace Li-ion batteries as the next-gene...Aprotic rechargeable lithium-air batteries(LABs)with an ultrahigh theoretical energy density(3,500 Wh kg^(-1))are known as the‘holy grail’of energy storage systems and could replace Li-ion batteries as the next-generation high-capacity batteries if a practical device could be realized.However,only a few researches focus on the battery performance and reactions in the ambient air environment,which is a major obstacle to promote the practical application of LABs.Here,we have summarized the recent research progress on LABs,especially with respect to the Li metal anodes.The chemical and electrochemical deteriorations of the Li metal anode under the ambient air are discussed in detail,and the parasitic reactions involving the cathode and electrolyte during the charge-discharge processes are included.We also provide stability perspectives on protecting the Li metal anodes and propose design principles for realizing high-performance LABs.展开更多
Aims:Few studies have investigated differences in sequential transarterial chemoembolization(TACE),radiofrequency ablation(RFA),and simultaneous RFA-TACE for the treatment of hepatocellular carcinoma(HCC)using the Mil...Aims:Few studies have investigated differences in sequential transarterial chemoembolization(TACE),radiofrequency ablation(RFA),and simultaneous RFA-TACE for the treatment of hepatocellular carcinoma(HCC)using the Milan criteria.This study explored the differences in safety and prognosis between sequential TACE-RFA and simultaneous RFA-TACE.Methods:This retrospective real-world study included 109 patients with HCC within the Milan criteria who underwent sequential TACE-RFA(n=75)or simultaneous RFA-TACE(n=34)at the Eastern Hepatobiliary Surgery Hospital between January 2017 and 2021.Postoperative complications,length of hospital stay,and long-term prognosis were compared.The median follow-up duration of these patients was 39.1 months.Overall survival(OS)and time to tumor recurrence(TTR)curves were plotted using the Kaplan−Meier method and were compared using the logarithmic rank test.Independent risk factors for OS and tumor recurrence(TR)were analyzed using the Cox risk regression model.Results:Multivariate analysis showed that tumor diameter>3 cm(hazard ratio[HR]:2.201,95%confidence interval[CI]:1.106-4.378,p=0.025;HR:2.236,95%CI:1.271-3.934,p=0.005,respectively)and alphafetoprotein(AFP)>400μg/L(HR:2.362,95%CI:1.195-4.668,p=0.013;HR:1.798,95%CI:1.048-3.086,p=0.033,respectively)were independent risk factors for OS and TTR,whereas the presence of multiple tumors(HR:2.352,95%CI:1.127-4.907,p=0.023)was an independent risk factor for TTR.Simultaneous RFA-TACE did not have an effect on OS or TTR.After propensity score-matched,comparable results were obtained and RFATACE still had no effect on OS or TTR.No significant differences were observed in grade III/IV complications(2/75[2.7%]vs.1/34[2.9%],p=1.000)between the two groups.However,the RFA-TACE group had fewer complications than the TACE-RFA group(24/34[70.6%]vs.66/75[88.0%],p=0.026).The RFA-TACE group had a shorter hospital stay and less total cost during hospitalization compared with the TACE-RFA group(6.0 vs.10.0 days,p<0.001;30,000 vs.35,000 CNY,p<0.001).Conclusions:For HCC within the Milan criteria,there was no significant difference in OS and TTR between RFA-TACE and TACE-RFA.However,RFA-TACE could reduce all-grade complications and shorten the length of hospital stay compared with TACE-RFA.Therefore,simultaneous RFA-TACE may be considered for patients with HCC and good liver function falling within the Milan criteria.展开更多
Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2)...Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2) discharge product reduces the energy efficiency and triggers a series of side reactions that cause the Li-O_(2) batteries to have a limited lifetime.Herein,Co-doped C_(3)N_(4)(Co-C_(3)N_(4))photocatalysts were designed by an in situ thermal evaporation method to take advantage of the photo-assisted charging technology to conquer the shortcomings of Li-O_(2) batteries encountered in the charge process.Different from the commonly used photocatalysts,the Co-C_(3)N_(4) photocatalysts perform well no matter with and without illumination,owing to the Co doping induced conductivity and electrocatalytic ability enhancement.This makes the Co-C_(3)N_(4) reduce the charge and discharge overpotentials and improve the cycling performance of Li-O_(2) batteries(from 20 to 106 cycles)without illumination.While introducing illumination,the performance can be further improved:Charge voltage reduces to 3.3 V,and the energy efficiency increases to 84.84%,indicating that the Co-C_(3)N_(4) could behave as a suitable photocathode for Li-O_(2) batteries.Besides,the low charge voltage and the continuous illumination together weaken the corrosion of the Li anode,making the long-term high-efficiency operation of Li-O_(2) batteries no longer just extravagant hope.展开更多
Aprotic lithium-air batteries(LABs)have been known as the holy grail of energy storage systems due to their extremely high energy density.However,their real-world application is still hindered by the great challenges ...Aprotic lithium-air batteries(LABs)have been known as the holy grail of energy storage systems due to their extremely high energy density.However,their real-world application is still hindered by the great challenges from the Li anode side,like dendrite growth and corrosion reactions,thus a pure oxygen atmosphere is usually adopted to prolong the lifetime of LABs,which is a major obstacle to fully liberate the energy density advantages of LABs.Here,a gel polymer electrolyte has been designed through in-situ polymerization of 1,3-dioxolane(DOL)by utilizing the unique semi-open nature of LABs to protect the Li anode to conquer its shortcomings,enabling the high-performance running of LABs in the ambient air.Unlike common liquid electrolytes,the in-situ formed gel polymer electrolyte could facilitate constructing a gradient SEl film with the gradual decrease of organic components from top to bottom,preventing the Li anode from dendrite growth and air-induced corrosion reactions and thus realizing durable Li repeated plating/stripping(2000h).Benefiting from the anode protection effects of the gradient SEI film,the LABs display a long lifetime of 17o cycles,paving an avenue for practical,long-term,and high-efficiency operation of LABs.展开更多
Typical Internet of Things(IoT)systems are event-driven platforms,in which smart sensing devices sense or subscribe to events(device state changes),and react according to the preconfigured trigger-action logic,as know...Typical Internet of Things(IoT)systems are event-driven platforms,in which smart sensing devices sense or subscribe to events(device state changes),and react according to the preconfigured trigger-action logic,as known as,automation rules.“Events”are essential elements to perform automatic control in an IoT system.However,events are not always trustworthy.Sensing fake event notifications injected by attackers(called event spoofing attack)can trigger sensitive actions through automation rules without involving authorized users.Existing solutions verify events via“event fingerprints”extracted by surrounding sensors.However,if a system has homogeneous sensors that have strong correlations among them,traditional threshold-based methods may cause information redundancy and noise amplification,consequently,decreasing the checking accuracy.Aiming at this,in this paper,we propose“EScope”,an effective event validation approach to check the authenticity of system events based on device state correlation.EScope selects informative and representative sensors using an Neural-Network-based(NN-based)sensor selection component and extracts a verification sensor set for event validation.We evaluate our approach using an existing dataset provided by Peeves.The experiment results demonstrate that EScope achieves an average 67%sensor amount reduction on 22 events compared with the existing work,and increases the event spoofing detection accuracy.展开更多
基金supported by the National Natural Science Foundation of China,No.82074533(to LZ).
文摘Recent studies have demonstrated that neuroplasticity,such as synaptic plasticity and neurogenesis,exists throughout the normal lifespan but declines with age and is significantly impaired in individuals with Alzheimer’s disease.Hence,promoting neuroplasticity may represent an effective strategy with which Alzheimer’s disease can be alleviated.Due to their significant ability to self-renew,differentiate,and migrate,neural stem cells play an essential role in reversing synaptic and neuronal damage,reducing the pathology of Alzheimer’s disease,including amyloid-β,tau protein,and neuroinflammation,and secreting neurotrophic factors and growth factors that are related to plasticity.These events can promote synaptic plasticity and neurogenesis to repair the microenvironment of the mammalian brain.Consequently,neural stem cells are considered to represent a potential regenerative therapy with which to improve Alzheimer’s disease and other neurodegenerative diseases.In this review,we discuss how neural stem cells regulate neuroplasticity and optimize their effects to enhance their potential for treating Alzheimer’s disease in the clinic.
基金supported by Natural Science Foundation of China(No.62002006,U2241213,U21B2021,62172025,61932011,61932014,61972018,61972019,61772538,32071775,91646203)Defense Industrial Technology Development Program(No.JCKY2021211B017)。
文摘Handover authentication in high mobility scenarios is characterized by frequent and shortterm parallel execution.Moreover,the penetration loss and Doppler frequency shift caused by high speed also lead to the deterioration of network link quality.Therefore,high mobility scenarios require handover schemes with less handover overhead.However,some existing schemes that meet this requirement cannot provide strong security guarantees,while some schemes that can provide strong security guarantees have large handover overheads.To solve this dilemma,we propose a privacy-preserving handover authentication scheme that can provide strong security guarantees with less computational cost.Based on Orthogonal Time Frequency Space(OTFS)link and Key Encapsulation Mechanism(KEM),we establish the shared key between protocol entities in the initial authentication phase,thereby reducing the overhead in the handover phase.Our proposed scheme can achieve mutual authentication and key agreement among the user equipment,relay node,and authentication server.We demonstrate that our proposed scheme can achieve user anonymity,unlinkability,perfect forward secrecy,and resistance to various attacks through security analysis including the Tamarin.The performance evaluation results show that our scheme has a small computational cost compared with other schemes and can also provide a strong guarantee of security properties.
文摘Through caching popular contents at the network edge,wireless edge caching can greatly reduce both the content request latency at mobile devices and the traffic burden at the core network.However,popularity-based caching strategies are vulnerable to Cache Pollution Attacks(CPAs)due to the weak security protection at both edge nodes and mobile devices.In CPAs,through initiating a large number of requests for unpopular contents,malicious users can pollute the edge caching space and degrade the caching efficiency.This paper firstly integrates the dynamic nature of content request and mobile devices into the edge caching framework,and introduces an eavesdroppingbased CPA strategy.Then,an edge caching mechanism,which contains a Request Pattern Change-based Cache Pollution Detection(RPC2PD)algorithm and an Attack-aware Cache Defense(ACD)algorithm,is proposed to defend against CPAs.Simulation results show that the proposed mechanism could effectively suppress the effects of CPAs on the caching performance and improve the cache hit ratio.
基金Supported by Special Project for National Educational Information Technology Research"Twelfth Five-Year"Plan 2012"Study on Construction and Application of Education Support Service Platform for Scientific and Technological Farmers in Western Liaoning"(122330890)。
文摘This study summarized the main achievements of farmers’training and rural informatization construction in the past few years,and explored the needs of rural informatization in western Liaoning Province.The current status of agricultural development in western Liaoning and farmers’needs for education and training and rural education informatization were surveyed.The construction of an education and technical support service platform for scientific and technological farmers in western Liaoning was proposed,aiming to use information technology to train modern professional farmers.Through independent and self-learning education and training methods,it is expected to promote great improvement in the scientific and technological quality and moral level of farmers in western Liaoning and cultivate professional farmers who are educated and understand both agricultural techniques and business management.
文摘In order to develop the conversion of heavy oil with a high yield of propylene in the catalytic cracking process, ZSM-5 zeolite was modified by tungsten and phosphorus, which was proved to be an effective method. Characterization results show that the improvement of catalytic performance could be correlated to the interaction of phosphorus and tungsten species on ZSM-5. P inhibited the aggregation of tungsten species on ZSM-5 and was conductive to convert the tungsten species with octahedral coordination into tetrahedral coordination. And this ultimately led to that more acid sites were reserved after hydrothermal treatment in the tungsten and phosphorus co-modified ZSM-5 catalyst. Phosphorus species played an important role to restrain the dehydrogenation activity of tungsten. In addition, a model reflecting the interaction between tungsten species and ZSM-5 framework was proposed.
基金supported by National Natural Science Foundation(No.81260315)Foundation of the Education Department of Guangxi Province,China(No.201010LX375)the Foundation of the Nature Science Fund,Guangxi Province,China(No.2012GXNSFBA053121)
文摘Objective： Previous studies have investigated the role of cytotoxic T-lymphocyte antigen-4 （CTLA-4） and tumor necrosis factor-alpha （TNF-a） in carcinogenesis of osteosarcoma, but their results were inconsistent. We aimed to clarify the associations between CTLA-4, TNF-a polymorphism and osteosarcoma risk by using meta-analysis. Methods： We searched relevant studies without language restriction in PubMed, EMbase, Cochrane Library, Google Scholar databases, Chinese National Knowledge Infrastructure （CNKI） and conference literature in humans published prior to March 2013. The strengths of the associations between genetic variants and osteosarcoma risk were estimated by odds ratio （OR） with 95% confidence interval （95% CI）. Results： A total of seven studies with 1,198 osteosarcoma patients and 1,493 controls were selected. Four studies were eligible for CTLA-4 （1,003 osteosarcoma and 1,162 controls）, and three studies for TNF-a （195 osteosarcoma and 331 controls）. Pooled results showed that rs231775 polymorphism of CTLA-4 was associated with osteosarcoma risk （GG vs. AA： OR=1.63, 95% CI=1.24-2.13; GG ＋ GA vs. AA： OR=1.56, 95% CI=1.21-2.01; AA ＋ GA vs. GG： OR=0.83, 95% CI=0.71-0.97; G vs. A： OR=1.21, 95% CI=1.08-1.36）. No significant heterogeneity was observed across the studies. No significant associations were found between rs5742909 polymorphism of CTLA-4 or rs1800629 polymorphism of TNF-a and osteosarcoma risk. Conclusions： These results suggest that the rs231775 polymorphism of CTLA-4 may play an important role in carcinogenesis of osteosarcoma.
文摘Previous works mainly focused on estimating direct relationship strength in social networks. If two users are not directly connected in a social network, there is no direct relationship. In order to estimate the relationship strength between two indirectly connected users as well as directly connected users, this paper proposes an estimation method for relationship strength in weighted social network graphs, which is based on the trust propagation strategy and the estimation of direct relationship strength. Our method considers the length of a relationship path, the number of relationship paths and the edge weights (direct relationship strength) along with a relationship path to estimate the strength of indirect relationship. Then it synthesizes the direct and indirect relationship strength to represent the strength of relationship between two users in social net- works. Thus our method can fully estimate the relationship strength between any two users in a social network no matter whether they are directly connected or not.
基金This project was supported by the National Natural Science Foundation of China(No.61571024)the National Key Research and Development Program of China(No.2016YFC1000307)for valuable helps.
文摘In January 2015,the first quantum homomorphic signature scheme was proposed creatively.However,only one verifier is allowed to verify a signature once in this scheme.In order to support repeatable verification for general scenario,we propose a new quantum homomorphic signature scheme with repeatable verification by introducing serial verification model and parallel verification model.Serial verification model solves the problem of signature verification by combining key distribution and Bell measurement.Parallel verification model solves the problem of signature duplication by logically treating one particle of an EPR pair as a quantum signature and physically preparing a new EPR pair.These models will be beneficial to the signature verification of general scenarios.Scheme analysis shows that both intermediate verifiers and terminal verifiers can successfully verify signatures in the same operation with fewer resource consumption,and especially the verified signature in entangled states can be used repeatedly.
基金This project is supported by the National Natural Science Foundation of China(No.61571024,No.61971021)Aeronautical Science Foundation of China(No.2018ZC51016)the National Key Research and Development Program of China(No.2016YFC1000307)for valuable helps.
文摘Establishing entanglement is an essential task of quantum communication technology.Beyond entanglement,quantum discord,as a measure of quantum correlation,is a necessary prerequisite to the success of entanglement distribution.To realize efficient quantum communication based on quantum discord,in this paper,we consider the practical advantages of continuous variables and propose a feasible continuous-variable quantum network coding scheme based on quantum discord.By means of entanglement distribution by separable states,it can achieve quantum entanglement distribution from sources to targets in a butterfly network.Compared with the representative discrete-variable quantum network coding schemes,the proposed continuous-variable quantum network coding scheme has a higher probability of entanglement distribution and defends against eavesdropping and forgery attacks.Particularly,the deduced relationship indicates that the increase in entanglement is less than or equal to quantum discord.
基金supported by the National Natural Science Foundation of China(No.U1362201)the National 973 Program of China(No.2012CB215006)
文摘The catalytic performance of Cs-substituted phosphomolybdic salts was studied for selective oxidation of isobutane. The results of activity tests revealed that 360 °C was the optimal reaction temperature. It was demonstrated that oxidizing sites not only took dominating part in the activation of isobutane, but also influenced the product distribution. Besides, appropriate Cs addition led to moderate acidity of catalysts, favoring the selectivity to desired products. Furthermore, to obtain partially reduced catalysts, different calcination atmospheres were investigated and certain proportion of Mo^（5＋） produced during calcination was crucial for the redox reaction. The catalyst calcined in N2 showed the highest yield of MAA（7.0%）. Fe-substitution enhanced the activity of catalysts by rapid reoxidation of Mo^（5＋）.
基金a Grant from the Research Fund of Department of Health of Jiangxi Province,No.20061072
文摘BACKGROUND： Previous studies have shown that autonomic dysfunction results in gastrointestinal motility disorders and ultimately results in bacterial translocation following acute spinal cord injury （SCI）. Intensive methylprednisolone dosing improves neurological recovery in SCI patients. However, it remains uncertain whether high-dose methylprednisolone inhibits bacterial translocation and endotoxin release following acute SCI. OBJECTIVE： To investigate the inhibitory effect of methylprednisolone on bacterial translocation and endotoxin release from the gut in paraplegic rats. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Orthopedic Lab, First Affiliated Hospital, Nanchang University, China, from April to December 2008. MATERIALS： Methylprednisolone （Pfizer, USA）, automatic microbial identification instrument ATB Expression and reagent ID 32 system （BioMerieux, France）, Limulus test kit （ACC, USA）, and optical microscope （Olympus, Japan） were used in this study. METHODS： A paraplegia model was established following SCI in 48 Wistar rats, aged 7 weeks. The rats were equally and randomly assigned to saline and methylprednisolone groups. Immediately post-injury, the methylprednisolone group was administered 30 mg/kg methylprednisolone via caudal intravenous infusion, followed by a 23-hour infusion of 5.4 mg/kg per hour. The saline group received an equal volume of saline as placebo. MAIN OUTCOME MEASURES： At 24 hours, 72 hours, and 1 week after SCI, blood samples were collected for bacterial cultures, and bacteria and endotoxin were identified using ATB Expression and Limulus test kits. In addition, mesenteric lymph node, spleen, and liver samples were collected for bacterial cultures. Histological examinations of mesenteric lymph node, spleen, liver, jejunum, and ileum were performed 1 week post-injury. Locomotor function in the hind limb was evaluated using the Basso, Beattie, and Bresnahan score at pre-injury time point, as well as 24 hours, 72 hours, and 1 week post-injury. RESULTS： Endotoxemia and bacterial growth were identified at 24 hours post-injury in both groups. However, plasma endotoxin levels were significantly decreased in the methylprednisolone group compared with the saline group at 72 hours and 1 week post-injury （P 〈 0.05）. Translocated bacteria mainly comprised Bacillus coli, Enterobacter cloacae, Escherichia coli, Proteus vulgaris, and Enterococcus faecalis following SCI combined with paraplegia. Histological changes were not as severe in the methylprednisolone group compared with the saline group 1 week after injury. Basso, Beattie, and Bresnahan scores were significantly better in the methylprednisolone group compared with the saline group 1 week after injury （P 〈 0.05）. CONCLUSION： High-dose methylprednisolone inhibited bacterial translocation from the gut and endotoxin release in rats with SCI.
基金supported by the National Key Research and Development Program of China(No.2016YFC1000307)the National Natural Science Foundation of China(No.61571024,No.61971021).
文摘With the rapid development of the genomic sequencing technology,the cost of obtaining personal genomic data and effectively analyzing it has been gradually reduced.The analysis and utilization of genomic dam gradually entered the public view,and the leakage of genomic dam privacy has attracted the attention of researchers.The security of genomic data is not only related to the protection of personal privacy,but also related to the biological information security of the country.However,there is still no.effective genomic dam privacy protection scheme using Shangyong Mima(SM)algorithms.In this paper,we analyze the widely used genomic dam file formats and design a large genomic dam files encryption scheme based on the SM algorithms.Firstly,we design a key agreement protocol based on the SM2 asymmetric cryptography and use the SM3 hash function to guarantee the correctness of the key.Secondly,we used the SM4 symmetric cryptography to encrypt the genomic data by optimizing the packet processing of files,and improve the usability by assisting the computing platform with key management.Software implementation demonstrates that the scheme can be applied to securely transmit the genomic data in the network environment and provide an encryption method based on SM algorithms for protecting the privacy of genomic data.
基金the 973 Project of the National Ministry of Science and Technology,No. 2006cb500700
文摘BACKGROUND： Studies addressing the correlation between prion protein gene codon 129 polymorphism, Alzheimer＇s disease, and cognitive disorders have mainly focused on Caucasians. However, prion protein gene codon 129 polymorphism is thought to also affect the Chinese Han and Wei populations. OBJECTIVE： To analyze the differences of prion protein gene codon 129 distribution among the elderly Chinese Han, East Asian, and Caucasian populations, and to study the correlation between prion protein gene codon 129 distribution and late-onset Alzheimer＇s disease. DESIGN, TIME AND SETTING： A gene polymorphism analysis was performed in the Institute of Geriatrics, General Hospital of Chinese PLA between January 2006 and January 2007. PARTICIPANTS： A total of 152 elderly Chinese Han people were selected from the Beijing Troop Cadre＇s Sanitarium. Among them, 60 patients with late-onset Alzheimer＇s disease, with a mean age of （82 ± 7） years （range 67-94 years） and disease course of （5.9 ± 4.4） years, comprising 44 males with a mean age of （83 ± 7） years and 16 females with a mean age of （78 ±7） years, were selected for the case group. An additional 92 healthy elderly subjects, with a mean of （76 ± 9） years （range 60-94 years）, comprising 76 males with a mean age of （77 ± 9） years and 16 females with a mean age of （70 ± 8） years, were selected for the control group. There were no significant differences in age and gender between the two groups （P〉 0.05）. METHODS： DNA was extracted from peripheral blood leukocytes using routine phenol/chloroform methodology. Prion protein gene codon 129 potymorphism and ApoE polymorphism were measured using PCR-restriction fragment length polymorphism. The ApoEε allele was considered the standard for analyzing correlations between prion protein gene codon 129 polymorphism and late-onset Alzheimer＇s disease. MAIN OUTCOME MEASURES： Prion protein gene codon 129 distribution; correlation between genotypic frequency and allele frequency of prion protein gene codon 129 with Alzheimer＇s disease; relationship between methionine/methionine genotype of priori protein gene, ApoEε4 allele, gender, and age of Alzheimer＇s disease patients. RESULTS： Methionine/methionine genotypic frequency of prion protein gene codon 129 was 94.08% in the Chinese elderly population, and the methionine/valine genotypic frequency was 5.92%. However, valine/valine homozygotes were not determined. There was no significant difference in prion protein gene codon 129 polymorphism between the Chinese elderly and East Asian populations （P〉 0.05）. However, there was a significant difference between the Chinese elderly and the Caucasian population （P 〈 0.05）. The methionine/methionine genotype for the positive and negative ApoEε4 alleles was a risk factor for increased incidence of Alzheimer＇s disease, but there was no significant difference between the positives and the negatives （odds ratio = 1.33, 95% confidence interval = 0.32-6.49, P〉 0.05）. CONCLUSION： Prion protein gene codon 129 distribution in the Chinese elderly was different from the Caucasian population, which suggested that the methionine/methionine genotype of prion protein gene codon 129 negatively correlated with late-onset Alzheimer＇s disease.
文摘In wireless quantum networks, nodes communicate by means of pre-distribution for entangled pairs and relay path establishment for quantum teleportation. However, simple point-to-point communication seriously restricts the efficiency of quantum communication. Inspired by sharing idea of quantum secret sharing (QSS), which is based on three collaborative nodes with pre-shared GHZ (Greenberger-Horne-Zeilinger) states, we propose a quantum secret broadcast scheme to improve network performance. In a cluster net-work cored on three parties of QSS, three cluster heads with pre-shared GHZ states are senders, while cluster members are receivers. One cluster head encodes secret messages on auxiliary particles by performing certain operations on them with GHZ particles, then three cluster heads measure their own par-ticles and broadcast measurement results honestly. Based on the specific correlation of measurement results and secret messages, all receivers can re-cover the secret messages. Furthermore, to prevent eavesdropping, cluster heads can update an encoding key periodically. Analysis shows the proposed scheme is more efficient than previous schemes in wireless quantum net-works, especially when the number of receivers is larger. Besides, in the proposed scheme, attacks on quantum channel based on GHZ state can be detected, and eavesdroppers cannot recover messages correctly for lack of suitable decoding key.
基金financially supported by the National Key R&D Program of China(2020YFE0204500)the National Natural Science Foundation of China(52071311,52271140)+2 种基金Jilin Province Science and Technology Development Plan Funding Project(20220201112GX)Changchun Science and Technology Development Plan Funding Project(21ZY06)Youth Innovation Promotion Association CAS(2020230,2021223)。
文摘Aprotic rechargeable lithium-air batteries(LABs)with an ultrahigh theoretical energy density(3,500 Wh kg^(-1))are known as the‘holy grail’of energy storage systems and could replace Li-ion batteries as the next-generation high-capacity batteries if a practical device could be realized.However,only a few researches focus on the battery performance and reactions in the ambient air environment,which is a major obstacle to promote the practical application of LABs.Here,we have summarized the recent research progress on LABs,especially with respect to the Li metal anodes.The chemical and electrochemical deteriorations of the Li metal anode under the ambient air are discussed in detail,and the parasitic reactions involving the cathode and electrolyte during the charge-discharge processes are included.We also provide stability perspectives on protecting the Li metal anodes and propose design principles for realizing high-performance LABs.
基金The State Key Project on Infectious Diseases of China,Grant/Award Number:2018ZX10723204-001The Joint Tackling Project of Emerging Frontier Technologies in Shanghai Hospitals in 2017,Grant/Award Number:SHDC12017122+3 种基金The Clinical Research Plan for SHDC,Grant/Award Number:SHDC2020CR2038BThe Explorer Program of Shanghai Scientific and Technological Committee,Grant/Award Number:21TS1400500The Scientific Research Project of Shanghai Municipal Health Commission,Grant/Award Number:20234Y0151The Program of Science and Technology Commission of Shanghai Municipality,Grant/Award Number:21Y11912700。
文摘Aims:Few studies have investigated differences in sequential transarterial chemoembolization(TACE),radiofrequency ablation(RFA),and simultaneous RFA-TACE for the treatment of hepatocellular carcinoma(HCC)using the Milan criteria.This study explored the differences in safety and prognosis between sequential TACE-RFA and simultaneous RFA-TACE.Methods:This retrospective real-world study included 109 patients with HCC within the Milan criteria who underwent sequential TACE-RFA(n=75)or simultaneous RFA-TACE(n=34)at the Eastern Hepatobiliary Surgery Hospital between January 2017 and 2021.Postoperative complications,length of hospital stay,and long-term prognosis were compared.The median follow-up duration of these patients was 39.1 months.Overall survival(OS)and time to tumor recurrence(TTR)curves were plotted using the Kaplan−Meier method and were compared using the logarithmic rank test.Independent risk factors for OS and tumor recurrence(TR)were analyzed using the Cox risk regression model.Results:Multivariate analysis showed that tumor diameter>3 cm(hazard ratio[HR]:2.201,95%confidence interval[CI]:1.106-4.378,p=0.025;HR:2.236,95%CI:1.271-3.934,p=0.005,respectively)and alphafetoprotein(AFP)>400μg/L(HR:2.362,95%CI:1.195-4.668,p=0.013;HR:1.798,95%CI:1.048-3.086,p=0.033,respectively)were independent risk factors for OS and TTR,whereas the presence of multiple tumors(HR:2.352,95%CI:1.127-4.907,p=0.023)was an independent risk factor for TTR.Simultaneous RFA-TACE did not have an effect on OS or TTR.After propensity score-matched,comparable results were obtained and RFATACE still had no effect on OS or TTR.No significant differences were observed in grade III/IV complications(2/75[2.7%]vs.1/34[2.9%],p=1.000)between the two groups.However,the RFA-TACE group had fewer complications than the TACE-RFA group(24/34[70.6%]vs.66/75[88.0%],p=0.026).The RFA-TACE group had a shorter hospital stay and less total cost during hospitalization compared with the TACE-RFA group(6.0 vs.10.0 days,p<0.001;30,000 vs.35,000 CNY,p<0.001).Conclusions:For HCC within the Milan criteria,there was no significant difference in OS and TTR between RFA-TACE and TACE-RFA.However,RFA-TACE could reduce all-grade complications and shorten the length of hospital stay compared with TACE-RFA.Therefore,simultaneous RFA-TACE may be considered for patients with HCC and good liver function falling within the Milan criteria.
基金the National Key Research and Development(R&D)Program of China(No.2017YFE0198100)the National Natural Science Foundation of China(No.21725103)+2 种基金Key Research Program of the Chinese Academy of Sciences(No.ZDRW-CN-2021-3)Youth Innovation Promotion Association of Chinese Academy of Sciences(No.2020230)Changchun Science and Technology Development Plan Funding Project(No.21ZY06).
文摘Li-O_(2) batteries with extremely high specific energy density have been regarded as a kind of promising successor to current Li-ion batteries.However,the high charge overpotential for the decomposition of Li_(2)O_(2) discharge product reduces the energy efficiency and triggers a series of side reactions that cause the Li-O_(2) batteries to have a limited lifetime.Herein,Co-doped C_(3)N_(4)(Co-C_(3)N_(4))photocatalysts were designed by an in situ thermal evaporation method to take advantage of the photo-assisted charging technology to conquer the shortcomings of Li-O_(2) batteries encountered in the charge process.Different from the commonly used photocatalysts,the Co-C_(3)N_(4) photocatalysts perform well no matter with and without illumination,owing to the Co doping induced conductivity and electrocatalytic ability enhancement.This makes the Co-C_(3)N_(4) reduce the charge and discharge overpotentials and improve the cycling performance of Li-O_(2) batteries(from 20 to 106 cycles)without illumination.While introducing illumination,the performance can be further improved:Charge voltage reduces to 3.3 V,and the energy efficiency increases to 84.84%,indicating that the Co-C_(3)N_(4) could behave as a suitable photocathode for Li-O_(2) batteries.Besides,the low charge voltage and the continuous illumination together weaken the corrosion of the Li anode,making the long-term high-efficiency operation of Li-O_(2) batteries no longer just extravagant hope.
基金supports from the National Key R&D Program of China(Nos.2020YFE0204500 and 2021YFF0500600)National Natural Science Foundation of China(Nos.52171194 and 52271140)+2 种基金CAS Project for Young Scientists in Basic Research(No.YSBR-058)Youth Innovation Promotion Association of Chinese Academy of Sciences(Nos.2020230 and 2021223)Changchun Science and Technology Development Plan Funding Project(No.21ZY06).
文摘Aprotic lithium-air batteries(LABs)have been known as the holy grail of energy storage systems due to their extremely high energy density.However,their real-world application is still hindered by the great challenges from the Li anode side,like dendrite growth and corrosion reactions,thus a pure oxygen atmosphere is usually adopted to prolong the lifetime of LABs,which is a major obstacle to fully liberate the energy density advantages of LABs.Here,a gel polymer electrolyte has been designed through in-situ polymerization of 1,3-dioxolane(DOL)by utilizing the unique semi-open nature of LABs to protect the Li anode to conquer its shortcomings,enabling the high-performance running of LABs in the ambient air.Unlike common liquid electrolytes,the in-situ formed gel polymer electrolyte could facilitate constructing a gradient SEl film with the gradual decrease of organic components from top to bottom,preventing the Li anode from dendrite growth and air-induced corrosion reactions and thus realizing durable Li repeated plating/stripping(2000h).Benefiting from the anode protection effects of the gradient SEI film,the LABs display a long lifetime of 17o cycles,paving an avenue for practical,long-term,and high-efficiency operation of LABs.
基金supported in part by the National Natural Science Foundation of China(Nos.62172027,U1733115,and 61871023)the Beijing Natural Science Foundation(No.4202036)the National Key R&D Program of China(No.2020YFB1005601).
文摘Typical Internet of Things(IoT)systems are event-driven platforms,in which smart sensing devices sense or subscribe to events(device state changes),and react according to the preconfigured trigger-action logic,as known as,automation rules.“Events”are essential elements to perform automatic control in an IoT system.However,events are not always trustworthy.Sensing fake event notifications injected by attackers(called event spoofing attack)can trigger sensitive actions through automation rules without involving authorized users.Existing solutions verify events via“event fingerprints”extracted by surrounding sensors.However,if a system has homogeneous sensors that have strong correlations among them,traditional threshold-based methods may cause information redundancy and noise amplification,consequently,decreasing the checking accuracy.Aiming at this,in this paper,we propose“EScope”,an effective event validation approach to check the authenticity of system events based on device state correlation.EScope selects informative and representative sensors using an Neural-Network-based(NN-based)sensor selection component and extracts a verification sensor set for event validation.We evaluate our approach using an existing dataset provided by Peeves.The experiment results demonstrate that EScope achieves an average 67%sensor amount reduction on 22 events compared with the existing work,and increases the event spoofing detection accuracy.
