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Functional tremor is the most common subtype of functional movement disorder (FMD). At present, there is no "gold standard" for diagnosis. Most clinical manifestations coincide with organic tremor, which can easily lead to misdiagnosis and mistreatment. Characteristic electrophysiological manifestations can provide objective and repeatable diagnostic information, effectively supplement the history and physical examination, and can also be used in the differential diagnosis from organic tremor. This article reviews the electrophysiological characteristics of functional tremor and its application in diagnosis and differential diagnosis, in order to improve the clinical understanding of this disease.

In order to study the effect of ultrafine grinding time on the quality characteristics of whole wheat flour and dough, wheat was used as raw material and the whole grain wheat was ultra-finely ground by direct grinding method. The effects of particle size on the gelatinization characteristics, thermomechanical properties of whole wheat flour rheological properties of dough, color and texture of dough were investigated. The results showed that with the increase of crushing time, the particle size of whole wheat flour decreased, and the D50 decreased from 107.20 um to 45.65 um. The particle size distribution was more concentrated. The peak viscosity decreased, and the setback value decreased from 623.33 mPa·s to 485.33 mPa·s. The reduction of particle size could delay the aging of dough and product. The hardness of dough gradually decreased with the decrease of particle size, and the elasticity and cohesion gradually increased. The water absorption rate of dough increased from 65.7% to 76.7%, and the stabilization time also showed an upward trend. The low-temperature ultrafine grinding technology of wheat grains can improve the quality of whole wheat flour, and it is feasible to apply this technology to the field of whole grain processing.

The virtual coupling technology of urban rail trains offers an effective solution to unbalanced temporal and spatial distribution of passenger flow. Based on the key requirements for urban rail trains, namely punctuality, comfort and sufficient time for platform operations, this study proposed a cooperative speed planning algorithm for virtual coupling, featuring information centralized decision-making, following an investigation into train traction and braking characteristics, vehicle kinematics and dynamics models. This algorithm was further devised to incorporate constraint conditions, objective functions, and optimal solutions, and then used to calculate the planning sequence of displacements, speeds, accelerations, traction or braking forces, jerks and operating conditions during the operation of two coupled trains over time. In subsequent field experiments, the arrival time differences of the coupled trains were less than 3 s, stopping time differences between the preceding and following trains were less than 2 s, jerks were maintained at less than 0.1 m/s3, and smooth switching was achieved between traction and braking conditions, demonstrating the efficacy of the proposed algorithm in facilitating safe, punctual, comfortable and efficient operation of coupled trains. The study outcomes lay a solid foundation for future engineering applications.

To investigate the effect of combined treatment with L-ascorbic acid (AA) and ultrasound (US) (AS) on the storage quality of fresh-cut taro, the present study measured changes in the sensory quality and browning-related enzyme activities during storage of Yongding grown fresh-cut Liuyuehong taro soaked in 2% AA solution for 15 minutes, followed by US treatment (53 kHz and 400 W for 10 minutes). Compared with the control group, combined treatment with AS could reduce the water loss rate of fresh-cut taro, maintain higher hardness, delay the increase in browning index, reduce cell membrane permeability, inhibit the accumulation of malondialdehyde (MDA), and suppress surface microbial growth, thereby maintaining higher sensory quality of fresh-cut taro. In addition, AS treatment could also maintain higher activities of catalase (CAT) and superoxide dismutase (SOD), decrease the activities of peroxidase (POD), polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL), inhibit the consumption of phenolic substances, slow down the loss of nutrients such as starch, soluble proteins, and soluble solids, suppress the accumulation of soluble quinones, and delay the flavor deterioration of fresh-cut taro during storage. These results indicated that AS treatment could maintain better storage quality of fresh-cut taro.

Purposes Zero-dimensional carbon nanomaterial-based targeting drug delivery system has shown broad application prospects in the field of tumor therapy since the complex is constructed by using carbon nanomaterials with good stability and biocompatibility as drug carries and carries drugs, genes, and targeting components. Methods In this review, the structure of zero-dimensional carbon nanomaterial as drug carriers, the construction of targeting drug delivery systems, and their applications in chemotherapy, gene therapy, and integration of diagnosis and treatment are reviewed. First, the structure of zero-dimensional carbon nanomaterial is classified. Second, the construction strategies of carbon nanomaterial-based targeting drug delivery system are summarized from two aspects: targeting modification and drug loading. Finally, the application advances of zero-dimensional carbon nanomaterial-based targeting drug delivery system is reviewed, and the current problems they face in tumor treatment are presented. Conclusions This work provides some theoretical support and practical experience for the extensive application of zero-dimensional carbon nanomaterial-based targeting drug delivery systems in the biomedical field.

The spacer grid models are important models for simulating the thermal-hydraulics phenomena during reflooding process. The spacer grid pressure drop model, wall heat transfer enhancement model, interfacial heat transfer enhancement model, droplet breakup model, spacer grid re-wet model and grid temperature model are integrated in COSINE multiphase sub-channel code. In this paper, the typical rod bundle heat transfer (RBHT) reflooding tests were selected to assess the spacer grid model in the code. The calculation results show that the spacer grid models can significantly enhance the code predicted heat transfer capacity, accelerate the quench rate and reduce the peak cladding temperature (PCT) during the reflooding process, and the calculated results are in good agreement with the experimental measurements. In addition, the deviation of the PCT predicted by the code is reduced from 10% to 7% due to the adoption of the spacer grid models. The spacer grid models have the ability to enhance the interfacial heat transfer between vapor and droplet, therefore the calculated results with the spacer grid models show a significantly faster decrease in vapor temperature than that without the spacer grid models. And the calculated vapor temperatures with spacer grid models are in good agreement with the experimental measurements. The trend of the code predicted spacer grid temperature agrees well with the experimental results, but the code predicted spacer grid temperature is slightly higher than the experimental measurements. Furthermore, the early wetting of the temperature probe located on the spacer grid in the experiment results in a rapid decrease in the spacer grid temperature, however，the code predicted spacer grid temperature does not show as sharp a decrease as the experimental results due to the interpolation method in the calculation of the spacer grid temperature. The spacer grid models adopted in the code can simulate the breakup of droplets across the spacer grid, the diameter ratio of the shattered droplets predicted by the code is in good agreement with the experimental measurements, and the calculation results of the Cheung model are more accurate than those of the Paik model in the test case 7151. In addition to this, the code can predict the trend of droplet velocity near the spacer grid during reflooding process, but the calculated droplet velocity decreases significantly faster than the experimental measurements, and it needs more work in future. In general, the calculated results with the spacer grid models are in good agreement with the experimental results, and the spacer grid models adopted in the code are reasonable and reliable.

The loss of biodiversity not only means the loss of genes, species and ecosystems, but also threatens the human cultural diversity. Thangka is known as the ‘encyclopaedia’ of traditional Tibetan culture, covering social, historical, cultural, religious and medicinal aspects. Qinghai Regong Thangka is one of the most important sects of Thangka, and has vivid and delicate depiction of images, and the numerous depictions of natural landscapes. By combining the methods of literature analysis, work analysis and ethnobiological fieldwork, the biocultural aspects of Regong Thangka are studied in terms of the traditional knowledge related to biodiversity in the painting techniques of Regong Thangka and the analysis of the connotation of biological images. The study revealed the biological origins and production processes of the traditional painting tools and 12 natural plant-derived pigments for Regong Thangka; explored the origins and functions of the biological images often found in the Thangka works; explained the ecological concepts conveyed from Regong Thangka. In general, Regong Thangkas are not only resulted from nature, but also provide feedbacks to nature in their content. In the future, we should pay attention to the protection and inheritance of the traditional skills and biodiversity related traditional knowledge of Regong Thangka, and further explore its functions of traditional knowledge dissemination and nature education.

Hydroxyl-terminated polybutadiene/polyether (HT-PB/PE), serving as binders and fuel for rocket propellants, has been widely studied and applied. To meet the developing demand of industrialization, the modification of HT-PB/PE based on their structural and functional characteristics has become one of the hot topics. In this study, the modified HTPB and the modified HTPE were prepared by modification of end groups and main chains. After the preparation, the characteristic functional groups of the binders were characterized by infrared spectroscopy (FTIR) to determine the effective end-group modification. Nuclear magnetic resonance hydrogen spectroscopy (1H-NMR) was used to characterize the main chain on modified binders through the variation of chemical environment of hydrogen. The analysis of the pyrolysis properties of the modified binders was performed by thermo gravimetric analyzer (TGA). The results effectively reflected the initial and maximum decomposition temperatures, as well as the pyrolysis stage of the above binders. The above characterization results confirmed the effective synthesis of modified binders and their good thermal properties. However, the present reports lacked the studies on the pyrolysis mechanism of these modified binders. To further investigate the effect of end group and main chain modification on the pyrolysis properties of binders, the pyrolysis of modified binders was conducted in a U-shaped fixed-bed reactor, which was connected to photoionization mass spectrometry (SPI-MS). SPI-MS was used to monitor the dynamic evolution of the pyrolysis product as a function of temperature in real-time. The mechanism of the pyrolysis process of the modified binders was studied based on the above tests. The results showed that the end-groups and main-chain modified binders of HTPB exhibited different thermal stabilities. The influence of main chain modification on the pyrolysis behavior was greater than that of end group modification. The pyrolysis mechanism of modified binders followed random bond breaking of C—C and C—O bonds and the increasing varieties of products. The esters and acids were found in the pyrolysis products of the end-group modified binders. The epoxides and alcohols were found in the pyrolysis products of the main-chain modified binder, showing the more pathways during their pyrolysis process.

Objective To investigate the effects of niclosamide on S100A4 expression and pathological angiogenesis of hepatopulmonary syndrome (HPS) in rats. Methods Thirty male SD rats were randomly divided into control group (Sham group, n=6), common bile duct ligation (CBDL) group (n=18) and niclosamide treatment group (NIC group, n=6). The rats of the NIC group were gavaged with niclosamide suspension for 1 week since the first day of the third week after modelling, and the rats were dissected at the end of the fifth week to assess the pathological changes and disease progression of liver and lung tissues by HE and Masson staining. Immunofluorescence assay was used to detect the location and intensity of S100A4 and CD31 expression in the lung of rats. The expression of S100A4 at mRNA and protein levels was detected using qPCR and Western blotting. Pulmonary microvascular endothelial cells (PMVECs) were treated with small interfering RNA (siRNA) serum of HPS rats and nichosamide, respectively, and their effects on cell migration and tube-forming abilities were observed. Results Both mRNA and protein expression of S100A4 in lung tissue of the CBDL group rats were increased with disease progression, and the expression levels were higher than those in the Sham group (P < 0.000 1); The lung mRNA and protein levels of S100A4 were lower in the NIC group than the CBDL group at the 5th week, but still higher than those in the Sham group. After knockdown of S100A4 using siRNA in PMVECs, the migration and tube-forming abilities were reduced when compared with the NC group (P < 0.000 1). HE staining displayed that pulmonary pathological changes were milder in the NIC group than the CBDL group at the 5th week, while no such effect was found in the liver tissues. Masson staining showed that hepatic fibrosis was not obviously ameliorated in the NIC group. The migration and tube-forming abilities of the cells was significantly increased in the CBDL group after the 5 weeks of serum stimulation compared to the Sham rats, while niclosamide treatment reversed this phenomenon (P < 0.000 1). Conclusion S100A4 can accelerate the progression of HPS by promoting pulmonary micro-angiogenesis in HPS rats, and niclosamide inhibits the expression of S100A4 in the lung and thus delays the progression of HPS.

Objective To investigate the feasibility of epidural catheters in parotid gland duct anastomosis and the function of the affected side gland after parotid gland duct anastomosis. Methods Thirteen patients who were treated in the Department of Oral and Maxillofacial Surgery of Xuzhou Central Hospital using an epidural catheter as the scaffold for parotid gland catheter anastomosis were enrolled from Jan. 2019 to June 2021. The swelling, salivary fistula and catheter patency in the parotid gland area were evaluated two weeks after the operation. 99mTcO4- single photon emission computed tomography (SPECT) was used for quantitative detection of salivary gland secretion function. Results Thirteen patients had no swelling or salivary fistula in the parotid gland area of the affected side two weeks after the operation, and the catheter secretion was unobstructed. There was no significant difference in the uptake rate between the parotid gland on the affected side and the parotid gland on the healthy side (t = -0.859, P = 0.399), and there was no significant difference in the excretion rate between the parotid gland on the affected side and the parotid gland on the healthy side (t = 0.693, P = 0.495). The parotid gland excretion function of the affected side was excellent three months after the operation. Conclusion Parotid duct anastomosis with an epidural catheter as the stent has good feasibility, and parotid gland secretion function recovers well after the operation, which is worthy of clinical application.

Objective To investigate the effect of inhibiting the expression of miRNA⁃193a⁃5p on neuronal damage and apoptosis in hippocampus of epileptic rats, and to explore its role in the pathogenesis of temporal lobe epilepsy. Methods Epileptic rat models were prepared with lithium chlorine⁃pilocarpine and randomly divided into model group, miRNA⁃193a⁃5p inhibitor group (miRNA⁃193a⁃5p antagomir group) and negative control group (antagomir⁃NC group). The frequency of abnormal brainwaves per unit time was recorded at first, 3th and 7th day after model preparation. On the 7th day, the expression of hippocampal inflammatory factors [interleukin⁃1β (IL⁃1β), interleukin⁃6 (IL⁃6), tumor necrosis factor⁃α (TNF⁃α)] were detected by enzyme⁃linked immunosorbent assay (ELISA), the activity of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were detected by chemical colorimetry, and the number of neuronal apoptosis was calculated by TUNEL staining. The relative expression of miRNA⁃193a⁃5p and G⁃protein coupled receptor 39 (GPR39), and expression of cleaved Caspase⁃3, Bax, Bcl⁃2, and GPR39 proteins were detected by fluorescence quantitative polymerase chain reaction (PCR) and Western blotting, respectively. Double luciferase reporter assay confirmed the targeting relationship between miRNA⁃193a⁃5p and GPR39. Results 1) There were statistically significant differences in each index in different treatment groups and at each observation time point (P=0.000, for all). Compared with normal control group, the relative expression of miRNA⁃193a⁃5p in model group, antagomir⁃NC group and miRNA⁃193a⁃5p antagomir group (P=0.000, for all), the expression of inflammatory factors [IL⁃1β (P＜0.05, for all), IL⁃6 (P=0.000, for all) and TNF⁃α (P=0.000, for all)], the content of MDA (P＜0.01, for all), the number of apoptosis of neurons (P=0.000, for all), the relative expression of cleaved Caspase⁃3 (P=0.000) and Bax (P=0.000) increased. The relative expression of SOD activity (P＜0.01, for all), Bcl⁃2 relative expression (P=0.000, for all), GPR39 mRNA (P=0.000, for all) and GPR39 protein (P＜0.01, for all) were decreased. Compared with model group and antagomir⁃NC group, the relative expression of miRNA⁃193a⁃5p in antagomir group (P=0.000, for all), the expression of inflammatory cytokines [IL⁃1β (P=0.000, for all), IL⁃6 (P=0.000, for all) and TNF⁃α (P＜0.01, for all)], the content of MDA (P=0.000, for all), the number of neuronal apoptosis (P=0.000, for all), the relative expression of cleaved Caspase⁃3 (P=0.000，for all) and Bax (P=0.000, for all), as well as the number of abnormal brain waves at day 1, 3 and 7 (P＜0.05, for all) were decreased. The relative expression of SOD activity (P=0.000, for all), Bcl⁃2 (P=0.000, for all), GPR39 mRNA (P=0.000, for all) and GPR39 protein (P=0.000, for all) increased. 2) Double luciferase assay showed the luciferase activity of HEK293T cells transfected with miRNA⁃193a⁃5p mimic was decreased after transfection of GPR39⁃WT, and was lower than that of mimic⁃NC group (t=16.340, P=0.000). Conclusions Inhibiting the expression of miRNA⁃193a⁃5p can reduce the expression of oxidative stress and inflammation in the hippocampus of epileptic rats, and inhibit hippocampal neuron apoptosis. The mechanism may be related to the targeted up⁃regulation of GPR39 expression.

The rack and pinion of the three gorges ship lift is a low speed and heavy load open gear transmission with hard tooth surface. Once the lubrication is poor, it is easy to cause damage such as tooth surface scuffing, which will affect the operation safety and reliability of the ship lift. This study is based on the actual operation data of the three gorges ship lift, and the lubrication of racks and pinions under various typical service conditions is systematically analyzed using the oil film thickness criterion. The relationship between the false water depth and the film thickness ratio in the ship compartment is deduced and the film thickness ratio of the lubrication state of the most dangerous meshing point under typical false water depth is calculated when the ship compartment is under constant speed. The worst lubrication condition of the rack and pinion is determined when the ship compartment is ascending and descending with variable speeds, and the relationship between the water depth in the ship compartment and the lubrication condition under variable speed typical operating conditions is analyzed. The position where the scuffing damage is more likely to occur is further determined. The results show that, when the ship lift is running at a constant speed, the lubrication state of the rack and pinion is the best under the optimum water depth in the ship compartment, and the film thickness ratio of the deviation from the optimal water level decreases with the power function λ∝±Δh-0.13 of the false water depth. When the rack and pinion is at the most dangerous meshing point, the root of the pinion and the top of the rack are in contact, and the lubrication condition between tooth surfaces is worse under large false water depth. When the ship lift moves at variable speeds, the working condition with poor lubrication condition is the upward acceleration and downward deceleration when the water depth of the ship chamber is 3.6 m. Due to the high contact frequency of the upper tooth surface on the rack and poor lubrication state, the risk of scuffing damage is higher.

Objective To discuss the treatment of pneumoparotid and to provide a reference for clinical practice. Methods A case of refractory pneumoparotid was reported, and the diagnosis and treatment of parotid emphysema were reviewed and analyzed in combination with the literature. Results This child had parotid gland enlargement without any obvious cause for more than 1 month. Conservative treatment, such as anti-inflammatory agents, psychological interventions and physical compression were ineffective. The patient had a history of cerebral palsy with epilepsy and involuntary cheek bulging behavior. Therefore, we considered it a refractory case. It was cured after parotid duct ligation and partial parotidectomy of the superficial lobe. A literature review showed that a pneumoparotid is a rare parotid enlargement. Most of the clinical cases were considered to be caused by the return of air into the parotid gland through the parotid duct due to an increase in oral pressure. The diagnosis of pneumoparotid mainly depends on intermittent parotid gland swelling and other clinical manifestations and imaging examination methods, such as ultrasound, CT, MRI and angiography. Its treatment mainly includes conservative anti-inflammatory treatment, physical therapy and psychological intervention. Surgical treatment is indicated for refractory parotid emphysema. Conclusion Pneumoparotid cases may further develop into parotid inflammation, which is generally treated conservatively. For some severe, recurrent and poor compliance cases, surgical treatment is sometimes needed.

Time-domain randomization makes side channel attacks difficult to align side information by inserting random delays, redundant operations, and variable frequency clocks, thereby reducing the efficiency. Aiming at the problem of time-domain misalignment of energy traces caused by time-dimensional randomization technology, this paper proposes an anti-time-domain randomization method based on Trend Series Dynamic Matching (TSDM). This method analyzes the distribution of attack interest points, and describes the shape feature of the energy trace, compresses the dimension of the energy trace, preserves the sensitive information of energy attacks, suppresses the negative impact of noise, realizes the dynamic alignment of data, and improves the efficiency of side channel attacks. This paper, conducts method verification and performance analysis for three typical time randomization techniques. Compared with various classical alignment methods, this method has better data alignment effect in different noise environments, and the number of energy traces required for the success rate of energy attack to reach 100% respectively decreased by 23.8%, 24.2%, 11.3%.

With the rapid development of life science, laboratory animals play an important role in many fields, such as biomedicine. In recent years, the national reforms “to delegate power, streamline administration and optimize government services” continues deepen, the laboratory animals administrative departments have paid more attention to interim and post-event supervision, in which the safety management of laboratory animals is the key and challenging point in the supervision process. In this paper, the information regarding licenses for laboratory animals in Jiangsu, facility areas, animal production and usage, employees, and other information the past three years were introduced. Combined with legal administrative management in recent years, the potential safety risks in the production and use of laboratory animals were analyzed, such as risks in management systems, employees, facility operation, animal quality control, accidental injury and zoonosis, animal transportation, and waste disposal. Additionally, the current construction, daily management services, and the list of interim and post-event supervision of the laboratory animal safety management system were introduced. Based on this discussion, we proposed relevant safety management countermeasures and suggestions and provided support for further improvements to laboratory animal safety management.

MXene has a wide application prospect in energy storage, electromagnetic interference shielding, catalysis, medicine and other fields due to its unique layered structure, high electronic conductivity and rich surface chemical properties.Ti3C2Tx, as the earliest discovered MXene material, has the possibility to achieve both high energy density and power density in the field of sodium ion batteries because of its inherent metal conductive characteristics, wide layer spacing and abundant surface functional groups, which is attracted by many researchers. Based on this, the research progress of Ti3C2Tx based materials in sodium ion batteries in recent years was reviewed in this paper. Firstly, the structure and electrochemical properties of Ti3C2Tx materials with multi-layer and few-layer were summarized by introducing the preparation of Ti3C2Tx. Then, combined with the application trend of the study, the influences of layer spacing modification, doping modification and morphology regulation on the sodium storage behavior of the two kinds of Ti3C2Tx materials were summarized. The structural design ideas of the two kinds of Ti3C2Tx based composites applied to the anode of the sodium ion battery were also analyzed. It was pointed out that the reasonable structural design is vital to the battery performance. Finally, some suggestions for the problems and challenges faced by Ti3C2Tx based composites in the field of sodium ion batteries were given.

Staddle monorail use rigid catenary, which often produce strong rigid vibrations and violent fluctuations in contact forces affecting pantograph receiving quality and service life during operation. Therefore, a semi-active control method for staddle monorail′s pantograph with sliding mode variable structure is proposed. The pantograph model with two lumped masses and magneto rheological damping are selected as the research object and the operating mechanism respectively. Firstly, the coupling relationship of the staddle monorail′s pantograph-catenary system is studied and the dynamics equations are derived. Secondly, with the support of the above theory, the active control system for pantograph is built by Simulink simulation method combined with sliding mode variable structure control. Finally, the reverse model of magneto rheological damper is established to realize semi-active control for pantograph. When magneto rheological damper receives the control signal transmitted by the controller, it outputs the desired control force by adjusting the current and finally acts on the pantograph, effectively solving the problem of violent fluctuation of contact force. The experimental results show that the proposed method is more accurate to control the contact force of the pantograph-catenary system, significantly reduces the standard deviation of the contact force by more than 17.34%, and avoids the occurrence of the offline situation of the pantograph-catenary system. The stability and superiority of the proposed method in improving the current quality of the pantograph-catenary system and prolongating the service life of the pantograph are verified.

Aiming at the shortcomings of isotope radon detection method, which has large workload, long period, and is easily restricted by climate and environmental factors this paper proposes the use of radon generated during the process of migration to the surface to accurately reflects the solid-state length of the cumulative value of parent radon over a period of time. Long-lived radon daughter 210Po fire detection method based on radiochemical analysis method to measure 210Po activity concentration to detect hidden mine fire areas. In order to explore the effect and accuracy of the radon progeny 210Po fire detection method in on-site detection, this paper carried out on-site experimental research in Liuwan Coal Mine where the fire source location is known. The radon gas concentration at the measuring point and the activity concentration of its solid long-lived daughter 210Po are measured. By comparing the correlation between radon gas concentration and 210Po activity concentration detection results and its influencing factors, the technology of using radon daughter 210Po to detect the location of coal spontaneous combustion in goaf is demonstrated. The results show that the radon concentration in the near-surface soil layer in the fire area has a strong correlation with the 210Po activity concentration in the overall distribution, but the 210Po activity concentration is less disturbed by external factors, and its distribution can more accurately reflect the underground coal spontaneous combustion fire area. Compared with the isotope radon detection method, the radon progeny 210Po fire detection method has higher detection accuracy, wider application range and higher application value.

In order to clarify the fatigue crack propagation behavior of pearlitic rail, the three-point bending fatigue crack propagation rate of U75V heavy rail steel in rolling state and heat treatment state was measured. The microstructure, lamella, fracture morphology and fatigue crack propagation trajectory of rail were observed by optical microscope, scanning electron microscope and EBSD. The results show that the average distance between fatigue striation of rolled and heat-treated rails is 252.5 nm and 215.4 nm, the fracture surface of rolled rail presents cleavage steps and river patterns, and the river patterns tend to merge.However, the fatigue fracture surface of the heat-treated rail presents a large number of cleavage steps, more microcracks and tear edges, and the river pattern is dominated by tributaries.The fatigue crack growth rate of heat-treated rail is much lower than that of rolled sample, and it is also slow to reach the stage of crack instability.The fatigue crack propagation mode of rolled and heat-treated rail is the mixed propagation mode of transgranular fracture and intergranular fracture dominated by transgranular fracture, the pearlite lamellae spacing of rolled and heat-treated rails is 272.2 nm and 148.4 nm respectively. The pearlite lamellae of heat-treated rails is fine and has various directions, while there are significant pearlite clusters in the heat-treated rail.There are many branch cracks and crack bridges in the crack growth path, which hinders the crack propagation in the heat-treated U75V heavy rail steel, which is an important reason why the fatigue crack propagation rate of the heat-treated rail is lower than that of the rolled rail.

Aiming at the problem of brake squeal of automobile disc brake, a method based on weighted brake squeal tendency coefficient is proposed to evaluate the brake squeal performance. On the basis of establishing a complex mode finite element model of the disc brake, the validity of the model is verified by the noise bench test. By combining the central composite test design, Response Surface Method （RSM） surrogate model method and the Pointer optimization algorithm, and taking the minimum weighted brake squeal tendency coefficient as the optimization goal, the structural optimization design is carried out for the unilateral disc height, heat sink rib height, elastic modulus and disc cap height of the brake disc. The results show that the optimization design method proposed can significantly improve the efficiency of the optimization solution, effectively reduce the squeal tendency of the disc brake in the full frequency band, and suppress the generation of brake squeal noise.

Objective To investigate the changes in myelin sheath of optic nerve in mice during the process of aging and explore the effect of clemastine, a pro-myelination drug, on visual function of aging mice. Methods The Cspg4-CreERt; mT/mG mice (4 and 13 months old) and wildtype C57/BL mice (4 and 13 months old) were employed in this study. The changes in number of oligodendrocytes (OLs) and newly-formed myelin were observed by immunofluorescence staining and quantitative immunoblotting. Their optical function was assessed with flash visual evoked potentials (fVEP). The reporter mice and wildtype mice at 13 months old were separately divided into control group and clemastine group. Immunostaining and fVEP test were used to observe the effects of clemastine on the newly-formed myelin and optical function. Results There was no significant difference in the density of NG2+ cells (oligodendrocyte precursor cells, OPCs) in the 13-month-old group in comparison with the 4-month-old group, but the count of CC1+ cells (mature OLs) was obviously decreased in the 13-month-old group (P < 0.01), and immunoblotting test also showed NG2+ protein level had no change between the groups. Immunofluorescence staining indicated that the area of mGFP+ NG2- (new myelin sheath) was declined greatly in the 13-month-old reporter mice (P < 0.05). fVEP test suggested that the latency of P2 wave was significantly prolonged in the 13-month-old group as compared with the 4-month-old group (P < 0.01). Clemastine treatment resulted in notably increased mGFP+ area (new myelin sheath) in the reporter mice (P < 0.05), and remarkably shorten the latency of P2 wave in 13-month-old mice (P < 0.01). Conclusion Inhibited myelinogenesis and decreased nerve conduction velocity in optic nerve are observed in aging mice. Clemastine treatment can greatly improve myelinogenesis and promote conduction velocity in optic nerve.

Firstly, this paper expounds the research status at home and abroad of three key technologies in the production process of fresh and wet rice flour: efficient powder dispersion, accurate weighing and automatic packaging, and focuses on the key technical problems existing in the research and development of technology and mechanical equipment; Secondly, on the basis of summarizing the development level of existing technology and equipment, this paper further analyzes the main reasons for these problems. Finally, the development direction of three key technologies in the automatic production of fresh and wet rice flour is prospected from the aspects of production technology, mechanical design and system algorithm optimization.

COSINE software package provides various functions in thermal-hydraulic analysis of pressurized water reactor (PWR) after years of development. In order to meet the engineering design and safety analysis requirements of the advanced passive reactor CAP1400, the multiphase field sub-channel code with higher calculation accuracy was developed based on the homogeneous sub-channel program (cosSUBC) in COSINE software package. The multiphase sub-channel code contained 11 basic equations including the mass conservation equations of the vapor, continuous liquid, and droplet, the axial momentum conservation equations of the gas, continuous liquid phase, droplet phase, the transverse momentum conservation equation of the gas, continuous liquid, and droplet, and the energy conservation equations of the gas and total liquid phases. The continuous liquid and the droplet were in energy equilibrium states in one cell was assumed, therefore the continuous liquid and droplet were merged into total liquid phases in energy conservation equation. The constitutive relation models between different phases were introduced in the code to realize the closure of the basic equations, the staggered discrete format in space and a semi-implicit time discrete format were adopted in multiphase field sub-channel code. The typical test cases and representative experiments were modeled and calculated in this paper to verify the calculation capability of the code. First, the test of droplet behavior was modeled to verify the correctness of droplet model adopted in the code. Then the turbulent mixing experiment was modeled to verify the correctness of turbulent mixing model used in the code. In the end, the wall heat transfer experiment and the reflooding process experiment were modeled to verify the simulation ability in the heat transfer regime especially in the post critical heat flux (post-CHF) condition. The results show that the droplet behaviors including the generation and the flow distribution of droplet phase are in good agreement with the reference code. And the code can well simulate the flow distribution phenomenon according the comparison between the calculation results and experimental data in flow distribution experiment and the turbulent mixing experiment. Besides, the code can well simulate the distribution of the wall temperature and the reflooding process in the post-CHF and heat transfer condition. Therefore, the calculation of the thermal-hydraulic phenomena in the core of reactor by the multiphase field sub-channel code is reasonable and right, and the code has the ability to calculate and simulate the thermal-hydraulic conditions in the core of PWR.

Objective: In view of the technical problems such as low efficiency and difficult automatic control of the automatic powder production line for factory rice noodle production. Methods: This research proposed a multi-station automatic powder loading system based on fuzzy control, selecting the deviation E1 between the detected value of the powder height and the preset value, the deviation change rate EC1 and the deviation between the current position of the powder loading car and the position to be loaded. The absolute value E2 was used as the input variable, and the motor speed U1 and the opening degree of the bin door U2 of the powder loading system were used as the output variables. The working efficiency of the powder loading system was improved by adjusting the motor speed and the opening of the bin door of the powder loading system through fuzzy control rules. The control system was built on the Siemens S7-1200 PLC platform, and the field test was carried out. Results: The test showed that for the 6-station automatic powder loading and conveying production line, the operation efficiency of this control system was improved by 103.2% compared with the existing control system, and the output of each station per unit time was increased by 31.4%. Conclusion: The number of stations that the system can accommodate 4 points have been raised. The experiment can be used for reference in the design of the control system for realizing high efficiency and automation of the factory rice flour production line.

Localized peripheral neuropathy amyloidosis is a rare disease that mainly occurred in elder people who present with focal neurological symptoms. AL is the main type of amyloid protein. Biopsy is the golden standard for diagnosis. Mass spectrometry and immunohistochemical analysis help to confirm the type of amyloid protein. This paper retrospectively analyzes the clinical and imaging data, auxiliary examinations, histological, and immunohistochemical markers. The patient, a 34-year-old woman, presented with a right neck mass and weakness of the right arm. Brachial plexus magnetic resonance imaging (MRI) showed a tumor-like lesion in the nerve root at C5 and C6 and in upper trunk. Electrophysiological studies revealed damage in the upper trunk of the brachial plexus. Positive staining with Congo red was found in brachial plexus biopsy. Mass spectrometry showed that the type of amyloid protein was AHL(G-λ). The patient underwent nerve graft for treatment. Meanwhile, literature review revealed that the average onset age of localized spinal nerve amyloidosis was 62.4 years old.The radial nerve was the most susceptible, followed by the lumbosacral plexus. Fifty percent of the type of amyloid protein is AL.Until now, no consolidated treatment is available. Here, we summarize the clinical characteristics of localized peripheral neuropathy amyloidosis in order to raise the awareness of the disease.

Objective To investigate the protective effect of blebbistatin, a non-muscle myosin Ⅱ (NMⅡ) inhibitor, on inflammatory injury of lung tissue after chronic common bile duct ligation (CBDL) in rats. Methods A total of 55 SPF male SD rats (200~220 g) were randomly divided into 3 groups, namely control group (Sham, n=11), high CBDL group (model group, n=22) and blebbistatin treatment after high CBDL group (treatment group, n=22). The treatment group was intraperitoneally injected with blebbistatin at a dose of 5 mg/kg once a day for a week, while the model group was only given the solvent (PEG-300∶saline=1∶1). The changes of lung tissue were observed with HE staining. Western blotting was performed to detect the expression of myeloperoxidase (MPO), IL-6, TNF-α, and superoxide dismutase (SOD3) in the lung tissues. The expression levels of MPO, IL-6, IL-1β, TNF-α, LY6B, CD163, and vascular endothelium related factor CD31 were also determined by immunohistochemical assay. Results The lung injury at the 3rd week after CBDL presented a large number of inflammatory cells infiltration, accompanied by local alveolar space and pulmonary interstitial hemorrhage. Immunohistochemical results demonstrated that the numbers of MPO positive cells, LY6B positive cells and CD163 positive cells were all increased significantly in the model group as compared with the Sham group (P < 0.01), with enhanced expression of IL-1β and TNF-α (P < 0.01). Western blotting results confirmed the up-regulated levels of MPO, IL-6 and SOD3 in the model group than the sham group (P < 0.05). In comparison with the model group, the treatment group showed decreased numbers of MPO positive cells, LY6B positive cells, and CD163 positive cells (P < 0.01), and declined levels of inflammatory factors IL-1β, IL-6, and TNF-α (P < 0.01). Western blotting indicated as well that the expression of MPO, IL-6 and TNF-α in the treatment group was reduced greatly (P < 0.05). Moreover, at the 5th week after surgery, the lung injury mainly manifested as pulmonary microvascular dilation, which was more severe in the model group than the Sham group (P < 0.01), while the severity of pulmonary microvascular dilatation was remarkably milder after treatment (P < 0.01). Conclusion Blebbistatin can effectively inhibit the infiltration of inflammatory cells in lung tissue, reduce pneumonia injury and alleviate pulmonary microvascular dilatation after CBDL.

The meaning and characteristics of refractory high entropy alloys were briefly described, and the preparation methods of various refractory high entropy alloys (bulk, film and coating) were summarized.The comprehensive properties of refractory high entropy alloys were emphatically expounded. It was suggested that the composition design should be optimized by constructing a special database of refractory high entropy alloys, and the manufacturability of different preparation methods should be focused on. In view of the shortcomings of high room temperature brittleness, high density and high cost of refractory high entropy alloys at present, different preparation methods could be selected according to the properties of refractory high entropy alloys for future industrial application.

Objective To determine the effects of maternal and infant separation(MS) on anxiety and depression-like behaviors, Wnt signaling molecules and receptors in the hippocampus of offspring rats. Methods Sixteen Sprague-Dawley (SD) pregnant rats (240~260 g) were randomly and equally divided into 2 groups. The offspring rats from the control group (CON) received no postpartum intervention, while those of the experiment group (MS) were given maternal-infant separation 3 h per day for 14 consecutive days since delivery. Elevated plus maze test (EPMT) and forced swimming test (FST) were conducted to evaluate the anxiety and depression-like behaviors of 1-month-old offspring rats. Real-time quantitative PCR was used to detect the levels of Wnt molecules in the hippocampus of the offspring rats, and Western blotting was adopted to determine the expression of Wnt2 and Wnt3a proteins as well as the Wnt signaling pathway inhibitory molecules DKK1 and sFRP3 in the hippocampus. Results The total number of arm entries (including open-arm and close-arm entries) was not statistically different between the MS and CON groups. However, the MS group had significantly lower percentages of open-arm entries (P < 0.01) and open-arm time (P < 0.05), and longer stationary time (P < 0.05) in the FST than the CON group, indicating obvious anxiety and depression-like behaviors. Moreover, the mRNA levels of Wnt2 and Wnt3a in the hippocampus were notably decreased (P < 0.01), while the protein levels of DKK1 and sFRP3 were increased remarkably (P < 0.01) in the MS group than the CON group. Conclusion Maternal and infant separation leads to depression and anxiety-like behaviors in offspring rats, which may be associated to the disorder of Wnt signaling molecules in the hippocampus.

ObjectiveTo explore an improved method for constructing a mouse model of aortic dissection (AD).MethodsAD was induced by the simultaneous administration of β-aminopropionitrile (BAPN) with angiotensin Ⅱ (Ang-Ⅱ) for 16 days in mice. One hundred 6-week-old male C57B1/6J mice were randomly divided into BAPN (BAPN 0.1 g•kg-1•d-1 + 0.9% saline), BAPN+Ang-Ⅱ (BAPN 0.1 g•kg-1•d-1 + Ang-Ⅱ), and control groups. BAPN (0.1 g•kg-1•d-1), freshly prepared and dissolved in drinking water, was administered to all mice in the BAPN and BAPN + Ang-Ⅱ groups for 16 days. Mice in the BAPN+Ang-Ⅱ group were treated with an additional subcutaneous injection of Ang-Ⅱ for 16 days. The concentration of Ang-Ⅱ was halved from 1.5 mg•kg-1•d-1 every week until it was set at 0.375 mg•kg-1•d-1 on day 15, and then maintained. The daily water intake and body weight were recorded from the beginning until the end of the study. If a mouse died during the experiment, an autopsy was performed to analyze the cause of death. On day 17, the mice were sacrificed, and each aorta was harvested. The formation of the aortic false lumen was observed pathologically using hematoxylin and eosin (HE) staining.ResultsCompared with the control group, the amount of water consumed and body weight in the BAPN+Ang-Ⅱ and BAPN groups were significantly reduced (P < 0.05). In the control group, the incidence of dissection and mortality was 0.0%. In the BAPN group, the incidence of AD and the mortality was 7.5% and 2.5%, respectively. In the BAPN+Ang-Ⅱ group, the incidence of AD and the mortality was 80.0% and 30.0%, respectively. Interestingly, the deaths in the BAPN+Ang-Ⅱ group occurred frequently at 1-3 days after dose adjustment, and 83.3% of the mice died a few minutes after the operation.ConclusionThis modified method for constructing an AD mouse model induced by BAPN drinking combined with Ang-Ⅱ subcutaneous injection was replicable, regular, effective, cheap, and quick.

This article investigates the administrative licensing data of laboratory animals in Jiangsu Province, summarizes the administrative licenses for laboratory animals in recent years, analyzes the status of the administrative management of laboratory animals in Jiangsu Province, and proposes corresponding countermeasures to provide a reference for the administration of laboratory animal industry in Jiangsu Province and other regions.

Objective To investigate the influencing factors of intracranial hemorrhage (ICH) of parenchymal hemorrhage type 2 (PH2) after endovascular treatment (EVT) in patients with acute ischemic stroke (AIS). Methods A total of 64 AIS patients who were admitted to the First Affiliated Hospital of Army Medical University and received endovascular treatment from April 1, 2020 to December 31, 2020 were enrolled in this study, and the presence of PH2 ICH was determined by cranial CT scanning within 72 h after operation. The clinical data of the patients were collected and retrospectively reviewed, including age, gender, hypertension, diabetes, hyperlipidemia, coronary heart disease, atrial fibrillation, stroke history, National Institutes of Health Stroke Scale (NIHSS) score, blood pressure, blood glucose, glycosylated hemoglobin, platelet, international normalized ratio (INR), cardiogenic embolism, preoperative antithrombotic therapy, preoperative intravenous thrombolysis, and Alberta Stroke Program Early CT Score (ASPECTS). Results Among all the 64 patients, 28 cases (28/64, 43.8%) were diagnosed with ICH within 72 h after surgery, among which 9 cases (9/64, 14.1%) had PH2 ICH. In the PH2 group, the median blood glucose (7.50 vs 6.58, P=0.039), proportion of women (77.8% vs 38.2%, P=0.035), and proportion of cardiogenic embolism (88.9% vs 49.1%, P=0.033) were significantly higher, whereas the median ASPECTS (6 vs7, P=0.026) and proportion of ASPECTS >6 (22.2% vs 63.6%, P=0.029) were greatly lower than those of the non-PH2 group. In addition, the increased blood glucose presented as a risk factor for the occurrence of PH2 ICH (OR=1.48, 95%CI: 1.00~2.18). Conclusion Elevated blood glucose may increase the risk of developing PH2 ICH after EVT in patients with AIS.

Apert syndrome (AS) is characterized by synostosis of coronal sutures, midfacial hypoplasia,abnormity of brain, syndactyly of hands and feet. Majority of AS is caused by gain-of-function mutation of fibro‐blast growth factor receptor 2 (FGFR2). To date, the treatment of AS is surgical correction for the deformed skull.The reconstruction of sutures is often executed several times, because of constant premature of sutures. Some dis‐eased tissues, such as brain, are difficult to treat with surgery. CRISPR/Cas9 gene editing technology exhibits pow‐erful prospect in the treatment of human genetic diseases. In this study, small guiding RNA (gRNA) specificallytargeting the Fgfr2 gene was screened and lentivirus mediated Cas9/gRNA was employed to treat mice (Fg‐fr2+/P253R) that mimicking human Apert syndrome in primary calvarial cells, calvarial explants or calvarial bone. Incultured primary calvarial cells, Cas9/gRNA reduced the phosphorylation of ERK1/2 and P38, and resultantly inhibited osteoblastic differentiation and matrix mineralization. Besides, Cas9/gRNA attenuated the premature closure ofcoronal suture and the decreased calvarial bone volume calvarial explants and AS mice. This study provides exper‐imental basis of gene therapy for Apert syndrome, and is prospective to provide new strategies for the treatment ofskeletal genetic diseases.

In order to solve the problem of the lack of life characteristic characterization ability in the prediction of the remaining life of the rolling bearing,a method of the residual life prediction of the rolling bearing based on multi-resolution singular value decomposition and ECNN-LSTM is proposed. Firstly,the time-frequency information of vibration signals in onedimensional multi-space scale is extracted by using the multi-resolution singular value decomposition method,and the health stage is divided according to the standard deviation at the initial time. Secondly,a high-efficiency channel attention mechanism module was added to the two-layer one-dimensional convolutional neural network structure,and the convolution kernel was adaptively adjusted for multi-channel interaction without dimension reduction,so as to fully extract bearing degradation characteristics and establish effective life degradation indicators. Finally,MSE loss function is used to achieve the residual life prediction on LSTM.The feasibility and effectiveness of the proposed method are verified by Cincinnati whole life data.

Objective To observe whether serotonin (5-HT)-mediated proliferation of pulmonary artery smooth muscle cells (PASMCs) is related to the increase of intracellular reactive oxygen species (ROS), and identify the role of NADPH oxidase (NOX) in the production of ROS and 5-HT-mediated proliferation. Methods Tissue block culture method was used to establish a cell line of human PASMCs. Then the cells were divided into 6 groups, normal control (no treatment), 5-HT treatment (1 μmol/L 5-HT), and 3 intervention groups. Then NOX activity was analyzed by using spectrophotometer to calculate the amount of NADPH consumed. ROS production was measured by DCF-DA assay. The expression of phosphorylated-ERK1/2 (p-ERK1/2) was detected by Western blotting. The changes of PASMC proliferation were determined 3H-TdR incorporation assay. Results 5-HT stimulation for 30 min obviously enhanced the NOX activity, ROS production, DNA synthesis, and expression of p-ERK1/2 (all P < 0.05). While the pretreatment of DPI, Tempol or PD98059 could significantly reverse the ERK1/2 phosphorylation and DNA synthesis induced by 5-HT stimulation (both P < 0.05). What's more, DPI also notably reduced the generation of ROS (P < 0.05). Conclusion NOX/ROS may be the key proteins in the signaling pathways of 5-HT mediated proliferation of PASMCs.

Objective To investigate the changes in the expression of fibroblast growth factor receptors 1-3 (FGFR1-3) at different stages of osteogenic differentiation and clarify the role of FGFR signaling in osteogenic differentiation. Methods Mouse osteoblasts in primary culture and osteoblast cell line MC3T3-E1 were induced for osteogenic differentiation, and the cell differentiation was identified by morphological observation, alkaline phosphatase (ALP) staining and alizarin red staining. qRT-PCR and Western blotting were used to detect the expression of FGFR1-3 and the genes involved in osteogenic differentiation, and the effect of blocking FGFR signaling on osteoblast differentiation was observed. Results The primary mouse osteoblasts were positive to ALP staining and alizarin red staining. The expression of COL 1α, RUNX2 and OPN was increased during osteogenic differentiation in both mouse osteoblasts and MC3T3-E1 cells. The expression of FGFR1, FGFR2 and FGFR3 was also increased in the cells during osteogenic differentiation, and blocking FGFR signaling significantly inhibited osteogenic differentiation of the cells, suggesting the regulatory role of FGFR signaling in osteoblast differentiation. Conclusion FGFR signaling promotes osteogenic differentiation of osteoblasts.

Through comparison, algorithm optimization, pipeline accelerated design and structural compatibility extension of a large number of mainstream algorithm, this paper propose an algorithm that is good for modulo operation structure compatibility: improved radix-4 interleaved modular multiplication algorithm. It has advantages of short path and simple structure, and has advantages in compatibility design, can achieve full flow accelerated operation, and achieve the high speed and reconfigurable design purposes. The improved radix-4 interleaved modular multiplication unit proposed in this paper can directly realize plus-minus module division and modular addition without adding extra structure, which solves the problem of the waste of independent resources. The unified modular unit is synthesized under the 65 nm CMOS process. The area is 0.117 mm2. The clock frequency is 526 MHz. A 576 bit modular multiplication and modular division are completed at 0.55 μs and 2.98 μs respectively.

Geological disaster data is a kind of multi-source heterogeneous data with multi-source, large quantity, multi-type, multi-format, multi-scale and multi-precision.It is a typical "big data".Relational database is the mainstream management method of geological disaster data at present.There are a large proportion of unstructured data in geological disaster data.Because it is difficult to manage unstructured data effectively by using relational model, the effect of this management method is not ideal.This weakness will be further amplified in the era of big data, and will have a certain impact on geological data mining and big data analysis.This paper focuses on the management mode of geological disaster data in the era of big data.Discusses the management of pan-structured geological data, application model and integration of distributed heterogeneous system.It is considered that the effective management of geological disaster data should combine file system, relational database and NoSQL, and a pan-structured geological data management and application mode based on the combination of double C model and middleware is proposed.The double C model has an implicit internal data access and management center and an explicit outer analysis and application center.Through the double C model, a variety of work can be integrated into a simple and orderly whole, such as geological data collection, management, statistics, calculation, retrieval, geological map compilation, three dimensional modeling, attribute analysis, spatial analysis and so on.

Microstrip line and coaxial are the two common transmission lines in microwave systems. The common interconnection method between the two transmission lines at the low frequency band is direct soldering. The coaxial inner conductor is soldered on the metal strip line of the microstrip line. The outer conductor is mounted on the ground plane of the microstrip line. This connection has little effect on the transmission of microwave signals in the low frequency band. In the millimeter wave band, this connection will result in an increase loss of the millimeter-wave signal. Therefore, a millimeter-wave band microstrip coaxial transition structure is designed. This transition structure adds a transition hole structure between the microstrip line and the coaxial, which can effectively reduce the voltage standing wave ratio and insertion loss of the microstrip-to-coaxial transition structure, and improve the performance of the overall system.

The surface of EA4T steel was repaired by ultrasonic vibration assisted laser cladding.The influence of ultrasonic vibration on the forming quality, microstructure and phase composition of laser cladding of EA4T steel were compared and analyzed by optical microscopy (OM),scanning electron microscopy(SEM),X ray diffraction(XRD),and the microhardness of the cladding layer and matrix was tested by microhardness tester.The results show that the cladding forming quality is improved, and the dendritic structure with strong original orientation is broken under the effect of ultrasonic vibration,which reduces the segregation of dendrites within the cladding layer.At the same time,ultrasonic vibration refined grain, promotes the precipitation of Cr23C6 carbide on the dendrites, but it does not change the phase composition of cladding layer.Compared with that without ultrasonic vibration applied,the microhardness distribution of cladding layer is more uniform under the ultrasonic vibration, the average microhardness of cladding layer is increased by 126.2HV0.2,and the average microhardness of heat-affected zone is decreased by 31.2HV0.2.

The escapement mechanism is considered to be the crucial component in a mechanical watch with a complicated motion. A dynamics model of the escapement mechanism is established based on the continuous impact force model,the dynamics simulation and calculation are carried out by using ADAMS. The results show that the dynamics response of each part under different input moment of escapement wheel can be directly predicted by the model,and therefore the corresponding instantaneous daily rate is calculated. Compared with the experimental data,the simulated results are able to predict the trend of the instantaneous daily rates in different driving torques in a moderate precision level. The model could be used to improve the performance of the escapement mechanism in the future.

BackgroundThe highly charged nitrogen ions (Nq+, q=3, 5, 6) are one of the main charged ions in the solar wind. Study of K-shell X-ray emissions in collisions of Nq+ (q=3, 5, 6) ions with a Cu surface is of great significance for understanding the de-excitation process of "hollow atoms" and the generation mechanism of comet X-rays.PurposeThis study aims to investigate characteristics of K-shell X-ray emission in impacts of Nq+ (q=3, 5, 6) ions with a Cu surface.MethodsThe Nq+ (q=3, 5, 6) ion beam was generated by the electron cyclotron resonance ion source (ECRIS) in Institute of Modern Physics, Chinese Academy of Sciences. The K-shell X-ray spectra resulted from collisions of the Nq+ ions with the Cu surface were acquired by a silicon drift detector (SDD). Based on the X-ray spectra, K-shell X-ray yields and ionization cross sections were calculated.ResultsThe results show that, for the Nq+ (q=3, 5) ion incidence, K-shell X-ray emissions are attributed to close collisions of the ions with Cu atoms on the subsurface of the target, and that the K-shell X-ray yields and ionization cross sections increase monotonically with the increase of kinetic energy of the incident ions. For the N6+ ion incidence, the K-shell X-ray yields have no obvious dependence on kinetic energy of the incident ions. The K-shell X-rays are primarily emitted from the above-surface of Cu target through the de-exciting of the formed "hollow N atoms", and they account for about 97% of the total X-rays. In addition, the X-ray yield of the N5+ ion incidence is higher than that of N3+ ions.ConclusionsThis study provides basic data for the understanding the de-excitation process of "hollow atoms" and the generation mechanism of comet X-rays.

[Objectives] This paper presents research into the interaction between a free surface,shock wave and bubble.[Methods] Based on the Discontinuous Galerkin method and combined with the Level Set method and Real Ghost Fluid method,the characteristics of shock wave propagation and bubble motion are analyzed,the generation and evolution of waves in fluid fields are described in detail.[Results] The results show the presence of complex waves in the fluid field after the interaction,including multiple rarefaction waves and shock waves. The collapse speed of the bubble is slowed down with the existence of the free surface,while the shock wave of the incident accelerates the collapse speed of the bubble and increases the up warp motion of the free surface.[Conclusions] The conclusions drawn from this paper can be used as reference points for further research into the damage mechanisms of ship structures subjected to underwater explosions.

Plasma electrolytic borocarbonitriding (PEB/C/N) was successfully used to achieve ternary borocarbonitriding layer on industrial pure iron at the bath voltages of 340, 360V and 380V respectively. The morphology, composition, phase constituents and microhardness profiles of PEB/C/N layers were investigated. The influence of bath voltages on wear behaviors of PEB/C/N layers was evaluated by ball-disc friction and wear tester under dry sliding against ZrO2 ball, and their wear mechanism were analyzed. The results show that the thickness and maximum hardness of PEB/C/N layer on pure iron increase with the increase of bath voltage. After 1h discharge treatment at 380V, the boride layer and transition layer of the PEB/C/N sample reach 26μm and 34μm respectively, and the maximum microhardness of PEB/C/N layer can reach 2318HV. The wear rate of PEB/C/N layer is only 1/10 of that of the pure iron substrate. The friction coefficient and wear rate of pure iron are greatly reduced after the PEB/C/N surface treatment, but the friction coefficient and wear rate of PEB/C/N layer vary little under different bath voltages.

To improve the aero- engine fault diagnosis accuracy grade,by using the DET and PNN classification techniques,a bearing fault diagnosis technique based on feature selection and PNN is put forward.Firstly,the bearing fault test data are extracted to form the multi- domain fault diagnosis feature set composed of 14 time- domain features and 13 frequency- domain features. Secondly,to increase classification efficiency and reduce the influence on classification result from coupling characters between features,the feature selection technique based on DET is applied to obtain feature parameters which can be classified easily. On this basis,the PNN technique is applied to carry on research of bearing fault diagnosis. The bearing simulation fault experiment data is applied for verification,the results prove that compared with diagnosis techniques of BP neural network and support vector machines,the PNN is higher in the respect of diagnosis accuracy grade. Meanwhile,the efficiency and accuracy grade of diagnosis are further improved for the reason of employing feature selection technique.

Objective To study the correlation between the movement distance of small intestinal contents and survival time in female SD rat models after one-time satiation, and to evaluate its application value for postmortem interval estimation. Methods Adult female SD rats were randomly divided into postprandial groups （1, 2, 3, 4 and 5 h after feeding） and control group. The postprandial groups were fed for 1 h, meanwhile control group was kept fasting. All rats were sacrificed at the given time. The contents in stomach and small intestine were observed, described, compared and photographed, and the movement distance of small intestinal contents was measured. The data of postprandial groups were analysed by one-way analysis of variance. Results The stomach and duodenum of control group were empty with a little thin and yellow small intestinal liquid. The gastral cavities of 1 h postprandial group were full of undigested food. The evolutionary changes of character, colour and content were observed in the gastric and small intestinal contents of other postprandial groups. The movement distance of intestinal contents increased while the empty part decreased gradually. The differences among the postprandial groups were statistically significant （P

Atomic fluorescence spectrometry (AFS) has such characteristics of chemical vapor separation and non dispersive optical system. It is one of the most successful analytical methods available to determine trace As, Sb, Bi, Hg, Se, Te and Ge elements. Researchers in China have made important contributions to the development of AFS. Many technological patents have been invented, for example, the high-strength hollow cathode lamp, small flame atomization, and argon-hydrogen flame low temperature automatic ignition device. The multi-channel atomic fluorescence spectrometer, hydride generation and flame atomic fluorescence spectrometer and atomic fluorescence RoHS analyzer have also been further developed. New chemical vapor generation systems and specific reagents for the determination of Pb, Zn, Cr and Cd. A new method for indirect determination of I and Mo by AFS have also been established. Five monographs have been published and many achievements in research and application have been published annually. Described herein is an overview of the development of AFS in the past nearly twenty years, synthetically described on monograph publications, review literatures, equipment, technology and applications respectively in geological, biological, water, air, metals, alloys, chemical raw materials and reagents, etc. The developments of AFS in the form and valence state analysis are also reviewed in this article. It points out that research on a new type of laser excitation source, the development of a more stable and reliable high-strength hollow cathode lamp, broadening the testing elements and areas, and an in-depth study on the reaction mechanism are the future direction of the development of AFS.

The single-transmitting-dual-receiving polarimetric SAR system has only two receving channels, which induces lack of prior information for calibration. Due to the polarization diversity of this kind of system (which operates on different dual and compact polarimetric modes), there has not a general algorithm currently. In this paper, a new general calibration algorithm is proposed for single-transmitting-dual-receiving polarimetric SAR system, which can be widely applied to diverse polarization modes. The transmitting and receiving distortion can be estimated using trihedral, 0° dihedral and 45° dihedral as ideal point targets without any assumption on the scene and system. The basic principle of this new algorithm is induced theoretically. The effect of calibrator error on the distortion estimation is analyzed by simulation. Point targets’calibration results and polarization signatures verify this algorithm.

Understanding water use characteristics of plants and their interrelations is essential for achieving sustainable vegetation restoration of desert steppe. This study focused on five dominant plant species inhabiting two habitats : sierozem ( Populus euphratica, Caragana liouana ; and Stipa breviflora) and aeolian sandy soil ( P. euph-ratica' Salix psammophila; and Leymus secalinus). We analyzed S2 H and Sl8O isotopes in xylem; soil water; groundwater; and precipitation. By integrating soil water content and root data at various depths ; we employed the MixSIAR model to quantitatively assess water utilization characteristics. Results revealed that these plants primarily relied on soil water during the growing season, with variations in water uptake depths at different growth stages. In the sierozem habitat, Populus exhibited significant variations in water source throughout the growing season. Early in the growing season (May to June), P. euphratica primarily extracted soil water from depths of 60-100 cm. During the peak growth period (July to August), water source shifted to depths of 100-200 cm, and returned to the depth of 0-20 cm by the end of the season ( September). C. liouana initially utilized soil water at 60-100 cm but shifted to 0-20 cm during and after peak growth. S. breviflora predominantly tapped into soil water at 20-60 cm early and late in the growing season, but shifted to 0-20 cm during peak growth. In the aeolian sandy soil habitat, P. euphratica initially utilized soil water at 60-100 cm but shifted to 0-20 cm during and after peak growth. S. psammophila primarily utilized soil water at 60-100 cm early and during peak growth, shifting to 100-200 cm by the end of the season. L. secalinus mainly relied on soil water at 20-60 cm throughout the growing season. Soil moisture, seasonal precipitation variation, and root distribution influenced vegetation water use patterns. Throughout the growing season, trees, shrubs, and herbs in the sierozem habitat exhibited hydrological niche partitioning, which facilitated their water distribution and utilization. Conversely, dominant plants in the aeolian sandy soil habitat showed hydro-logical niche overlap, which intensified water competition, particularly between trees and shrubs. Therefore, species traits and soil properties should be given full consideration when selecting species combinations for vegetation restoration. Introducing species combinations with complementary water use characteristics is essential for fostering species diversity and sustainable vegetation restoration in desert steppe. [ABSTRACT FROM AUTHOR]

In order to solve the technical problems of the super-diameter slurry shield in the waterinrush, sand-bursting and mud-bursting strata at the entrance of the receiving tunnel in the water-rich silt and sand strata near the sea, the differences between the super-diameter and the small-diameter shield in the underwater reception are analyzed by taking the key receiving technology of the super-diameter slurry shield in the water-rich strata of the Shantou Bay Tunnel Project as an example. Based on the receiving process of super-large diameter shield, this paper expounds the solution methods of super-large diameter slurry shield in the aspects of end reinforcement, receiving shaft plugging wall construction, receiving base construction, single-layer glass fiber reinforced concrete tunnel door breaking, penetration measurement, receiving tunneling and grouting, tunnel door plugging, etc., including shield posture control, tunneling parameter control, grouting control, segment re-tightening The key technologies of the super-large diameter shield receiving are analyzed from several aspects of the temporary plugging of the tunnel portal. The mortar receiving base is set to provide sufficient reaction force for the shield receiving to ensure the safety of the shield tunneling. The synchronous grouting and secondary grouting closing is employed to improve the reinforcement quality, strengthen the segment re-tightening and ensure the stability of the shield tunnel structure strength. For the last five rings, special perforated ring segments are used to improve the grouting effect. Then, the drainage and sand removal is carried out, and the reinforcement framework and shotcrete are constructed from top to bottom to block the tunnel door, reduce the exposure time of the tunnel door without blocking, ensure the construction safety of the tunnel door, and other measures are taken to ensure the safety of the underwater reception. [ABSTRACT FROM AUTHOR]