Corrosion Test of the Steel Plate in a WJ-8 Fastener for High Speed Rail

It was found that the steel plate in the composite plate in the WJ-8 fastener used in high speed rail is rusty. The objective of this study is to test the zinc coating of the steel plate. A literature review was conducted to identify the zinc coating techniques, and the companies that can provide different coating service was identified. A salt fog chamber was built that was in compliance with the ANSI B117 code, and the steel plates that were coated by the identified companies were tested using the salt fog chamber. The results indicated that the coating technique that had the best performance in preventing corrosion was the Greenkote plates with passivation. The galvanized option had the roughest coating layer, and it was the most reactive in the salt water solution. This makes it non-ideal for the dynamic rail environment because the increased friction of the plate could damage the supports, especially during extreme temperatures that would cause the rail to expand or contract. Greenkote with Phosphate and ArmorGalv also provided increased corrosion prevention with a smooth, strong finish, but it had more rust on the surface area than the Greenkote with ELU passivation. The ArmorGalv sample had more rust on the surface area than the Greenkote samples. This may not be a weakness in the ArmorGalv process;rather, it likely was the result of this particular sample not having the added protection of a colored coating.

Solid Bi_(2)O_(3)-derived nanostructured metallic bismuth with high formate selectivity for the electrocatalytic reduction of CO_(2)

CO_(2) electrochemical reduction(CO_(2)ER)is an important research area for carbon neutralization.However,available catalysts for CO_(2) reduction are still characterized by limited stability and activity.Recently,metallic bismuth(Bi)has emerged as a promising catalyst for CO_(2) ER.Herein,we report the solid cathode electroreduction of commercial micronized Bi2O3as a straightforward approach for the preparation of nanostructured Bi.At-1.1 V versus reversible hydrogen electrode in a KHCO3aqueous electrolyte,the resulting nanostructure Bi delivers a formate current density of~40 mA·cm^(-2) with a current efficiency of~86%,and the formate selectivity reaches97.6% at-0.78 V.Using nanosized Bi2O3as the precursor can further reduce the primary particle sizes of the resulting Bi,leading to a significantly increased formate selectivity at relatively low overpotentials.The high catalytic activity of nanostructured Bi is attributable to the ultrafine and interconnected Bi nanoparticles in the nanoporous structure,which exposes abundant active sites for CO_(2) electrocatalytic reduction.

Data-driven prediction of dimensionless quantities for semi-infinite target penetration by integrating machine-learning and feature selection methods

This study employs a data-driven methodology that embeds the principle of dimensional invariance into an artificial neural network to automatically identify dominant dimensionless quantities in the penetration of rod projectiles into semi-infinite metal targets from experimental measurements.The derived mathematical expressions of dimensionless quantities are simplified by the examination of the exponent matrix and coupling relationships between feature variables.As a physics-based dimension reduction methodology,this way reduces high-dimensional parameter spaces to descriptions involving only a few physically interpretable dimensionless quantities in penetrating cases.Then the relative importance of various dimensionless feature variables on the penetration efficiencies for four impacting conditions is evaluated through feature selection engineering.The results indicate that the selected critical dimensionless feature variables by this synergistic method,without referring to the complex theoretical equations and aiding in the detailed knowledge of penetration mechanics,are in accordance with those reported in the reference.Lastly,the determined dimensionless quantities can be efficiently applied to conduct semi-empirical analysis for the specific penetrating case,and the reliability of regression functions is validated.

Hybrid bonding of GaAs and Si wafers at low temperature by Ar plasma activation

High-quality bonding of 4-inch GaAs and Si is achieved using plasma-activated bonding technology.The influence of Ar plasma activation on surface morphology is discussed.When the annealing temperature is 300℃,the bonding strength reaches a maximum of 6.2 MPa.In addition,a thermal stress model for GaAs/Si wafers is established based on finite element analysis to obtain the distribution of equivalent stress and deformation variables at different temperatures.The shape varia-tion of the wafer is directly proportional to the annealing temperature.At an annealing temperature of 400℃,the maximum protrusion of 4 inches GaAs/Si wafers is 3.6 mm.The interface of GaAs/Si wafers is observed to be dense and defect-free using a transmission electron microscope.The characterization of interface elements by X-ray energy dispersion spectroscopy indi-cates that the elements at the interface undergo mutual diffusion,which is beneficial for improving the bonding strength of the interface.There is an amorphous transition layer with a thickness of about 5 nm at the bonding interface.The preparation of Si-based GaAs heterojunctions can enrich the types of materials required for the development of integrated circuits,improve the performance of materials and devices,and promote the development of microelectronics technology.

Discrete Element Modelling of Damage Evolution of Concrete Considering Meso-Structure of ITZ

The mechanical properties of interfacial transition zones(ITZs)have traditionally been simplified by reducing the stiffness of cement in previous simulation methods.A novel approach based on the discrete element method(DEM)has been developed for modeling concrete.This new approach efficiently simulates the meso-structure of ITZs,accurately capturing their heterogeneous properties.Validation against established uniaxial compression experiments confirms the precision of thismodel.The proposedmodel canmodel the process of damage evolution containing cracks initiation,propagation and penetration.Under increasing loads,cracks within ITZs progressively accumulate,culminating in macroscopic fractures that traverse themortarmatrix,forming the complex,serpentine path of cracks.This study reveals four distinct displacement patterns:tensile compliant,tensile opposite,mixed tensile-shear,and shear opposite patterns,each indicative of different stages in concrete’s damage evolution.The widening angle of these patterns delineates the progression of cracks,with the tensile compliant pattern signaling the initial crack appearance and the shear opposite pattern indicating the concrete model’s ultimate failure.

Application of Circulating Tumor Cells in Peripheral Blood in Judging the Prognosis of Patients with Renal Cancer and Related Indexes of Blood Coagulation

Objective: To investigate the value of the number of circulating tumor cells (CTC) in peripheral blood in the prognosis and coagulation-related indicators of patients with renal cancer. Methods: 65 patients with renal cell carcinoma (RCC) confirmed pathologically were divided into CTC positive group and CTC negative group according to the CTC count (5 pcs/3.5 ml). Compare the age, gender, tumor location, TNM (clinical stage), pathological grade, tissue type, lymph node metastasis, distant metastasis, prognosis and prothrombin time (PT), fibrinogen (FIB), partial coagulation of the two groups of patients The correlation between the results of zymogen time (APTT) and D-dimer (DD) and the number of CTC. Results: There were significant differences in TNM, lymph node metastasis, and distant metastasis between the two groups (P < 0.05). The number of CTC in patients was correlated with FIB and D-D levels (P < 0.05). Conclusion: The number of CTC in patients with renal cell carcinoma is correlated with some clinical phenotypes (TNM, lymph node metastasis, distant metastasis) and some coagulation indexes (FIB, D-D), and can jointly predict the prognosis of renal cancer.

Deep Learning-Based Stock Price Prediction Using LSTM Model

The stock market is a vital component of the broader financial system,with its dynamics closely linked to economic growth.The challenges associated with analyzing and forecasting stock prices have persisted since the inception of financial markets.By examining historical transaction data,latent opportunities for profit can be uncovered,providing valuable insights for both institutional and individual investors to make more informed decisions.This study focuses on analyzing historical transaction data from four banks to predict closing price trends.Various models,including decision trees,random forests,and Long Short-Term Memory(LSTM)networks,are employed to forecast stock price movements.Historical stock transaction data serves as the input for training these models,which are then used to predict upward or downward stock price trends.The study’s empirical results indicate that these methods are effective to a degree in predicting stock price movements.The LSTM-based deep neural network model,in particular,demonstrates a commendable level of predictive accuracy.This conclusion is reached following a thorough evaluation of model performance,highlighting the potential of LSTM models in stock market forecasting.The findings offer significant implications for advancing financial forecasting approaches,thereby improving the decision-making capabilities of investors and financial institutions.

国内外代表性物理化学教材知识体系与教学内容的比较

高质量的教材是支撑高水平教学的重要基础。本文对国内外15本具有代表性的物理化学教材进行了对比研究,对编写理念、教学内容、编排体系、教学目标以及教材的编写和出版情况等16个方面进行了对比研究,分析了我国物理化学教材的优势与不足,提出了十四五期间开展物理化学教材建设需要重视的7个方面建议,对教材的编写和出版具有一定的参考价值。

国内外代表性物理化学教材电化学部分的比较

电化学是物理化学重要的三级学科,已成为物理化学教材中不可缺少的部分。本文对国内外13本具有代表性的物理化学教材中电化学部分的编写理念、教学内容的组织、教学内容的选择以及新知识的引入等几个角度展开对比研究,对物理化学教材中电化学部分的编写和教学具有一定的参考价值。

Study on Circulating Tumor Cells and Various Clinical Features and Blood-Related Indexes in Patients with Renal Cancer

Objective: To investigate the value of CTC clinical features and blood-related test indicators in renal cancer patients by detecting the number of circulating tumor cells (CTC) in patients with renal cancer. Methods: To analyze 59 patients with renal cell carcinoma (RCC) admitted to the Department of Urology, Affiliated Hospital of Chengde Medical College from May 2018 to October 2019. According to the CTC count (5 pcs/3.5 ml), they were divided into CTC positive group and CTC negative group. The age, gender, tumor location, tumor size, hematuria, CEC (circulating endothelial cells), CTC Cluster (aggregate), gene mutation, platelet (PLT), albumin (ALB), hemoglobin (HB), alkaline phosphatase (AKP), lactate dehydrogenase (LDH) were compared between the two groups of patients and the correlation of the number of CTCs. Results: There were significant differences in tumor size, CEC, and gene mutations between the two groups (P < 0.05). The number of CTC in patients was correlated with the levels of HB, PLT and LDH (P < 0.05). Conclusion: The number of CTC in RCC patients is correlated with some clinical features (tumor size, CEC, gene mutation) and some related test indicators (HB, PLT, LDH), and can be combined with the above related indicators to predict the occurrence, metastasis and prognosis of renal cancer.

The Effect of Different Surgical Methods on the Number of Circulating Tumor Cells in the Peripheral Blood of Patients with Renal Cell Carcinoma

Objective: The objective is to explore the effects of different surgical methods-retroperitoneal laparoscopic radical nephrectomy (RLRN) and open radical nephrectomy (ORN) on the number of circulating tumor cells (CTC) in the peripheral blood of patients with renal cancer. Methods: The clinical data of 63 patients in the Department of Urology, Affiliated Hospital of Chengde Medical College who underwent radical surgery for renal cancer were divided into CTC positive group (18 cases of open surgery and 16 cases of minimally invasive surgery) and CTC negative group (14 cases of open surgery), 15 cases of minimally invasive surgery), overall group (32 cases of open surgery, 31 cases of minimally invasive surgery). Observe the changes in the number of CTC 1 week before operation and 1 week after operation. Results: In the positive group, whether it was open surgery or minimally invasive surgery, the postoperative CTC level of patients was significantly reduced (P < 0.05). In the negative group, the CTC decreased significantly after open surgery (P > 0.05), and the CTC level decreased significantly after minimally invasive surgery (P < 0.01). In the overall group, both open and minimally invasive surgery CTC decreased significantly, and the difference was statistically significant (P < 0.05). Conclusion: The two different surgical methods can reduce the level of CTC, but compared with ORN, RLRN can significantly reduce the number of postoperative CTC. Patients in the CTC-negative group may be less suitable for open surgery. CTC levels have certain potential in the selection and guidance of treatment modes for patients with renal cell carcinoma (RCC).

The Effects of Boron-Doping on the Electronic Properties of Blue Phosphorene

In this paper, the effects of different boron (nitrogen)-doping on the electronic properties of blue phosphorene have been investigated by the first- principles calculations. We have taken eight doping configurations into account, the calculated results show that the bond length of P-B is decreasing with the doping concentration increasing. For the four boron atoms doping configuration, the geometric structure appears the distinct distortion. The band gap is decreasing with the doping concentration increasing, and it appears the transition from indirect band gap to direct band gap for boron doping configurations. It is hoped that the calculated results may be useful for designing electronic devices based on blue phosphorene.

碳纤维复合材料回收与再利用技术进展

随着复合材料在各领域的广泛使用,废弃复合材料的回收与再利用成为了必须面对的问题。大多数结构件所采用的是热固性树脂基复合材料,正是由于其优良的耐腐蚀性,复合材料的回收与再利用存在一定的挑战。文中归纳了碳纤维复合材料的回收技术,并调研了回收碳纤维在国内外的应用现状,发现目前热裂解回收方法在国外已经得到了成熟的应用,回收纤维也已用于规模化生产航空、地面交通等领域的结构零件;但国内碳纤维回收和回收纤维产业化的报道则较少。结合碳纤维复合材料的3D打印技术,如果将回收的碳纤维用作3D打印原材料,既有利于环境保护,又能降低复合材料3D打印制件的成本,具有重要的社会效应和经济价值。

树脂基复合材料成型用炭泡沫模具技术的研究现状

炭泡沫是一种由孔泡和相互连接的孔泡壁组成的具有三维网状结构的多孔材料,具备强度高、密度低、热电性能可调、热膨胀系数低、耐高温、可设计性强、易加工等特点。用其做成的树脂基复合材料成型模具在模具制造、质量、变形、可维修、运输等方面都具有明显优势。文中先综述了模具用炭泡沫材料和炭泡沫模具技术发展,然后与传统模具对比说明炭泡沫模具的性能优势,进而对炭泡沫模具设计和制造中的关键技术进行归纳,最后对国内开展炭泡沫模具的研发提出建议。

SHP2 promotes proliferation of breast cancer cells through regulating Cyclin D1 stabilityviathe PI3K/AKT/GSK3β signaling pathway

Objective:The tyrosine phosphatase SHP2 has a dual role in cancer initiation and progression in a tissue type-dependent manner.Several studies have linked SHP2 to the aggressive behavior of breast cancer cells and poorer outcomes in people with cancer.Nevertheless,the mechanistic details of how SHP2 promotes breast cancer progression remain largely undefined.Methods:The relationship between SHP2 expression and the prognosis of patients with breast cancer was investigated by using the TCGA and GEO databases.The expression of SHP2 in breast cancer tissues was analyzed by immunohistochemistry.CRISPR/Cas9 technology was used to generate SHP2-knockout breast cancer cells.Cell-counting kit-8,colony formation,cell cycle,and EdU incorporation assays,as well as a tumor xenograft model were used to examine the function of SHP2 in breast cancer proliferation.Quantitative RT-PCR,western blotting,immunofluorescence staining,and ubiquitination assays were used to explore the molecular mechanism through which SHP2 regulates breast cancer proliferation.Results:High SHP2 expression is correlated with poor prognosis in patients with breast cancer.SHP2 is required for the proliferation of breast cancer cellsin vitro and tumor growthin vivo through regulation of Cyclin D1 abundance,thereby accelerating cell cycle progression.Notably,SHP2 modulates the ubiquitin–proteasome-dependent degradation of Cyclin D1viathe PI3K/AKT/GSK3βsignaling pathway.SHP2 knockout attenuates the activation of PI3K/AKT signaling and causes the dephosphorylation and resultant activation of GSK3β.GSK3βthen mediates phosphorylation of Cyclin D1 at threonine 286,thereby promoting the translocation of Cyclin D1 from the nucleus to the cytoplasm and facilitating Cyclin D1 degradation through the ubiquitin–proteasome system.Conclusions:Our study uncovered the mechanism through which SHP2 regulates breast cancer proliferation.SHP2 may therefore potentially serve as a therapeutic target for breast cancer.

ZBP1(DAI/DLM-1) promotes osteogenic differentiation while inhibiting adipogenic differentiation in mesenchymal stem cells through a positive feedback loop of Wnt/β-catenin signaling

The lineage specification of mesenchymal stem/stromal cells(MSCs) is tightly regulated by a wide range of factors. Recently, the versatile functions of ZBP1(also known as DAI or DLM-1) have been reported in the blood circulation and immune systems.However, the biological function of ZBP1 during the lineage specification of MSCs is still unknown. In the present study, we found that ZBP1 was upregulated during osteogenesis but downregulated during adipogenesis in mouse bone marrow-derived MSCs(m BMSCs). ZBP1 was highly expressed in osteoblasts but expressed at a relatively low level in marrow adipocytes. Knockdown of ZBP1 inhibited alkaline phosphataseactivity, extracellular matrix mineralization, and osteogenesis-related gene expression in vitro and reduced ectopic bone formation in vivo. Knockdown of ZBP1 also promoted adipogenesis in MSCs in vitro. Conversely, the overexpression of ZBP1 increased the osteogenesis but suppressed the adipogenesis of MSCs. When the expression of ZBP1 was rescued, the osteogenic capacity of ZBP1-depleted m BMSCs was restored at both the molecular and phenotypic levels.Furthermore, we demonstrated that ZBP1, a newly identified target of Wnt/β-catenin signaling, was required for β-catenin translocation into nuclei. Collectively, our results indicate that ZBP1 is a novel regulator of bone and fat transdifferentiation via Wnt/β-catenin signaling.

Facile and Scalable Preparation of Fluorescent Carbon Dots for Multifunctional Applications

The synthesis of fluorescent nanomaterials has received considerable attention due to the great potential of these materials for a wide range of applications, from chemical sensing through bioimaging to optoelectron- ics. Herein, we report a facile and scalable approach to prepare fluorescent carbon dots （FCDs） via a one-pot reaction of citric acid with ethylenediamine at 150 ℃ under ambient air pressure. The resultant FCDs pos- sess an optical bandgap of 3.4 eV and exhibit strong excitation-wavelength-independent blue emission （λEm = 450 nm） under either one- or two-photon excitation. Owing to their low cytotoxicity and long fluorescence lifetime, these FCDs were successfully used as internalized fluorescent probes in human cancer cell lines （HeLa cells） for two-photon excited imaging of cells by fluorescence lifetime imaging microscopy with a high-contrast resolution. They were also homogenously mixed with commercial inks and used to draw fluo- rescent patterns on normal papers and on many other substrates （e.g., certain flexible plastic films, textiles, and clothes）. Thus, these nanomaterials are promising for use in solid-state fluorescent sensing, security labeling, and wearable optoelectronics.

Crucial role of Anxa2 in cancer progression:highlights on its novel regulatory mechanism

Anxa2 is the most studied member of the calcium-mediated phospholipid-binding protein family annexins and is a biomarker in cancers.In this review,we listed clinical findings and confirmed the value of Anxa2 in early diagnosis and prognostic prediction due to its overexpression and adverse effect on the outcome in most tumors.Anxa2 plays a pivotal role in cancer cell proliferation,migration,invasion,metastasis,and treatment resistance.Improved understanding of its cancer-promoting function might make it an ideal target for cancer therapy.Here,we systematically summarized the mechanism of Anxa2 in regulating epithelialmesenchymal transition(EMT),cytoskeleton dynamicity,cell cycle,apoptosis,angiogenesis,and immunology by using various tumor models.These data emphasize the potential of Anxa2 for targeted intervention in tumors.Altering Anxa2 expression,neutralizing the cell surface Anxa2,or inhibiting its activation,such as through Tyr23 phosphorylation,could be considered based on the regulatory mechanism of Anxa2 in tumor progression.

Discrete Element Modelling of Dynamic Behaviour of Rockfills forResisting High Speed Projectile Penetration

This paper presents a convex polyhedral based discrete element method for modelling the dynamic behaviour ofrockfills for resisting high speed projectile penetration. The contact between two convex polyhedra is defined by theMinkowski overlap and determined by the GJK and EPA algorithm. The contact force is calculated by a Minkowskioverlap based normal model. The rotational motion of polyhedral particles is solved by employing a quaternionbased orientation representation scheme. The energy-conserving nature of the polyhedral DEM method ensures arobust and effective modelling of convex particle systems. The method is applied to simulate the dynamic behaviourof a rockfill system under impact of a high speed projectile. The rockfill sample is generated by a three-dimensionalVoronoi meso method with a specific particle size distribution. The penetrating process of the projectile strikingthe rockfill target is simulated. Some physical quantities associated with the projectile such as the residual velocity,penetration resistance, and deflection angle are monitored which can reflect the influence of the characteristics ofthe rockfill target on its anti-penetration performance. It can be concluded that the developed polyhedral DEMmethod is a very promising numerical approach in analysing the dynamic behaviour of rockfill systems subject tohigh speed projectile impact.

Electronic, optical property and carrier mobility of graphene, black phosphorus, and molybdenum disulfide based on the first principles

The band structure, density of states, optical properties, carrier mobility, and loss function of graphene, black phosphorus（BP）, and molybdenum disulfide（MoS_2） were investigated by the first-principles method with the generalized-gradient approximation. The graphene was a zero-band-gap semiconductor. The band gaps of BP and MoS_2 were strongly dependent on the number of layers. The relationships between layers and band gap were built to predict the band gap of few-layer BP and MoS_2. The absorption showed an explicit anisotropy for light polarized in（1 0 0） and（0 0 1） directions of graphene, BP,and MoS_2. This behavior may be readily detected in spectroscopic measurements and exploited for optoelectronic applications. Moreover, graphene（5.27 × 10~4 cm^2·V^（-1）·s^（-1））, BP（1.5 × 10~4 cm^2·V^（-1）·s^（-1））, and MoS_2（2.57×102 cm2·V-1·s-1）have high carrier mobility. These results show that graphene, BP, and MoS_2 are promising candidates for future electronic applications.