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Diabetic retinopathy (DR), one of the chronic complications of diabetes, is a serious and irreversible blinding disease. It is difficult to detect in the early stage, to control in the progressive stage, to operate in the advanced stage of DR. Recently, the "14th Five-year plan" for National Eye Health proposed to "improve the management mode of chronic eye disease, and build a chronic disease management system". The project team used artificial intelligence technology based on cloud platform, joint outpatient service, virtual ward to explore the comprehensive management of DR from the aspects of early screening, multidisciplinary collaborative diagnosis and treatment, and refined blood glucose management during perioperative period. In the future, it is urgent to integrate DR chronic disease management with other systemic chronic diseases to reduce the blindness caused by DR.糖尿病性视网膜病变（diabetic retinopathy，DR）是糖尿病慢性并发症之一，是严重的、难逆转的致盲性眼病，早期难发现、中期难控制、晚期难手术。近期“十四五”全国眼健康规划提出了“完善慢性眼病患者管理模式，构建眼病慢病管理体系”。本项目团队前期运用基于云平台的人工智能技术、联合门诊、云端虚拟病房等方式从早期筛查、进展期多学科协作诊疗、晚期围手术期血糖精细化管理等方面探索DR全病程慢病综合管理。未来亟待将DR慢病管理与全身系统性疾病综合管理融合链接，减少DR导致的盲。.

Previous preliminary clinical trials have confirmed that edoxaban can be efficacious for venous thromboembolism (VTE). This meta-analysis was considered to evaluate edoxaban's short-term efficacy and safety for venous thromboembolism after arthroplasty.A comprehensive search was performed in these databases: PubMed, MEDLINE, Web of Science, and EMBASE on March 2022. All eligible trials should be randomized controlled trials (RCTs) when evaluating short-term efficacy and safety outcomes of edoxaban for VTE after total hip or knee arthroplasty.Nine RCTs with 4274 patients were involved in this meta-analysis. Edoxaban in the VTE group prevented the incidence of VTE and indicated valuable clinical efficacy. The incidence of adverse events (AEs) and adverse drug reactions (ADRs) in the edoxaban group was decreased than that in other groups. Edoxaban increased the incidence of all bleeding events. However, in the edoxaban group and other groups, there was no statistical difference between major bleeding events and clinically relevant non-major or minor bleeding events. Edoxaban subgroups included edoxaban 15 mg, edoxaban 30 mg and edoxaban 60 mg prevented the incidence of VTE. Edoxaban 30 mg and 60 mg group increased the risk of all bleeding events. Edoxaban 30 mg can increase the incidence of major bleeding events. There was no difference in clinically relevant non-major or minor bleeding events. Edoxaban 30 mg can decrease the incidence of AEs.Edoxaban was an efficacious and safe option to prevent and treat VTE in patients undergoing arthroplasty. However, we need further trials to explore edoxaban's long-term efficacy and safety.

Synthetic hydroxyapatite (HA) and its related materials have made great progress in basic research and clinical application in spinal repair and reconstruction. However, the effect of HA and its composites used in spinal fusion still remained controversial. This meta-analysis aimed at evaluating the efficacy and safety of HA compared with autologous bone.A systematic search in PubMed, MEDLINE, China National Knowledge Internet, EMBASE, and the Cochrane Library was conducted for relevant studies from inception until May 2021. Studies investigating the application of HA and its related composites in spinal fusion were selected for analysis.The operation time of patients treated with artificial bone containing HA was less than that of patients with autologous bone (p = 0.02). The amount of operative blood loss in patients in the HA group was less than that in the autograft group (p = 0.007). Patients treated with autologous bone got a more significant advantage in fusion rate at 6 months (p = 0.009). Nevertheless, there was no significant difference in the fusion rate between patients in the two groups at 12 months or no less than 24 months postoperatively (p = 0.24; p = 0.87). Compared to the autograft group, the HA group significantly decreased postoperative adverse events (p = 0.03). Furthermore, there was no significant difference in the Oswestry Disability Index (p = 1.00) nor the Visual Analogue Scale score (p = 0.94) between the two groups.This meta-analysis suggests that the clinical application of HA and its related composite materials in spinal reconstruction is comparable to that of autologous bone, with satisfactory efficacy and safety.

A mesoscopic model was established to investigate thermo-fluid dynamic behavior in selective laser melting of 316L stainless steel. A powder packing model, including particle size distribution based on the discrete element method, was developed to describe the relative density variation of the powder bed with different layer thicknesses. A finite element method model with Gaussian laser beam was established to predict the dynamic thermal behavior and flow mechanism of the particles for a single-line scanning. The level-set method was used to trace the free surface of the molten metal with temperature-dependent surface tension. A function to describe the relative density of the powder bed with its thickness was obtained. An evaporation model considering the influence of mass, energy loss, and evaporation on the surface morphology of the molten pool was established. According to the temperature and velocity field in the molten pool, a vortex formed by the Marangoni effect might decrease the depth and increase the width of the molten pool. The molten pool was not disconnected by Plateau–Rayleigh instability due to the small length/diameter ratio at low scanning speeds. The model assuming regularly arranged powder bed underestimates the maximum temperature as compared to the model considering a randomly packed powder bed because a higher relative density of the former facilitates heat conduction. The simulated results are consistent with experimental results, including porosity, material loss, and surface defects.

The laminated natural rubber bearings (NRBs) used in offshore or sea-crossing bridges, are subjected to marine environments over an extended period and therefore vulnerable to the effect of alternating ageing and sea corrosion caused by weather conditions such as temperature, rain, sun, sea winds, waves etc. In addition, there are no systematic theories about the tension capability for NRBs now. Therefore, in this paper, the alternating of ageing and sea corrosion test on 12 NRBs was conducted for 60 days to investigate the deterioration trend of its tension shear property with different horizontal shear strains. Test results show that initial tension stiffness, yield stiffness and yield tension stress with different horizontal shear strains, all decrease with the alternating ageing and sea corrosion test time. Further, tension failure stress and strain with 50% and 100% horizontal shear strain, also decreases with the alternating ageing and sea corrosion test time. After testing for 60 days, both the tension failure stress and tension failure strain with 100% horizontal shear strain have the biggest drop. Additionally, only broken rubber is left after NRB failure before and after testing for 60 days.

胆囊神经内分泌肿瘤相对罕见，而同时含有多种不同上皮性及肉瘤成分的混合性神经内分泌肿瘤在胆囊则更为罕见。胆囊混合性神经内分泌肿瘤患者早期缺乏特异性症状往往导致延期诊断，其预后也比单纯性肿瘤更差，因此正确的病理诊断对临床评估患者预后及选择治疗方案具有重要意义。该文报道1例发生在胆囊同时含有大细胞神经内分泌癌、腺癌和肉瘤成分的混合性肿瘤，探讨其临床病理特征、诊断及鉴别诊断，并进行讨论。.

Today’s small rotor helicopter vehicles mostly use electric motors and batteries as power sources. Most helicopter power configurations are either front powered or rear powered, causing the center of the helicopter to be offset. This kind of offset should be overcome by structural compensation or by adjusting the angle of attack of the blades, but some lift of the angle of attack will be sacrifice at the same time. This paper proposes a new type of electric helicopter powertrain design. The advantage of new type helicopter design is setting the centre of gravity at the centre position of helicopter. The main shaft of the helicopter through the power transmission method of the electric motor built into the internal gear of the star gear, which improves the design of the center offset of the helicopter. That is improved the flight stability of the helicopter. At the same time, in terms of power transmission, the motor power consumed by the primary gear power of the star gear, while the traditional helicopter power transmission method has three or four gear power losses. The new concept of electric motor with star gear structure proposed in this paper can effectively reduce the transmission power loss of the gear. In addition, the distributed power control system proposed in this paper also reduces the possibility of helicopter crash due to motor failure.

Aims. We present secular multiwavelength broadband photometry, spanning over 93 days, performed at the Yaoan High Precision Telescope on comet 64P/Swift-Gehrels in its 2018–2019 apparition. Our aim is to study its dust activity, coma properties, and the accidentally discovered mini-outburst. Methods. We used aperture photometry to measure the Afρ value and correct the back-scattering effect based on phase angle. We deployed azimuthally averaged image enhancement methods to identify the coma morphology and the outburst. Secular color measurement was also conducted on the comet. Results. We identified a −0.5 mag mini-outburst around January 3, 2019, with coma morphology study showing an obvious dust jet feature strengthened during the outburst. The maximum A(0)fρ value of 64P/Swift-Gehrels recorded is 313 cm at the top of the fitted curve and 334 cm at the outburst event. Both volatile-driven pressure mechanisms and nonvolatile-driven mechanisms could be the major explanation for the outburst. We obtain a mean color B − V = 0.68 ± 0.03 and V − R = 0.08 ± 0.01. The B − V color is similar to the mean value for Jupiter Family comets, but the V − R color turns out to be bluest among all the recorded short-period comets. The cause of this anomaly remains unknown.

The ability to correctly perceive time and extract accurate timing information is crucial during social interaction. In fact, several activities during social interaction, such as appropriate feedback, turn-taking, coordination with peers, and even empathy and engagement exhibition directly depend on it. One of the aspects of cognitive malfunctioning in children with Autistic Spectrum Disorders is time perception deficit. Learning to pay attention to and correctly assess timing is thus a critical first step to improve social skills for children with Autism. In this paper, we present a novel sensing system and algorithm for estimating a subject's rhythmic motion timing from visual information using Recurrent Neural Network (RNN) coupled with FFT. This system will enable a robot saxophonist to estimate the rhythmic period from a child's motion during a robot-based music therapy session. Fast-Fourier- Transform (FFT) is an algorithm widely applied in rhythmic body movement detection, due to advantages such low computation and easy integration. However, long transient time delay is a critical limitation, reducing the correct motion timing estimation during period transitions. The novel system presented in this article is shown to significantly reduce transient time delay. The results of both a simulation and an evaluation experiment show that, compared with FFT processing alone, this algorithm gives a better performance due to its smaller average offset error and shorter transient time delay, allowing a more precise assessment of the child's synchronization response.

The necrotrophic pathogen

To explore the influence of micro ribonucleic acid (miR)-34a on renal ischemia-reperfusion by regulating Kruppel-like factor 4 (KLF4).A total of 36 Sprague-Dawley (SD) rats weighing 180-200 g were randomly divided into sham operation group (n=12), model group (n=12), and miR-34a inhibitor group (n=12). Renal ischemia-reperfusion modeling was performed in rats of model group and miR-34a inhibitor group. Those in the sham operation group received the same procedures without ligation. 200 μL of miR-34a inhibitor was pre-injected before modeling in rats of miR-34a inhibitor group. An automatic biochemical analyzer was used to detect serum creatinine and urea nitrogen levels in each group of rats, thus reflecting renal functions. The expressions of B-cell lymphoma 2 (Bcl-2), an apoptotic protein, and KLF4, a transcription factor, were detected via Western blotting. Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) assay was conducted to measure the expression levels of miR-34a and KLF4 in rat renal tissues in each group. Immunohistochemistry was employed to determine the expressions of inflammatory factors tumor necrosis factor-alpha (TNF-α) and interleukin-10 (IL-10). Additionally, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) staining was utilized to determine the apoptotic rate in rat kidney tissues in each group.Compared with those in the sham operation group, serum creatinine level, urea nitrogen level, expressions of miR-34a, TNF-α and Bcl-2 (p0.05) increased, while the levels of KLF4 and IL-10 (p0.05) decreased in the model group. Apoptosis rate was also higher in the model group than the controls. In comparison with the model group, miR-34a inhibitor group had lowered serum creatinine level, urea nitrogen level, expressions of miR-34a, TNF-α and Bcl-2, and apoptotic rate (p0.05), but raised levels of KLF4 and IL-10 (p0.05), showing statistically significant differences.Downregulation of miR-34a ameliorates inflammatory response and apoptosis induced by renal ischemia-reperfusion by promoting KLF4 level, thus improving renal functions in rats.

1. Over the past decade, rapid advancement in isolation methods for identifying markers of the once elusive intestinal stem cell (ISC) populations has laid the foundation for unravelling their complex interrelationships during homeostasis. Study on ISC in avian intestinal tissue might play a pivotal foundation for further studies on the epithelial-to-mesenchymal transition (EMT) in gastrointestinal disease and cell-based therapy as well as intestinal tissue engineering. 2. The following experiment isolated a population of fibroblast-like, plastic adhering cells derived from chick embryo intestine, showing a strong self-renewing and proliferative ability, which was maintained in vitro up to passage 25. The findings included growth characteristics, detected expression of cell surface markers and characterised the capability of these cells to differentiate towards the osteogenic, adipogenic, and chondrogenic cell lineages. 3. RT-PCR analysis showed that these cells from chick embryos expressed mesenchymal stromal cell markers CD44, CD90 and VIMENTIN as well as ISC-specific genes LGR5, MI1, SMOC2, BMI1, and HOPX. Immunofluorescence and flow cytometry confirmed this biology characterisation further. 4. In conclusion, cells were isolated from the intestine of 18-day-old chicken embryos that exhibited the biological characteristics of mesenchymal stromal cells as well as markers of intestinal stem cells. Our findings may provide a novel insight for in vitro cell culture and characteristics of ISCs in avian species, which may also indicate a benefit for obtaining cell source for intestinal tissue engineering as well as cell-based investigation for gastrointestinal disease and treatment.

Because of the small square dimension, a soldered-stacked-square (3S) high-temperature superconducting (HTS) wire with 1 mm width is considered as a candidate for cabling large current conductors through twist process. For studying the twist structure, in this work, we prepared several twisted 3S wire samples fabricated from the same piece of the 3S wire with 10 m length. For the 3S wire, the uniformity of critical current was evaluated. As well, we investigated basic electrical and mechanical characteristics for the twisted 3S wire. The main results show that the critical current distribution for the 3S wire is relatively uniform at the average value of 90 A; the allowable minimum twist pitch of the twisted 3S wire is about 60 mm; the critical current of the twisted 3S wire shows isotropy characteristics; through the test for frequency dependence of self-field loss, we can know the eddy-current loss in the twisted 3S wire can be ignored, and the measured losses are identical to the calculated one from the thin strip equation; the minimum bending diameter and allowable tensile force for the twisted 3S wire are approximately 80 mm and 400 N, respectively.

Low temperature has become a major abiotic stress factor that can reduce maize yield and cause a number of economic loss. This study was designed to identify key genes and pathways associated with coldresistance of maize. The gene expression profile GSE46704, including 4 control temperature treated plants and 4 low temperature treated plants, was downloaded from the Gene Expression Omnibus database. Differentially-expressed genes (DEGs) were identified by limma package. Then, protein-protein interaction (PPI) network and module selection were constructed using Cytoscape. Moreover, the DEGs were re-matched based on the Zea mays L. gene ID and symbol data from PlantRegMap. Finally, the re-matched DEGs were performed functional and pathway enrichment analyses by the DAVID online tool. A total of 750 DEGs were screened (including 387 up-regulated and 363 down-regulated genes) In the PPI network, GRMZM2G070837_P01 and GRMZM2G114578_P01 had higher degrees. Besides, carbohydrate metabolic process, starch and sucrose metabolism and biosynthesis of secondary metabolites were significantly enriched in functional and pathway enrichment analysis. GRMZM2G070837_P01 and GRMZM2G114578_P01 might play a critical role in cold-resistance of maize. Meanwhile, carbohydrate metabolic process, starch and sucrose metabolism and biosynthesis of secondary metabolites might function in cold-resistance of maize.

The influence of various concentrations of imazapic residues (0–800 μg kg–1) on the growth, chlorophyll content, and photosynthetic characteristics of maize seedlings was studied in a greenhouse pot experiment. Plant height, root length, shoot dry mass, root dry mass, and total dry mass of maize declined with the increase of imazapic residue concentrations. The root/shoot ratio initially decreased and then increased in presence of imazapic, which indicated that the effects of imazapic residues on plant height and root length might differ in maize seedlings. Lowered chlorophyll content and net photosynthetic rate were observed in leaves of maize seedlings in all treatments and indicated a dose-response relationship to imazapic concentrations. Intercellular carbon dioxide concentration, transpiration rate, and stomatal conductance also declined to varying extents, but the chlorophyll a/b ratio increased gradually together with the increase of imazapic residue concentrations. Generally, the maize seedlings were negatively affected by the imazapic residues in soil. Response of root length and biomass to imazapic residues could be the important index for maize variety selection.

Long non-coding RNAs (lncRNAs) exhibit important roles in a variety of biological properties of tumors. LncRNA HCG18 (HCG18) is a newly identified lncRNA whose roles in tumor progression remains largely unclear. The objective of our current research was to explore the roles and the underlying mechanisms of HCG18 in nasopharyngeal carcinoma (NPC).Reverse Transcription-Polymerase Chain Reaction (RT-PCR) was used to determine the levels of HCG18 in NPC tissue and cell lines. Clinical significances and prognostic values of HCG18 were analyzed using the statistical methods. Cell Counting Kit-8 (CCK-8) assays, clonogenic survival assays, flow cytometry, wound-healing assays, and transwell assays were used to examine the tumorigenesis functions of HCG18 in vitro. Insights of the mechanism of ceRNAs were gained from bioinformatic methods and Luciferase analysis. Western blot was performed to determine the expression of tumor-related pathways.We found that HCG18 expression was upregulated in both NPC specimens and cell lines. Higher levels of HCG18 were associated with positive lymph node metastasis and poor prognosis of NPC patients. Importantly, the multivariate analysis confirmed that HCG18 was an independent risk factor for outcome. Functionally, the downregulation of HCG18 exhibited tumor-suppressive effects via the inhibition of cell proliferation and metastasis. Mechanistically, HCG18 may directly bind to miR-140 and effectively act as a ceRNA for miR-140 to increase the expression of cyclin D1 (CCND1). In addition, HCG18 may contribute to NPC progression via modulating Wnt/β-catenin signaling and Hedgehog pathway.Our findings suggested that HCG18 served as an oncogenic lncRNA in NPC progression, which may provide a novel biomarker of an unfavorable outcome and a potential therapeutic target for NPC.

Systematic measurements of electrical resistivity and Hall coefficient under high pressure were performed on CaFe

患者产后2个月逐渐出现双手背散在水疱，光照后加重，避光后减轻，伴瘙痒，无疼痛。发病时尿色发红，常与病情严重程度一致，缓解期尿色正常。检查结果显示，尿胆色素原（PBG）试验阴性，尿曝光试验阳性，尿卟啉试验阳性。基因检测发现编码原卟啉原氧化酶（PPOX）基因发生突变（c.471GA），诊断为变异型卟啉病。.

In recent years, more and more studies on the strength of interpersonal relationship show that there are some positive social connections in online social networks. In addition, in the process of information dissemination, there may be some key nodes. In order to determine the key nodes of online social networks, we propose a method of edge weight recognition based on historical interaction records. According to the forwarding quantity, the influence of nodes is quantified, and the top node is selected as the key node. We apply our method to a real network and get good results.

Internal spiral groove dry gas seal (ISGDGS) are used to seal special positions of rotating machinery. There is an urgent need to address the problems caused by contacting of rotating and static rings during high-speed rotation of ISGDGS. The main aim of this study is to investigate the influence of spiral groove structural parameters on ISGDGS sealing performance. Fluid-solid-thermal coupling method was used to analysis the relationship of sealing performance (opening force, leakage, friction power, and gas film stiffness) and spiral-groove structural parameters. The test analysis method is used to study the sealing performance under four different structural parameters, and the obtained trends are the same as the analysis results. According to the analysis results, the value range of structural parameters for optimal sealing performance is proposed This thesis has provided a deeper insight into the influence of the structural parameters of end face on the sealing performance, and provides a basis for its optimal design.

Compared with the metal bristles, the flexible bristles can reduce the heat and wear caused by the friction between the bristles bundle and the rotor, and improve the working stability and working life of the brush seal. In this paper, the L-shaped numerical mode is established to analyze leakage characteristics of flexible bristle brush seal. The flow field of brush seal is analyzed, and the effects of differential pressure, rotating speed and temperature on the leakage rate were studied as well. The leakage rate of the flexible bristles brush seal under different pressure and rotating speed was measured and compared with the numerical results. The results show that: Pressure drop mainly occurred in bristles pack; Small pressure difference, high temperature and high speed can improve the sealing performance, which, shows that the flexible bristles brush seal can well adapt to high temperature and high speed conditions; The leakage rate after running-in is slightly lower than that before running-in, and has better sealing performance, and the brush bristles arrangement is complete and tight after test, indicating that the flexible bristle brush seal has the ability of lasting and stable seal; The error between experimental results and numerical simulation results is less than 10%, and the variation trend is consistent, confirming the accuracy of the leakage rate obtained by numerical simulation.

In this paper, several explicit formulas for the number of representations of a positive integer by sums of mixed numbers are determined by employing theta function identities and the [Formula: see text]-parametrization of theta functions due to Alaca, Alaca and Williams. It is interesting that the formulas proved in this paper are linear combinations of [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text], [Formula: see text] and [Formula: see text].

In high temperature superconducting (HTS) cable applications, AC loss is always a critical issue and an obstacle to the commercialization, and the cables are usually composed of conductors with cylindrical structure. To study the effect of the magnetic field distribution with noncircular shape on AC losses, four hexagonal single-layer conductors are prepared using BSCCO, YBCO, and YBCO NiW tapes. Besides the BSCCO and YBCO conductors, conductors consisting of YBCO NiW tape are tested with the Ni-W located in two positions that is the inside and the outside of the conductor. Moreover, we achieve the magnetic field of the noncircular shapes through various transport modes. The results show that AC losses of all conductors get a minimum in the simultaneous mode which means the six tapes of the conductor are energized together. For the BSCCO, YBCO, and NY conductor, the AC loss of the tape strongly depends on transport modes and the cylindrical configuration can obviously decrease AC loss. However for the YN conductor, the transport mode dependence is quite weak and the cylindrical configuration can hardly decrease AC loss. Furthermore, the AC losses of the YBCO conductor is optimal, and the AC loss of the YN conductor is the greatest because of the hysteresis loss of the NiW layers located outside of the conductor.

To analyze the association between sleep duration and athletic performance, and provide scientific basis to improve the 50 m and endurance performance in children and adolescents.All the 119 462 subjects aged 9-15 years in both genders were sampled from 2014 National Physical Fitness and Health Surveillance by using stratified random cluster sampling method, to measure the height, weight, 50 meters and endurance performance and investigate sleep duration with questionnaire. Their body mass indexes (BMI) were calculated and the students' 50 m, endurance run scores and sleep durations were assessed. Binary Logistic regression was used to analyze the difference between the different sleep groups, and multifactor Logistic regression was used to analyze the relationship between the sleep condition and athletic performance.The prevalence of insufficient sleep was 94.67% in the total subjects, the prevalence was higher among the girls (95.26%)than the boys (94.09%, χThe prevalence of insufficient sleep has increased, and the sleep condition in children and adolescents is severe. Children and adolescents with sufficient sleep have better athletic performance, so we should strengthen the prevention and control of the lack of sleep in children and adolescents.

To study the secular evolution of the activity of Centaur 166P/2001 T4 (Near Earth Asteroid Tracking, NEAT) and its physical properties, we present the results of optical observations of the Centaur taken on 2009 March 29 with the Keck 10-m telescope located atop Mauna Kea, Hawaii. It was still active at r(h) = 11.9 au post-perihelion. An upper limit of the nucleus radius of a(N) < 14.32 km is derived. The colour index is B - R = 1.59 +/- 0.05. The Af rho value is measured to be 288 +/- 19 cm and the corresponding dust production rate is 252 kg s(-1). Finally, a possible mechanism of activity is discussed.

Substrates of high temperature superconductor (HTS) wires can change the magnetic field distribution of the wires, with the consequence that they can affect AC losses of the HTS wires, which is a critical issue in HTS applications. In this study, in order to investigate the effects of the substrates on the AC losses of cylindrical single layer conductors which are usually used in HTS power cables, we first experimentally and numerically evaluated self-field losses of the HTS wires and investigated the influence of the substrates on their self-field losses. Next various HTS cylindrical single layer conductors were prepared using different HTS wires and their AC loss characteristics were discussed from the perspective of magnetic substrate. The main results show that the magnetic materials in HTS wires do affect their losses and the magnetic field distribution. For our pentagonal conductors, magnetic flux does not exist outside of the conductor when the magnetic substrates are located outside. Moreover, the AC losses of the bismuth strontium calcium copper oxide (BSCCO) and yttrium barium copper oxide (YBCO) conductors are quite similar and the AC losses of the NY and YN conductors are larger than the losses of the other two conductors. Especially, the AC loss of the YN conductor is the greatest in the low current region.

In a high-voltage dc (HVDC) transmission system, a high-temperature superconducting (HTS) dc cable is a feasible candidate due to its high power density. However, the dc in the grid includes ac ripple generated from switching devices and the environment, which can cause ac losses. In this paper, two pentagonal conductors consisting of second-generation (2G) wires are prepared, and their ac losses are investigated under the application of current with ac and dc components. Moreover, a numerical analysis is performed for both conductors to compare the measured losses. The results show that the measured ac losses correspond well with the numerical ones calculated by our models. The dc offset current does not affect the ac losses when the total current is smaller than the critical current, and the ac losses depend on the amplitude of the ac component. All measured losses are verified by evaluating the dependence on the arrangement of the voltage leads, the contact position, and the frequency.

It is widely accepted that the mechanical behaviour of lead–rubber bearing for bridge will change distinctly with temperature variation. This paper outlines an experimental study for 300 × 300 square type lead–rubber bridge bearing. The experimental results of temperature dependency for horizontal shear performance of lead–rubber bearing are presented. It can be seen that the horizontal shear stiffness of the bearing will be reduced as the temperature rises. The horizontal damping ratio of the bearing will be reduced as the temperature increases, but such a trend will not be obvious when the temperature is higher than 23°C. By using the classical regression analysis, estimation of the formula for temperature dependency for horizontal shear stiffness and horizontal damping ratio of 300 × 300 mm square lead–rubber bearings are given.

The effects of vanadium and austempering temperature on the microstructure and mechanical properties of carbidic austempered ductile iron were researched. The results showed that the microstructure of as-cast samples mainly consisted of pearlite, nodular graphite, and carbides, and the amount of carbides increased gradually with the increase of vanadium content (0–0.71 wt%). After austenitizing at 900 °C for 1.5 h and austempering at different temperatures for 1.5 h, the microstructure was mainly composed of acicular ferrite, retained austenite, carbides, and nodular graphite. The x-ray diffraction analysis indicated that the carbides consisted of (Cr, Fe)3 C and VC. With the increase of V (0–0.71 wt%) at the same austempering temperature, the tensile strength and impact toughness increased initially and then decreased above a critical V concentration, the Rockwell hardness and wear resistance always increased. As the austempering temperature (220–320 °C) increased, the tensile strength increased initially and then decreased after a critical austempering temperature, but the impact toughness increased, the Rockwell hardness and wear resistance decreased.