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Coal and coal-related fly ash often contain rare earth elements (REEs) that have the potential to be utilized as valuable mineral resources. Accurately determining the REE content in coal and fly ash is crucial for resource evaluation. The conventional approach involves using hydrofluoric acid (HF) to dissolve silicates and release REEs, which, however, prolongs the digestion process due to the additional step of complexing fluoride ions (F−) with boric acid (H3BO3). Determining the correct amount of H3BO3 for neutralization can be challenging, and in some instances, the binding of fluoride ions with certain lanthanides (Lns) hampers the accurate determination of all 14 naturally occurring rare earth elements in a single digestion batch by inductively coupled plasma mass spectrometry (ICP-MS). In this study, we present an alternative method that achieves the accurate determination of all 14 naturally occurring REEs using tetrafluoroboric acid (HBF4) followed by ICP-MS analysis. This approach eliminates the need for an F− complexing step. We tested this method on certified REE reference materials, including NIST 1632e (coal) and NIST 1633c (fly ash), as well as the REE geological reference material USGS AGV-1 (andesite). Our results demonstrated excellent recovery rates (relative standard deviation, RSD < ±10%), with a correlation coefficient (r2) exceeding 0.99. Using this method, we investigated the concentrations of all 14 REEs in coal and fly ash samples collected from various locations in the southwestern USA. This improved digestion technique streamlines the analysis process and enhances the accuracy of REE determination, facilitating a more comprehensive evaluation of REE-rich coal and fly ash deposits for resource exploration. [ABSTRACT FROM AUTHOR]

Background: With the rapid development of China's chemical industry, although researchers have developed many methods in the field of chemical safety, the situation of chemical safety in China is still not optimistic. How to prevent accidents has always been the focus of scholars' attention. Methods: Based on the characteristics of chemical enterprises and the Heinrich accident triangle, this paper developed the organizational-level accident triangle, which divides accidents into group-level, unit-level, and workshop-level accidents. Based on 484 accident records of a large chemical enterprise in China, the Spearman correlation coefficient was used to analyze the rationality of accident classification and the occurrence rules of accidents at different levels. In addition, this paper used TF-IDF and K-means algorithms to extract keywords and perform text clustering analysis for accidents at different levels based on accident classification. The risk factors of each accident cluster were further analyzed, and improvement measures were proposed for the sample enterprises. Results: The results show that reducing unit-level accidents can prevent group-level accidents. The accidents of the sample enterprises are mainly personal injury accidents, production accidents, environmental pollution accidents, and quality accidents. The leading causes of personal injury accidents are employees' unsafe behaviors, such as poor safety awareness, non-standard operation, illegal operation, untimely communication, etc. The leading causes of production accidents, environmental pollution accidents, and quality accidents include the unsafe state of materials, such as equipment damage, pipeline leakage, short-circuiting, excessive fluctuation of process parameters, etc. Conclusion: Compared with the traditional accident classification method, the accident triangle proposed in this paper based on the organizational level dramatically reduces the differences between accidents, helps enterprises quickly identify risk factors, and prevents accidents. This method can effectively prevent accidents and provide helpful guidance for the safety management of chemical enterprises. [ABSTRACT FROM AUTHOR]

With the development of electronic game technology, the content of electronic games presents a larger number of units, richer unit attributes, more complex game mechanisms, and more diverse team strategies. Multi-agent deep reinforcement learning shines brightly in this type of team electronic game, achieving results that surpass professional human players. Reinforcement learning algorithms based on Q-value estimation often suffer from Q-value overestimation, which may seriously affect the performance of AI in multi-agent scenarios. We propose a multi-agent mutual evaluation method and a multi-agent softmax method to reduce the estimation bias of Q values in multi-agent scenarios, and have tested them in both the particle multi-agent environment and the multi-agent tank environment we constructed. The multi-agent tank environment we have built has achieved a good balance between experimental verification efficiency and multi-agent game task simulation. It can be easily extended for different multi-agent cooperation or competition tasks. We hope that it can be promoted in the research of multi-agent deep reinforcement learning. [ABSTRACT FROM AUTHOR]

In this paper, mechanic–electric–circuit coupling algorithm based on the finite‐difference time‐domain (FDTD) method is proposed to analyze a one‐order microwave bulk acoustic wave (BAW) filter. FDTD method is used to solve the coupled mechanic–electric–circuit system equations to obtain the voltage and current at port position of the BAW filter in the time domain. Then S parameters of the BAW filter in the frequency domain are calculated using the Fourier transform. In our work, a one‐order BAW filter consists of two film bulk acoustic resonators (FBARs) by means of series and parallel. These two FBARs in the BAW filter are coupled together through an equivalent electrical connection. Similarly, multiphysical mechanic–electric–circuit analysis of the BAW filter is implemented in the commercial software COMSOL, which is realized by the time‐domain finite element method. The accuracy of the proposed method is verified by comparison with simulation results in COMSOL. In addition, the computational time and memory of the proposed method have obvious advantages over those of COMSOL. [ABSTRACT FROM AUTHOR]

Background: There is no evidence supporting the feasibility of laparoscopic pancreaticoduodenectomy (LPD) compared to open pancreatoduodenectomy (OPD) following neoadjuvant chemotherapy (NACT) for pancreatic ductal adenocarcinoma (PDAC). Methods: The clinical data of consecutive patients with borderline resectable PDAC who received NACT and underwent either LPD or OPD between January 2020 and December 2022 at Fudan University Shanghai Cancer Center was prospectively collected and retrospectively analyzed. Results: The analysis included 57 patients in the OPD group and 20 in the LPD group. Following NACT, the LPD group exhibited a higher median CA19-9 decrease rate compared to the OPD group (85.3% vs. 66.9%, P = 0.042). Furthermore, 3 anatomically borderline PDACs in the LPD group and 5 in the OPD group were downstaged into resectable status (30.0% vs. 12.3%, P = 0.069). According to RECIST criteria, 51 (66.2%) patients in the entire cohort were evaluated as having stable disease. The median operation time for the LPD group was longer than the OPD group (419 vs. 325 min, P < 0.001), while the venous resection rate was 35.0% vs. 43.9%, respectively (P = 0.489). There was no difference in the number of retrieved lymph nodes, with a median number of 18.5 in the LPD group and 22 in the OPD group, and the R1 margin rate (15.0% vs. 12.3%) was also comparable. The incidence of Clavien-Dindo complications (35.0% vs. 66.7%, P = 0.018) was lower in the LPD group compared to the OPD group. Multivariable regression analysis revealed that a tumor diameter > 3 cm before NACT (HR 2.185) and poor tumor differentiation (HR 1.805) were independent risk factors for recurrence-free survival, and a decrease rate of CA19-9 > 70% (OR 0.309) was a protective factor for early tumor recurrence and overall survival. Conclusions: LPD for PDAC following NACT is feasible and oncologically equivalent to OPD. Effective control of CA19-9 levels is beneficial in reducing early tumor recurrence and improving overall survival. [ABSTRACT FROM AUTHOR]

Background: This work aimed to study natural humoral immune response to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. Methods: Chemiluminescent immunoassay (CLIA) was used to detect the neutralizing antibody (Nabs) and IgG. Results: Nabs peaked on days 57–96 after symptom onset and remained detected on days 97–132. The Nabs in the 32 patients who were dynamically monitored showed four changing patterns. The titers of Nabs and IgG were correlated, and three modes of relationship were found between them. Conclusions: Nabs showed a regular change in the course of coronavirus disease 2019 (COVID-19). The detection of Nabs is very important for monitoring the course of COVID-19 and predicting the strength of antibody protection. [ABSTRACT FROM AUTHOR]

Currently, the development of nonmetallic oxygen reduction reaction (ORR) catalysts based on heteroatomic-doped carbon materials is receiving increaseing attention in the field of fuel cells. Here, we used enzymolytic lignin (EL), melamine, and thiourea as carbon, nitrogen, and sulfur sources and NH4Cl as an activator to prepare N- and S-codoped lignin-based polyporous carbon (ELC) by one-step pyrolysis. The prepared lignin-derived biocarbon material (ELC-1-900) possessed a high specific surface area (844 m2 g−1), abundant mesoporous structure, and a large pore volume (0.587 cm3 g−1). The XPS results showed that ELC-1-900 was successfully doped with N and S. ELC-1-900 exhibited extremely high activity and stability in alkaline media for the ORR, with a half-wave potential (E1/2 = 0.88 V) and starting potential (Eonset = 0.98 V) superior to those of Pt/C catalysts and most non-noble-metal catalysts reported in recent studies. In addition, ELC-1-900 showed better ORR stability and methanol tolerance in alkaline media than commercial Pt/C catalysts. [ABSTRACT FROM AUTHOR]

A sensitive photoelectrochemical biosensor was constructed for the detection of chlorpyrifos. The sensor was prepared on indium tin oxide (ITO) electrode using photoelectric material bismuth vanadate (BiVO4) and acetylcholinesterase (AChE). It is found that the photocurrent of ITO/BiVO4 electrode was largely dependent on its treatment temperature. The highest anodic photocurrent response of the ITO/BiVO4 photoelectrode was obtained after the treatment at 300°C. The thiocholine, produced in the catalytic reaction at ITO/BiVO4/AChE electrode surface, can greatly enhanced the anodic photocurrent. In addition, the adsorption of chlorpyrifos on the surface of the AChE caused a decrease in the intensity of the photocurrent. Under the optimisation of experimental conditions, the decrease of the photocurrent showed a good linear range from 1 pM to 10 nM under irradiation of visible light. The detection limit is calculated as 0.25 pM with a 10% inhibition rate. The ITO/BiVO4/AChE photoelectrode exhibited high sensitivity, acceptable stability and good reproducibility. The biosensor can be provided to the potential applications for detection of pesticide residues in food. [ABSTRACT FROM AUTHOR]

Older adults show declines in spatial memory, although the extent of these alterations is not uniform across the healthy older population. Here, we investigate the stability of neural representations for the same and different spatial environments in a sample of younger and older adults using high-resolution functional MRI of the medial temporal lobes. Older adults showed, on average, lower neural pattern similarity for retrieving the same environment and more variable neural patterns compared to young adults. We also found a positive association between spatial distance discrimination and the distinctiveness of neural patterns between environments. Our analyses suggested that one source for this association was the extent of informational connectivity to CA1 from other subfields, which was dependent on age, while another source was the fidelity of signals within CA1 itself, which was independent of age. Together, our findings suggest both age-dependent and independent neural contributions to spatial memory performance. [ABSTRACT FROM AUTHOR]

Selective hydrogenolysis of abundant C–O bonds of β-O-4 linkages in natural lignin or lignin models has been considered as a key strategy for the generation of value-added organic chemicals. Herein, we report a mild, efficient, and selective photocatalytic strategy for hydrogenolytic cleavage of lignin β-O-4 models by using Ni-containing polyoxometalate (POM) catalysts and CdS quantum dots. Upon blue LED light irradiation, the present photocatalytic system can effectively transform various lignin β-O-4 models to the corresponding hydrogenolysis products (phenols and ketones) with >95% conversion and >93% product selectivity. A tentative photocatalytic mechanism is proposed based on various experimental and spectroscopic analyses. The facile strategy presented in our work could be extended to the photocatalytic preparation of various value-added chemicals from natural biomass or other biomass derivatives in the near future. [ABSTRACT FROM AUTHOR]

Purpose: The glymphatic system is a fluid exchange pathway that clears waste products that is crucial for the maintenance of brain homeostasis. However, the exact role it plays in the emergence of fibromyalgia (FM) is still not fully understood. Here, we explored the changes in non-invasive MRI proxy probably related to the glymphatic function in FM patients, and explored brain-behavior relationships. Methods: A total of 40 participants, consisting of 20 individuals with FM and 20 healthy controls (HCs), were included in the study. The participants underwent structural T1-weighted MRI, diffusion tensor imaging (DTI), and clinical assessment. The data was obtained from an open access dataset. The study compared non-invasive MRI indices, including choroid plexus (CP) volume and DTI analysis along the perivascular space (ALPS), between the FM and HC groups. Furthermore, correlation analysis was conducted to determine the correlation between clinical parameters and both CP volume and DTI-ALPS index. Results: Patients with FM had significantly higher CP volume and a lower DTI-ALPS index than HCs adjusting for age and intracranial volume. Higher CP volume was associated with lower DTI-ALPS index, and longer disease duration. Conclusion: Our findings demonstrate aberrant glymphatic function in FM, and that dysfunction in the brain glymphatic system may play a role in the neural mechanisms underlying FM. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of 2‐amino‐4‐aryl‐6‐styrylpyrimidines by the reactions of various distyryl ketones with guanidine hydrochloride through aza‐Michael addition/nucleophilic addition/dehydrogenation cascade processes is described. The salient features of this protocol are the use of easy‐to‐obtain substrates, transition‐metal‐free system, mild reaction conditions, high atom economy, wide substrate scope, satisfactory yield, and simple work‐up procedures. [ABSTRACT FROM AUTHOR]

Melittin, a naturally occurring polypeptide found in bee venom, has been recognized for its potential anti-tumor effects, particularly in the context of lung cancer. Our previous study focused on its impact on human lung adenocarcinoma cells A549, revealing that melittin induces intracellular reactive oxygen species (ROS) burst and oxidative damage, resulting in cell death. Considering the significant role of mitochondria in maintaining intracellular redox levels and ROS, we further examined the involvement of mitochondrial damage in melittin-induced apoptosis in lung cancer cells. Our findings demonstrated that melittin caused changes in mitochondrial membrane potential (MMP), triggered mitochondrial ROS burst (Figure 1), and activated the mitochondria-related apoptosis pathway Bax/Bcl-2 by directly targeting mitochondria in A549 cells (Figure 2). Further, we infected A549 cells using a lentivirus that can express melittin-Myc and confirmed that melittin can directly target binding to mitochondria, causing the biological effects described above (Figure 2). Notably, melittin induced mitochondrial damage while inhibiting autophagy, resulting in abnormal degradation of damaged mitochondria (Figure 5). To summarize, our study unveils that melittin targets mitochondria, causing mitochondrial damage, and inhibits the autophagy-lysosomal degradation pathway. This process triggers mitoROS burst and ultimately activates the mitochondria-associated Bax/Bcl-2 apoptotic signaling pathways in A549 cells. [ABSTRACT FROM AUTHOR]

The degradation of ribavirin(RBV) by ferrate(Fe(Ⅵ)) was systematically investigated for the first time by experiment and degradation process fitting. The results indicated that the reaction between Fe(Ⅵ) and RBV is pH dependent and followed second order kinetics. The species-specific rate constants of the Fe(Ⅵ) species(HFeO 4 -) were higher than FeO 4 2- species when react with RBV. Fe(VI) made significant contribution to the removal of RBV. Liquid chromatography-triple quadrupole mass spectrometry(LC-TQ-MS) was used to determine the intermediate of RBV which degradated by Fe(Ⅵ), in order to infer its main degradation pathway. This study used Dual Descriptor and Fukui function to calculate the active sites of RBV and its intermediates during the degradation of RBV by Fe(Ⅵ), then verified their accuracy with actual reaction sites deduced based on LC-TQ-MS data. The results showed that Dual Descriptor prediction was more accurate than Fukui function in the process of RBV degradation by Fe(Ⅵ). Some common anions in natural waters, such as SO 4 2-, NO 3 -, Cl- and CO 3 2- had no effect on the removal of RBV by Fe(Ⅵ). 50 mg/L HA reduced the 120 min removal efficiency of RBV by 15.07%. Both toxicity analysis by ECOSAR software and E. coli toxicity experiments showed that Fe(VI) achieves toxicity reduction of RBV. This study indicated that Fe(Ⅵ) can effectively remove RBV from water and using Dual Descriptor to analyze the active sites of intermediates in the RBV degradation pathway can enhance the rationality of predicting the reaction pathway. [Display omitted] [ABSTRACT FROM AUTHOR]

In this study, a generalized torque estimation method is proposed for synchronous motors, including surface permanent magnet synchronous motors (SPMSMs), synchronous reluctance motors (SynRMs), and interior permanent magnet synchronous motors (IPMSMs) for building the analytical motor model. The average motor torque is estimated using the Lorentz force by the generated flux density in the air gap to determine the relationships among torque, flux density, and injected current. In the proposed method, the generated flux density is derived step by step by considering the effects of magnetic flux saturation, the stator slot, the rotor barrier, and permanent magnets (PMs) to ensure that the generated average torque complies with the operating condition of the motor. To verify the proposed method, the output torque of finite element analysis (FEA), Maxwell 2D, is compared to the proposed method in a SPMSM. Moreover, a phasor diagram is plotted to determine the mechanism through which torque is generated in SynRMs and IPMSMs. A SynRM and an IPMSM with ferrites PMs are analyzed using the proposed method, FEA, and the experimental results of this study indicate the effectiveness. [ABSTRACT FROM AUTHOR]

In programming education, the result of plagiarism detection is a crucial criterion for assessing whether or not students can pass course exams. Recently, the prevalent methods for detecting student plagiarism have been proposed by analyzing source code. These methods extract features (such as token, abstract syntax tree and control flow graph) from the source code, examine the similarity of codes using various similarity detection methods, and then perform plagiarism detection based on a predefined plagiarism threshold. However, these previous methods for plagiarism detection have some problems. First, they are less effective in detecting code modification related to structure. Second, they require a considerable number of training data, which demand high computing time and space. Third, they cannot determine whether students plagiarize in time. We propose a novel plagiarism detection method by analyzing the behavioral features of students during the coding process. Specifically, we extract five behavioral features based on students' programming habits. Then, we use a feature ranking-based suspiciousness algorithm to obtain the possibility of student plagiarism. Based on our proposed method, we develop the Online Integrated Programming Platform. To evaluate the accuracy of our method, we conduct a series of experiments. Final experimental results indicate that our method achieves promising results with Accuracy, Precision, Recall and F 1 values of 0.95, 0.90, 0.95 and 0.92, respectively. Finally, we also analyze the correlation between whether students plagiarized and their regular and final grades, which can further verify the effectiveness of our proposed method. [ABSTRACT FROM AUTHOR]

In recommender systems, user reviews on items contain rich semantic information, which can express users' preferences and item features. However, existing review-based recommendation methods either use the static word vector model or cannot effectively extract long sequence features in reviews, resulting in the limited ability of user feature expression. Furthermore, the impact of different or useless feature interactions between users and items on recommendation performance is ignored. Therefore, we propose an attentional factorization machine with review-based user–item interaction for recommendation (AFMRUI), which first leverages RoBERTa to obtain the embedding feature of each user/item review, and combines bidirectional gated recurrent units with attention network to highlight more useful information in both user and item reviews. Then we adopt AFM to learn user–item feature interactions to distinguish the importance of different user–item feature interactions and further to obtain more accurate rating prediction, so as to promote recommendation. Finally, we conducted performance evaluation on five real-world datasets. Experimental results on five datasets demonstrated that the proposed AFMRUI outperformed the state-of-the-art review-based methods regarding two commonly used evaluation metrics. [ABSTRACT FROM AUTHOR]

Improving the resilience of the livestock industry chain is of great significance to ensure the stability and security of domestic food supplies, which is also an internal requirement to promote the development of Chinese-style modernization. On the basis of steady growth of animal husbandry production capacity, the gradual upgrading of development mode, the steady increase in the number of green products, further supported by science and technology application, with ecological development as the direction and animal husbandry safety as the driving force, study and determine the focus of improving the toughness of animal husbandry industry chain under the background of Chinese-style modernization. Therefore, we can accelerate the transformation of sustainable development momentum, improve resource utilization efficiency, accelerate the innovation of animal husbandry technologies, and consolidate the foundation of animal husbandry policies to enhance the resilience of the animal husbandry industry chain in the future. [ABSTRACT FROM AUTHOR]

BACKGROUND: Early postoperative activity, an important part of enhanced recovery after surgery (ERAS) in clinical practice, is considered to be a significant component of postoperative quality care. OBJECTIVE: To evaluate the effect of a standardized early activity program on ERAS in patients after surgery for pulmonary nodules. METHODS: A total of 100 patients with pulmonary nodules who underwent a single-port thoracoscopic segmental resection or a wedge resection of the lung were selected for the present study. These patients were divided into a control group (n = 50) and an intervention group (n = 50) by a digital random method. The patients in the control group received routine perioperative nursing intervention for thoracic surgery due to lung cancer, and those in the intervention group received an intervention using a standardized early activity program along with routine nursing care. The evaluation indexes in both groups included postoperative indwelling time of the closed chest drainage tube, the time to the first off-bed activity after surgery, the incidence of postoperative pulmonary complications, the length of postoperative hospital stay, and patient satisfaction. RESULTS: The postoperative indwelling time of the closed chest drainage tube and the time to the first off-bed activity in the intervention group were less than in the control group. The length of the postoperative hospital stay in the intervention group was shorter than in the control group, and the patient satisfaction in the intervention group was higher than in the control group. The difference for these evaluation indexes were statistically significant (P < 0.05). The number of cases of postoperative complications was four and eight in the intervention group and the control group, respectively, and the difference was not statistically significant (P > 0.05). CONCLUSION: A standardized early activity program is a safe and effective nursing measure for ERAS for patients after surgery for pulmonary nodules, which can promote earlier off-bed activity, shorten the postoperative indwelling time of the closed chest drainage tube, shorten the postoperative hospital stay, improve patient satisfaction, and promote rapid recovery. [ABSTRACT FROM AUTHOR]

This study introduces a novel large three-dimensional physical model experimental system (PMES) for studying the geomechanical problems related to deep underground engineering. The apparatus is mainly composed of a counterforce frame, a hydraulic loading subsystem, a sample installation and transportation subsystem, an excavation subsystem, an integrated monitoring subsystem, and auxiliary facilities. During the design and development of the PMES apparatus, key technological issues were addressed. A high-stiffness frame structure with opening and closing function was developed. Uniform, gradient, and designed non-uniform stresses can be applied with high accuracy. An independent long-term load-holding unit and a surface dynamic disturbance unit were designed. The basic and innovative functions of the apparatus were verified through calibration experiments. A large physical model experiment was conducted to simulate the excavation of a deep-buried drainage tunnel in China's Jinping-II hydropower station. The experiment obtained the failure processes of the surrounding rock masses induced by high in-situ stress, specific engineering geological structures and excavation disturbance. The internal fracturing and strain evolution within the sample were successfully captured by the integrated monitoring subsystem. The results also validated the reliability of this novel apparatus. The development of this novel apparatus provides a new tool for the study of geomechanical problems in deep underground engineering. Highlights: A novel large three-dimensional physical model experimental system for studying the geomechanical problems related to deep underground engineering was established. The basic and innovative functions of the apparatus were verified through calibration experiments. A large physical model experiment was conducted to simulate the excavation of a deep tunnel in China's Jinping-II hydropower station. [ABSTRACT FROM AUTHOR]

Heat transfer in jointed rock masses exhibits characteristics of discontinuous, heterogeneous, and anisotropic due to the effects of rock discontinuities. In this work, thermal contact resistance (TCR) evolution of granite joints under normal stress was investigated. A novel method was proposed for the measurement of TCR for rough rock joints. A numerical calculation program was established for the determination of contact area based on the initial morphology of the joint surfaces and the monitored joint closure during the experiment. An estimation model of TCR for granite joints based on the equivalent joint aperture was established. It is found that TCR of granite joints shows decreasing trend with normal stress. The decreasing rate is relatively large at the initial loading stage and gradually reduces with normal stress. The values of TCR eventually stabilize. TCR of granite joint has no obvious correlation with joint roughness coefficient. It is more significantly affected by the contact area. Plastic deformation and rupture of the micro-convex body on the joint surfaces occurred due to the application of normal stress, which improve the heat transfer efficiency and lead to the decrease in TCR. In general, predication results of the TCR estimation model show good consistency with the experimental data. The model is more suitable for the cases with small joint apertures. This study can provide knowledge to the better understanding of heat transfer in rock masses containing different kinds of discontinuities. Highlights: A novel method was proposed for the measurement of thermal contact resistance for rough rock joints. A numerical calculation program was established for the determination of contact area for rough rock joints. Evolution of thermal contact resistance with normal stress and joint contact area was obtained and analyzed. An estimation model of thermal contact resistance for granite joints based on the equivalent joint aperture was established. [ABSTRACT FROM AUTHOR]

The study aims to lessen the monetary burden on patients and society by decreasing the price of proprietary drugs used in leukemia therapy. Flow cytometry, reverse transcription polymerase chain reaction, western blot, and a patient-derived xenograft mouse model were used to confirm the therapeutic effect of Pinellia ternata extract on leukemia. Three types of leukemia cells (K562, HL-60, and C8166 cell lines) were found to undergo early apoptosis (P ≤.05) after being exposed to P. ternata extract, as measured by flow cytometry. Reverse transcription polymerase chain reaction results showed that P. ternata extract at both middle (300 μg/mL) and high (500 μg/mL) concentrations was able to down-regulate Bcl-2 and upregulate mRNA expression of Bax and caspase-3. In the patient-derived xenograft mouse model formed by BALB/c-nu/nu nude mice, immunohistochemistry indicated that P. ternata extract effectively suppressed the proliferation of leukemia cells. Therefore, P. ternata extract at 300 μg/mL and 500 μg/mL could effectively inhibit myeloid and lymphocytic leukemia cell proliferation and promote leukemia cell apoptosis by regulating Bax/Bcl-2 and caspase-3. [ABSTRACT FROM AUTHOR]

For artificial snowfall, snow particle size can have a direct impact on snow quality. The operating conditions of the snow-makers and environmental factors will influence the atomization and crystallization processes of artificial snow making, which consequently affect snow particle size. This paper investigates the size distribution of snow particles during artificial snow making under different operating conditions and environmental parameters. For this purpose, an environmental chamber is designed and structured. The laser scattering method was used to measure the size distribution of snow under different parameters in the room. The results show that the distribution of snow crystal particle size aligns closely with the Rosin–Rammler (R-R) distribution. The higher the height of the snowfall, the longer the snow crystals grow and the larger the snow crystal particle size. It has been found that a higher air pressure favors atomization, while the opposite is true for water pressure, which results in a higher air–water pressure ratio, producing smaller snow particle sizes. Additionally, an ambient temperature in the range of −5 °C to −15 °C contributes to the snow crystal form transforming from plates to columns and then back to plates; the snow particle size first decreases and then increases. Snow crystal particles at −10 °C have the smallest size. Outdoor snow-makers should be operated at the highest possible air–water pressure ratio and snow height, and at a suitable ambient temperature. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li−S) batteries are promising due to ultrahigh theoretical energy density. However, their cycling lifespan is crucially affected by the electrode kinetics of lithium polysulfides. Herein, the polysulfide solvation structure is correlated with polysulfide electrode kinetics towards long‐cycling Li−S batteries. The solvation structure derived from strong solvating power electrolyte induces fast anode kinetics and rapid anode failure, while that derived from weak solvating power electrolyte causes sluggish cathode kinetics and rapid capacity loss. By contrast, the solvation structure derived from medium solvating power electrolyte balances cathode and anode kinetics and improves the cycling performance of Li−S batteries. Li−S coin cells with ultra‐thin Li anodes and high‐S‐loading cathodes deliver 146 cycles and a 338 Wh kg−1 pouch cell undergoes stable 30 cycles. This work clarifies the relationship between polysulfide solvation structure and electrode kinetics and inspires rational electrolyte design for long‐cycling Li−S batteries. [ABSTRACT FROM AUTHOR]

Lithium–sulfur (Li−S) batteries are promising due to ultrahigh theoretical energy density. However, their cycling lifespan is crucially affected by the electrode kinetics of lithium polysulfides. Herein, the polysulfide solvation structure is correlated with polysulfide electrode kinetics towards long‐cycling Li−S batteries. The solvation structure derived from strong solvating power electrolyte induces fast anode kinetics and rapid anode failure, while that derived from weak solvating power electrolyte causes sluggish cathode kinetics and rapid capacity loss. By contrast, the solvation structure derived from medium solvating power electrolyte balances cathode and anode kinetics and improves the cycling performance of Li−S batteries. Li−S coin cells with ultra‐thin Li anodes and high‐S‐loading cathodes deliver 146 cycles and a 338 Wh kg−1 pouch cell undergoes stable 30 cycles. This work clarifies the relationship between polysulfide solvation structure and electrode kinetics and inspires rational electrolyte design for long‐cycling Li−S batteries. [ABSTRACT FROM AUTHOR]

The heart is widely acknowledged as the unique driver of blood circulation. Recently, we discovered a flow-driving mechanism that can operate without imposed pressure, using infrared (IR) energy to propel flow. We considered the possibility that, by exploiting this mechanism, blood vessels, themselves, could propel flow. We verified the existence of this driving mechanism by using a three-day-old chick-embryo model. When the heart was stopped, blood continued to flow for approximately 50 minutes, albeit at a lower velocity. When IR was introduced, the postmortem flow increased from ~41.1 ± 25.6 μm/s to ~153.0 ± 59.5 μm/s (n = 6). When IR energy was diminished under otherwise physiological conditions, blood failed to flow. Hence, this IR-dependent, vessel-based flow-driving mechanism may indeed operate in the circulatory system, complementing the action of the heart. [ABSTRACT FROM AUTHOR]

The high temperature environment makes the buckling of composite laminated plate happen earlier. Further weight savings can be achieved once the plate has a favorable postbuckling stiffness. This study aims to address this issue by developing a ROM-driven lamination optimization to maximize the buckling and postbuckling performance of compressed plates under initial temperature field. The reduced-order model(ROM) constructed using the improved Koiter theory is reformulated to be suitable for thermal-mechanical buckling problems. A linear subspace of the force space is represented to be the span of the mechanical load, the thermal load and a set of predefined perturbation loads. The thermal load related to the initial temperature field is constant during the increase of in-plane compressive load. An independently additional degree of freedom corresponding to the thermal load is implemented into the construction of the reduced-order model. The buckling and postbuckling performance can be extracted from the solution of reduced-order model, and then subsequently selected as inputs to achieve the optimal laminate. The main novelty of this work is to achieve the thermal-mechanical buckling and postbuckling optimization, benefitting from the highly efficient single run of thermoelastic geometrically nonlinear analysis. Various numerical examples have been selected to validate the performance of the proposed method, considering the influences of length-to-width ratio, α1/α2, ply number and nonuniform temperature field. [ABSTRACT FROM AUTHOR]

Extranodal natural killer/T-cell lymphoma (ENKTL) with hepatosplenic involvement is rare, accounting for approximately 0.2% of ENKTL cases. The clinicopathologic features of ENKTL with hepatosplenic involvement are still poorly understood. Seven cases of ENKTL with hepatosplenic involvement were investigated retrospectively by clinical features, pathology, immunophenotype, genotype, Epstein-Barr virus (EBV) status, and survival analysis. The median age was 36 years; three patients (3/7) had a history of primary nasal ENKTL. Six cases (6/7) presented liver or spleen structures that were replaced by neoplasms, and the neoplastic cells displayed diffuse infiltration; one case (1/7) displayed neoplastic cells scattered in hepatic sinuses and portal areas. The cellular morphology and immunohistochemical features were similar to those of ENKTL involving other sites. Follow-up data were available in five of the seven patients. All five patients received first-line chemotherapy based on L-asparaginase. Three patients died, and two were still alive by the last follow-up. The median overall survival (OS) was 21 months. ENKTL with hepatosplenic involvement is rare, regardless of whether it is initial or secondary. There are two histopathologic patterns of ENKTL with hepatosplenic involvement, and L-asparaginase-based chemotherapy combined with AHSCT might yield good efficacy. [ABSTRACT FROM AUTHOR]

Background Proteinuria is commonly measured to assess the renal status of chronic kidney disease (CKD) patients before the 20th week of gestation during pregnancy. High levels of proteiuria have been associated with adverse pregnancy outcomes. However, researchers have not clearly determined what baseline proteinuria levels would be associated with adverse pregnancy outcomes. This study aimed to analyse associations between proteinuria levels and adverse pregnancy outcomes among CKD patients treated with or without steroids/immunosuppressive therapy in early pregnancy. Methods This retrospective study included the clinical information of 557 pregnant patients with CKD from 1 January 2009 to 31 December 2021. A multivariable logistic regression analysis was conducted to evaluate the risk of adverse pregnancy outcomes across various proteinuria ranges, which were further stratified by whether the patients were receiving steroids/immunosuppressive therapy. Results (i) Proteinuria was assessed on 24-h urine collection. The median (quartile) baseline proteinuria levels were 0.83 g (0.20, 1.92) and 0.25 g (0.06, 0.80) in the steroids/immunosuppressive therapy and therapy-free groups, respectively. (ii) CKD patients with adverse pregnancy outcomes had significantly higher proteinuria levels in the first trimester than patients without adverse pregnancy outcomes. (iii) The risk of adverse pregnancy outcomes increased with increasing baseline proteinuria levels (P  < .001). (iv) In the early-pregnancy steroids/immunosuppressive therapy group, the risk of severe preeclampsia was higher in patients with higher baseline proteinuria levels (P  < .007) [odds ratio (OR) 30.86 for proteinuria ≥5.00 g/24 h]; in the therapy-free group, the risks of severe preeclampsia, very-low-birth-weight infants, early preterm birth and foetal–neonatal death were higher in patients with higher baseline proteinuria levels (OR 53.16 for proteinuria ≥5.00 g/24 h; OR 37.83 for proteinuria ≥5.00 g/24 h; OR 15.30 for proteinuria ≥5.00 g/24 h; and OR 18.83 for proteinuria ≥5.00 g/24 h, respectively; P  < .001, P  < .001, P  < .001 and P  = .006, respectively). Conclusions As shown in the present study, a baseline 24-h proteinuria level >1.00 g was associated with adverse maternal outcomes. Furthermore, a 24-h proteinuria level >2.00 g increased the incidence of adverse foetal events among CKD patients. [ABSTRACT FROM AUTHOR]

Separate-layer CO2 flooding has increasingly been used to improve the overall development of multi-layer heterogeneous reservoirs. Due to their field technical limitations, layer combinations have to be carried out to reduce the number of layer-groups required for the separate injection of CO2. Currently there are few studies of the method of designing layer combinations. In field practice, the layer combinations are often made based on the permeability ratio of the layers to be developed, but it is not possible to accurately obtain the optimal scheme in many cases. Therefore, in this paper, a new design and optimization method based on the weighted standard deviation of permeability is proposed, which comprehensively considers the effects of multiple geological and fluid properties in different layers. The new method is applied to study the layer combination schemes in separate-layer CO2 flooding in H block, Daqingzijing Oilfield, Jilin, China. The prioritization of all of the schemes is obtained via the method, and a related numerical model is also established to perform verification and quantitative analysis. The results show that designing layer combinations using the new proposed method can achieve better development effect than using the conventional permeability ratio based method. It can achieve a more uniform interlayer CO2 displacement with an obvious improvement in the CO2 swept volume in low permeability layers and a higher overall oil recovery. According to the numerical simulation results, using the optimal layer combination scheme designed via the new proposed method, the ten-year swept volume of CO2 in the low permeability layer can be increased by 16.2%, and the ten-year overall oil recovery efficiency can be increased by 3.3%, with both measures showing a remarkable improvement. The work can provide a significant reference point for the field design of layer combinations in separate-layer CO2 flooding. [ABSTRACT FROM AUTHOR]

Abstract Due to the variability of train loads, soil properties, and other factors, the cumulative settlement of high-speed railway soft soil subgrade induced by cyclic trains holds strong randomness and evolutionary characteristics. Thus, the prediction of cumulative settlement and assessment of the subgrade status is important to ensure the safety of high-speed trains. For this purpose, a vehicle-track-subgrade interaction model is established for calculating the dynamic stresses of the subgrade, and then the cumulative settlement and its evolution characteristics are predicted. Furthermore, the direct probability integral method (DPIM) is introduced to implement the uncertainty quantification and reliability assessment of cumulative settlement, especially spatial distribution, 3D-probability density function and the variation of reliability index with load cycles. A comparison between Monte Carlo method and DPIM is performed to demonstrate the accuracy and efficiency of stochastic analysis with respect to cumulative settlement. The sensitivity and reliability assessment of the cumulative settlement under the cases of different speed, train load and soil strength are investigated by numerical examples to illustrate the robustness of the proposed method. The results show that cumulative settlement is most sensitive to soil strength, followed by train axle loads. Besides, a reliability assessment method proposed in this work, which considers cumulative settlement, provides guidance for the design and maintenance of subgrade in this paper. [ABSTRACT FROM AUTHOR]

An efficient method for the synthesis of 4‐arylpyrimidin‐2‐amines by the reactions of various aromatic aldehydes, guanidine and calcium carbide through one‐pot three‐component procedure is described. The salient features for this protocol are the use of an inexpensive and easy‐to‐handle solid calcium carbide instead of flammable and explosive gaseous acetylene as an alkyne source, cheap transition‐metal mediator, commercially available starting materials, wide substrate scope, satisfactory yield, and the simple workup procedure. The related reaction can also be extended to gram scale. [ABSTRACT FROM AUTHOR]

Purpose. To explore the correlation between the axial length (AL) difference (myopic and nonmyopic eye) and the refractive error in children with unilateral myopia anisometropia (UMA) and to elucidate its clinical application in the process of Ortho-K lenses review following nonstop wearing. Methods. This study retrospectively analyzed the data of 70 children with UMA (age, 8–15 years) whose myopic eyes were treated with Ortho-K lenses. The spherical equivalent refractive errors (SERE) of the myopic eye ranged from −0.75 D to −4.25 D, and astigmatism was no less than −1.50 D. In addition, SERE of nonmyopic eyes were no less than −0.50 D. AL, and the refractive data of both eyes were measured at baseline. A multivariate linear regression was used to analyze the relationship between the AL difference and refractive error, and paired t-test was used to analyze the changes in AL in both eyes. Results. Every 1 mm axial length change corresponds to −1.627 D (95% CI: −1.921 D, −1.333 D; P < 0.001) change in refractive error in children. The association between the AL change and the degree of myopia did not change with age (P = 0.751). Among the 70 subjects, 51 (72.86%) had myopia in the right eye, and the 95% confidence interval (CI) for myopia occurring in the right eye was 62.4%–83.3%. The paired t-test showed that the average AL growth was significantly slower in myopic eyes treated with Ortho-K lenses than in nonmyopic eyes (t = 9.805, P < 0.001). Conclusion. Every 1 mm AL change would cause an average refractive error increase. Age did not influence the association between AL changes and the degree of myopia. The right eye is more likely to be affected in children with UMA. The Ortho-K lens treatment slowed down the growth of AL in the myopic eye in children with UMA. [ABSTRACT FROM AUTHOR]

In order to ensure the high precision and good dynamic characteristics of the dual‐axis linear motor when machining components, the tracking error and contour error should be reduced with more complex machining trajectory. In this study, the characteristic model of position control of the linear motor is established by using the modelling principle of the characteristic model, and the intelligent adaptive controller is designed. In addition, a new calculation method of the equivalent contour error is proposed innovatively, and the dual axis is compensated by proportional feedback control, to improve the contour accuracy of the permanent magnet synchronous linear motor dual‐axis control system. Finally, through the simulation and experiment of the dual‐axis motor platform, the effectiveness of the proposed contour error calculation method and the intelligent adaptive controller can make the dual‐axis motion control system have higher accuracy and strong robustness and can also make the motor run more smoothly. [ABSTRACT FROM AUTHOR]

This study simulated the spatial distribution of wind speeds and wind energy density by using the WRF model, and we used the WRF-simulated results to evaluate the sea surface wind speeds retrieved from the HY-2C and CFOSAT satellite-borne microwave scatterometers over the Yellow Sea region. The main conclusions were as follows: (1) The combination of the MRF boundary layer parameterization scheme, the MM5 near-surface parameterization scheme, and the Global Data Assimilation System (GDAS) initial field demonstrated the best performance in simulating the 10 m wind speed in the Yellow Sea region, with a root-mean-square error (RMSE) of 1.57, bias of 1.24 m/s, and mean absolute percentage error (MAPE) of 17%. (2) The MAPE of the HY-2C inversion data was 9%, while the CFOSAT inversion data had an MAPE of 6%. The sea surface wind speeds derived from the HY-2C and CFOSAT satellite scatterometer inversions demonstrated high accuracy and applicability in this region. (3) The wind speed was found to increase with altitude over the Yellow Sea, with higher wind speeds observed in the southern region compared to the northern region. The wind power density increased with altitude, and the wind power density in the southern area of the Yellow Sea was higher than in the northern region. (4) The CFOSAT satellite inversion products were in good agreement with the WRF simulation results under low wind speed conditions. In contrast, the HY-2C satellite inversion products showed better agreement under moderate wind speed conditions. Under high wind speed conditions, both satellite inversion products exhibited minor deviations, but the HY-2C product had an overall overestimation, while the CFOSAT product remained within the range of −1 to 1 m/s. (6) The wind power density increased with the satellite-inverted 10 m wind speed. When the 10 m wind speed was less than 9 m/s, the wind power density exhibited a roughly cubic trend of increase. However, when the 10 m wind speed exceeded 9 m/s, the wind power density no longer increased with the rise in 10 m wind speed. These findings provide valuable insights into wind energy resources in the Yellow Sea region and demonstrate the effectiveness of satellite scatterometer inversions for wind speed estimation. The results have implications for renewable energy planning and management in the area. [ABSTRACT FROM AUTHOR]

Molecular dynamics method is employed to characterize the mechanical properties of polydimethylsiloxane (PDMS) materials reinforced by graphene nanoplatelets (GNPs). Modeling results demonstrate that the addition of GNPs to PDMS significantly improves the damping properties of PDMS at high temperatures. The underlying physical mechanism is further investigated, and it is found that the interfacial interactions between the GNPs and PDMS play a crucial role in the energy dissipation capabilities. At elevated temperatures, a decrease in the interaction energy between the GNPs and PDMS matrix is observed, increasing the interfacial shipment, and improving the energy dissipation. In addition, GNPs will reflect more impact energy at a higher temperature. This study provides valuable insights into the use of GNPs for the improvement of the damping performance of PDMS materials at high temperatures. [ABSTRACT FROM AUTHOR]

• Acute morphine stimulation produces analgesic effects by inhibiting adenylyl cyclase activity through D2 receptors. • MORs interact with opioid or non-opioid receptors in the VTA to mediate morphine analgesia and tolerance. • Morphine enhances or inhibits VTA-DA neuron activity in the RMTg-VTA circuit to produce analgesia or tolerance. Morphine has a strong analgesic effect and is suitable for various types of pain, so it is widely used. But long-term usage of morphine can lead to drug tolerance, which limits its clinical application. The complex mechanisms underlying the development of morphine analgesia into tolerance involve multiple nuclei in the brain. Recent studies reveal the signaling at the cellular and molecular levels as well as neural circuits contributing to morphine analgesia and tolerance in the ventral tegmental area (VTA), which is traditionally considered a critical center of opioid reward and addiction. Existing studies show that dopamine receptors and μ-opioid receptors participate in morphine tolerance through the altered activities of dopaminergic and/or non-dopaminergic neurons in the VTA. Several neural circuits related to the VTA are also involved in the regulation of morphine analgesia and the development of drug tolerance. Reviewing specific cellular and molecular targets and related neural circuits may provide novel precautionary strategies for morphine tolerance. [ABSTRACT FROM AUTHOR]

Next Point-of-Interest (POI) recommendation has shown great value for both users and providers in location-based services. Existing methods mainly rely on partial information in users' check-in sequences, and are brittle to users with few interactions. Moreover, they ignore the impact of multi-dimensional auxiliary information such as user check-in frequency, POI category on user preferences modeling and the impact of dynamic changes in user preferences over different time periods on recommendation performance. To address the above limitations, we propose a novel method for next POI recommendation by modeling long and short term user preferences with multi-dimensional auxiliary information. In particular, the proposed model includes a static LSTM module to capture users' multi-dimensional long term static preferences and a dynamic meta-learning module to capture users' multi-dimensional dynamic preferences. Furthermore, we incorporate a POI category filter into our model to comprehensively simulate users' preferences. Experimental results on two real-world datasets demonstrate that our model outperforms the state-of-the-art baseline methods in two commonly used evaluation metrics. [ABSTRACT FROM AUTHOR]

In the field of cardiovascular disease, recurrent events such as stroke or myocardial infarction (MI) are often encountered, leading to an increase in the risk of death. Accurately evaluating the prognosis of patients and dynamically predicting the risk of death by considering the historical recurrent events can improve medical decisions and lead to better health care outcomes. Recently proposed joint modeling approaches within the Bayesian framework have inspired the development of a dynamic prediction tool, which can be applied for subject‐level prediction of death with implementation in software packages. The prediction model incorporates subject heterogeneity with subject‐level random effects that account for unobserved time‐invariant factors and an extra copula function capturing the part caused by unmeasured time‐dependent factors. Thereafter, given the prespecified landmark time t′$$ {t}^{\prime } $$, the survival probability for a prediction horizon time of interest t$$ t $$ can be estimated for each individual. The prediction accuracy is assessed by time‐dependent receiving operating characteristic curve and the area under the curve and the Brier score with calibration plots is compared to traditional joint frailty models. Finally, the tool is applied to patients with multiple attacks of stroke or MI in the Cardiovascular Health study and the Atherosclerosis Risk in Communities study for illustration. [ABSTRACT FROM AUTHOR]

Prussian blue analogues (PBAs) cathodes can host diverse monovalent and multivalent metal ions due to their tunable structure. However, their electrochemical performance suffers from poor cycle life associated with chemo‐mechanical instabilities. This study investigates the driving forces behind chemo‐mechanical instabilities in Ni‐ and Mn‐based PBAs cathodes for K‐ion batteries by combining electrochemical analysis, digital image correlation, and spectroscopy techniques. Capacity retention in Ni‐based PBA is 96% whereas it is 91.5% for Mn‐based PBA after 100 cycles at C/5 rate. During charge, the potassium nickel hexacyanoferrate (KNHCF) electrode experiences a positive strain generation whereas the potassium manganese hexacyanoferrate (KMHCF) electrode undergoes initially positive strain generation followed by a reduction in strains at a higher state of charge. Overall, both cathodes undergo similar reversible electrochemical strains in each charge–discharge cycle. There is ~0.80% irreversible strain generation in both cathodes after 5 cycles. XPS studies indicated richer organic layer compounds in the cathode‐electrolyte interface (CEI) layer formed on KMHCF cathodes compared to the KNHCF ones. Faster capacity fades in Mn‐based PBA, compared to Ni‐based ones, is attributed to the formation of richer organic compounds in CEI layers, rather than mechanical deformations. Understanding the driving forces behind instabilities provides a guideline to develop material‐based strategies for better electrochemical performance. [ABSTRACT FROM AUTHOR]

Background: Delayed onset muscle soreness (DOMS) is a self-healing muscle pain disorder. Inflammatory pain is the main feature of DOMS. More and more researchers have realized that changes in mitochondrial morphology are related to pain. However, the role of mitochondria in the pathogenesis of DOMS and the abnormal immune microenvironment is still unknown. Methods: Mitochondria-related genes and gene expression data were obtained from MitoCarta3.0 and NCBI GEO databases. The network of mitochondrial function and the immune microenvironment of DOMS was constructed by computer algorithm. Subsequently, the skeletal muscle of DOMS rats was subjected to qPCR to verify the bioinformatics results. DOMS and non-DOMS histological samples were further studied by staining and transmission electron microscopy. Results: Bioinformatics results showed that expression of mitochondria-related genes was changed in DOMS. The results of qPCR showed that four hub genes (AMPK, PGC1-α, SLC25A25, and ARMCX1) were differentially expressed in DOMS. These hub genes are related to the degree of skeletal muscle immune cell infiltration, mitochondrial respiratory chain complex, DAMPs, the TCA cycle, and mitochondrial metabolism. Bayesian network inference showed that IL-6 and PGC1-α may be the main regulatory genes of mitochondrial damage in DOMS. Transmission electron microscopy revealed swelling of skeletal muscle mitochondria and disorganization of myofilaments. Conclusions: Our study found that skeletal muscle mitochondrial damage is one of the causes of inflammatory factor accumulation in DOMS. According to the screened-out hub genes, this study provides a reference for follow-up clinical application. [ABSTRACT FROM AUTHOR]

In recommender systems, user reviews on items contain rich semantic information, which can express users' preferences and item features. However, existing review-based recommendation methods either use the static word vector model or cannot effectively extract long sequence features in reviews, resulting in the limited ability of user feature expression. Furthermore, the impact of different or useless feature interactions between users and items on recommendation performance is ignored. Therefore, we propose an attentional factorization machine with review-based user–item interaction for recommendation (AFMRUI), which first leverages RoBERTa to obtain the embedding feature of each user/item review, and combines bidirectional gated recurrent units with attention network to highlight more useful information in both user and item reviews. Then we adopt AFM to learn user–item feature interactions to distinguish the importance of different user–item feature interactions and further to obtain more accurate rating prediction, so as to promote recommendation. Finally, we conducted performance evaluation on five real-world datasets. Experimental results on five datasets demonstrated that the proposed AFMRUI outperformed the state-of-the-art review-based methods regarding two commonly used evaluation metrics. [ABSTRACT FROM AUTHOR]

This study investigated whether teacher expectations had significant effects on ethnic minority students' second language and foreign language learning in senior high schools. The participants of this study were 52 teachers and 836 ethnic minority students from 10 senior high schools in southwest China. Data of teacher expectations for students' second language achievement, teacher expectations for students' foreign language achievement, students' prior achievement in a standardized test of the second language and foreign language at the beginning of senior high school, and students' achievement in a standardized test of the second language and foreign language at the end of senior high schools were collected respectively. Regression analysis showed that with students' prior achievement being controlled, 1) teacher expectations had significant effects on ethnic minority students' foreign language learning, but 2) teacher expectations were not closely related to ethnic minority students' second language learning, suggesting a moderation effect of the subject. Implications for expectancy theories and multilingual instructions are further discussed. [ABSTRACT FROM AUTHOR]

This paper presents an analytical framework for predicting three-dimensional (3D) seismic active earth pressures for soils governed by a nonlinear strength criterion. The kinematic limit analysis method that incorporates a pseudodynamic approach is used to carry out the analysis. A generalized tangential technique is adopted to realize transition of the nonlinear criterion into the commonly used linear form. A 3D failure mechanism of rigid rotation is employed. Because the use of the modified pseudodynamic approach leads to a variation of seismic forces along the depth, the work rate due to earthquake effects is calculated by using a horizontal layer–wise summation method. By virtue of the balance equation of work and energy, the thrust of active earth pressures is determined, and the final solutions are expressed as dimensionless active earth pressure coefficients. A comparison between the solutions obtained in this paper and those of the existing studies shows the effectiveness of the developed method. A parametric analysis is carried out to investigate the influences of several parameters. The findings of this work can help understand the service behavior of retaining structures subjected to seismic loadings, which could provide references for designs. [ABSTRACT FROM AUTHOR]

In order to obtain better dynamic response and steady-state accuracy of permanent magnet synchronous linear motor (PMSLM), a hyperlocal model-free position control (LOMFC) method with load disturbance observer was designed to solve the problems of poor control accuracy and stability of traditional PI control methods. The second order hyperlocal model is used to integrate the position controller and the velocity controller to simplify the control structure and optimize the PI control. The double closed-loop model-free position control (MFPC) and triple closed-loop PI control systems were built, and the simulation and experimental comparison of sudden loading and unloading and steady-state operation were carried out respectively. The comparative experiment shows the superiority of this method. [ABSTRACT FROM AUTHOR]

Cross wedge rolling process provides a new way with short production chain and precise control for high-performance blade preforming used in aeroengine, but the issue of central damage needs to be paid attention and investigated. Therefore, this paper aims to understand the formation mechanism of central damage on CWR of GH4169 alloy. The uniaxial hot tensile test and CWR experiments were carried out to explore the high-temperature deformation behavior of GH4169 alloy, as well as the central damage of GH4169 alloy CWR process. Moreover, the finite element model was established and used to analyze the evolution of stress and strain at different position. The results showed that central part of the workpiece is in the state of higher stress triaxiality η, which is easy to cause damage. And the micro-holes in the center of workpiece mainly nucleated around the detached NbC carbide. Meanwhile, the first principal stress σ 1 and the maximum shear stress τ max are the dominant factors which affect the central damage. Therefore, a novel damage criterion suitable for CWR of GH4169 alloy was developed with considering the effect of stress triaxiality η and the sensitivities of deformation temperature and strain rate on the central damage evolution. In addition, initial forming temperature T0 is the most important factor affecting the central damage, and the maximum area reduction φ and rolling speed n are related to the initial deformation temperature T0. And in order to inhibit the damage, the initial forming temperature should be controlled below 1020℃, and the area reduction and rolling speed should not be higher than 55% and 10r/min, respectively. [ABSTRACT FROM AUTHOR]

Stellar occultation instruments detect the transmission of stellar spectra through the planetary atmosphere to retrieve densities of various atmospheric components. This paper introduces an idea of using instruments with bandpass filters for stellar occultation detection. According to the characteristics of the occultation technique for oxygen density measurement, a full-link forward model is established, and the average transmission under a typical nocturnal atmosphere is calculated with the help of the HITRAN database, occultation simulation and a 3D ray-tracing program. The central wavelength and bandwidth suitable for 760 nm oxygen A-band absorption measurement are discussed. This paper also compares the results of the forward model with GOMOS spectrometer data under this band, calculates the observation signal-to-noise ratio corresponding to different instrument parameters, and target star magnitudes. The results of this paper provide a theoretical basis for the development of a stellar occultation technique with a bandpass filter and guidance on the instrument design. [ABSTRACT FROM AUTHOR]

In most of the piezoelectric stacked motors studied, the stator usually adopts two compound modes to drive the rotor to do step motion. This design method not only improves the utilization rate of the stator but also improves the torque output to a certain extent and increases the output displacement. In this study, a new type of multi-degree of freedom piezoelectric actuator is proposed for the utilization of a stator. The actuator realizes three compound vibration modes of bending-longitudinal-bending on a single stator, which changes the two compound modes of longitudinal bending and also changes the single motion mode of the stepper motor along a straight line. The rotor is set as a ball to drive it to rotate. The designed motor presents a different driving signal under which the rotor will no longer be accompanied by a return displacement. The finite element method is used to complete the design analysis, and the experimental analysis of the designed motor is carried out after the prototype is made. The multi-degree-of-freedom piezoelectric actuator can achieve a speed of 8.56 mm/c and a driving load of 1200 g at a voltage of 400 v and a working frequency of 42.7 kHz. [ABSTRACT FROM AUTHOR]