Carbon nanocages bridged with graphene enable fast kinetics for dual-carbon lithium-ion capacitors

Lithium-ion capacitors(LICs) combining the advantages of lithium-ion batteries and supercapacitors are considered a promising nextgeneration energy storage device. However, the sluggish kinetics of battery-type anode cannot match the capacitor-type cathode, restricting the development of LICs. Herein, hierarchical carbon framework(HCF) anode material composed of 0D carbon nanocage bridged with 2D graphene network are developed via a template-confined synthesis process. The HCF with nanocage structure reduces the Li^(+) transport path and benefits the rapid Li^(+) migration, while 2D graphene network can promote the electron interconnecting of carbon nanocages. In addition, the doped N atoms in HCF facilitate to the adsorption of ions and enhance the pseudo contribution, thus accelerate the kinetics of the anode. The HCF anode delivers high specific capacity, remarkable rate capability. The LIC pouch-cell based on HCF anode and active HCF(a-HCF) cathode can provide a high energy density of 162 Wh kg^(-1) and a superior power density of 15.8 kW kg^(-1), as well as a long cycling life exceeding 15,000cycles. This study demonstrates that the well-defined design of hierarchical carbon framework by incorporating 0D carbon nanocages and 2D graphene network is an effective strategy to promote LIC anode kinetics and hence boost the LIC electrochemical performance.

Two methods for separating the magnetospheric solar wind charge exchange soft X-ray emission from the diffuse X-ray background

Solar wind charge exchange(SWCX)is the process of solar wind high-valence ions exchanging charges with neutral components and generating soft X-rays.Recently,detecting the SWCX emission from the magnetosphere is proposed as a new technique to study the magnetosphere using panoramic soft X-ray imaging.To better prepare for the data analysis of upcoming magnetospheric soft X-ray imaging missions,this paper compares the magnetospheric SWCX emission obtained by two methods in an XMM-Newton observation,during which the solar wind changed dramatically.The two methods differ in the data used to fit the diffuse X-ray background(DXB)parameters in spectral analysis.The method adding data from the ROSAT All-Sky Survey(RASS)is called the RASS method.The method using the quiet observation data is called the Quiet method,where quiet observations usually refer to observations made by the same satellite with the same target but under weaker solar wind conditions.Results show that the spectral compositions of magnetospheric SWCX emission obtained by the two methods are very similar,and the changes in intensity over time are highly consistent,although the intensity obtained by the RASS method is about 2.68±0.56 keV cm^(-2)s^(-1)sr^(-1)higher than that obtained by the Quiet method.Since the DXB intensity obtained by the RASS method is about 2.84±0.74 keV cm^(-2)s^(-1)sr^(-1)lower than that obtained by the Quiet method,and the linear correlation coefficient between the difference of SWCX and DXB obtained by the two methods in diffe rent energy band is close to-1,the diffe rences in magnetospheric SWCX can be fully attributed to the diffe rences in the fitted DXB.The difference between the two methods is most significant when the energy is less than 0.7 keV,which is also the main energy band of SWCX emission.In addition,the difference between the two methods is not related to the SWCX intensity and,to some extent,to solar wind conditions,because SWCX intensity typically va ries with the solar wind.In summary,both methods are robust and reliable,and should be considered based on the best available options.

Influence of backfilling rate on the stability of the"backfilling bodyimmediate roof"cooperative bearing structure

To reduce the cost of backfilling coal mining and utilize the underground space of coal mines,a new backfilling mining method with low backfilling rate called constructional backfilling coal mining(CBCM)is proposed.The "backfilling body-immediate roof" cooperative bearing structure of CBCM is analyzed by establishing the model of the medium thick plate on an elastic foundation.The influence of the backfilling rate on the stability of overlying strata is analyzed by the numerical simulation experiment.The control effect of CBCM is verified by a physic similar simulation test.The economic benefit of CBCM is analyzed.The conclusions are:the deformation characteristics of the immediate roof and critical backfilling spacing in CBCM can be analyzed based on the Hu Haichang’s theory.Exerting the bearing capacity of the immediate roof is beneficial to the stability of the overlying strata.The CBCM has a good control effect on the overburden in Xinyang Mine when the backfilling rate is lower than 25%.The backfilling cost of per ton coal is 37.39 yuan/t when the backfilling rate is 13.7%,with a decrease rate of 56.63%than the full-filling.The research results can provide theoretical support for the application of CBCM in coal mining.

Analysis and Optimization on Partition-Based Caching and Delivery in Satellite-Terrestrial Edge Computing Networks

As a viable component of 6G wireless communication architecture,satellite-terrestrial networks support efficient file delivery by leveraging the innate broadcast ability of satellite and the enhanced powerful file transmission approaches of multi-tier terrestrial networks.In the paper,we introduce edge computing technology into the satellite-terrestrial network and propose a partition-based cache and delivery strategy to make full use of the integrated resources and reducing the backhaul load.Focusing on the interference effect from varied nodes in different geographical distances,we derive the file successful transmission probability of the typical user and by utilizing the tool of stochastic geometry.Considering the constraint of nodes cache space and file sets parameters,we propose a near-optimal partition-based cache and delivery strategy by optimizing the asymptotic successful transmission probability of the typical user.The complex nonlinear programming problem is settled by jointly utilizing standard particle-based swarm optimization(PSO)method and greedy based multiple knapsack choice problem(MKCP)optimization method.Numerical results show that compared with the terrestrial only cache strategy,Ground Popular Strategy,Satellite Popular Strategy,and Independent and identically distributed popularity strategy,the performance of the proposed scheme improve by 30.5%,9.3%,12.5%and 13.7%.

Heterogeneous isomorphism hollow SiGe nanospheres with porous carbon reinforcing for superior electrochemical lithium storage

Silicon is emerging as a promising next-generation lithium-ion battery anode because of its high theoretical capacity and low cost.However,the poor cyclability and inferior rate performance hinder its largescale applications.Here,hollow silicon/germanium(H-SiGe)nanospheres with a binary-active component and heterogeneous structure combined with porous carbon(pC)reinforcing are synthesized as lithium-ion battery anodes.Experimental studies demonstrate that the H-SiGe/pC anodes possess tiny volume expansion,high ion/electron conductivity,and stable electrode interface.Theoretical calculations confirm that through the replacement of Si using Ge with rational component control,the diffusion energy barrier of lithium will be reduced and lithium storage ability can be improved because of the slight charge polarization.Benefiting from these unique merits,the H-SiGe/pC anodes display a high initial specific capacity of 2922.2 mA h g^(-1)at 0.1 A g^(-1),superior rate capability(59.4%capacity retention from 0.5 to 8 A g^(-1)),and excellent cycling stability(81%retention after 700 cycles at 5 A g^(-1)at 1.0–1.2 mg cm^(-2)).An outstanding stability is preserved even at a high loading of 3.2 mg cm^(-2)with an improved reversible capacity of 429.1 mA h g^(-1)after 500 cycles at 4 A g^(-1).Furthermore,the full-cell with the prelithiated H-SiGe/pC anode and LiFePO4cathode exhibits an impressive capacity performance.

DNA methylation and alternative splicing modulate FBXW11 gene expression in Holstein bull testis and are correlated with sperm quality

F-box and WD-40 domain protein 11(FBXW11)is an important component of the E3 ubiquitin-ligase enzyme that plays a key role in the ubiquitin-dependent regulation of spermatogenesis.In our previous research,the mRNA expression of FBXW11 in bull sperm with high motility is significantly higher than that with low motility.In the present study,the protein expression levels of FBXW11 in bull testicular tissues with low-performance sperm quality groups were significantly higher than those in normal performance groups.The immunohistochemistry result demonstrated that FBXW11 protein was located in the periphery of Leydig cells and seminiferous tubules.Three splice variants of the FBXW11 gene,namely,FBXW11-tv1,FBXW11-tv2,and FBXW11-tv3,were identified in testicular tissues.The splicing patterns of the three variants are exon skipping.The transcript FBXW11-tv2 expressions were the highest in each sample.The low-performance groups displayed higher FBXW11-tv1 and FBXW11-tv2 transcript expressions than the normal performance groups.Two CpG islands were located within the 5’UTR and exon 1-2 region of the FBXW11 gene.Bisulfite sequencing PCR results demonstrated that the methylation levels of 11 methylation sites in the CpG island 2 from−99 to−43 in the normal performance groups were significantly lower than those in the low-performance groups.Pearson correlation analysis suggested that the CpG island 2 methylation level was negatively correlated with sperm motility and the transcript FBXW11-tv2 expression level.Our data revealed that alternative splicing and DNA methylation jointly regulated FBXW11 gene expression and were correlated with sperm quality traits during spermatogenesis in Holsteins.

构建青少年化学科普活动内容分级素材库

在收集和分析常见化学类科普素材的基础上,通过整合素材内容与科学教育体系的对应关系,为化学教育和化学科普工作者搭建一个有实践参考价值的内容分级素材库。本研究着眼新时期社会发展的政策导向和现实需求,旨在为青少年化学类科普活动的具体实践提供一种框架性和建设性的新视角。

化学教育走进雄安——白洋淀环保主题暑期实践活动

在京津冀一体化、雄安新区建设和“绿水青山就是金山银山”生态文明思想的三大政策背景下,由首都师范大学化学(师范)专业师生组成的京冀科育团队于2019年暑假走进雄安新区,以化学教育为核心、以环境保护为主题、以提升学科核心素养为导向,开展了兼具化学专业特色和教师教育特色的暑期实践活动。

Research on ultrasonic-based investigation of mechanical properties of ice

Arctic sea ice area and thickness have declined dramatically during the recent decades.Sea ice physical and mechanical properties become increasingly important.Traditional methods of studying ice mechanical parameters such as ice-coring cannot realize field test and long-term observation.A new principle of measuring mechanical properties of ice using ultrasonic was studied and an ultrasonic system was proposed to achieve automatic observation of ice mechanical parameters(Young’s modulus,shear modulus and bulk modulus).The ultrasonic system can measure the ultrasonic velocity through ice at different temperature,salinity and density of ice.When ambient temperature decreased from 0°C to-30°C,ultrasonic velocity and mechanical properties of ice increased,and vice versa.The shear modulus of the freshwater ice and sea ice varied from 2.098 GPa to 2.48 GPa and 2.927 GPa to 4.374 GPa,respectively.The bulk modulus of freshwater ice remained between 3.074 GPa and4.566 GPa and the sea ice bulk modulus varied from 1.211 GPa to 3.089 GPa.The freshwater ice Young’s modulus kept between 5.156 GPa and 6.264 GPa and sea ice Young’s modulus varied from 3.793 GPa to 7.492 GPa.The results of ultrasonic measurement are consistent with previous studies and there is a consistent trend of mechanical modulus of ice between the process of ice temperature rising and falling.Finally,this ultrasonic method and the ultrasonic system will help to achieve the long-term observation of ice mechanical properties of ice and improve accuracy of sea ice models.

Comparison of drug-coated balloon versus drug-eluting stent in patients with drug-eluting stent in-stent restenosis: insight from randomized controlled trials

Purpose Both drug-coated balloon (DCB) and drug-eluting stent (DES) were used for treatment of in-stent restenosis but it is unclear about their effects of magnitude.

Surficial modification enabling planar Al growth toward dendrite-free metal anodes for rechargeable aluminum batteries

Al metal possesses ultrahigh theoretical volumetric capacity of 8,040 m Ah cm^(-3),and gravimetric capacity of 2,980 m Ah g^(-1),and thus is highly attractive for electrochemical energy storage.However,it suffers from several issues,such as the dendrite formation,during Al stripping-deposition cycling,which has been verified to account for the short circuit and limited cyclic performance.Herein,we use a facile and applicable method to in-situ reconstruct the Al anode surface with F-Al-O chemical bonds,which could preferentially induce the planar growth of Al along the interface plane,thus leading to the dendrite-free morphology evolution during the cycling.Benefiting from F-Al-O chemical bonds on the surface of Al anodes,long lifespan of symmetric cells can be realized even under 1 m A cm^(-2)and 1 m Ah cm^(-2).Coupling the F-Al anode with graphite-based cathodes,high-voltage dual-ion Al metal batteries can be achieved with long-term cycle stability up to 1,200 cycles(at 0.5 m A cm^(-2)),surpassing the counterparts using pristine Al metal anode.Furthermore,the effectiveness of this surficial modification strategy is also elucidated with the aid of theoretical calculation.This work provides novel insights on low-cost and facile strategies against the Al dendrite growth in aluminum batteries.

Real-time Risk-averse Dispatch of an Integrated Electricity and Natural Gas System via Condi-tional Value-at-risk-based Lookup-table Ap-proximate Dynamic Programming

The real-time risk-averse dispatch problem of an integrated electricity and natural gas system(IEGS)is studied in this paper.It is formulated as a real-time conditional value-at-risk(CVaR)-based risk-averse dis-patch model in the Markov decision process framework.Because of its stochasticity,nonconvexity and nonlinearity,the model is difficult to analyze by traditional algorithms in an acceptable time.To address this non-deterministic polynomial-hard problem,a CVaR-based lookup-table approximate dynamic programming(CVaR-ADP)algo-rithm is proposed,and the risk-averse dispatch problem is decoupled into a series of tractable subproblems.The line pack is used as the state variable to describe the impact of one period’s decision on the future.This facilitates the reduction of load shedding and wind power curtailment.Through the proposed method,real-time decisions can be made according to the current information,while the value functions can be used to overview the whole opti-mization horizon to balance the current cost and future risk loss.Numerical simulations indicate that the pro-posed method can effectively measure and control the risk costs in extreme scenarios.Moreover,the decisions can be made within 10 s,which meets the requirement of the real-time dispatch of an IEGS.Index Terms—Integrated electricity and natural gas system,approximate dynamic programming,real-time dispatch,risk-averse,conditional value-at-risk.

Transfer-based Approximate Dynamic Programmingfor Rolling Security-constrained Unit Commitment with Uncertainties

This paper studies the rolling security-constrained unit commitment(RSCUC)problem with AC power flow and uncertainties.For this NP-hard problem,it is modeled as a Markov decision process,which is then solved by a transfer-based approximate dynamic programming(TADP)algorithm proposed in this paper.Different from traditional approximate dynamic programming(ADP)algorithms,TADP can obtain the commitment states of most units in advance through a decision transfer technique,thus reducing the action space of TADP significantly.Moreover,compared with traditional ADP algorithms,which require to determine the commitment state of each unit,TADP only needs determine the unit with the smallest on-state probability among all on-state units,thus further reducing the action space.The proposed algorithm can also prevent the iter-ative update of value functions and the reliance on rolling forecast information,which makes more sense in the rolling decision-making process of RSCUC.Finally,nu-merical simulations are carried out on a modified IEEE 39-bus system and a real 2778-bus system to demonstrate the effectiveness of the proposed algorithm.

The benefits of PCSK9 inhibitors in patients with acute coronary syndrome:a systematic review and meta-analysis

Background:Proprotein convertase subtilisin/kexin 9(PSCK9)inhibitors have been beneficial for many patients with hyperlipidemia.The objective of this study was to investigate the benefit of PSCK9 inhibitors in patients with acute coronary syndrome(ACS).Methods:We systematically searched PubMed,EMBASE,and Cochrane Clinical Trials(published before January 2023;no language restriction)to compare the treatment of patients with ACS using PCSK9 inhibitors and placebo.The primary end points were major adverse cardiovascular events,nonfatal myocardial infarction,cardiogenic death,stroke,hospitalization for recurrent ACS,and coronary revascularization.Fixed-or random-effects models were used to assess the aggregated data.Results:Of the 1686 identified studies,5 were eligible and included in our analysis(of a total of 38,005 participants,18,609 cases were placed in the PCSK9 inhibitor treatment group and 19,396 cases in the placebo group).Compared with the placebo group,PCSK9 inhibitors significantly reduced the major adverse cardiovascular events(odds ratio[OR]:0.83;95%confidence interval[CI]:0.77–0.88;P<0.00001)for patients following ACS.The incidence of nonfatal myocardial infarction(relative risk:0.80;95%CI:0.74–0.87;P<0.00001),cardiovascular death(OR:0.96;95%CI:0.83–1.10;P=0.56),stroke(OR:0.74;95%CI:0.63–0.88;P=0.0007),hospitalization for recurrent ACS(OR:0.57;95%CI:0.40–0.83;P=0.003),or coronary revascularization(OR:0.82;95%CI:0.76–0.88;P<0.00001)all demonstrated a significant decrease in the comparison between the 2 groups.Conclusion:This meta-analysis demonstrated that treatment with PCSK9 inhibitors in patients with ACS reduced the probability of multiple cardiovascular events and improved patient prognosis.

Plotinus:A Satellite Internet Digital Twin System

The development of space-air-ground integrated networks (SAGIN) requires sophisticated satellite Internet emulation tools that can handle complex, dynamic topologies and offer in-depth analysis. Existing emulation platforms struggle with challenges like the need for detailed implementation across all network layers, real-time response, and scalability. This paper proposes a digital twin system based on microservices for satellite Internet emulation,namely Plotinus,which aims to solve these problems. Plotinus features a modular design, allowing for easy replacement of the physical layer to emulate different aerial vehicles and analyze channel interference. It also enables replacing of path computation methods to simplify testing and deploying algorithms. In particular, Plotinus allows for real-time emulation with live network traffic,enhancing practical network models. The evaluation result shows Plotinus’s effective emulation of dynamic satellite networks with real-world devices. Its adaptability for various communication models and algorithm testing highlights Plotinus’s role as a vital tool for developing and analyzing SAGIN systems, offering a cross-layer,real-time,and scalable digital twin system.

Sphalerite Rb-Sr Dating and in situ Sulfur Isotope Analysis of the Daliangzi Lead-Zinc Deposit in Sichuan Province, SW China

This study reports the sphalerite Rb-Sr age and LA-MC-ICP-MS in situ sulfur isotope analysis results of the Daliangzi Lead-Zinc Deposit in the Sichuan-Yunnan-Guizhou （SYG） triangle. Sphalerite Rb-Sr dating yields a Mississippian age of 345.2±3.6 Ma （MSWD=I.4）, which is older than the published Late Triassic mineralization ages （230-200 Ma） of some other deposits. This indicates that at least two stages of lead-zinc mineralization have occurred in the SYG lead-zinc triangle. The first stage occurred in the Mississippian under an extensional environment, while the second stage occurred in the Late Triassic under a compressional environment. In situ sulfur isotope analysis of sphalerite growth zoning presents relatively large δ^34S values of 11.3‰-15.2‰ with small variations. The large δ^34S values indicate a reduced sulfur source of thermochemical reduction of seawater sulfates. Abundant organic matter in the black fracture zone possibly supplied reductants for thermochemical sulfate reduction （TSR） at the mineralization site. The small variation of δ^34S values suggests a slow and stable TSR process that could prevent the sudden supersaturation of sphalerite in the fluid and the resulting of fast participation. This is consistent with the well-crystallized characteristic of the sphalerite of the Daliangzi Deposit.

Science with the 2.5-meter Wide Field Survey Telescope(WFST)

The Wide Field Survey Telescope(WFST) is a dedicated photometric surveying facility being built jointly by University of Science and Technology of China(USTC) and the Purple Mountain Observatory(PMO). It is equipped with a 2.5-meter diameter primary mirror, an active optics system, and a mosaic CCD camera with 0.73 gigapixels on the primary focal plane for highquality image capture over a 6.5-square-degree field of view. The installation of WFST near the summit of Saishiteng mountain in the Lenghu region is scheduled in summer of 2023, and the operation is planned to start three months later. WFST will scan the northern sky in four optical bands(u, g, r and i) at cadences from hourly/daily in the deep high-cadence survey(DHS) program, to semi-weekly in the wide field survey(WFS) program. During a photometric night, a nominal 30 s exposure in the WFS program will reach a depth of 22.27, 23.32, 22.84, and 22.31(AB magnitudes) in these four bands, respectively, allowing for the detection of a tremendous amount of transients in the low-z universe and a systematic investigation of the variability of Galactic and extragalactic objects. In the DHS program, intranight 90 s exposures as deep as 23(u) and 24 mag(g), in combination with target of opportunity follow-ups, will provide a unique opportunity to explore energetic transients in demand for high sensitivities, including the electromagnetic counterparts of gravitational wave events, supernovae within a few hours of their explosions,tidal disruption events and fast, luminous optical transients even beyond redshift of unity. In addition, the final 6-year co-added images, anticipated to reach g■25.8 mag in WFS or 1.5 mags deeper in DHS, will be of fundamental importance to general Galactic and extragalactic science. The highly uniform legacy surveys of WFST will serve as an indispensable complement to those of the Vera C. Rubin Observatory's Legacy Survey of Space and Time(LSST) that monitors the southern sky.

Formation of present desert landscape surrounding Jilantai Salt Lake in northern China based on OSL dating

The Jilantai Salt Lake （JSL）, a lake of importance due to its salt production in China since the early Qing dynasty, is surrounded by sand dunes. Exploration of the development of these sand dunes will be helpful for identifying the forces underlying the desert landscape and for identifying a solution to protect the salt resources. Through field investigation, we found sand dunes overlying either lacustrine and bog deposits on the lake bed at a lower altitude or littoral sediments on the higher lakeshores. Optically Stimulated Luminescence （OSL） dating results indicate that sands started to accumulate around the JSL as early as the early Holocene （around 11 ka）, while the rapid development of sand dunes occurred within the latest 0.1 ka. By comparison with climatic documents and human activities in adjacent regions, the initiation of sand accumulation around the JSL as early as the early Holocene is considered to be the result of low effective moisture in the Jilantai area. However, the rapid development of the sand dunes in the vast area surrounding the JSL was likely initiated by the intensified human activities which occurred within the latest 0.1 ka under warm and dry climatic conditions.

Flexible Hall sensor made of laser-scribed graphene

Graphene has shown considerable potential for sensing magnetic fields based on the Hall Effect,due to its high carrier mobility,low sheet carrier density,and low-temperature dependence.However,the cost of graphene in comparison to conventional materials has meant that its uptake in electronic manufacturing has been slow.To lower technological barriers and bring more widespread adoption of graphene Hall sensors,we are using a one-step laser scribing process that does not rely on multiple steps,toxic chemicals,and subsequent treatments.Laser-scribed graphene Hall sensors offer a linear response to magnetic fields with a normalized sensitivity of~1.12 V/AT.They also exhibit a low constant noise voltage floor of~50 nV√Hz p for a bias current of 100μA at room temperature,which is comparable with state-of-the-art low-noise Hall sensors.The sensors combine a high bendability,come with high robustness and operating temperatures up to 400°C.They enable device ideas in various areas,for instance,soft robotics.As an example,we combined a laser-scribed graphene sensor with a deformable elastomer and flexible magnet to realize low-cost,compliant,and customizable tactile sensors.

Scientific objectives of the Hot Universe Baryon Surveyor(HUBS) mission

The Hot Universe Baryon Surveyor(HUBS) is a proposed space-based X-ray telescope for detecting X-ray emissions from the hot gas content in our universe. With its unprecedented spatially-resolved high-resolution spectroscopy and large field of view,the HUBS mission will be uniquely qualified to measure the physical and chemical properties of the hot gas in the interstellar medium, the circumgalactic medium, the intergalactic medium, and the intracluster medium. These measurements will be valuable for two key scientific goals of HUBS, namely to unravel the AGN and stellar feedback physics that governs the formation and evolution of galaxies, and to probe the baryon budget and multi-phase states from galactic to cosmological scales. In addition to these two goals, the HUBS mission will also help us solve some problems in the fields of galaxy clusters, AGNs, difuse X-ray backgrounds, supernova remnants, and compact objects. This paper discusses the perspective of advancing these fields using the HUBS telescope.