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Abstract In this paper, we introduce a new method to solve the low-entropy problem in a quasi-static environment. We utilize a simultaneous transmission and reflection reconfigurable intelligent surface (STAR-RIS) that transmits and reflects incoming signals to users located on different sides of the surface. Specifically, we design the flow of multi-user channel probing when STAR-RIS is assisted, analyze and derive the analytical expression of the secret key capacity (SKC) of STAR-RIS-assisted system from the perspective of information theory, and finally analyze how to maximize the SKC and sum of all users under three different working protocols of STAR-RIS. The simulation results show that: (1) STAR-RIS can achieve better SKC performance than the conventional reflection/transmission RIS; and (2) the SKC is determined by the number of STAR-RIS elements, correlation coefficient, pilot length and RIS-reflected channel quality, and the time switching protocol can obtain higher SKC than the energy splitting protocol and mode switching protocol.

Abstract Physical layer key generation (PLKG) is a technique of information-theoretic security to tackle the problem of key distribution between resource-constrained legitimate users and is a promising candidate for the one time pad (OTP) technique. However, in quasi-static, the key rate is greatly limited due to low entropy. Reconfigurable intelligent surface (RIS) is introduced to adaptively reconfigure the radio environment. However, how to allocate time slots in the OTP to counter the increasingly powerful adversary model is an urgent problem to be solved. In this paper, we propose a very powerful adversary model and give an attack strategy called eavesdropping channel search, which allows Eve to use its search and eavesdropping capabilities to maximize the probability of successful attacks. Meanwhile, we propose a time slot allocation algorithm in the OTP to ensure the security of the key. Simulations validate that our proposed attack strategy is more powerful than any existing adversary model and our proposed time slot allocation algorithm does not have any security loss.

Abstract Electrochemical-mechanical coupling poses enormous challenges to the interfacial and structural stability but create new opportunities to design innovative all-solid-state batteries from scratch. Relying on the solid-solid constraint in the space-limited domain structure, we propose to exploit the lithiation-induced stress to drive the active materials creep, thereby improving the structural integrity. For demonstration, we fabricate the creep-type all-solid-state cathode using creepable Se material and an all-in-one rigid ionic/electronic conducting Mo6Se8 framework. As indicated by the in-situ experiment and numerical simulation, this cathode presents unique capabilities in improving interparticle contact and avoiding particle fracture, leading to its superior electrochemical performance, including a superior long-cycle life of more than 3000 cycles at 0.5 C and a high volumetric energy density of 2460 Wh/L at the cathode level. We believe this innovative strategy to utilize mechanics to boost the electrochemical performance could shed light on the future design of all-solid-state batteries for practical applications.

BackgroundThe gut microbiota plays a vital role in the development of sepsis and in protecting against pneumonia. Previous studies have demonstrated the existence of the gut-lung axis and the interaction between the gut and the lung, which is related to the prognosis of critically ill patients; however, most of these studies focused on chronic lung diseases and influenza virus infections. The purpose of this study was to investigate the effect of faecal microbiota transplantation (FMT) on Klebsiella pneumoniae-related pulmonary infection via the gut-lung axis and to compare the effects of FMT with those of traditional antibiotics to identify new therapeutic strategies.MethodsWe divided the mice into six groups: the blank control (PBS), pneumonia-derived sepsis (KP), pneumonia-derived sepsis + antibiotic (KP + PIP), pneumonia-derived sepsis + faecal microbiota transplantation(KP + FMT), antibiotic treatment control (KP+PIP+PBS), and pneumonia-derived sepsis+ antibiotic + faecal microbiota transplantation (KP + PIP + FMT) groups to compare the survival of mice, lung injury, inflammation response, airway barrier function and the intestinal flora, metabolites and drug resistance genes in each group.ResultsAlterations in specific intestinal flora can occur in the gut of patients with pneumonia-derived sepsis caused by Klebsiella pneumoniae. Compared with those in the faecal microbiota transplantation group, the antibiotic treatment group had lower levels of proinflammatory factors and higher levels of anti-inflammatory factors but less amelioration of lung pathology and improvement of airway epithelial barrier function. Additionally, the increase in opportunistic pathogens and drug resistance-related genes in the gut of mice was accompanied by decreased production of favourable fatty acids such as acetic acid, propionic acid, butyric acid, decanoic acid, and secondary bile acids such as chenodeoxycholic acid 3-sulfate, isodeoxycholic acid, taurodeoxycholic acid, and 3-dehydrocholic acid; the levels of these metabolites were restored by faecal microbiota transplantation. Faecal microbiota transplantation after antibiotic treatment can gradually ameliorate gut microbiota disorder caused by antibiotic treatment and reduce the number of drug resistance genes induced by antibiotics.ConclusionIn contrast to direct antibiotic treatment, faecal microbiota transplantation improves the prognosis of mice with pneumonia-derived sepsis caused by Klebsiella pneumoniae by improving the structure of the intestinal flora and increasing the level of beneficial metabolites, fatty acids and secondary bile acids, thereby reducing systemic inflammation, repairing the barrier function of alveolar epithelial cells, and alleviating pathological damage to the lungs. The combination of antibiotics with faecal microbiota transplantation significantly alleviates intestinal microbiota disorder, reduces the selection for drug resistance genes caused by antibiotics, and mitigates lung lesions; these effects are superior to those following antibiotic monotherapy.

In recent years, the widespread application of internet of vehicles technology has garnered attention due to its complex nature and point-to-point communication characteristics.Critical and sensitive vehicle information is transmitted between different devices in internet of vehicles, necessitating the establishment of secure and reliable lightweight keys for encryption and decryption purposes in order to ensure communication security.Traditional key generation schemes have limitations in terms of flexibility and expandability within the vehicle network.A popular alternative is the physical layer key generation technology based on wireless channels, which offers lightweight characteristics and a theoretical basis of security in information theory.However, in the context of internet of vehicles, the movement speed of devices impacts the autocorrelation of generated keys, requiring improvements to traditional channel modeling methods.Additionally, the randomness and consistency of generated wireless keys are of higher importance in applications in internet of vehicles.This research focused on a key generation system based on the wireless physical layer, conducting channel modeling based on line-of-sight and multipath fading effects to reflect the impact of vehicle speed on autocorrelation.To enhance the randomness of key generation, a differential quantization method based on cumulative distribution function was proposed.Furthermore, an information reconciliation scheme based on neural network auto-encoder was introduced to achieve a dynamic balance between reliability and confidentiality.Compared to the implementation of Slepian-Wolf low-density parity-check codes, the proposed method reduces the bit disagreement rate by approximately 30%.

Redox of the transition metals is definitely the most important way of charge compensation in the conventional electrode materials. Utilization of oxygen redox (or more popularly the anionic redox) is another effective strategy to capture extra capacities in the oxide cathode materials (OCMs). Oxygen redox has been realized in oxides with diversified structures in addition to the conventional Li-rich Mn-rich layered oxide (LMR) cathode materials. However, a unified theory is still lacking about the oxygen redox mechanism in these materials. Moreover, the oxygen redox is often accompanied with undesired structural and performance degradations, which turn to hinder the application of the conventional materials at high potentials and the development of novel oxygen-redox based cathode materials. Considering that oxygen constructs the framework of OCMs and its electronic structure has a strong impact on the electrochemical performance of OCMs, it is necessary to summarize the correlation between oxygen redox and the structure of the oxides. This review recalls the recent advances in oxygen redox in different oxide materials, its impacts on the structural transformation, and strategies to suppress or promote the oxygen redox. On the basis of these, a perspective on enhancing the structural stability and performance of the oxygen-redox OCMs is proposed.

Abstract As one of the most promising alternatives to graphite negative electrodes, silicon oxide (SiO x ) has been hindered by its fast capacity fading. Solid electrolyte interphase (SEI) aging on silicon SiO x has been recognized as the most critical yet least understood facet. Herein, leveraging 3D focused ion beam-scanning electron microscopy (FIB-SEM) tomographic imaging, we reveal an exceptionally characteristic SEI microstructure with an incompact inner region and a dense outer region, which overturns the prevailing belief that SEIs are homogeneous structure and reveals the SEI evolution process. Through combining nanoprobe and electron energy loss spectroscopy (EELS), it is also discovered that the electronic conductivity of thick SEI relies on the percolation network within composed of conductive agents (e.g., carbon black particles), which are embedded into the SEI upon its growth. Therefore, the free growth of SEI will gradually attenuate this electron percolation network, thereby causing capacity decay of SiO x . Based on these findings, a proof-of-concept strategy is adopted to mechanically restrict the SEI growth via applying a confining layer on top of the electrode. Through shedding light on the fundamental understanding of SEI aging for SiO x anodes, this work could potentially inspire viable improving strategies in the future.

Highlights The microstructure of graphite upon rapid Li+ intercalation is a mixture of differently staging structures in the macroscopic and microscopic scales due to the incomplete and inhomogeneous intercalation reactions hindered by the sluggish reaction kinetics. The Li+ interface diffusion dominates the reaction kinetics at high rates in thin graphite electrode, while Li+ diffusion through the electrode cannot to be neglected for thick graphite electrode.

Abstract High-performance Li-ion/metal batteries working at a low temperature (i.e.,

Abstract Inorganic sulfide solid-state electrolytes, especially Li6PS5X (X = Cl, Br, I), are considered viable materials for developing all-solid-state batteries because of their high ionic conductivity and low cost. However, this class of solid-state electrolytes suffers from structural and chemical instability in humid air environments and a lack of compatibility with layered oxide positive electrode active materials. To circumvent these issues, here, we propose Li6+xMxAs1-xS5I (M=Si, Sn) as sulfide solid electrolytes. When the Li6+xSixAs1-xS5I (x = 0.8) is tested in combination with a Li-In negative electrode and Ti2S-based positive electrode at 30 °C and 30 MPa, the Li-ion lab-scale Swagelok cells demonstrate long cycle life of almost 62500 cycles at 2.44 mA cm−2, decent power performance (up to 24.45 mA cm−2) and areal capacity of 9.26 mAh cm−2 at 0.53 mA cm−2.

In recent years, widely used hash algorithms such as MD5 and SHA-1 have been found to have varying degrees of security risks.The iterative structure of the SHA-2 algorithm is similar to that of SHA-1, making it vulnerable to attacks as well.Meanwhile, SHA-3 has a complex internal structure and low implementation efficiency.To address these issues, a keyed hash function was designed and implemented based on chaotic neural network and C-MD structure.The approach involved improving the Merkle-Damgard structure by proposing the chaotic neural network Merkle-Damgard (C-MD) structure.This structure can be used to design a hash function that can withstand attacks such as the middle attack, multiple collision attack, and second pre-image attack for long information.Besides, the chaotic neural network was used as the compression function to increase the complexity of the hash function and improve its collision resistance, while also enabling it to output multiple lengths.Moreover, a plaintext preprocessor was designed, which used the coupled image lattice to generate chaos sequence related to the length of the plaintext to fill the plaintext, thus enhancing the ability of the hash function to resist length expansion attacks.Simulation results demonstrate that the proposed hash function performs faster than SHA-2, SHA-3 and the same type of chaotic hash function proposed by Teh et al.It can resist second pre-image attack, multi-collision attack and differential attack, while also exhibiting better collision resistance and mapping uniformity.In addition, the proposed Hash function can output Hash values of different lengths, making it suitable for use in digital signature, key generation, Hash-based message authentication code, deterministic random bit generator, and other application fields.

The anionic redox reaction (ARR) is a promising charge contributor to improve the reversible capacity of layered-oxide cathodes for Na-ion batteries; however, some practical bottlenecks still need to be eliminated, including a low capacity retention, large voltage hysteresis, and low rate capability. Herein, we proposed a high-Na content honeycomb-ordered cathode, P2–Na5/6[Li1/6Cu1/6Mn2/3]O2 (P2-NLCMO), with combined cationic/anionic redox. Neutron powder diffraction and X-ray diffraction of P2-NLCMO suggested P2-type stacking with rarely found P6322 symmetry. In addition, advanced spectroscopy techniques and density functional theory calculations confirmed the synergistic stabilizing relationship between the Li/Cu dual honeycomb centers, achieving fully active Cu3+/Cu2+ redox and stabilized ARR with interactively suppressed local distortion. With a meticulously regulated charge/discharge protocol, both the cycling and rate capability of P2-NLCMO were significantly improved, demonstrating reasonable capacity and eliminating voltage hysteresis. Overall, this work contributes a well-defined layered oxide cathode with combined cationic/anionic redox towards rational designing advanced Na-ion batteries.

The implementation of Li metal anode with high-voltage Ni/Co rich cathode is plagued by low coulombic efficiency and inferior cycling stability. Here authors propose an anion-enriched interface to facilitate the columnar-structure of Li deposits to solve this issue.

The development of Li2S-P2S5 glass ceramics is greatly hampered by the low room temperature lithium conductivity. Here, the authors propose a nanocrystallization strategy to fabricate super lithium conductive glass ceramics.

Cloud storage has the advantages of high efficiency and scalability.Users can save local storage cost and share data with others through cloud storage technology.However, when data is uploaded to cloud servers, its owner also loses the physical control, and hence there needs a corresponding mechanism to ensure the integrity of data stored in the cloud.The Provable Data Possession (PDP) mechanism allows users or a Third-Party Auditor (TPA) appointed by the user to verify data integrity.In practice, data is usually maintained by multiple users.Users may reveal their identities while making an integrity verification request in traditional auditing processes.Anonymous cloud auditing ensures anonymity of users against the TPA during auditing.Currently, in identity-based systems, anonymous cloud auditing schemes usually resort to identity-based ring signature or group signature schemes.As a result, the size of a tag is related to the number of users, which makes it not compact and causes high storage cost.In order to solve this issue, a general construction of identity-based anonymous cloud auditing scheme was proposed.With a signature scheme and an anonymous cloud auditing scheme, a concrete identity-based anonymous cloud auditing scheme based on the general construction was proposed.It combined theBLS signature and an anonymous cloud auditing scheme with compact tags.The main advantage of this solution is that the tags are compact, which can significantly reduce storage cost and improve storage efficiency.Furthermore, the uncheatability and anonymity of the scheme are proved.

Abstract Background Vaginally assisted laparoscopic sacrocolpopexy (VALS) refers to the placement of synthetic meshes through the vagina in addition to traditional laparoscopic sacrocolpopexy. In this study, we aimed to investigate the medium- to long-term efficacy and safety of VALS for treating stage III–IV pelvic organ prolapse (POP). Methods The study was designed as a case series at a single center. Patients with stage III–IV POP in our hospital from January 2010 to December 2018 were included. Perioperative parameters, objective and subjective outcomes, and complications were assessed. Results A total of 106 patients completed the follow-up and were included in our study. Within a median follow-up duration of 35.4 months, the objective cure ratio of VALS reached 92.45% (98/106), and the subjective success rate was 99.06% (105/106). Patients reported significant improvements in subjective symptoms. In eight patients suffering anatomic prolapse recurrence, two posterior POP cases were treated by posterior pelvic reconstruction surgery, while six anterior POP cases did not need surgical therapies. The reoperation rate was 1.89% (2/106). No intraoperative complications occurred. Three patients (2.83%) had postoperative fever, and one (0.94%) had wound infection during hospitalization. Six patients (5.66%) had mesh exposure on the vaginal wall, and de novo urinary incontinence occurred in two patients (1.89%) during the follow-up period. Conclusion VALS is an effective and safe surgical method for treating severe POP. Therefore, VALS should be considered in the treatment of severe POP due to its favorable subjective and objective outcomes, relatively low rate of infection and acceptable rate of mesh exposure.

With the development of quantum computers, the classical public key encryption system is not capable enough to guarantee the communication security of internet of things (IoT).Because the mathematical puzzles which post-quantum encryption algorithms are based on cannot yet be broken by quantum computers, these new algorithms have good anti-quantum computing security.In particular, the lattice-based cryptography is expected to become the main technology of the next generation public key cryptosystem.However, post-quantum encryption algorithms have the disadvantages of large amount of computation and high storage space.The communication efficiency of IoT will be affected if post-quantum encryption algorithms are directly applied to the lightweight device under IoT environment.In order to better guarantee the communication security and improve the commutation efficiency of IoT, Sym-BRLWE (symmetrical binary RLWE) encryption scheme was proposed.Sym-BRLWE was improved from the existing post-quantum encryption scheme based on BRLWE (binary ringlearning with errors) problem.Specifically, Sym-BRLWE encryption algorithm met the efficiency requirements of IoT via improving the random number selection on the discrete uniform distribution and the calculation of the polynomial multiplication.Sym-BRLWE encryption algorithm achieved high efficiency and high security via adding encryption security precautions, then it is more suitable for IoT lightweight devices.From the security analysis, the proposed Sym-BRLWE encryption scheme had high security.It could theoretically resist lattice attacks, timing attacks, simple power analysis (SPA) and differential power analysis (DPA).From simulation experiments, which were carried out in a binary computing environment simulating an 8-bit micro-device, the proposed Sym-BRLWE encryption scheme has high efficiency and small key size in encryption and decryption.It could reduce the total encryption time by 30% to 40% when compared with other BRLWE-based encryption schemes with the parameter selection of the 140 bit quantum security level.

Sulfide-based all-solid-state lithium-ion batteries (ASSLIBs) are one of the most promising energy storage technologies due to their high safety and ionic conductivity. To achieve greater energy density, a Ni-rich layered oxide LiNixCoyM1-x-yO2 (NCM, M ​= ​Mn/Al, x ​≥ ​0.6) is desirable due to its relatively high voltage and large capacity. However, interfacial side reactions between the NCM and sulfide solid electrolytes lead to undesirable interfacial passivation layers and low ionic conductivity, thereby degrading the electrochemical performance of NCM sulfide all-solid-state batteries. Herein, a time-/cost-effective sulfidation strategy is exploited to sulfidize a Ni-rich NCM88 cathode in a mixed gas atmosphere of N2 and CS2. A new type of cathode (NCM88-S) with an ultrathin (∼2 ​nm) surface layer is obtained, which significantly reduces the interfacial side reactions/resistance and improves the interfacial stability. The resulting NCM88-S/Li6PS5Cl/Li4Ti5O12 ASSLIB exhibits superior performance, including a high discharge specific capacity (200.7 mAh g−1) close to that of liquid batteries, excellent cycling performance (a capacity retention of 87% after 500 cycles), and satisfactory rate performance (158.3 mAh g−1 at 1C).

The public key infrastructure (PKI), as an significant component of the current Internet security infrastructure, guarantees the information transmission with the necessary authenticity, integrity, confidentiality and non-repudiation.However, the existing PKI also has shortcomings of excessive power of certification authority and difficulties in revoking and querying.Blockchain can be used to solve those problems by leveraging its advantages, such as decentralization, high transparency and flat structure.Furthermore, the ability and efficiency of the entire Internet to establish trust relationships may be improved.The transparent public key infrastructure (PKI) certification protocol based on the blockchain was proposed.The TS-PBFT algorithm was designed in the proposed protocol by adopting the threshold signature technology to the Practical Byzantine fault tolerance (PBFT) algorithm.The TS-PBFT algorithm reduced the communication overhead via reducing the communication complexity, strengthened the supervision via introducing external monitoring mechanism in the master node election of the view change protocol, and also improved the performance of the consensus mechanism via adding a batch processing mechanism.Moreover, a transparent blockchain-based PKI certification protocol was designed.The proposed protocol increased the security of certificate revocation and query, it also improved the efficiency of the certificate query by the introduction of counting bloom filters.Besides, the proposed protocol added audit function into the certificate lifecycle management.Accordingly, it can supervise the behavior of the certificate authority (CA), prompt it to improve security standards, and then achieve the purpose of limiting its authority.According to the security analysis and efficiency experiments, the proposed protocol was equipped with security properties, such as the resistance to spoofing certificate application attacks, and it achieved the best performance on TLS/SSL handshake time compared with existing PKI protocols.

Solid-state polymer electrolytes are crucial for developing future rechargeable batteries, but they are still limited in performance. Here, the authors designed a topological polymeric solid electrolyte, enabling an all-solid-state high-voltage lithium metal pouch cell to cycle 200 times efficiently.

Abstract Electrochemical batteries with organic electrode materials have attracted worldwide attention due to their high safety, low cost, renewability, low contamination, and easiness of recycling. However, the practical application of such system is limited by low density, low electronic/ionic conductivity, and the dissolution of organic electrode materials in conventional liquid electrolytes. Herein, a novel battery configuration is proposed to replace liquid electrolyte/solid organic cathode with solid electrolyte/liquid organic cathode to ultimately solve the shuttle effect and dissolution problem of organic cathodes. More importantly, this configuration combines room‐temperature high‐safety liquid lithium metal anode Li‐BP‐DME that can essentially inhibit lithium dendrite nucleation/growth and sulfide SE with ultrahigh room‐temperature ionic conductivity for facilitated ion‐conduction.

Shuicheng District is a karst mountain area, located in Guizhou Province, China. Its fragile stratum and frequent underground mining activities makes it prone to landslides. Owning to its wide coverage and frequent revisit, the InSAR technology has advantages in potential landslide identification and deformation monitor. However, affected by dense vegetation and atmospheric delay, it is much difficult to get sufficient effective targets to derive the deformation in this area. Besides, deformation derived from single orbit SAR data can result in the missing identification of some potential landslides and the misinterpreting of the real kinematics process of landslides. In this study, the multi-source SAR data, atmospheric error correction by quadratic tree image segmentation method, and phase-stacking method were selected to derive the surface deformation of this area. Besides, DS-InSAR and MSBAS method were combined to derive the deformation of Pingdi landslide. First, the potential landslides in this area were identified, surface deformation result, optical remote sensing images and geomorphological features were jointly considered. Then, the landslide distribution characteristics was analyzed in terms of slope, elevation and stratum. After that, the deformation along the LOS direction was acquired using the DS-InSAR method. The MSBAS method was used to retrieve the two-dimensional deformation of Pingdi landslide. Finally, the comprehensive analysis of triggering factors and failure process were conducted according to the spatial-temporal deformation characteristics and field investigation. The results indicated that landslides in Shuicheng district were mostly located in the junction of T1 and P3 stratum and mining related. Mining activity was the main cause of the Pingdi landslide deformation, the precipitation was the driving factor of the landslide instability. The research provides an insight into the explore the unstable slope distribution characteristic and the failure process of the landslides.

Solid-state lithium batteries are flourishing due to their excellent potential energy density. Substantial efforts have been made to improve their electrochemical performance by increasing the conductivity of solid-state electrolytes (SEs) and designing a compatible battery configuration. The safety of a solid lithium battery has generally been taken for granted due to the nonflammability and strength of SEs. However, recent results have shown the release of dangerous gases and intense heat due to the formation of lithium dendrites, indicating the safety of solid-state lithium batteries may have been overestimated. In this review, we introduce a safety evaluation methodology, then focus on the garnet Li7La3Zr2O12 (LLZO) and sulfide-based SEs, summarizing their structure, conductivity, compatibility with a lithium metal anode, electrochemical/chemical stability, and mechanical/thermal stability, which correlate closely with battery safety. We also evaluate the safety of all-solid-state lithium batteries, then conclude by discussing future avenues for improving the safety of SE-based batteries.

Catastrophic landslides occur frequently in Guizhou Province, China, and the landslides in this area have special geomorphological, geological, and anthropogenic features. In order to detect and explore the distribution pattern and control factors of active landslides in Guizhou, firstly, a total of 693 active landslides throughout Guizhou Province were mapped based on the deformation rate, which was obtained by spatiotemporal filtering and Intermittent Small Baseline Subset (ISBAS) Interferometric Synthetic Aperture Radar (InSAR) techniques. Then, the relationships between the detected landslides and elevation, aspect, slope gradient, and stratigraphic lithology were analysed. Moreover, it was found that the landslides were mainly concentrated in three stratigraphic combinations, that is T1f~P2l−d, T1f~T1yn, and T2g~T1yn. Thereafter, the correlation coefficients between the landslide density and elevation and distance to the stratigraphic boundary were 0.54 and −0.19, indicating that the distribution of landslides was significantly controlled by the elevation and the boundary of specific stratigraphic combinations. Finally, we chose a typical landslide to explore how landslide development was controlled by the combined effects of elevation and stratigraphy by using ascending and descending InSAR results. We revealed that landslides occurred primarily in areas with a steep slope and a stratigraphy characterized by mudstone and sandstone.

With the popularization of deep learning, more and more attention has been paid to its security issues.The adversarial sample is to add a small disturbance to the original image, which can cause the deep learning model to misclassify the image, which seriously affects the performance of deep learning technology.To address this challenge, the attack form and harm of the existing adversarial samples were analyzed.An adversarial examples defense method based on image reconstruction was proposed to effectively detect adversarial examples.The defense method used MNIST as the test data set.The core idea was image reconstruction, including central variance minimization and image quilting optimization.The central variance minimization was only processed for the central area of the image.The image quilting optimization incorporated the overlapping area into the patch block selection.Considered and took half the size of the patch as the overlap area.Using FGSM, BIM, DeepFool and C＆amp;W attack methods to generate adversarial samples to test the defense performance of the two methods, and compare with the existing three image reconstruction defense methods (cropping and scaling, bit depth compression and JPEG compression).The experimental results show that the central variance minimization and image quilting optimization algorithms proposed have a satisfied defense effect against the attacks of existing common adversarial samples.Image quilting optimization achieves over 75% classification accuracy for samples generated by the four attack algorithms, and the defense effect of minimizing central variance is around 70%.The three image reconstruction algorithms used for comparison have unstable defense effects on different attack algorithms, and the overall classification accuracy rate is less than 60%.The central variance minimization and image quilting optimization proposed achieve the purpose of effectively defending against adversarial samples.The experiments illustrate the defense effect of the proposed defense algorithm in different adversarial sample attack algorithms.The comparison between the reconstruction algorithm and the algorithm shows that the proposed scheme has good defense performance.

The low ionic conductivity of solid-state electrolytes (SSEs) and the inferior interfacial reliability between SSEs and solid-state electrodes are two urgent challenges hindering the application of solid-state sodium batteries (SSSBs). Herein, sodium (Na) super ionic conductor (NASICON)-type SSEs with a nominal composition of Na3+2xZr2–xMgxSi2PO12 were synthesized using a facile two-step solid-state method, among which Na3.3Zr1.85Mg0.15Si2PO12 (x = 0.15, NZSP-Mg0.15) showed the highest ionic conductivity of 3.54 mS∙cm−1 at 25 °C. By means of a thorough investigation, it was verified that the composition of the grain boundary plays a crucial role in determining the total ionic conductivity of NASICON. Furthermore, due to a lack of examination in the literature regarding whether NASICON can provide enough anodic electrochemical stability to enable high-voltage SSSBs, we first adopted a high-voltage Na3(VOPO4)2F (NVOPF) cathode to verify its compatibility with the optimized NZSP-Mg0.15 SSE. By comparing the electrochemical performance of cells with different configurations (low-voltage cathode vs high-voltage cathode, liquid electrolytes vs SSEs), along with an X-ray photoelectron spectroscopy evaluation of the after-cycled NZSP-Mg0.15, it was demonstrated that the NASICON SSEs are not stable enough under high voltage, suggesting the importance of investigating the interface between the NASICON SSEs and high-voltage cathodes. Furthermore, by coating NZSP-Mg0.15 NASICON powder onto a polyethylene (PE) separator (PE@NASICON), a 2.42 A∙h non-aqueous Na-ion cell of carbon|PE@NASICON|NaNi2/9Cu1/9Fe1/3Mn1/3O2 was found to deliver an excellent cycling performance with an 88% capacity retention after 2000 cycles, thereby demonstrating the high reliability of SSEs with NASICON-coated separator.

Abstract Intercalation provides to the host materials a means for controlled variation of many physical/chemical properties and dominates the reactions in metal‐ion batteries. Of particular interest is the graphite intercalation compounds with intriguing staging structures, which however are still unclear, especially in their nanostructure and dynamic transition mechanism. Herein, the nature of the staging structure and evolution of the lithium (Li)‐intercalated graphite was revealed by cryogenic‐transmission electron microscopy and other methods at the nanoscale. The intercalated Li‐ions distribute unevenly, generating local stress and dislocations in the graphitic structure. Each staging compound is found macroscopically ordered but microscopically inhomogeneous, exhibiting a localized‐domains structural model. Our findings uncover the correlation between the long‐range ordered structure and short‐range domains, refresh the insights on the staging structure and transition of Li‐intercalated/deintercalated graphite, and provide effective ways to enhance the reaction kinetic in rechargeable batteries by defect engineering.

Toxicity, emissions and structural damage results on lithium-ion battery (LIB) thermal runaway triggered by the electrothermal method were performed in this work. The electrothermal triggering method was determined to study the thermal runaway behaviors of three types of commercial LIBs. The structural damage of the cathode material of the batteries after thermal runaway was observed by scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffraction (XRD). It was found that as the state of charge (SOC) of the battery increases, the lower the temperature at which thermal runaway occurs, and the more badly the structural damage of the electrode material after thermal runaway. Qualitative analysis of products from LIBs thermal runaway emissions was conducted by GC-MS, and the toxicity and formation mechanism of the emissions were analyzed in detail. Dozens of toxic substances were detected from the emissions after thermal runaway of batteries using LixNi1/3Co1/3Mn1/3O2 and LiCoO2 as the cathode material, the types of toxic substances increase gradually with the increase in the SOC, while as for batteries using LiFePO4 as the cathode material, most types of toxic substances were detected from 30% SOC.

The extraction of underground minerals in hilly regions is highly susceptible to landslides, which requires the application of InSAR techniques to monitor the surface displacement. However, repeated mining for multiple coal seams can cause a large displacement beyond the detectable gradient of the traditional InSAR technique, making it difficult to explore the relationship between landslides and subsurface excavations in both temporal and spatial domains. In this study, the Tengqing landslide in Shuicheng, Guizhou, China, was chosen as the study area. Firstly, the large-gradient surface displacement in the line of sight was obtained by the fusion of SAR offset tracking and interferometric phase. Subsequently, a multi-segment logistic model was proposed to simulate the temporal effect induced by repeated mining activities. Next, a simplified probability integral method (SPIM) was utilized to invert the geometry of the mining tunnel and separate the displacement of the mining subsidence and landslide. Finally, the subsurface mining parameters and in situ investigation were carried out to assess the impact of mining and precipitation on the kinematic process of Tengqing landslides. Results showed that the repeated mining activities in Tengqing can not only cause land subsidence and rock avalanches at the top of the mountain, but also accelerate the landslide displacement. The technical approach presented in this study can provide new insights for monitoring and modeling the effects of repeated mining-induced landslides in mountainous areas.

Abstract Thermal safety is one of the major issues for lithium‐ion batteries (LIBs) used in electric vehicles. The thermal runaway mechanism and process of LIBs have been extensively studied, but the thermal problems of LIBs remain intractable due to the flammability, volatility and corrosiveness of organic liquid electrolytes. To ultimately solve the thermal problem, all‐solid‐state LIBs (ASSLIBs) are considered to be the most promising technology. However, research on the thermal stability of solid‐state electrolytes (SEs) is still in its initial stage, and the thermal safety of ASSLIBs still needs further validation. Moreover, the specified reviews summarizing the thermal stability of ASSLIBs and all types of SEs are still missing. To fill this gap, this review systematically discussed recent progress in the field of thermal properties investigation for ASSLIBs, form levels of materials and interface to the whole battery. The thermal properties of three major types of SEs, including polymer, oxide, and sulfide SEs are systematically reviewed here. This review aims to provide a comprehensive understanding of the thermal stability of SEs for the benign development of ASSLIBs and their promising application under practical operating conditions.

Abstract All‐solid‐state batteries (ASSBs) have been widely acknowledged as the key next‐generation energy storage technology/device, due to their high safety and energy density. Among all solid electrolytes (SEs) that have been studied for ASSBs, sulfide SEs represent the most promising technical route due to their ultra‐high ionic conductivity and desirable mechanical property. However, few results have been reported to study the thermal stability/safety issue of sulfide SEs and ASSBs. Herein, we develop the first‐of‐its‐kind theoretical paradigm and a new conceptual parameter Th to quantitatively calculate/predict the essential thermal stability of sulfide SEs. This theoretical paradigm takes all types of parameters (e.g. crystal structure, localized polyhedra configuration, bond energy, bond type, bond number, normalization factor, and the energy correction factor) into consideration, and more importantly, can be simplified into one straightforward equation for its convenient application in any crystalline systems. To prove its functionality, the typical experimental strategies (stoichiometric ratio control and elemental doping) are adopted for typical sulfide SEs (Li7P3S11, Li3PS4) to improve their thermal stabilities, based on the predictions obtained from the derived theory and equation. Moreover, the potential doping elements to improve thermal stability of sulfide SEs are screened throughout the whole periodic table, and the theoretically predicted trends correspond well with experimental evidence. This work may represent the most critical breakthroughs in the research field of thermal stability for sulfide SEs, not only because it fills the gap of this field, but also due to its precise and quantitative prediction based on a complete consideration of all parameters that determine their thermal stabilities. The handy model developed herein can also be applied to any crystalline materials.

Abstract The utilization of anionic redox is one of the most prospective strategies to obtain high specific capacities in addition to the transition metal redox. The specific local environments around the oxygen atoms lead to the transference of the oxygen electrons with different difficulties for the excess capacity of the cathode materials. Nevertheless, the structural and performance degradation is closely related to the irreversible anionic redox, resulting in serious challenges for the commercialization of the cathode materials. Therefore, it is necessary to summarize the correlation between the oxygen configuration for the anionic redox and the resultant structural features to better utilize the anionic redox for the cathode materials with better performances. This review summarizes the latest advances of oxygen redox in the cathode materials in terms of their oxygen configurations. First, the fundamental mechanisms of anionic redox are discussed. On the basis of the local atoms and configurations, the recent strategies are then discussed that are promising to boost the reversibility of the anionic redox and mitigate the side reaction triggered by the oxygen redox. At last, an outlook is presented on the strategies to optimize the reversibility of the anionic redox for achieving the high energy‐density cathode materials.

Understanding the effect of the space charge layer (SCL) in all-solid-state lithium-ion batteries is challenging due to lack of direct experimental observations. Here the authors visualize the SCL using an in-situ DPC-STEM imaging technique, based on which they further introduce a built-in electric field to suppress its formation.

In order to solve the efficiency problem of the existing public key infrastructure cross-domain authentication scheme,a cross-domain authentication model based on the consortium blockchain which has the advantages of distributed and difficult to be tamperd with was proposed.On the one hand,the dynamic join and exit function was added to the practical Byzantine fault tolerant (PBFT) algorithm,the primary node election mode was improved,and the three-stage broadcast was reduced to two-stage broadcast for the reducation of communication overhead.On the other hand,the cross-domain authentication system architecture based on consortium chain was designed,the blockchain certificate format and the cross-domain authentication protocol were presented,the security and efficiency were analyzed.The results shows that in term of security,the proposed model has security attributes such as resisting distributed attacks.In terms of performance,the proposed model has advantages in both computational overhead and communication overhead when it was compared with the existing cross-domain authentication schemes.

Purpose – This paper aims to study the affecting factors on bird nesting on electronic railway catenary lines and the impact of bird nesting events on railway operation. Design/methodology/approach – First, with one year’s bird nest events in the form of unstructured natural language collected from Shanghai Railway Bureau, the records were structured with the help of python software tool. Second, the method of root cause analysis (RCA) was used to identify all the possible influencing factors which are inclined to affect the probability of bird nesting. Third, the possible factors then were classified into two categories to meet subsequent analysis separately, category one was outside factors (i.e. geographic conditions related factors), the other was inside factors (i.e. railway related factors). Findings – It was observed that factors of city population, geographic position affect nesting observably. Then it was demonstrated that both location and nesting on equipment part have no correlation with delay, while railway type had a significant but low correlation with delay. Originality/value – This paper discloses the principle of impacts of nest events on railway operation.

Mimic defense is an active defense theory, which aims to fundamentally change the “easy to attack and difficult to defend” situation of network security. In this paper, we propose an evaluation method based on the probability of being attack successfully, and improve the evaluation scheme of historical confidence. We combine the two evaluation schemes with the TOPSIS (technique for order performance by similarity to ideal solution) algorithm, and finally form a complete heterogeneous variant dynamic scheduling model. Different from traditional multi-mode voting algorithms, the effect of the heterogeneous degree in voting is considered, and we use Bayesian estimation to obtain the optimal result in the probabilistic sense. Finally, simulation results show that the proposed algorithm can effectively enhance the dynamic and security of the mimic defense model, and give full play to the characteristics of mimic defense.

Abstract Flexible energy storage devices have gained significant attention because of the increasing needs of bendable displays, wearable electronics, and flexible displays. Flexible Na‐based rechargeable batteries are the promising power sources in such products due to their low cost and wide availability. In this review, we firstly introduce the structural superiority of flexible Na‐based batteries and summarize their main components including cathodes, electrolytes, and anodes. Moreover, fabrication of their flexible components is discussed in detail, with specific emphasis on material selection, particularly for solid‐state electrolytes. This is followed by an overview highlighting recent progress in the development of prototypes of flexible Na‐ion batteries and beyond. Finally, perspectives on future challenges for the development of flexible Na batteries are proposed.

Lithium metal is a promising anode material for its low redox potential and high theoretical specific capacity. However, the commercial application of the lithium metal anode is hindered with safety concerns arising from the uncontrolled growth of the lithium dendrites and significant volume variation during the lithium plating and stripping processes. Modification to the current collector is effective in tailoring the morphology of the deposited lithium and improving the cycling performance of the lithium metal batteries This review summarizes at first the global research advances in the structural design and the selection of the current collectors and their textures. It then presents some of our efforts in realizing controlled lithium deposition by designing current collectors in three aspects, lithium deposition induced by the micro-to-nano structures, lithiophilic alloys and iron carbides. Finally, conclusions and prospects are made for the further research of the current collectors.

Na-ion batteries (NIBs) have received significant interest as potential candidates for large-scale energy storage owing to the widespread distribution of sodium and superior low-temperature performance. However, their commercial application is usually hindered by the high production cost and inadequate performance for electrode materials, particularly for cathodes. Na3(VOPO4)2F (NVOPF) has been recognized as one of the most promising cathodes for high-energy NIBs owing to the high working voltage and energy density. Here, we report a facile highly efficient room-temperature solution protocol for large-scale synthesis of NVOPF cathode for NIBs. By simply regulating pH, NVOPF can be obtained, which delivered a discharge capacity of 120.2 mAh g-1 at 0.1 C and 72% capacity retention over 8000 cycles at 25 C. Besides, the kilogram-level NVOPF products have been synthesized, and 26650 cylindrical cells were fabricated, which exhibit excellent cycling stabilities, remarkable low-temperature performance with comparable safety features. We hope our findings could provide insights on the industrial application of NVOPF in NIBs.

Recently, lithium-ion batteries (LIBs) have faced bottlenecks in terms of energy/power density and safety issues caused by flammable electrolytes. In this regard, all-solid-state batteries (ASSBs) may be one of the most promising solutions. However, many key battery materials (such as solid electrolytes (SEs), cathodes, and anodes) are unstable to air/water, which greatly limits their production, storage, transportation, practical applications, and the development of ASSBs. Herein, the research status on air/water stability of SEs, cathodes, and anodes is reviewed. The mechanisms for their air/water instability are revealed in details. The corresponding modification methods are also proposed, with emphasis on the construction strategies of air/water stable protective layers, including ex situ coatings and in situ reactions. Moreover, the application of air/water-stable protective layers in ASSBs is discussed correspondingly. Last but not least, the advantages and disadvantages of various protective layer construction strategies are analyzed, in which their applications in practical production are prospected.

The growing concern about scarcity and large-scale applications of lithium resources has attracted efforts to realize cost-effective phosphate-based cathode materials for next-generation Na-ion batteries (NIBs). In previous work, a series of materials (such as Na _4 Fe _3 (PO _4 ) _2 (P _2 O _7 ), Na _3 VCr(PO _4 ) _3 , Na _4 VMn(PO _4 ) _3 , Na _3 MnTi(PO _4 ) _3 , Na _3 MnZr(PO _4 ) _3 , etc) with ∼120 mAh g ^−1 specific capacity and high operating potential has been proposed. However, the mass ratio of the total transition metal in the above compounds is only ∼22 wt%, which means that one-electron transfer for each transition metal shows a limited capacity (the mass ratio of Fe is 35.4 wt% in LiFePO _4 ). Therefore, a multi-electron transfer reaction is necessary to catch up to or go beyond the electrochemical performance of LiFePO _4 . This review summarizes the reported NASICON-type and other phosphate-based cathode materials. On the basis of the aforementioned experimental results, we pinpoint the multi-electron behavior of transition metals and shed light on designing rules for developing high-capacity cathodes in NIBs.

Summary: Solid-electrolyte interphase (SEI) is regarded as the most important but the least understood part of lithium (Li)-ion batteries. A comprehensive understanding of the nature of the SEI and especially its interplay with active materials during cycling is crucial since it governs the charge transfer and Li+ transport. Herein, the dynamic interplay between SEI and silicon (Si) anode during cycling is revealed quantitatively and qualitatively by titration gas chromatography (TGC), cryogenic transmission electron microscopy (cryo-TEM), and other techniques to probe charge transfer, nanostructure, and equilibrium. The results show that it is difficult to construct an equilibrium interplay between the SEI and LixSi due to the intrinsic instability of some SEI components (e.g., Li2O and carbonates) and the pulverization of Si anode, resulting in the continuous formation of the SEI and inactive LixSi. The addition of fluoroethylene carbonate helps construct such equilibrium interplay through formation of a LiF-rich SEI, thus improving cyclability.

Landslide inventory mapping (LIM) is a key prerequisite for landslide susceptibility evaluation and disaster mitigation. It aims to record the location, size, and extent of landslides in each map scale. Machine learning algorithms, such as support vector machine (SVM) and random forest (RF), have been increasingly applied to landslide detection using remote sensing images in recent decades. However, their limitations have impeded their wide application. Furthermore, despite the widespread use of deep learning algorithms in remote sensing, for LIM, deep learning algorithms are limited to less unbalanced landslide samples. To this end, in this study, full convolution networks with focus loss (FCN-FL) were adopted to map historical landslides in regions with imbalanced samples using an improved symmetrically connected full convolution network and focus loss function to increase the feature level and reduce the contribution of the background loss value. In addition, K-fold cross-validation training models (FCN-FLK) were used to improve data utilization and model robustness. Results showed that the recall rate, F1-score, and mIoU of the model were improved by 0.08, 0.09, and 0.15, respectively, compared to FCN. It also demonstrated advantages over U-Net and SegNet. The results prove that the method proposed in this study can solve the problem of imbalanced sample in landslide inventory mapping. This research provides a reference for addressing imbalanced samples in the deep learning of LIM.

As the foundation of quantum secure communication, the quantum key distribution (QKD) network is impossible to construct by using the operation mechanism of traditional networks. In the meantime, most of the existing QKD network routing schemes do not fit some specific quantum key practicality scenarios. Aiming at the special scenario of high concurrency and large differences in application requirements, we propose a new quantum key distribution network routing scheme based on application priority ranking (APR-QKDN). Firstly, the proposed APR-QKDN scheme comprehensively uses the application’s priority, the total amount of key requirements, and the key update rate for prioritizing a large number of concurrent requests. The resource utilization and service efficiency of the network are improved by adjusting the processing order of requests. Secondly, the queuing strategy of the request comprehensively considers the current network resource situation. This means the same key request may adopt different evaluation strategies based on different network resource environments. Finally, the performance of the APR-QKDN routing scheme is compared with the existing schemes through simulation experiments. The results show that the success rate of application key requests of the APR-QKDN routing scheme is improved by at least 5% in the scenario of high concurrency.

Abstract The continuous energy density increase of lithium ion batteries (LIBs) inevitably accompanies with the rising of safety concerns. Here, the thermal runaway characteristics of a high‐energy 5 Ah LiNi0.5Co0.2Mn0.3O2/graphite pouch cell using a thermally stable dual‐salt electrolyte are analyzed. The existence of LiH in the graphite anode side is innovatively identified in this study, and the LiH/electrolyte exothermic reactions and H2 migration from anode to cathode side are proved to contribute on triggering the thermal runaway of the pouch cell, while the phase transformation of lithiated graphite anode and the O2‐releasing from cathode are just accelerating factors for thermal runaway. In addition, heat determination during cycling at two boundary scenarios of adiabatic and isothermal environment clearly states the necessity of designing an efficient and smart battery thermal management system for avoiding heat accumulation. These findings will shed promising lights on thermal runaway route map depiction and thermal runaway prevention, as well as formulation of electrolyte for high energy safer LIBs.

NASICON- (Na superionic conductor-) based solid-state electrolytes (SSEs) are believed to be attracting candidates for solid-state sodium batteries due to their high ionic conductivity and prospectively reliable stability. However, the poor interface compatibility and the formation of Na dendrites inhibit their practical application. Herein, we directly observed the propagation of Na dendrites through NASICON-based Na3.1Zr2Si2.1P0.9O12 SSE for the first time. Moreover, a fluorinated amorphous carbon (FAC) interfacial layer on the ceramic surface was simply developed by in situ carbonization of PVDF to improve the compatibility between Na metal and SSEs. Surprisingly, Na dendrites were effectively suppressed due to the formation of NaF in the interface when molten Na metal contacts with the FAC layer. Benefiting from the optimized interface, both the Na||Na symmetric cells and Na3V2(PO4)3||Na solid-state sodium batteries deliver remarkably electrochemical stability. These results offer benign reference to the maturation of NASICON-based solid-state sodium batteries.