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Freezing fraction and collision coefficient are the key parameters in the ice accretion model, which should be calculated to predict the icing trend for transmission lines. Here a mathematical relation between freezing fraction and collision coefficient was derived using the simplified head balance model of transmission lines icing. Combined with the empirical formula of the liquid water content in air, a calculation method of the freezing fraction and collision coefficient was proposed using the ice surface temperature of transmission lines and the icing mass growth rate. The method to measure the icing mass growth rate based on online monitoring data and icing experiments was proposed. The icing experiments were carried out in the low‐temperature ice chamber with the same parameters as the online monitoring environmental parameters. The values of the freezing fraction and collision coefficient were calculated by using the online monitoring data and icing experiments data respectively, the calculation results were compared. The maximum relative differences between the calculation results from the online monitoring data and the icing experiments data do not exceed 18%, which proves the validity of the calculation method of the freezing fraction and collision coefficient in ice accretion model of transmission lines.

The blood brain barrier (BBB) is an essential component in regulating and maintaining the homeostatic microenvironment of the central nervous system (CNS). During the occurrence and development of glioblastoma (GBM), BBB is pathologically disrupted with markedly increased permeability. Due to the obstruction imposed by the BBB, strategies currently employed for GBM therapeutics still obtain a very low success rate and lead to systemic toxicity. Moreover, chemotherapy could promote pathological BBB functional restoration, accompanied with a prominent decrease of intracerebral therapeutics transportion during GBM multiple administration, resulting in chemotherapy failure for GBM treatment. The effective delivery of therapeutics into the brain still faces with severe challenges. Regulation of pathological BBB for enhanced transporting of therapeutics across the barrier may provide new opportunities for effective and safe treatment of GBM. This article reviews the structure and function of BBB in physiological state, the mechanisms underlying BBB pathological fenestration during the development of GBM, and the therapeutic strategies of GBM based on BBB intervention and therapeutic drugs transporting across the BBB.

In recent years, neural image compression (NIC) algorithms have shown powerful coding performance. However, most of them are not adaptive to the image content. Although several content adaptive methods have been proposed by updating the encoder-side components, the adaptability of both latents and the decoder is not well exploited. In this work, we propose a new NIC framework that improves the content adaptability on both latents and the decoder. Specifically, to remove redundancy in the latents, our content adaptive channel dropping (CACD) method automatically selects the optimal quality levels for the latents spatially and drops the redundant channels. Additionally, we propose the content adaptive feature transformation (CAFT) method to improve decoder-side content adaptability by extracting the characteristic information of the image content, which is then used to transform the features in the decoder side. Experimental results demonstrate that our proposed methods with the encoder-side updating algorithm achieve the state-of-the-art performance., Comment: V1 is accepted to ECCV 2022. V2 is the improved version

This paper considers a robust time-consistent mean-variance-skewness portfolio selection problem for an ambiguity-averse investor by taking into account wealth-dependent risk aversion and wealth-dependent skewness preference as well as model uncertainty. The robust equilibrium investment strategy and corresponding equilibrium value function are characterized for such a problem by employing an extended Hamilton-Jacobi-Bellman-Isaacs (HJBI) system via a game theoretic approach. Furthermore, the robust equilibrium investment strategy and corresponding equilibrium value function are obtained in semi-closed form for a special robust time-consistent mean-variance-skewness portfolio selection problem. Finally, some numerical experiments are provided to indicate several new findings concerned with the robust equilibrium investment strategy and the utility losses.

The previous deep video compression approaches only use the single scale motion compensation strategy and rarely adopt the mode prediction technique from the traditional standards like H.264/H.265 for both motion and residual compression. In this work, we first propose a coarse-to-fine (C2F) deep video compression framework for better motion compensation, in which we perform motion estimation, compression and compensation twice in a coarse to fine manner. Our C2F framework can achieve better motion compensation results without significantly increasing bit costs. Observing hyperprior information (i.e., the mean and variance values) from the hyperprior networks contains discriminant statistical information of different patches, we also propose two efficient hyperprior-guided mode prediction methods. Specifically, using hyperprior information as the input, we propose two mode prediction networks to respectively predict the optimal block resolutions for better motion coding and decide whether to skip residual information from each block for better residual coding without introducing additional bit cost while bringing negligible extra computation cost. Comprehensive experimental results demonstrate our proposed C2F video compression framework equipped with the new hyperprior-guided mode prediction methods achieves the state-of-the-art performance on HEVC, UVG and MCL-JCV datasets., Comment: CVPR2022

To ensure the continuous operation of the voltage source converter based multi-terminal HVDC system (VSC-MTDC), there has been much concern regarding how to isolate the single-pole earth fault by means of protective relaying. However, when the boundary components are not on the dc transmission lines, conventional main protections for the HVDC systems perform less satisfactorily. To solve this problem, a local measurement-based ultra-high-speed main protection is proposed, in this paper. The proposed method is achieved by the cooperation of the single-end directional start-up criterion and the surge arrival time difference between the 0-mode and 1-mode traveling waves. According to the simulation results, the proposed method has satisfactory performance against internal faults and is quite reliable in external fault and operating condition changes. Meanwhile, the reach is also wide enough to cover most of the protected line. Comparison studies are also conducted among the proposed protection and three types of existing protection schemes, highlighting the advantages of the proposed protection in terms of selectivity, operating speed, and resistive tolerance.

Mining activities can result in serious contamination of soil by heavy metal(loid)s. In this study, the sources and spatial distribution of metal(loid)s, and the risks to public health from these metal(loid)s at an abandoned arsenic mine site were explored. The mean concentrations of arsenic (As), cadmium (Cd), mercury (Hg), manganese (Mn), lead (Pb), antimony (Sb), strontium (Sr), and thallium (Tl) in the soil in the mining area were higher than the mean background values. The main pollutants from the mining activities were As, Hg, and Sb. Five pollutant sources were identified using an approach that combined statistical methods, a positive matrix factorization model, and historical information analysis. As, Hg, Sb, and Tl were associated with the mining resources and related activities (37.29%); Mn (15.57%) and Sr (15.96%) were mainly from crustal origin and pedogenesis, respectively; Pb, Sb, and Tl were mainly from industrial sources (17.57%), and Cd was mainly from the production and application of phosphorous fertilizer (13.60%). Using incremental spatial autocorrelation crystallized that As, Hg, and Sb were mainly contained within 500 m of their source. There were formed existing non-carcinogenic hazards and carcinogenic risks from As, and potential carcinogenic risks from Cd, in the soil for those living locally.

To investigate the optimal radial-arranged-position of the optical fiber in the cross-linked polyethylene (XLPE) power cable, the fibers were arranged into three positions, including segmental conductor center, the insulation shield surface, and the waterproof compound center, respectively, and temperatures were measured based on the Brillouin optical time-domain reflectometry (BOTDR) technology while the thermocouples were arranged at the same positions mentioned above for comparison, respectively. Four cases of cable temperature rising experiments under the laying environments of duct and water were carried out. The conductor temperatures were calculated using the temperatures measured by the fibers at the insulation shield surface and waterproof compound center, and the differences between the calculated values and the measured temperatures by thermocouples were analyzed and compared. Results show the temperature differences at different axial positions of fibers at the insulation shield surface or the waterproof compound center were less than 0.22 °C. These were much less than the differences in different axial positions of thermocouples, among which the maximum is 4.8 °C. The maximum temperature differences between the fibers and the thermocouples at the three positions mentioned above were 4.9 °C, 3.2 °C, and 3.7 °C, respectively. The maximum transient relative differences of the conductor temperature between the calculated and measured values do not exceed 7.6% and 7.1%, respectively. And the steady-state relative differences do not exceed 2.6% and 4.7%, respectively. The insulation shield surface and waterproof compound center are recommended as the optical fiber arranged-position for calculating the conductor temperature.

In this paper, we propose a unified Multi-Object Tracking (MOT) framework learning to make full use of long term and short term cues for handling complex cases in MOT scenes. Besides, for better association, we propose switcher-aware classification (SAC), which takes the potential identity-switch causer (switcher) into consideration. Specifically, the proposed framework includes a Single Object Tracking (SOT) sub-net to capture short term cues, a re-identification (ReID) sub-net to extract long term cues and a switcher-aware classifier to make matching decisions using extracted features from the main target and the switcher. Short term cues help to find false negatives, while long term cues avoid critical mistakes when occlusion happens, and the SAC learns to combine multiple cues in an effective way and improves robustness. The method is evaluated on the challenging MOT benchmarks and achieves the state-of-the-art results., Comment: 10 pages, 7 figures

Based on various carbon nano materials, the ternary composite functionalized carbon nanotubes (FMWCNTs) @ carbon quantum dots (CQDs) @ polyaniline (PANI) was prepared by in-situ polymerization and hydrothermal method. The carbon-based material was made into an electrode sheet. The morphology and microscopic nanostructures were characterized by FTIR, field emission scanning electron microscopy and field emission transmission electron microscopy. Cyclic voltammetry and the galvanostatic charge discharge method was adapted to study the electrochemical properties of these active materials. Our results showed that the specific capacitance of FMWCNTs @ CQDs @ PANI was as high as 534 F/g, while it was 362 F/g, 319 F/g and 279 F/g for PANI @ FMWCNTs, PANI @ CQDs and polyaniline. This means that the specific capacitance of FMWCNTs @ CQDs @ PANI is increased by 47.5%, 67.4% and 91.4% comparing with the capacitance of PANI @ FMWCNTs, PANI @ CQDs and polyaniline, respectively. Moreover, the specific capacitance retention rate of the ternary active electrode after 1000 times of constant current charge and discharge cycle reached 86%, while it was 60% for PANI @ FMWCNTs, 72% for PANI @ CQDs and 65% for polyaniline.

Nanostructured ferritic alloy and silicon carbide composite materials (NFA-SiC) were sintered with spark plasma sintering (SPS) method and systematically investigated through X-ray diffraction (XRD), scanning electron microscopy (SEM), as well as density and Vickers hardness tests. Pure NFA, pure SiC, and their composites NFA-SiC with different compositions (2.5 vol% NFA-97.5 vol% SiC, 5 vol% NFA-95 vol% SiC, 97.5 vol% NFA-2.5 vol% SiC, and 95 vol% NFA-5 vol% SiC) were successfully sintered through SPS. In the high-NFA samples, pure NFA and NFA-SiC, minor gamma-Fe phase formation from the main alfa-Fe matrix occurred in pure NFA 950 degree C and 1000 degree C. The densities of the pure NFA and NFA-SiC composites increased with sintering temperature but decreased with SiC content. The Vickers hardness of the pure NFA and NFA-SiC composites was related to density and phase composition. In the high-SiC samples, NFA addition of 2.5 vol% can achieve full densification for the NFA-SiC samples at relative low temperatures. With the increase in sintering temperature, the Vickers hardness of the pure SiC and NFA-SiC composite samples were enhanced. However, the NFA-SiC composites had relative lower hardness than the pure SiC samples. A carbon layer was introduced in the NFA particles to prevent the reaction between NFA and SiC. Results indicated that the carbon layer was effective up to 1050 degree C sintering temperature. Green samples of gradient-structured NFA-SiC composites were successfully fabricated through slip casting of an NFA-SiC co-suspension. Master of Science

The all digital PET system is attracting more and more attentions due to its flexibility, scalability, reusability and upgradability. Based on the Trans-PET formerly developed by us, we are trying to fulfill online parameter calibration of the all digital PET system. The ability of thorough and quick online parameter calibration will make the system well adaptive to application variation, environment disturbance, system upgrading or even the structure reforming. In this paper, we introduced the online calibration mechanism to realize accurate energy discrimination in the detector module, as the initial results of our endeavors. The results showed that nearly 45% data was discarded, most of which were scatter events. Accurate and flexible energy discrimination was achieved, without clogging the system transmission media. In addition, it costs almost nothing other than very little computation and memory resources.

We are developing the Trans-PET BioCaliburn, an all-digital positron emission tomography (PET) scanner designed for state-of-the-art molecular imaging of animals at Huazhong University of Science and Technology (HUST). The basic detector module (BDM) receives annihilation photons, generates scintillation pulses, which are digitized by use of the multivoltage threshold (MVT) sampling method previously developed and reported by us, and sends single events' time, energy, and position to a personal computer. In the personal computer, post acquisition energy calibration, crystal identification, and coincidence detection are performed. It can arrange the BDMs into various scanner geometries for different imaging needs. In this work, we describe the design and implementation of a hexagonal ring PET scanner with six BDMs, for small animal imaging studies. The scanner, Trans-PET BioCaliburn SH1.0 has a transaxial field-of-view (FOV) of 9.2 cm diameter and axial FOV of 5.3 cm. The typical energy resolution is 14.2% fullwidth-at-half-maximum (FWHM) at 511 keY, and the coincidence timing resolution is 1.4 ns FWHM. Phantom images show that our small animal PET scanner can resolve 1.2 mm diameter rods that are separated by 2.0 mm. We also demonstrate the imaging capabilities of the scanner with in vivo images of mice.

随着金融全球化、电子化以及期货期权等交易品种的异军突起，全球场内衍生品市场得到了迅速发展，并呈现出交易品种和规模扩大化、交易平台电子化、交易所一体化和公司化等特征。其相对有效的风险管理机制给在次贷危机中遭受；中击的场外衍生品市场也提供了一定的借鉴。文章展望了在防范风险的前提下未来场内衍生品市场的发展方向，以期为中国衍生品市场的发展提供借鉴。 Owing to the development of financial globalization, electronic trading and futures/option trading surges, the global exchange-traded derivatives market is growing rapidly, and shows some features such as expanded products and trading volumes, electronic trading platforms and incorporated exchanges. Its comparatively effective risk control can be used as reference for the OTC derivatives market, which has suffered from the subprime crisis. This paper discusses the future development of the exchange-traded derivatives market and its risk control, in view of the future development of China＇s derivatives market.