Mega-Constellations Based TT&C Resource Sharing: Keep Reliable Aeronautical Communication in an Emergency

With the development of the transportation industry, the effective guidance of aircraft in an emergency to prevent catastrophic accidents remains one of the top safety concerns. Undoubtedly, operational status data of the aircraft play an important role in the judgment and command of the Operational Control Center(OCC). However, how to transmit various operational status data from abnormal aircraft back to the OCC in an emergency is still an open problem. In this paper, we propose a novel Telemetry, Tracking,and Command(TT&C) architecture named Collaborative TT&C(CoTT&C) based on mega-constellation to solve such a problem. CoTT&C allows each satellite to help the abnormal aircraft by sharing TT&C resources when needed, realizing real-time and reliable aeronautical communication in an emergency. Specifically, we design a dynamic resource sharing mechanism for CoTT&C and model the mechanism as a single-leader-multi-follower Stackelberg game. Further, we give an unique Nash Equilibrium(NE) of the game as a closed form. Simulation results demonstrate that the proposed resource sharing mechanism is effective, incentive compatible, fair, and reciprocal. We hope that our findings can shed some light for future research on aeronautical communications in an emergency.

Adaptive subsequence adjustment with evolutionary asymmetric path-relinking for TDRSS scheduling

Due to the limited transmission resources for data relay in the tracking and data relay satellite system （TDRSS）, there are many job requirements in busy days which will be discarded in the conventional job scheduling model. Therefore, the improvement of scheduling efficiency in the TDRSS can not only help to increase the resource utilities, but also to reduce the scheduling failure ratio. A model of nonhomogeneous parallel machines scheduling problems with time window （NPM-TW） is firstly built up for the TDRSS, considering the distinct features of the variable preparation time and the nonhomogeneous transmission rates for different types of antennas on each tracking and data relay satellite （TDRS）. Then, an adaptive subsequence adjustment （ASA） framework with evolutionary asymmetric path-relinking （EvAPR） is proposed to solve this problem, in which an asymmetric progressive crossover operation is involved to overcome the local optima by the conventional job inserting methods. The numerical results show that, compared with the classical greedy randomized adaptive search procedure （GRASP） algorithm, the scheduling failure ratio of jobs can be reduced over 11% on average by the proposed ASA with EvAPR.

Characterization and Performance Evaluation of Turbulent Plasma Sheath Channel

Radio waves are highly attenuated and distorted by turbulent plasma sheath around hypersonic vehicles in near space, leading to communication blackout. The purpose of the paper is to investigate the plasma channel characteristics and the communication performances over the channel. We treat the turbulent plasma medium as a fast fading wireless channel. The coherence time and the spectrum spread of the plasma sheath channel are obtained in terms of root-meansquare(RMS). Baseband simulation scheme is proposed based on a stratified model of the plasma flow field. Results indicate that the coherence time is on the order of milliseconds and decreases rapidly with the increasing electron density turbulence. The spectrum spread due to plasma turbulence is also significant. Extensive simulations have been carried out to make communication performance evaluations. Quantitative results show that error floor takes place for PSK and QAM, while FSK with noncoherent detection is a promising method to mitigate the blackout problem.

Water-soluble lipopolymer delivery of N-methyl-D-aspartic acid receptor 2B siRNA relieves chronic neuropathic pain in rats

Spinal dorsal horn N-Methyl-D-aspartic acid receptor 2B （NR2B） overexpression plays an important role in the production and maintenance of neuropathic pain. Because small interfering RNA （siRNA） can inhibit NR2B expression, siRNA may provide a novel approach to treat neuropathic pain and possibly nerve injury. However, an efficient and safe vector for NR2B siRNA has not been discovered. This study shows that a water soluble lipopolymer （WSLP） comprised of low molecular weight polyethyleneimine （PEI） and cholesterol can deliver siRNA targeting NR2B for the treatment of neuropathic pain. Results show that intrathecal injection of WSLP/siRNA complexes for 3 days inhibit NR2B gene expression with reductions in mRNA and protein levels by 59% and 54%, respectively, compared with control rats （P 〈 0.01）. Injection of WSLP complexed with scrambled siRNA, or PEI with siRNA did not show this inhibitory effect. Moreover, injection of WSLP/siRNA complexes significantly relieved neuropathic pain at 3, 7, 12, and 21 days, while injection of WSLP with scrambled siRNA or PEI with siRNA did not. These results demonstrate that WSLP can efficiently deliver siRNA targeting NR2B in vivo and relieve neuropathic pain.

Thermal stability and thermoelectric properties of Cd-doped nano-layered Cu2Se prepared using NaCl flux method

Cu2Se is a promising"phonon liquid-electron crystal"thermoelectric material with excellent thermoelectric performance.In this work,Cd-doped Cu2-xSeCdx(x=0,0.0075,0.01,and 0.02)samples were prepared using NaCl flux method.The solubility of Cd in Cu2Se at room temperature was less than 6%,and a second phase of CdSe was found in the samples with large initial Cd content(x=0.01 and 0.02).Field-emission scanning electron microscopic image showed that the arranged lamellae formed a large-scale layered structure with an average thickness of approximately 100 nm.Transmission electron microscopy demonstrated that doping of Cd atoms did not destroy the crystal integrity of Cu2Se.A small amount of Cd in Cu2Se could reduce the electrical and thermal conductivities of the material,thus significantly enhancing its thermoelectric performance.With the increase in Cd content in the sample,the carrier concentration decreased and the mobility increased gradually.Thermogravimetric differential thermal analysis showed that no weight loss occurred below the melting point.Excessive Cd doping led to the emergence of the second phase of CdSe in the sample,thus significantly increasing the thermal conductivity of the material.A maximum ZT value of 1.67 at 700 K was obtained in the Cu1.9925SeCd0.0075 sample.

Detecting While Accessing:A Semi-Supervised Learning-Based Approach for Malicious Traffic Detection in Internet of Things

In the upcoming large-scale Internet of Things(Io T),it is increasingly challenging to defend against malicious traffic,due to the heterogeneity of Io T devices and the diversity of Io T communication protocols.In this paper,we propose a semi-supervised learning-based approach to detect malicious traffic at the access side.It overcomes the resource-bottleneck problem of traditional malicious traffic defenders which are deployed at the victim side,and also is free of labeled traffic data in model training.Specifically,we design a coarse-grained behavior model of Io T devices by self-supervised learning with unlabeled traffic data.Then,we fine-tune this model to improve its accuracy in malicious traffic detection by adopting a transfer learning method using a small amount of labeled data.Experimental results show that our method can achieve the accuracy of 99.52%and the F1-score of 99.52%with only 1%of the labeled training data based on the CICDDoS2019 dataset.Moreover,our method outperforms the stateof-the-art supervised learning-based methods in terms of accuracy,precision,recall and F1-score with 1%of the training data.

系统视角下的6G通信创新展望

The history of wireless communications can be divided into two eras.The first was a discovery-inspired era,initiated by the great physicist Maxwell’s discovery of the classical theory of electromagnetism,while the second was a technology-driven era that began with Marconi’s creation of the first practical world-wide radio-based wireless telegraph system,Shannon’s information theory,and the later invention of cellular mobile communications from the first generation(1G)to the fourth(4G).Nowadays,the fifth generation(5G)is regarded as a leading information and communication technology.

A Quantitative Method of Detecting Transient Rossby Wave Phase Speed:No Evidence of Slowing Down with Global Warming

Based on the Complex Empirical Orthogonal Functions(CEOFs)of bandpass-filtered daily streamfunction fields,a quantitative method of detecting transient(synoptic)Rossby wave phase speed(RWPhS)is presented.The transient RWPhS can be objectively calculated by the distance between a high(or low)center in the real part of a CEOF mode and its counterpart in the imaginary part of the same CEOF mode divided by the time span between two adjacent peaks(or bottoms)of two principal component curves for the real and imaginary parts of that CEOF mode.The new detection method may partly reveal the spatiotemporal heterogeneity of Rossby wave prorogation.Although the mean westerly jet at 200 hPa doubles the speed of its counterpart at 500 hPa,the estimated RWPhS at both levels are around 1000 km d^(–1)and quantitatively consistent with the quasigeostrophic-theory-based RWPhS,confirming that the meridional potential vorticity gradient induced by the barotropic and baroclinic shears of mean flow,together with theβeffect,play an essential role in Rossby wave propagation.Both observations over the past four decades and a 150-year historical simulation suggest no evidence for slowing wintertime transient Rossby waves in the Northern Hemisphere,but possible regional changes are not excluded.We emphasize that not only the mean flow speed,but also the barotropic and baroclinic shears of the mean flow,and their associated contributions to the meridional potential vorticity(PV)gradient,should be considered in investigating the possible change of Rossby waves with global warming.

Total mesopancreas excision for pancreatic head cancer: analysis of 120 cases

Objective： To evaluate the feasibility and safety of total mesopancreas excision （TMpE） in the treatment of pancreatic head cancer. Methods： The clinical and pathological data of 120 patients with pancreatic head cancer who had undergone TMpE in our center from May 2010 to January 2014 were retrospectively analyzed. Results： The mean operative time was （275.0±50.2） min and the average intra-operative blood loss was （390.0±160.5） mL. Post-operative complications were reported in 45 patients, while no peri-operative death was noted. The specimen margins were measured in three dimensions, and 86 patients （71.6%） achieved R0 resection. Conclusions： TMpE is safe and feasible for pancreatic head cancer and is particularly helpful to increase the R0 resection rate.

Evolving Perspectives on Abrupt Seasonal Changes of the General Circulation

Professor Duzheng YE（Tu-cheng YEH） was decades ahead of his time in proposing a model experiment to investigate whether abrupt seasonal changes of the general circulation can arise through circulation feedbacks alone, unrelated to underlying inhomogeneities at the lower boundary. Here, we introduce Professor YEH＇s ideas during the 1950 s and 1960 s on the general circulation and summarize the results and suggestions of Yeh et al.（1959） on abrupt seasonal changes. We then review recent advances in understanding abrupt seasonal changes arising from model experiments like those proposed by Yeh et al.（1959）. The model experiments show that circulation feedbacks can indeed give rise to abrupt seasonal transitions.In these transitions, large-scale eddies that originate in midlatitudes and interact with the zonal mean flow and meridional overturning circulations in the tropics play central roles.

The theory of compression–shear coupled composite wave propagation in rock

The wave velocity analysis of rock medium is the main method used to explore the internal compositions in the crust and research seismic.In this paper,a compression–shear coupled nonlinear elastic constitutive relation is established,which is consistent with the mechanical properties of rock and mineral medium under high pressure.On this basis,numerical solutions of the wave equation and plane wave analytical solutions for the primary and secondary wave velocities are obtained.As is indicated by the comparison with the linear elastic constitutive theory,the results reflect the compression–shear coupling characteristics of the rock,including the stress path effect and the compression–shear coupling wave effect.With different parameter values,the velocity of the secondary wave changes from lower than that of the elastic shear wave,to higher than that of the elastic shear wave.The research results are expected to provide meaningful explanations for the physical mechanisms of the supershear wave and sub-Rayleigh wave,and guidance for the detection of rock and soil composition and the observation of seismic waves.

Characterization of circRNAs associated with resistance to defoliating insects in soybean

Circular RNAs (circRNAs) are new type of non-coding endogenous RNA characterized by presence of covalent bond linking 3′ and 5′ ends recently. Various endogenous circRNAs with potential biological functions have been identified in animals and plants.However, little is known regarding circRNAs in soybean. In this study, we have performed genome-wide profiling of circRNAs that associate with insect resistance in soybean through bulk segregant RNA-seq and bioinformatics analysis. In total, 5,367 circRNAs were identified,of which 3,377 and 3,457 ones were detected from resistant and susceptible bulks respectively. These circRNAs showed diverse expression patterns, and 199 circRNAs were found to be differentially expressed between resistant and susceptible samples under stress of defoliation-damage by cotton bollworm feeding. Functional categorization of circRNA-hostgenes revealed that various biology processes were triggered to be active during chewing injury. Intriguingly, some circRNAs were predicted to involve in insect resistance processes,such as tropane, piperidine and pyridine alkaloid biosynthesis, and monoterpenoid biosynthesis.Furthermore, 1,118 circRNAs were predicted to have enrichened miRNA binding sites in soybean. This research provid not only circRNAs resources, but also useful clues about their biological insights in response to defense biotic stress in plant.

Chen-Chao Koo and the Early Numerical Weather Prediction Experiments in China

Although the first successful numerical weather prediction(NWP)project led by Charney and von Neumann is widely known,little is known by the international community about the development of NWP during the 1950s in China.Here,a detailed historical perspective on the early NWP experiments in China is provided.The leadership in NWP of the late Professor Chen-Chao Koo,a protége of C.G.Rossby at the University of Stockholm during the late 1940s and a key leader of modern meteorology(particularly of atmospheric dynamics and physics)in China during the 1950s−70s,is highlighted.The unique contributions to NWP by Koo and his students,such as the ideas of formulating NWP as an“evolution”problem,in which the past data over multiple time steps are utilized,rather than an initial-value problem,and on the cybernetic aspects of atmospheric processes,i.e.,regarding the motion of the atmosphere at various time scales as an optimal control system,are also emphasized.

SIMPLE & SMART DESIGN: NEW PARADIGM REQUIRED FOR INNOVATIVE CHANGE

The go-go information and communication tech-nologies(ICT)led by 5G will have confirmed further developing opportunities.On the other hand,while continuing to promote 5G construction,appli-cation,and development,it is necessary to scientifi-cally study and judge the ICT development trend,and strategically plan its future.In particular,as the infrastructure scale of ICT being increasing rapidly,the system complexity is getting higher and higher,while a rational system capacity w.r.t scale is be-coming more and more difficult to characterize.How to achieve a systematic,predictive and creative de-velopment has become a prominent problem,which ushers in talented competition amongst global scien-tific and technological professionals in the field.

Constraining the Emergent Constraints

An accurate estimate of equilibrium climate sensitivity(ECS)is pivotal to humankind’s responses,including both the mitigation and adaptation,to future global climate change(not necessarily that of a distant future).However,the uncertainty in estimates of ECS remains large,as shown in the past assessments by the Intergovernmental Panel on Climate Change(IPCC)(see IPCC,2013),though the level of understanding on the physics and dynamics of Earth’s climate system has improved considerably during the past four decades since the appearance of the Charney report(Charney et al.,1979).

Visualization of nasal powder distribution using biomimetic human nasal cavity model

Nasal drug delivery efficiency is highly dependent on the position in which the drug is deposited in the nasal cavity.However,no reliable method is currently available to assess its impact on delivery performance.In this study,a biomimetic nasal model based on three-dimensional(3D)reconstruction and three-dimensional printing(3DP)technology was developed for visualizing the deposition of drug powders in the nasal cavity.The results showed significant differences in cavity area and volume and powder distribution in the anterior part of the biomimetic nasal model of Chinese males and females.The nasal cavity model was modified with dimethicone and validated to be suitable for the deposition test.The experimental device produced the most satisfactory results with five spray times.Furthermore,particle sizes and spray angles were found to significantly affect the experimental device’s performance and alter drug distribution,respectively.Additionally,mometasone furoate(MF)nasal spray(NS)distribution patterns were investigated in a goat nasal cavity model and three male goat noses,confirming the in vitro and in vivo correlation.In conclusion,the developed human nasal structure biomimetic device has the potential to be a valuable tool for assessing nasal drug delivery system deposition and distribution.

Regulation of the cellular uptake of nanopartides by the orientation of helical polypeptides

Controlling the cellular interactio n and internal izatio n of polymer-modified nan oparticles (NPs) is of central importa nee to the developme nt of promisi ng nano medici nes. Here, we describe the use of synthetic polypeptides for NP surface coati ng and regulati on of their cellular uptake behaviors by simply switching the conformation and anchoring orientation. Our results show that gold NPs (AuNPs) coated with a helical poly(Y-(2-(2-(2-methoxyethoxy)ethoxy)ethoxy)esteryl「glutamate)(L-P(EG3Glu)5o) from the C-terminus ((L-C)-AuNPs) exhibit greater zeta potential and more cellular uptake (2.0-5.5 fold higher) than those coated with the same polypeptide but anchored from the N-terminus ((L-N)-AuNPs), or from both the C- and N-terminus at a 1/1 molar ratio ((L-C/L-N)-AuNPs). A similar orientation-regulated cellular internalization pattern is observed in D-P(EG3Glu)50 but not the unstructured DL-P(EG3Glu)5o-rnodified AuNPs, suggesting an important and universal role of the helix-derived macrodipole in cellular uptake. Moreover, this orientation-governed internalization is successfully reproduced in P(EG3Glu)50-coated gold nano rods (AuNRs), and applied to the desig n of doxorubici reloaded polypeptide micelles. Simulation study offers time-resolved in sights regarding the NP-membrane in teracti ons and membrane remodeling. Thus, our study provides a delicate way of regulating the surface chemistry of NPs and the subsequent NP-cell interactions. Moreover, the results highlight the uniqueness of polypeptides in NP surface engineering, and urge a more careful consideration on the polymer orientation effect.

Inactivated SARS-CoV-2 booster vaccine enhanced immune responses in patients with chronic liver diseases

Chronic liver disease(CLD)entails elevated risk of COVID-19 severity and mortality.The effectiveness of the booster dose of inactivated SARS-CoV-2 vaccine in stimulating antibody response in CLD patients is unclear.Therefore,we conducted a cross-sectional study involving 237 adult CLD patients and 170 healthy controls(HC)to analyze neutralizing antibodies(NAbs)against SARS-CoV-2 prototype and BA.4/5 variant,anti-receptor binding domain(RBD)IgG,and total anti-SARS-CoV-2 antibodies.Serum levels of the total anti-SARS-CoV-2 antibodies,anti-RBD IgG and inhibition efficacy of NAbs were significantly elevated in CLD patients after the booster dose compared with the pre-booster dose,but were relatively lower than those of HCs.Induced humoral responses decreased over time after booster vaccination.The neutralization efficiency of the serum against BA.4/5 increased but remained below the inhibition threshold.All four SARS-CoV-2 antibodies,including total anti-SARS-CoV-2 antibodies,anti-RBD IgG and NAbs against prototype and BA.4/5,were lower in patients with severe CLD than those with non-severe CLD.After booster shot,age and time after the last vaccine were the risk factors for seropositivity of NAb against BA.4/5 in CLD patients.Additionally,white blood cell counts and hepatitis B core antibodies were the protective factors,and severe liver disease was the risk factor associated with seropositivity of total anti-SARS-CoV-2 antibodies.Overall,our data uncovered that antibody responses were improved in CLD patients and peaked at 120 days after the booster vaccines.All antibodies excepting total anti-SARS-CoV-2 antibodies declined after peak.CLD patients exhibited impaired immunologic responses to vaccination and weakened NAbs against BA.4/5,which hindered the protective effect of the booster shot against Omicron prevalence.Cellular immune responses should be further evaluated to determine the optimal vaccine regimen for CLD patients.