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Objective Axle box bearing is a key component of rail transit train bogie, and its health state directly affects the train operation safety. Therefore, it is necessary to establish a more scientific and efficient fault diagnosis method for axle box bearing to effectively extract bearing fault characteristic information under strong noise interference. Method With the vibration acceleration and acoustic signal (abbreviated as vibration-acoustic signal) as the research object, the fault characteristics of the axle box bearing are analyzed, and an optimal signal noise reduction method with bandpass convolution filtering is proposed. In this method, the original signal is divided into several frequency bands in the frequency domain, different bandpass filtering parameters of each frequency band are determined and a multi-channel bandpass convolution filter bank is constructed. The optimal filtered signal is selected by using time-domain index segmental kurtosis, and demodulated by weighted frequency energy operator to identify the bearing fault spot. Result & Conclusion With the proposed method, the fault characteristics of the vibration-acoustic signal can be extracted under strong interference noise. Both the simulation and on-site test results verify the validity of the method. The fault diagnosis conclusions of the vibration-acoustic signal can be mutually verified, further improving the accuracy of the axle box bearing fault diagnosis.

Objective: This study was to investigate the protective effect of Noni polysaccharides on ionizing radiation injury and its regulation of intestinal flora in mice. Methods: Fifty KM male mice were randomly divided into normal group, model group, noni polysaccharide low-dose group, noni polysaccharide medium-dose group and Noni polysaccharide high-dose group. The whole body of the mice was irradiated by the medical electron linear accelerator, thus establishing acute radiation-damaged mice model. Subsequently, survival quality of mice after irradiating was observed, and related biochemical indicators of serum and liver tissue of mice after irradiating for 72 h were detected. Furthermore, 16S rRNA sequencing of mouse feces was performed to analyze diversity of intestinal flora. Results: Noni polysaccharides could improve survival quality of radiation-damaged mice, and increase organ index, peripheral blood leukocyte (WBC) number, spleen nodule number, bone marrow DNA content. Moreover, noni polysaccharides could reduce the rate of bone marrow polychromatic erythrocyte micronucleus (MN-PCE), and increase the activities of antioxidant enzymes catalase (CAT), superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in serum and liver, and reduce malondialdehyde (MDA) content. Compared with the MC group, the increase rate of peripheral white blood cell count and number of splenic noduleswas 46.85%, 38.23%, and the content of bone marrow DNA increased by 51.95%, the reduction rate of MN-PCE was 38.84% of Noni polysaccharide high-dose group. Meanwhile, the oxidative stress of mice after irradiating had improvement in different degree of Noni polysaccharide. Additionally, Noni polysaccharides could promote the growth of intestinal flora of radiation-damaged mice in a direction of beneficial to host health. Meanwhile, Noni polysaccharides could accelerate the growth of probiotics and inhibit the colonization of harmful bacteria, and recover the changes of intestinal flora caused by ionizing radiation. Conclusion: Noni polysaccharides exhibited obvious protective effect on ionizing radiation-damaged mice caused by X-ray, and showed certain restoring effect on intestinal flora disturbance caused by radiation.

Objective To address the challenge of difficult fault identification in rail transit vehicle bogie axle box bearings under rail service conditions, it is necessary to investigate the acoustic characteristics of these faults. Method Focusing on the faulty axle box bearings of rail transit vehicle bogies as research object, by adding external loads and excitations and introducing irregular faults, a dynamics model of the axle box bearing system is established in conjunction with the rotor-bearing system. Based on the pulsating point sound source radiation method, numerical simulation software is used to construct an irregular fault sound signal model for the inner and outer rings of the bearings. The fault characteristics of inner and outer rings of axle box bearings under rail service conditions, the impact of load and rotational speed on the fault characteristics parameters of bearing sound signals are explored. Experiments are conducted on an axle box bearing test bench under different working conditions to capture the acoustic sound signals of faulty bearings, and the results are analyzed. Result & Conclusion The sound signals of both faulty and normal bearings of inner and outer rings exhibit corresponding characteristic frequencies and harmonics. However, there are modulation frequencies of the rotational frequencies near the harmonics of the inner ring fault bearing sound signals. As the rotational speed increases, the characteristic parameters of both inner and outer ring faulty and normal bearings exhibit a distinctive and obvious positive correlation trend. Specifically, the time-domain waveform indicators decrease with increasing rotational speed, while the amplitude of the characteristic frequencies increases linearly with rotational speed. As the load increases, the characteristic parameters of both inner and outer ring faulty and normal bearings also all show a distinctive and obvious positive correlation, among which the time-domain variance indicators increase with higher loads, and the amplitude of the characteristic frequencies increases linearly as load increases.

Oolong tea was highly favored by consumers for its rich aroma. However, there was significant loss of fragrance in Oolong tea products during processing and storage, urgently necessitating the development of corresponding technologies to stabilize aroma molecules. Addressing this, this study investigated the stabilization of aroma compounds in Rougui Oolong tea. Employing spinning cone column distillation, volatile organic compounds (VOCs) were extracted from the tea. The effect of hydroxypropyl-β-cyclodextrin on inhibiting the aromatic loss of these extracted VOCs during storage was assessed using gas chromatography-ion mobility spectrometry. Results showed that after 7, 21, and 42 days of storage at room temperature (25 ℃), the samples treated with hydroxypropyl-β-cyclodextrin (experimental group) consistently contained significantly higher quantities of VOCs compared to the untreated controls (P

Based on the coseismic response data of water temperature and water level of 26 observation wells in Yunnan well network from 2008 to 2023, the coseismic response characteristics of water temperature and water level of each observation well were compared and analyzed with 8 earthquakes that have a significant impact on Yunnan region. The coseismic response mechanism was discussed from the perspectives of seismic wave energy density, lithology, control of fault zone and dynamic coordination. The results indicate that the response of water temperature and water level in the well pattern of Yunnan to the far-field earthquakes is more significant than near earthquakes, with the response primarily concentrated in the middle of Yunnan. The water level exhibits a more pronounced response than the water temperature. The coseismic variation of water level is mainly characterized by oscillation and rise, while the water temperature is mainly characterized by pulses. Dehong Fapa Dian No.22 well and Lijiang Xiangshan well have better seismic reflection performance in Yunnan well pattern. On the other hand, No.06 well in Jianchuan, No.01 well in Huize Gangou Dian, Xiaoshao well in Kunming Guandu District, Dayao geothermal well, and Nanhua Zhen 2 well exhibit weaker coseismic responses compared to the other 21 wells. Further analysis shows that the linear fitting correlation coefficient between seismic wave energy density and epicenter distance is greater than −0.9, which is significantly negative correlation and positive correlation with magnitude, and shows the corresponding relationship between energy density and permeability coefficient. Finally, we analyzed the mechanism of coseismic response of water temperature and water level.

Objective: To explore the antioxidant mechanism of Shanxi aged vinegar on rats induced by high fat diet based on PI3K/AKT1 pathway. Methods: Thirty SPF male Wistar rats were randomly divided into 5 groups: Normal group (C, conventional diet), high fat model group (M, high fat emulsion), low (LV), medium (MV) and high (HV) Shanxi aged vinegar intervention groups (1.35, 2.7, 5.4 g/(kg·bw)). Modeling (5 weeks) at the same time given Shanxi aged vinegar intervention, the aged vinegar intervention continued for 5 weeks. Serum lipid content, liver injury index and antioxidant enzyme activity were detected. The histopathological status of liver was observed by HE staining. The mRNA and protein levels of PIK3CA and AKT1 in rat liver were detected by qRT-PCR and Western blotting, and the localization was analyzed by immunohistochemistry. Results: Compared with group C, liver steatosis was severe in group M, serum lipid content and degree of liver injury were significantly increased (P

【Objective】The research was carried out to clarify the field control effects of six agents on blossom blight of kiwifruit, and to screen efficient and safe agents for guiding the field production of kiwifruit.【Method】The field control experiment was carried out by using random block design, and the incidence rate and disease index of blossom blight of kiwifruit after the application of six agents were determined, and the control effects were evaluated by calculating the change values of incidence rate and disease index before and after treatment. The safety of each agent was evaluated by its effects on the growth situation of kiwifruit plants and the development characteristics of flowers and fruits.【Result】Six agents showed different control effects on blossom blight of kiwifruit, and all of them were safe to kiwifruit plants. The results of field trials showed that there was no significant difference in incidence rate and disease index between the treatment groups and the CK group before control. After two consecutive treatments, the incidence rates of treatment groups and CK group showed an increasing trend compared with those before control, and the change values of the disease situation were significantly different, among which the change value of the CK group was the largest, and the incidence rate and disease index increased by 13.29% and 6.84, respectively. The change values of kasumin • brothermothingonil and tetramycin • propyrithiazole were the smallest, with the increase of incidence rate less than 1.50% and the increase of disease index less than 1.00. The field control effect corresponded to the disease situation. After two consecutive treatments, the treatment of kasumin • brothermothingonil showed the highest control effect, followed by tetramycin • propyrithiazole, both of which were above75%. All agents had no phytotoxicity symptoms and other adverse effects on kiwifruit plants after the application of agents, and showed different degrees of flower protection, fruit protection and yield increase compared with the CK group. The results showed that among the six agents, kasumin • brothermothingonil and tetramycin • propyrithiazole were the most effective in delaying the transmission and spread of the pathogen of blossom blight of kiwifruit, reducing the disease severity, and controlling blossom blight of kiwifruit efficiently and safely.【Conclusion】Two effective and safe agents - kasumin • brothermothingonil and tetramycin • propyrithiazole are screened for blossom blight of kiwifruit, which can be promoted in field production of kiwifruit.

With the increasing melting of Arctic sea ice, the importance of studying Arctic issues is becoming more and more prominent. By using ScienceDirect database as the main search scope, the authors systematically combed foreign literature on Arctic issues from 2007 to 2021, and analyzed the research status of foreign Arctic issues from four aspects: Arctic routing, economy, politics and environment. It was concluded that the future research on Arctic routing would focus on the operation mode; The research on Arctic economic issues would focus on regional economy and industry development; The research on Arctic politics would still focus on how to cooperate in the governance of the Arctic. Although there will be more qualitative and descriptive analyses in current research on Arctic politics, quantitative analysis and theoretical innovation would be increased in the future; Research on Arctic environmental issues will focus on the balance between economic development and environmental protection in the Arctic, and further pay attention to the sustainable development of the Arctic.

To investigate the effect and potential mechanism of ethyl acetate extracts from Inonotus obliquus in inhibiting the replicaton of prion, multiple methods were utilized. Using CCK-8 assay to evaluate the cytotoxicity of dichloromethane extracts, ethyl acetate extracts, n-butanol extracts and obtain the maximal concentrations of various extracts. Prion-infected cell model SMB-S15 were treated with three extracts at safe concentrations (0.1×2−14~0.1×2−8 mg/mL) and the inhibitory effects of different extracts on prion replication were analyzed by PrP-specific Western blots. The expression of reactive oxygen species, hydrogen peroxide and related antioxidant factors were measured in SMB-S15 cells treated with ethyl acetate extracts. The results showed that the maximum safe concentrations of dichloromethane extracts, ethyl acetate extracts and n-butanol extracts was 0.1×2−8 mg/mL. Prion replication was significantly inhibited in SMB-S15 cells treated with ethyl acetate extracts at this concentration of 0.1×2−8 mg/mL for 3 days (P

Objective: To establish a method for quantitative detection of adulterated apple components in cherry based on droplet digital PCR (ddPCR). Methods: By screening the component specific primer probes of cherry and apple, the quantitative detection method of ddPCR was established. The fitting curve between quality and DNA content and the fitting curve between DNA content and copy number were constructed. Taking DNA content as the intermediate value, the calculation formulas of quality and amplified copy number were obtained. The linear fitting curves R2 were all above 0.99, and the corresponding adulteration model was established to verify the accuracy of the method. Results: The formula for calculating the mass and amplified DNA copy number of cherry and apple: Mcherry=0.0833C−3.8420, Mapple=0.4084C−1.5747. In the adulteration model of cherries and apples, the maximum relative error was −19.17%, which met the statistical requirements. Conclusion: The establishment of a rapid detection method for European sweet cherry products provides a powerful means to combat the adulteration of European sweet cherries, protects the rights and interests of consumers, and is of great significance for promoting the healthy development of the small berry and its product industry.

To deeply analyze the thalassochemical conditions and organic matter enrichment mechanism during the Early Cambrian (541-509 Ma)and actively evaluate the potential of shale gas resources of the Lower Cambrian Qiongzhusi Formation(Fm) in the southwestern Sichuan Basin, based on the analysis of the petrology, organic geochemistry, element characteristics, pore structure and adsorption capacity of Qiongzhusi Formation, Well W-207, Weiyuan area, this study has discussed the Early Cambrian paleo-ocean environment, organic matter enrichment control factors and gas-bearing properties of shale gas in the upslope area of the Upper Yangtze Platform. Sedimentary cycle shows that multiple interactive conversioncycles of deep-water continental shelf and shallow-water continental shelf are developed during the fine-grained deposition period of Qiongzhusi Formation under the control of eustasy. In particular, the slope turbidite (fan) and gravity flow sediments indicate that shallow-water continental shelf facies are dominant, and the wells in the upslope of the Weiyuan area are not in deep-water for a long time, with the sedimentary thickness of organic-rich black shale limited. Organic geochemistry evidence indicates that the organic matter of Qiongzhusi Formation in Well W-207 is mainly Type-Ⅰ kerogen, with a high degree of thermal evolution, fewer residual hydrocarbons and a low hydrocarbon generation capacity. The redox parameters indicate that the marine environment on the upslope has a medium restrictive degree, and there is a certain degree of upwelling. The seawater has experienced the transformation process of "anoxic-oxidation-anoxic-secondary oxidation- oxidation". Therefore, the paleo-ocean productivity level in the upslope area is generally low, with an obvious downward trend from bottom to top. The pore structure and nitrogen adsorption curve show that the reservoirs of the Qiongzhusi Formation are mainly complex and irregular slit pores. The methane adsorption capacity is positively correlated with TOC but negatively correlated with temperature, indicating that the high-pressure and high-temperature conditions generally faced by the Qiongzhusi Fm are not suitable for methane adsorption. As a result, the geological conditions of shale gas for Qiongzhusi Fm in the upslope area are complex. With high exploration risk, this study suggests that the resource evaluation direction should change to the intracratonic sag (downslope area), which is characterized by deep-water continental shelf facies.

The karst areas in southern China are characterized by a high rock exposure ratio and shallow and unevenly distributed soil layers.How this special geotechnical fabric affects the hydrological process is of great significance for the accurate estimation of carbonate weathering carbon sink flux.Hydrochemical runoff is a commonly used method for calculating carbonate weathering carbon sink flux at the watershed scale, and basin area and discharge, as two important parameters, are often difficult to accurately obtain in karst areas.To overcome this problem, we designed a rock-soil fabric simulation test site, including different rock-soil ratios(1:1 and 4:1) and soil thicknesses(5, 20, 100 cm) at the Puding Karst Ecosystem Research Station, Chinese Academy Sciences.The effects of rock exposure and soil layer thickness on hydrological processes and carbonate weathering carbon sink flux were quantitatively studied by monitoring the flow and hydrochemistry during a hydrological year.The results show that the average carbonate weathering carbon sink flux is 17±3 gC/m2/a, which is controlled by the leakage amount and accounts for 95% in the rainy season(from May to October); The influence of the rock exposure ratio(between the two groups of rock fabric) on the leakage amount is up to 14%, and the infiltration coefficient increases with increaseing of rock exposure ratio; The effect of the soil layer thickness on seepage is only 1%-2%.In addition, it is found that the correlation between the infiltration coefficient and carbonate weathering carbon sink flux is the most significant by analysis the observed data of 8 field basins from previous studies.The infiltration coefficient is the main factor affecting and controlling the carbonate weathering carbon sink flux, which is due to the geological background of different rock and soil fabrics in the karst area.At the same time, the influence may change with the rainfall variation, that is, the infiltration coefficient is not constant.

Objective: To investigate α-glucosidase inhibitory and high blood glucose regulation of methanol extracts from Amomum tsao-ko in aged mice. Methods: Using 4-N-trophenyl-α-D-glu-copyranoside(PNPG) method with acarbose as positive control, α-glucosidase inhibition test in vitro was carried out to evaluate α-glucosidase inhibition rate of methanol extract from Amomum tsao-ko. The mouse model of abnormal blood glucose was established by feeding mice with high-fat diet. On the basis of high-fat diet, 100 and 200 mg/kg of methanol extracts from Amomum tsao-ko were added for 6 weeks to evaluate the effects of methanol extracts from Amomum tsao-ko on fasting blood glucose, glucose tolerance and insulin resistance in mice. Results: When the concentration of methanol extracts solution was 500 mg/L, the inhibition rate of α-glucosidase reached 63.72%. Half inhibitory concentration (IC50) of methanol extract from Amomum tsao-ko on α-glucosidase was 0.145 mg/mL. The fasting blood glucose of mice in the herb group began to decrease and maintain stability after 2 weeks of intervention by intragastric administration of low and high dose methanol extracts of Amomum tsao-ko groups. The area under the curve (AUC) values of glucose tolerance curve in low and high dose methanol extracts of Amomum tsao-ko groups after 6 weeks intervention were lower than that of model group (P

Most of the interfaces for mobile application and server interaction use the Web API for communication,but the Web API introduced by these mobile applications may introduce new security issues.To facilitate the study of the security of Web API,a system for automatically discovering the server-side Web API interface in APK files based on the conventional Android program testing framework was designed and implemented.This system can help to develop the research on private server-side Web API interface security.

Background and objective The Expand Access Program (EAP) of Iressa(gefitinib, ZD1839) in China was initiated in 2001 with the aim of providing gefitinib to non-small cell lung cancer (NSCLC) patients who failed to respond to standard treatment or who could not tolerate chemotherapy. The primary objective was to describe the quality of life (QoL), tumor control status, drug safety, and clinical/genomic features of active long-term survivors enrolled in the EAP. The secondary objective was to determine the clinical characteristics of long-term survivors in the EAP program. Methods In this descriptive observational study, data were collected based on epidemiological research methods. The data of patients who were actively participating in the EAP and still undergoing gefitinib treatment were collected in a cross-sectional manner to reflect the current status of each patient. Meanwhile, the data of patients who had been on gefitinib treatment for more than three years and had already been terminated from the EAP or those who were fast progressors were collected retrospectively. Results A total of 934 patients were screened in the EAP database. Among these patients, 25 were active long-term survivors still enrolled in the EAP and 34 were long-term survivors who had been terminated from the program. These 59 patients were enrolled in 15 different centers in China, and the remaining 875 patients were fast progressors. The median scores for the Functional Assessment of Cancer Therapy-Lung (FACT-L), Trial Outcome Index (TOI), and Lung Cancer Subscale (LCS) of the 25 long-term survivors were 64.5, 37 and 12.5, respectively. The performance status 0-1 accounted for 91.6% of the data observed during the cross-sectional survey. For active long-term survivors, the objective response rate was 37.5%, the disease control rate was 87.5%, and the median duration of response time was almost 68 months. In the long-term survivor group, no serious and new adverse events were reported. Patients who were aged under 65 years (68.5%), affected with adenocarcinoma (81.4%), female (55.9%), or had never smoked (71%) accounted for majority of the long-term survivors. The percentage of females was significantly higher in the long-term survivor group than in the fast progressor group (P=0.02). Three tissue samples were collected from each of the 24 active long-term survivors, and one patient was found to be positive of EGFR mutation. Twenty-two blood samples were also collected, and one patient tested positive for EGFR mutation. The Ki67 protein expression was also tested in three tissue samples, and two of these were found positive for Ki67 protein expression, with a response duration time of over 73 months. Conclusion A 250 mg dose of gefitinib offers good QoL and is safe for advanced NSCLC long-term survivors even after more than three years of treatment. According to the evaluation of the current tumor control statuses of patients, gefitinib demonstrates good efficacy in these active long-term survivors.

The aim of the experiment was to study the effects of Astragalus compound Chinese herbal medicine on the serum immune indexes, meat quality, and muscle nutrients of finishing pigs. A total of 250 finishing pigs of 170 days of age with similar body condition and body weight were randomly divided into five groups with five replicates per group and 10 finishing pigs per replicate. The control group was fed a basal diet, and the experimental groups were fed diets supplemented with 0.6%, 0.8%, 1.0%, and 1.2% Astragalus compound Chinese herbal medicine (ACM), respectively. The experiment lasted for 60 days. The results showed that the contents of serum immunoglobulin and complement protein were significantly higher in the 0.8% ACM group and 1.0% ACM group than in the control group (P<0.05). Compared with the control group, the muscle water loss rate of the experimental groups decreased significantly (P<0.05), the redness value of meat color increased significantly (P<0.05), and the yellowness value decreased significantly (P<0.05). Compared with the control group, the water content in meat of the experimental groups decreased significantly (P<0.05), the content of crude fat in meat of the 1.0% ACM group increased significantly (P<0.05), and the content of crude protein in meat of the 0.8% ACM group and 1.2% ACM group increased significantly (P<0.05). Adding 1.2% ACM significantly increased the content of total amino acids and essential amino acids (P<0.05), and adding 0.8% ACM significantly increased the content of polyunsaturated fatty acids (P<0.05). The study indicates that the dietary addition of 0.8%~1.0% ACM can improve serum immune function and meat quality of finishing pigs. [ABSTRACT FROM AUTHOR]

To explore the fallibility of lo-grapheme (FAG) used as the combustion catalyst of ammonium pe-chiorate (AP), the iirs--plinciples calculations based on deniity functional theory (DFT) were employed to investigate the decompositin of HClO4 and NH3 though the catalysis of FG, and he decompositiion mechanism of AP was expounded. Based on the analyis of he activation energy bames and reaction heas of he elemenraty reactions among reaction network, the main reaction channel of the decomposition of HClO4 on the surface of FG were proposed and determined. The resuis show that the main decomposition pah of The rate-dete-mining ttep of rhis reacJion pathway is the decomposition to CO from HClO4 with the activation eneggy of 1. 675 eV. The adsorbed O* atoms generated by the decompositiion of HClO4 inhbit the furher decomposition of HClO4 on the FG surface. Meanwhle, hese O* atoms p-omote the dehyd-ogenaJion -eacJion of NH3 on he FG surface and generate OH* groups. The OH* group can easily react with NH3 and is dehydrogenation p-oducss to generate H2O molecule, causing he O atom to desoom the FG surface. The eneggy barne- of the dehyd-ogenaJion reacJion between NH3 and F atom ss 0. 284 eV, indicatiing that NH3 can easily decompose and adsob on the catalyst surrace inrtead of adsorbing on AP surface, hus inhbiting the degon of AP. The FG caralyst can ellminate the sragnaion decomposition process during the decomposition of AP, and enhance is comburJion performance. [ABSTRACT FROM AUTHOR]

Objective To investigate the resource allocation status of blood testing laboratories in 14 blood stations in Gansu Province, explore the impact of differences in basic conditions on the comprehensive testing ability of laboratories, so as to promote the homogenization and standardization of blood screening capacity in blood stations in Gansu and improve blood safety and effectivenes. Methods An evaluation index system of laboratory resource allocation was constructed and a question-naire was designed. The data of human resources, infrastructure and key equipment of 14 blood stations were collected. The entropy weight -TOPSIS method was used to evaluate and rank the resource allocation of 14 blood stations. Results In the comprehensive evaluation of blood testing laboratory resource allocation in 14 blood stations in Gansu, the top three were laboratories A, B and I, and the last three were laboratories G, M and J. On the whole, the main issue was unreasonable structure of human resources: most laboratories had unreasonable age structure; except for Laboratory A, there was no personnel with bachelor's degree or above in laboratories; most laboratories had not established a team with intermediate professional titles. In terms of infrastructure, the size of seven laboratories could not meet the needs of modern laboratory testing, and all eight blood stations had no spare nucleic acid laboratories nor a mutual spare laboratory with other blood stations As for the key equipment, 5 laboratories had no automatic blood grouping diagnostic instrument, 5 laboratories only had one set of enzyme immunoassay detection system, 3 laboratories had no spare equipment for the key equipment, which means if the equipment failure could not be repaired in time, the release of results would be affected. Conclusion There were significant differences in human resources, infrastructure and key equipment of blood testing laboratories in 14 blood stations in Gansu, which had a great impact on laboratory testing capacity and subsequent development. It is suggested that governments at all levels and health administrative departments optimize the input of laboratory resource allocation according to the blood collection volume of blood stations to gradually narrow the differences in resource distribution between different regions, improve the degree of laboratory automation and optimize the personnel structure, so as to build high-quality and efficient blood testing laboratories and ensure the safety of clinical blood use.

The education expenditure of a novice is a necessary cost of the healthcare system, which can deteriorate the shortage of nurses. The turnover rate of the novice in an operation room of a medical center in Taiwan was 55%. The investigation of this shortcoming revealed the following reasons: 1. stress from the workload, 2. unable to catch up to the work progress, 3. inconsistency in the tutoring skills of preceptors, 4. the frequency of preceptors in changing shifts, 5. preceptors working under pressure, and 6. impractical design of learning profile. Therefore, the purpose of this project is to reduce the turnover rate of new recruits in the operating room during the trial period. We implemented the following strategies: hold symposiums of the novice; redesign the educational program for the novice; periodic events for the surgical specialist education programs; demonstration and reverse demonstrations of surgical techniques; conduct a positive mindset camp for preceptors to improve their energy; regularly conduct clinical preceptors consensus conference; hiring of more certificated preceptors; fixed working shifts; provide stress relief programs; and revise the learning passport for the novice. After the implementation of the program, the turnover rate of novices in the operating room fell to 16.7%, thus achieving the purpose of the project. [ABSTRACT FROM AUTHOR]

The high-end transmission equipment such as the new generation of aero-engines faces the challenge of extreme service environments such as high speed, high temperature and heavy load. Scuffing failure is one of the main failure modes of gears, which seriously affects life and reliability. The common Chinese gear scuffing design standards include GB/Z 6413—2003 and HB/Z 84.4—1984. However, the calculation results of these standards for the scuffing loading capacity of gears are different, and difference exists in the application scope of these formulae. Thus, a comparative study of the cylindrical involute gear scuffing capacity standards based on GB/Z 6413 and HB/Z 84.4 is carried out from three aspects: theoretical analysis, parameter comparison and case studies. For FZG A type gears, dozens of case groups have been calculated. The results show that the calculated average friction coefficient of HB/Z 84.4 is higher than that of GB/Z 6413.2, and the calculated results of HB/Z 84.4 are conservative. It is found that calculation results of the surface temperature of GB/Z 6413.1 and GB/Z 6413.2 are consistent in a large range of torque, oil temperature, and speed. However, the difference in the tooth surface temperature of the two methods becomes larger as the tooth module decreases. The temperature results are generally consistent with each other as the tooth module lies within the range of 4-7 mm.

Objective To compare the metabolism pattern of the brain in patients with cerebral amyloid angiopathy (CAA) and Alzheimer's disease (AD), and to evaluate the value of brain imaging of 18F-fluorodeoxy glucose (FDG) positron emission tomography/computed tomography (PET/CT) in differentiating CAA and AD. Methods We retrospectively recruited patients with probable CAA (revised Boston diagnostic criteria) and AD of similar age from December 2020 to June 2021 at Peking Union Medical College Hospital. Patients with normal cognition that underwent 18F-FDG PET/CT during the same period were randomly included as controls. We performed visual analysis and quantitative analysis of PET/CT imaging in the three groups. Results Ten patients with probable CAA (CAA group), 10 patients with AD (AD group), and 11 control subjects with normal cognitive function (control group) that met the inclusion and exclusion criteria were enrolled. Visual analysis showed that, compared with the control group, the AD group showed mostly bilateral symmetrical hypometabolism in temporoparietal lobes, with the most significant hypometabolism in the medial temporal lobe and posterior cingulate gyrus; the CAA group exhibited unspecific cortical hypometabolic areas corresponding to hemorrhage. Quantitative analysis of voxel-based brain metabolism images showed that metabolism in the posterior cingulate gyrus, parahippocampal gyrus, parietal lobe, and medial temporal lobe was significantly reduced in the AD group compared with the control group (P < 0.01); metabolism was significantly reduced in the extensive white matter areas, as well as in the caudate nucleus head, corpus callosum, anterior cingulate gyrus, and lateral temporal cortex in the CAA group (P < 0.01). Quantitative analysis based on brain regions showed that the standardized uptake value ratio (SUVr) of 18F-FDG in the occipital/posterior cingulate (O/PC) was significantly lower in the CAA group than in the AD group (0.91±0.05 vs. 1.07±0.08, P < 0.001); the area under the curve for O/PC SUVr identification of probable CAA and AD was 0.98 (95% CI: 0.93-1.00), with an optimal threshold of 0.96, exhibiting sensitivity of 100% and specificity of 90%. Conclusions Probable CAA and AD patients exhibited distinct brain hypometabolism patterns. O/PC SUVr can be a sensitive indicator for differential diagnosis between CAA and AD.

With self-developed similar simulation test device and particle flow code (PFC), the BBR research system, in which the boundary of top-coal, drawing body, recovery ratio and rock mixed ratio of top-coal were studied as a whole,was established by systematic research on the top-coal drawing law in longwall top-coal caving mining. The shape of the boundary of top-coal affected by the existence and movement of shied support was analyzed and the method of fitting the boundary curve by parabola was proposed. The developing process of drawing body can be divided into three stages: incomplete development stage, basically mature stage and mature stage. The front part of the drawing body develops faster than any other part because of the influence of shield beam and it is always beyond the ellipsoid area. The drawing body of top-coal is a non-standard ellipsoid cut by the shield beam, which can be defined as cut-variation ellipsoid. To improve the recovery ratio and reduce the rock mixed ratio of top-coal, the overlap area between the drawing body and the boundary of top-coal should be expanded as much as possible, which can be realized by selecting reasonable drawing technology parameters and controlling the shape of the boundary of top-coal. Top-coals to be drawn are in the distressed zone under the pressure arch between the rock in gob and the canopy of shield support, and it is easy for the top-coals around the drawing opening toform arches. [ABSTRACT FROM AUTHOR]

For better roof control in the western coal mine, the convex structure model was built and verified by laboratory experiments to explain the mechanical mechanism of friction coefficient and roof stability of the mining face under the condition of water and sand inrush. The influence on the friction coefficient between rocks of surface convex structure, water, dry sand, wet sand, water-sand, etc were studied systematically. The results indicate that the convex-like structure will be formed at the interface between rocks due to the water and sand inrush, and sand will abrade convex structure, water will lower its shear strength, which all make the convex direction angle to converge to zero, and eventually make the friction coefficient be greatly reduced. It also explains why the rough surface friction coefficient is higher than the value of smooth surface, and why it's easy to result in sliding instability and bench convergence instead of deformation instability in the face under the condition of water and sand inrush. In the position where rock starts to fracture, the contact is perfectly fit, so the activating friction coefficient is very big, and that is particularly important for the maintenance of roof stability. Specifically, to fill the mined-out area and strengthen the supporting measures can maintain the activating friction. At the same time, the more water in the water-sand, the lower friction coefficient is. Therefore, drainage is also critical in mining operation. [ABSTRACT FROM AUTHOR]

In addition to that the in-cooperate behavior, caused by the dental anxiety, would influence medical quality, the on-purpose oblivion of the booked schedule to avoid the clinical dental examination is detrimental to the children's dental health in the long run. Therefore how to reduce the dental anxiety for the children has been an important issue for many years. From the service encounter point of view, satisfaction during the clinical dental examination could also influence the revisiting willingness. However, how satisfaction and anxiety influence revisiting willingness simultaneously has been discussed less before. This research, based on the convenience sampling on the children in Taichung Area, is trying to explore how anxiety and satisfaction affect revisiting willingness simultaneously. With 387 valid responses, the empirical results showed that the more the anxiety, the less the revisiting willingness. The more the satisfaction is, the higher the revisiting willingness. Though satisfaction did not play the moderating role on the relationship between anxiety and revisiting willingness, it played the mediating role significantly. In other words, anxiety would reduce the revisiting willingness and satisfaction, but still the revisiting willingness could be enhanced through the increase of satisfaction. The empirical results have important practical significance in addition to filling up the gap in the literature about how satisfaction and anxiety affect revisiting willingness simultaneously. [ABSTRACT FROM AUTHOR]

In order to resolve the control problems of the roof and rib of high efficient longwall workface, on the basis of site investigation and theoretical research, this paper introduced the development of support capacity in mining work face and basic methods to determine support capacity at home and abroad. It also pointed out that these methods take roof load control as the starting point. In order to achieve high efficient mining, resistance of the roof load and binary criterion of shield support capacity determination were established. The conclusion that roof pressure is the main factor to affect rib stability was obtained by analyzing effect of roof pressure to rib stability and effect of support capacity to reducing rib pressure, therefore it proposed conforming criteria of support capacity with keeping coal rib stability. The roof will impact shield support when main roof structure is instability, according to this, calculation method of dynamic load that depends on calculating support capacity to control roof is presented in this paper. [ABSTRACT FROM AUTHOR]

The solid-liquid mixed fuel explodes to form a fuel air cloud. The detonation strength depends largely on the air cloud state. The cloud distribution is the base of the design of cloud detonation devices. The dispersal process of solid-liquid mixed fuel is investigated by numerical simulation, and a numerical simulation method of solid-liquid mixed fuel is explored. The diffusion process of fuel dispersal in space and time are obtained. The radial dispersal velocity, cloud range and turbulent diffusion process in simulation agree well with the experimental results. The results show that the numerical model established in this study can simulate the dispersal process of the solid-liquid mixed fuel, which opens a new way of research for the optimal design of FAE devices. [ABSTRACT FROM AUTHOR]

To solve the local minimum problem in existing path planning for mobile robot, a multi-behavior fusion approach for path planning was proposed. The proposed approach contains three kind basic behaviors which were designed for selecting the proper one to complete the mission of path planning. The behavior of escaping the local minimum can assess whether the robot is in the local minimum with the trial principle and employ the angle-compensation method to escape the obstacle with the local minimum. The results of simulation and experiment demonstrate the adaptability of proposed approach, being more reliable and extensive than some existing methods. [ABSTRACT FROM AUTHOR]

In fully mechanized top-coal caving mining, the top-coal is broken into loose state under stratum pressure, whose mechanical characteristics are different from the complete rock. Based on the three-dimensional Particle Flow Code (PFC3D), established the top-coal caving 3-D numerical simulation model, which can truly reflected the top-coal caving process, and carried out with different caving ratios and drawing interval simulations. During the initial caving process, top-coal particles will form a stable velocity field and the second loose region; the draw body is a deflect quasi-ellipsoid constrained by support shield, the deflect angle of axis decreases exponentially with the increasing of drawing time, the height of draw body decreases with increase in drawing time which presents the power function relationship; draw body cuts coal and gangue interface and forms a three-dimensional hopper surface, of which the central axis deflects towards the gob; under different cutting-caving ratios and drawing intervals, the top-coal extraction ratio shows a typical progressive stabilization effect with the face forward distance. [ABSTRACT FROM AUTHOR]

The movement features of overlying strata are different from that of mining by caving method since gob areas are occupied by fillings, and the processes of faces mining and gangue filling were simulated in laboratory by numerical calculations. Stress changes and movement features of overlying strata were simulated under different filling ratio conditions by the approaches of changing the initial support power, working resistance of support, and tamping forces of filling material, then by combining field measured results, the regularity of overlaying strata was revealed. And three main conclusions were drawn in this research as follows: working resistance of support play a significant role to the filling effects, high initial power and working resistance of support can restrict deformation of roof and ensure enough time to fill more filling materials to gob area, thus can decrease the height of gradual subsidence zone and regulate surface deformation. Immediate roof is regulated by gob area' s filling materials, which can control the deformation, subsidence and caving of immediate roof. Rupture and collapse are the main forms of immediate roof. And then it arranges in good order on goaf waste rock after collapse. Forms of main roof, which correspond to immediate roof shifting, are in curve subsidence types. Besides, the collapse height of overlaying strata will reduce strikingly. [ABSTRACT FROM AUTHOR]

Four kinds of organic inorganic cementing and coating materials were prepared by a coating method using water as the solvent, and the corresponding cemented and coated fertilizers (B2, PS, F2, and F2F) were produced by disc pelletizer. The tests on the properties of these fertilizers showed that the granulation rate, compression strength, and film forming rate were B2>PS>F2>F2F. Soil column leaching experiment showed that the curve of accumulated nitrogen dissolving rate was the gentlest for B2. In 48 days, the accumulated nitrogen dissolving rate was in the order of B2, 54.65%F2>F2F. [ABSTRACT FROM AUTHOR]

Ordovician karsts are well developed in the Yingmaili and Halahatang areas of the North Tarim Basin. The ancient karsts are an important factor for forming Ordovician hydrocarbon reservoirs in the central and western regions of the North Tarim Basin. They are distributed, like successive broad belts, along the south side of the North Tarim uplift and constitute a large complex ancient karst reservoir system together with the Lunnan bulge. The main controlling factors of the Ordovician karsts are uplift, interlamination parallel unconformity, fault systems, rock physical properties and high-energy sedimentary phases. The Ordovician karsts can be divided into uplift-controlled karst areas, the strata- and fault-controlled karst areas and limited karst areas while karsts of different origins can overlay each other. The ancient karsts are developed mainly in four periods: the Caledonian, Hercynian, Indo-China Yanshan, and Yanshan, and karsts of different periods overlay each other, too. The condition for developing large-scale ancient karst reservoirs exists in the area and the complex ancient karst systems can be rich in oil and gas. Along both sides of the Middle-Upper Ordovician clastic pinch-outs are the more favorable areas for large ancient karst reservoirs. 摘 要: 塔里木盆地北部哈拉哈塘和英买力地区的奥陶系古岩溶非常发育，随着勘探程度的提高和地质认识的深入开始引起重视。研究认为，古岩溶是塔北中西部地区奥陶系油气成藏的重要控制因素，沿塔北隆起南翼呈宽幅带状连片分布，与轮南凸起一起构成一套大型复合古岩溶储集体系。奥陶系岩溶发育的主要控制因素有隆升作用、层间平行不整合、断裂系统、岩石物理性质和高能相区等，平面上可以划分出隆控岩溶区、层控-断控岩溶区及局限岩溶区，多种成因的岩溶彼此之间可以复合叠置。此外，该区古岩溶具有分期多次发育的特点，主要期次有四个：加里东、海西、印支—燕山和燕山等，并存在多期叠置的特征。塔北隆起中西部地区具备形成大型古岩溶油气藏的条件，塔北复合古岩溶体系有望整体连片含油，沿中上奥陶统碎屑岩尖灭线两侧是寻找大规模古岩溶油气藏群的有利地区。 Key words: Tarim Basin, North Tarim uplift, Yingmaili, Halahatang, ancient karst, hydrocarbon reservoir

The supercritical carbon dioxide (S-CO2) nuclear energy and power system uses S-CO2 as the working fluid to convert nuclear heat directly or indirectly into electricity or mechanical energy. S-CO2 is considered one of the most promising working fluids for applications in conventional and high-temperature scenarios. The unique properties of S-CO2, such as its non-phase-change behavior, high density, compressibility near the pseudo-critical region, low thermal cycle compression ratio, minimal thermal inertia equipment requirements, and suitability for direct cycle and power generation propulsion technologies, simplify the system, reduce volume, lower weight, improve maneuverability, reduce noise, and enhance thermal efficiency. The advantages of S-CO2 power conversion technology not only meet the development needs of the next generation of advanced energy conversion technology but also align with the future trends of nuclear power systems. Leading energy technology countries, including the United States, conducted extensive research on S-CO2 power conversion technology in areas such as fossil fuel power generation, nuclear energy, waste heat recovery, and solar thermal power. Some of these projects have already entered the engineering demonstration phase. In China, S-CO2 power conversion technology was included in the “14th Five-Year Plan” for scientific and technological innovation in the energy sector. Numerous universities and industrial sectors in China are actively conducting research and development in this field. The development of S-CO2 nuclear power system in three historical stages for nearly 60 years, including the concept creation, research restart, and collaborative innovation, was summarized in this paper. The research status of S-CO2 nuclear energy and power system in reactor design, material technology, thermohydraulics, heat exchangers, turbomachines, system operation, control, and security policies was also introduced. The technical challenges and key research directions faced by S-CO2 nuclear energy and power system in basic research and engineering were pointed out. Currently, energy superpowers represented by China and the United States have completed laboratory tests of S-CO2 power conversion systems, and are expected to move towards medium-scale engineering demonstration or even large-scale application in the next 5 to 10 years. S-CO2 nuclear energy and power system has the prerequisites for engineering development, and is expected to lead the transformation of advanced nuclear energy technologies. Nevertheless, numerous technical challenges are still existing in core design, materials, thermal-fluid mechanics, and safety analysis. Additionally, engineering efforts are required to tackle challenges related to high-efficiency heat exchangers, highpower high-speed electric motors, heavy-duty electromagnetic bearings, and turbine power generation systems. Simultaneously, coordinated efforts in both fundamental and applied research are essential to enhance the advanced nature and engineering feasibility of S-CO2 nuclear energy and power systems.