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Objective Contact force is a crucial aspect of comprehensive detection in the rail transit PC (pantograph-catenary) system and serves as an important evaluation factor of PC system performance. However, during the detection process, the external environment factors often lead to abnormal detection data. Currently, the elimination of abnormal PC contact force detection data mainly relies on manual methods, which affect data analysis efficiency. Therefore, there is a need to conduct in-depth research on an identification algorithm for PC contact force abnormality in PC system. Method The common abnormal forms of PC contact force are categorized, and the characteristics of contact force detection data under different abnormal conditions are analyzed. An identification algorithm for PC contact force abnormality based on LSTM (long short-term memory) prediction error is proposed. Using normal contact force data to train an LSTM model enables it to predict the trend of contact force variations. To achieve precise differentiation between normal segments and abnormal points, an abnormal data detection method based on the confidence interval is used. To mitigate the impact of long-distance abnormal data on LSTM model prediction performance, a prediction value replacement method for handling abnormal data is proposed. The effectiveness of identifying three common abnormal forms of PC contact force is verified using real detection data obtained from high-speed comprehensive inspection trains. Result & Conclusion Research results show that the proposed algorithm can effectively identify abnormalities in the PC contact force.

Objective There is limited research on the impact of mechanical method connecting passage construction on mainline tunnels and surrounding soil of metro shield interval in water-rich sandy stratum. Method Taking a metro shield tunnel interval project with mechanical method connecting passage construction in water-rich sandy stratum as example, a numerical model is established using ABAQUS finite element software to simulate and analyze the entire process of this engineering. The effects of mechanical method connecting passage construction on mainline tunnels and surrounding soil are investigated. The calculation results are compared with actual engineering monitoring data to verify the reliability of the proposed numerical model. Result & Conclusion Land subsidence along the longitudinal direction of the mainline tunnel and connecting passage caused by mechanical method connecting passage construction exhibits a U-shaped curve, with a maximum land subsidence value of 4.60 mm. The effects of the construction on mainline tunnel deformation are mainly vertical deformation and horizontal deformation along the mainline tunnel. The maximum vertical deformation of the mainline tunnel is 1.08 mm, and the maximum horizontal deformation is 1.28 mm. During construction, the maximum stress in the mainline tunnel suddenly increases with the breakthrough of the connecting passage portal, reaching 52.54 MPa upon completion of the construction. Actual monitoring data show that the fitted land subsidence monitoring data aligns with the trend of numerical calculation results, validating the reliability of the numerical calculations.

Objective To investigate the characteristics of exertional rhabdomyolysis (ERB) and the predictive value of creatine kinase (CK), myoglobin/creatine kinase (Mb/CK) ratio and other indicators for ERB patients with acute renal injury (AKI). Methods The clinical data of 154 patients with ERB admitted to the Affiliated Hospital of Qingdao University from January 2013 to September 2022 were retrospectively analyzed. The patients were divided into AKI group (n=35) and non-AKI group (n=119) according to whether AKI was combined. Creatinine, CK and other laboratory indicators were collected. Univariate and multivariate logistic regression models were used to analyze the risk factors for AKI in ERB patients. Receiver operating characteristic (ROC) curve was used to evaluate the predictive value of related indicators, and the correlation between each indicator and serum creatinine was analyzed by Spearman correlation analysis. Results The main clinical manifestations of 154 ERB patients were muscle pain (140 cases), limb weakness (69 cases), and dark brown urine (36 cases). The levels of CK, creatine kinase isoenzyme (CK-MB), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) in non-AKI group were significantly higher than those in AKI group (P＜0.05). The levels of creatinine, lactate dehydrogenase (LDH), cystatin C, Mb/CK and creatinine/cystatin C in AKI group were higher than those in non-AKI group, and the differences were statistically significant (P

[Objective] Ammonia is acknowledged as an efficient hydrogen storage medium, having the potential of being a substitute for fossil fuels in achieving the vision of a “carbon-free future”. Due to its stable liquid-state attributes in storage and transport, establishing a transmission system integrating green ammonia and product oil using in-service product oil pipelines is of important significance for fostering a green ammonia industry chain. [Methods] This paper began with a comprehensive introduction to background information,including the production capacity distribution of green ammonia in China, the pros and cons of different transportation modes, and the potentiality of integrating liquid ammonia transmission into in-service product oil pipelines. Then the adaptability of the system in integrating liquid ammonia transmission was analyzed from six dimensions: properties of transmission mediums, long-distance pipeline structure, pipes and equipment, pipeline transmission technology, hydraulic calculation method, and safety considerations related to operational pressure and fow rates. Considering the coupling characteristics of green ammonia and product oil during transportation, a conceptual plan was outlined for establishing green ammonia and product oil integrated transmission systems based on the supply and demand patterns of “westeast ammonia transmission” and “north-south ammonia transmission”. [Results] As the production capacity of green ammonia continuously expands, pipelines have emerged as the preferred mode for long-distance transportation. Moreover, given the underutilized transmission capacity of existing product oil pipelines, notable potential exists in integrating liquid ammonia transmission into these pipelines to enhance economic benefits. Theoretically, current product oil pipelines bear striking resemblance to existing long-distance liquid ammonia pipeline systems, so they are capable of meeting specific requirements for liquid ammonia transport when offered with technological or equipment upgrades. Therefore, under the premise of implementing rational pressure and flow rate control strategies, the system integrating liquid ammonia transmission into operational product oil pipelines exhibits robust adaptability, necessitating further experimental validation of their feasibility. This paper envisioned the potential of these integrated systems across four key aspects: planning for green ammonia and product oil integrated transmission systems, optimization through collaboration of multiple transportation modes, defining operational boundaries for liquid ammonia pipeline transmission, and optimization of pipeline transmission batches. [Conclusion] The study outcomes can serve as a valuable reference for promoting the healthy development of the green ammonia industry and enhancing the safety and economic efficiency of green ammonia and product oil integrated transmission systems.

Can the spinal cord stimulation (SCS) regulate the autonomic nerves through the endothelin-1 (ET-1) and nerve growth factor (NGF)/p75NTR pathways and thus inhibit the occurrence of atrial fibrillation (AF)? In our research, 16 beagles were randomly divided into a rapid atrial pacing (RAP) group (n = 8) and a RAP + SCS group (n = 8), and the effective refractory period (ERP), ERP dispersion, AF induction rate, and AF vulnerability window (WOV) at baseline, 6 h of RAP, 6 h of RAP + SCS were measured. The atrial tissue was then taken for immunohistochemical analysis to determine the localization of ET-1, NGF, p75NTR, NF-kB p65, and other genes. Our results showed that SCS attenuated the shortening of ERP in all parts caused by RAP, and after 6 h of SCS, the probability of AF in dogs was reduced compared with that in the RAP group. Moreover, the expression of ET-1, NGF, and p75NTR in the atrial tissues of dogs in the RAP + SCS group was significantly increased, but the expression of NF-kB p65 was reduced. In conclusion, SCS promotes the positive remodeling of cardiac autonomic nerves by weakening NFκB p65-dependent pathways to interfere with the ET-1 and NGF/p75NTR pathways to resist the original negative remodeling and inhibit the occurrence of AF.

Transmission line dance is mainly caused by meteorology, geography, line structure and other factors, etc. Effective monitoring of transmission lines is conducive to ensuring the stable operation of the power system. The article analyzes the transmission line ice-covered dance based on the influence mechanism, the single degree of freedom, and the three degrees of freedom of the transmission line dance modeling. Combined with ANSYS software, the finite element model of the transmission line is designed, and the boundary conditions and loads of the model are set. The characteristics of transmission line dancing under different initial wind attack angles, wind speeds, and stall distances are analyzed by simulation software. A transmission line dance monitoring system was set up using distributed fiber optic sensing technology, and a tensile ice and temperature simulation experiment was devised to confirm its effectiveness. When the initial wind attack angle is 200° at the midpoint of the gear spacing, the amplitude of the dance in the torsional direction is only 0.25°, and the amplitude of the dance in the vertical direction reaches 3.62 m. The critical wind speed interval for the dance of the transmission line is 5~7 m/s. Under the condition of the transmission line overlying ice, the line is pulled off when the wire pulling force is 120% of the RTS, and the value of Brillouin frequency shift fluctuates between 10.03 GHz and 10.38 GHz. Fluctuating between. Fiber optic sensors are capable of monitoring the ice-covering stress and temperature changes of transmission lines and providing support for timely and effective measures against dancing.

Transmission lines are the arteries of power system operation, carrying the important task of conveying electric energy, which is the most fragile and fault-prone place in the power system. This paper first analyzes the traveling wave propagation characteristics of transmission lines. It builds a mathematical model for the refraction and reflection phenomena of traveling waves that occur in the process of readjustment and distribution of transmission lines. The three traveling wave monitoring points nearest to the fault point are used to localize the fault, and the principle of the phase difference of split-phase current is explored based on the fault component. By means of experimental analysis, the phase currents of the three measurement points are detected, and for the transient current waveforms at the time of lightning strikes and short-circuits, the lightning fault localization method of the transmission line based on wavelet transforms is proposed and analyzed for fault localization of the technique. The results of simulation experiments show that when a ground fault occurs in the L1 phase of the line, the current fault components of measurement point 2 and measurement point 3 increase rapidly, and the element between measurement points is more than 10kA. The phase difference of the components is 180°, so the fault interval of the transmission line is from measurement point 2 to measurement point 3, and the fault phase is the L1 phase. Upon analysis, it is apparent that the actual fault distance error of 0.838km is the measurement of the fault distance of the transmission line, and the method proposed in this paper has a high level of measurement accuracy.

ObjectiveTo understand the health-related life quality and its influencing factors in elderly community residents in Shanghai， and to provide reference for improving their life quality.MethodsDuring April to June 2021， a cross-sectional survey was conducted in five selected community health care centers， from Baoshan District， Minhang District， Songjiang District and Pudong New District of Shanghai， respectively. The elderly residents aged 65 and over who received physical examination were face-to-face interviewed using EQ-5D-5L scale. SPSS 26.0 and Stata 16 were used for statistical analysis. Binary logistic regression， multiple linear regression and Tobit regression were used to analyze influencing factors of each dimension in EQ-5D scale， EQ-VAS score and health utility value.ResultsA total of 1302 elderly residents were included in the study， and the proportions of problems in the five dimensions of EQ-5D-5L scale were pain/discomfort （13.9%）， mobility （9.1%）， daily activity （5.8%）， self-care ability （4.8%） and anxiety/depression （3.6%）， while age was a factor influencing problems in each dimension. The average score of EQ-VAS was 84.28±10.32， and the average health utility value based on Chinese population was 0.97±0.08， which was higher than the rest of the country. Tobit regression analysis showed that female （t=-3.96， P

The Al-Ti-C alloy was extruded in multiple passes in a continuous manner by continuous equal channel angular pressing process. Through observation of the microstructure evolution, the mechanism of grain refinement and changes in mechanical properties were discussed.The results show that continuous equal channel angular pressing process can effectively refine the microstructure of Al-Ti-C alloy, and the grain size is reduced to about 1 μm.The deformation induction is the most important grain refinement mechanism in the deformation process.The accumulation of high density dislocations causes cracks at the interface between the Al matrix and TiAl3 and voids inside the TiAl3. The cracks further propagate through the entire TiAl3 particles, ultimately leading to the refinement of the second phase TiAl3 structure.At the same time, the pinning mechanism and shearing mechanism of the fine second phase TiAl3 structure promote the refinement of the Al matrix.After one pass of continuous equal channel angular pressing, the hardness of the alloy increases most obviously, which is 59.2% higher than that of the original state.With the increase of the number of extrusion passes, the increasing trend of hardness slows down, the plasticity of the alloy decreases, and toughness increases.

Incorporating ultrahigh concentrations of deep-level dopants in silicon drastically alters silicon’s optoelectronic properties. Photodiodes built from silicon hyperdoped with gold extend light sensitivity into the shortwave infrared region, far beyond the absorption edge of a pristine silicon sample. Deep-level dopants, however, also enhance carrier recombination; even though hyperdoped silicon has great light absorption properties, short charge carrier lifetime limits its applications. In this work, using terahertz spectroscopy, we investigate the charge carrier lifetime of gold–hyperdoped silicon, where the gold dopants are introduced by either film deposition or ion implantation, followed by pulsed laser melting. Using reactive ion etching, we measure how carrier lifetime changes when dopant concentration profiles are altered. Furthermore, using a 1D diffusion and recombination model, we simulate carrier dynamics when electrons are excited by sub-bandgap light. Our results show that the dopant distribution profile heavily influences excited carrier dynamics. We found that etching improves the half-life by a factor of two. In the short-wave-infrared range, the gold dopants are both light absorption centers and recombination centers. Focusing on optoelectronic properties in the short-wave-infrared region, our results suggest that these samples are over doped—etching much of the gold dopants away has little impact on the number of excited electrons at a later time. Our results suggest that dopant profile engineering is important for building efficient optoelectronic devices using hyperdoped semiconductors.

To satisfied the requirement of the laser angle adjustment,this paper proposed a micro 3-PSP parallel robot with a special structure with the diameter of the static platform is 50 mm,the height of the system is about 74 mm-80 mm;Using the‘closed-loop vector method’to set up the inverse kinematics model of the parallel robot.Then get the solution of the inverse kinematics.On the basis of the inverse kinematics solution,the constraint of the shaft movement and the parameters of the mechanism,we get the 3 D working space of the parallel robot via MATLAB.Finally,we simulated the kinematics of the parallel robot by Solid Works and Adams,and the results show that the 3-PSP parallel robot could accomplish three dimensions moving with smooth.

Based on the recently developed active-passive multifunctional all-digital HF surface wave radar hardware platform of Wuhan University, an experiment study of integrated technology for shortwave communication and Over-The-Horizon Radar (OTHR) application is carried out. Firstly, from the point of communication are demonstrated the key technologies of orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing, OFDM) in the short-wave communication. Secondly, from the point of radar detection are analyzed OFDM parameters design guidelines and its impact on the over-the-horizon radar detection performance. After the description of some key technologies related to communication signal demodulation and radar signal processing, the configuration parameters of hardware platform and experimental results are provided. The results show that the OFDM wave is done well in radar-communication integration systems, which is of great significance on the netted OTHR detection research.

The brain and subesophageal ganglion (BR-SG) of the commercial silk worm, Bombyx mori, were stained immunohistochemically at the larval stage for circadian clock neurons with antibodies against Doubletime (DBT) of B. mori and Period (PER) of Periplaneta americana. The BR-SGs were also stained with antisera against [Arg7]-corazonin, which has been known to be present in B. mori and co-localized with PER in Manduca sexta, and against [His7]-corazonin, a homolog identified in other species. From co-localization of [Arg7]-corazonin and PER-like reactivities in the pars lateralis, [Arg7]-corazonin is suspected to be a downstream regulator of the circadian clock in M. sexta. DBT- and corazonin-like immunohistochemical reactivities were found in both the neurosecretory cells of the pars intercerebralis (PIC) and pars lateralis (PL) in B. mori. Small numbers of neurons shared both reactivities against anti-DBT and anti-corazonin. The majority of the immunopositive cells were common to both corazonins, but some cells were unique in expressing either reactivity against [His7]-corazonin or [Arg7]-corazonin only. The results suggest that there is a diversity in the clock output pathway among lepidopterans and that [His7]-corazonin may be present in B. mori, as well as [Arg7]-corazonin, although the former has not been chemically identified in this species. Corazonin may be a downstream regulator of circadian clocks in B. mori because of the co-localization of [His7]-corazonin at PIC and [Arg7]-corazonin at PL with anti-DBT.