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With the development of manufacturing technology, microtexturing technology has become a promising way to improve the wettability of heterogeneous metals. In this study, a novel laser-chemical hybrid surface texturing (LCHST) approach was developed to enhance the wettability of the Al/stainless-steel (SS) system. A modified sessile drop method was used to investigate the wetting behavior at high temperature of 4043Al on 301L SS with various groove spacings. The dynamic process was captured simultaneously from two orthogonal directions. The spreading mechanism was revealed by comprehensive analysis of surface characterization, microstructure identification of precursor film, and spreading kinetics. LCHST increased the specific surface area and changed the composition of the oxide film, resulting in higher surface energy with smaller groove spacing and enhanced wettability. The spreading process was driven by the capillary force, which relied on the subcutaneous infiltration mechanism that formed a precursor film of (Fe,Cr)Al3and (Fe,Cr)2Al5. The spreading kinetic analysis revealed that LCHST reduced the spreading activation energy in the parallel direction and increased it in the perpendicular direction, resulting in anisotropic wetting spreading. The new approach and the underlying spreading mechanism could offer new insights into the directional enhancement of the wettability of the Al/SS system.

Damage to the substrate hinders the application of laser paint stripping (LPS) on carbon fiber reinforced polymers (CFRP), but the damage mechanism is currently unknown. In this paper, the LPS characteristics of CFRP, such as paint stripping depth, surface morphology and dynamic behavior, are firstly obtained. Subsequently, the surface damage mechanism of CFRP is discussed in detail by theoretical analysis and finite element method, and the effect of substrate damage on adhesive properties is investigated. The results show that it is difficult for LPS to obtain a complete surface free of paint residue. The strong laser plasma impact and resin pyrolysis pressure cause the resin to crack and flake before the paint is fully ablated. The carbon fiber then breaks and are thrown outward by heat and forces, and the surface with slightly fracture of the fiber will facilitate bonding with the paint.

The cobalt-catalyzed Fischer–Tropsch reaction is used industrially to convert syngas (CO + H2) into long-chain (C5+) hydrocarbons, and the enhancement of catalytic performance by the judicious introduction of additives and promoters has drawn wide interest. Previously, we showed that cobalt-based metal–organic frameworks (MOFs) can be used as sacrificial templates to prepare carbon-supported Co materials (Co@C) with high activity and selectivity for C5+hydrocarbons. Here, we demonstrate that aluminum-promoted Co catalysts with excellent activity, selectivity, and stability can be readily obtained by simple mechanical mixing of a Co-MOF precursor with aluminum isopropoxide prior to pyrolysis. Under optimized conditions, CO conversions of 80% and C5+selectivities of 82% could be attained at 2.9 MPa, 300 °C, 0.3 L/gcat./min space velocity and H2/CO = 2. In contrast, analogous materials prepared by impregnation of the same Co-MOF with aluminum nitrate were completely inactive due to the extensive formation of poorly reducible CoAl2O4spinel. A combination of characterization techniques evinces a blocking effect served by the Al additives, which inhibits the aggregation of incipient cobalt nanoparticles during thermal decomposition. Overall, our findings could help guide the large-scale production of active Co catalyst systems.

In audio-magnetotellurics (AMT) inversion, the resistivity model derived from data is crucial for understanding geological properties. Current AMT inversion methods such as Gaussian–Newton (GN) and nonlinear conjugate gradient (NLCG) have limitations, including sensitivity to data errors and reliance on initial models, leading to nonuniqueness and slow convergence. To address these issues, we propose an AMT inversion framework incorporating borehole data and geological constraints. By leveraging borehole information and considering geological patterns, we develop three machine learning data construction methods that enhance the stability and speed of the inversion process. However, borehole data acquisition is costly and limited, and it represents geological properties discretely within a narrow range. Relying solely on it or unconstrained inversion can compromise accuracy. Our approach integrates borehole data into the supervised descent method (SDM) inversion, resolving data gaps and model variations. SDM results are then used as initial models for GN inversion. Synthetic and field data examples demonstrate the efficiency and feasibility of our framework, showing rapid convergence and high-quality results. This approach accelerates AMT inversion by effectively using borehole information, providing a practical solution for improving the process.

Laser texturing is a promising technology with wide-ranging applications in surface processing. In this study, a nanosecond laser was used to ablate the surface of Q355 steel, creating grooves of varying depths by different processing times. Satisfactory Al/Steel joints were obtained under different groove depths (0 μm, 6 μm, 26 μm and 56 μm). Interfacial microstructure evolutions were investigated and the observed results indicated that introduction of texture would enhance interfacial specific surface area, promote degree of atomic diffusion, thicken interfacial IMCs (intermetallic metallic compounds) while maintain interfacial reaction (η-Fe2(Al,Si)5 + θ-Fe(Al,Si)3). Numerical simulations results illustrated that existence of texture would reduce interfacial peak residual stress, homogenize residual stress distribution and induce compressive stress in the groove. Highest strength of 111 MPa with the fracture mode of tough-brittle compound fracture was produced in the joint when laser texturing processing times were 20, which was nearly 40 % higher compared to the untreated joint (80 MPa). This study provides a novel method to improve joints mechanical properties for laser welding-brazing of Al/Steel system, which may also provide a theoretical reference for the application of other dissimilar metal systems.

As an environmentally friendly new method for coating removal, laser cleaning has been widely used in aircraft skin paint removal recently. However, due to the thermal damage sensitivity of composite materials, current laser cleaning is still mainly used in aluminum alloy skins. In this work, we demonstrate a method for cleaning the surface paint of honeycomb sandwich structures by ultraviolet picosecond laser. The method achieves layer-by-layer and non-destructive removal of paint from composite surfaces. The results show that the top coat is selectively removed when the laser power is 8 W and the scanning speed is 1750 mm/s. When the laser power is 8 W and the scanning speed is 750 mm/s, both top coat and primer are completely removed without any morphological damage for the glass fiber. The temperature monitoring results show that the UV picosecond laser exhibits low-temperature paint removal. The paint removal mechanism of UV picoseconds is dominated by photochemical effects.

Multilayer paint on the surfaces of carbon fiber-reinforced polymer (CFRP) composites was cleaned using an ultraviolet picosecond laser (λ = 355 nm) under different parameters. The surface morphology of the composite after paint removal was investigated by scanning electron microscopy (SEM), chemical composition and functional group detection by energy dispersive spectroscopy (EDS) and FT-IR, while the sample temperature was monitored by an infrared thermal imager during cleaning. Additionally, CFRP performances were evaluated before and after paint removal. These results demonstrated that after three cleaning cycles with 12 W laser power, the paint layers on CFRP is removed, the surface epoxy resin is retained, and the carbon fiber does not have any morphological damage. At the same time, the surface after de-painting also met the re-painting conditions, and the tensile strength was not degraded compared with the original sample. It is noteworthy that the UV picosecond laser shows “low temperature cleaning”, which completely removes the paint layer on the CFRP surface at a temperature below 80 °C. This means that the paint stripping process will not cause potential thermal damage or degradation of mechanical properties for CFRP. Mechanism analysis indicated that the photochemical action led to the breaking of the chemical bond of the paint, thus achieving paint removal. This study demonstrates the feasibility of a laser cleaning process for de-painting from resin-based composite surfaces and guides the repair and maintenance of commercial aircraft.

In this work, mechanical alloying of the alternating stacked pure Al and Zn thin foils was accomplished via high-pressure torsion (HPT). In the alloyed Al-Zn system, an exotic phase transformation from hexagonal close-packed (HCP) to face-centered cubic (FCC) was identified. The atomic-scale evolution process and underlying mechanism of phase transformation down to atomic scale are provided by molecular dynamics simulation and high-resolution transmission electron microscopy. The HCP → FCC phase transformation was attributed to the sliding of Shockley partial dislocations generated at the Al-Zn grain boundaries, which resulted in an [21¯1¯0]/[011¯]and (0001)/(111) orientation relationship between the two phases. This work provides a new approach for the in-depth study of the solid phase transformation of Al-Zn alloys and also shed lights on understanding the mechanical properties of the HPT processed Al-Zn alloys.

Ground penetrating radar (GPR) is an important shallow electromagnetic nondestructive detection technology. The full waveform inversion (FWI) of GPR data utilizes all information, including dynamics and kinematics, theoretically has the highest imaging accuracy, and meets the increasingly sophisticated needs of engineering exploration imaging. However, the bottleneck restricting the FWI is the low calculation efficiency, which cannot meet the requirements of rapid reconstruction of underground medium in actual engineering. In order to improve the calculation efficiency, we introduce the data encoding into the GPR dual-parameter FWI. Data encoding often brings crosstalk noise, and the noise is closely related to the encoding methods and data types. For this reason, we select the encoding of the crosshole data, wide-angle reflection and refraction data, and common-offset data for inversion. The experiments show that data encoding can effectively reduce computing time, and three different GPR data require different encoding methods due to their different redundancies. Total variation (TV) regularization can suppress the noise caused by data encoding. Although it will slightly increase the calculation time, it can significantly improve the inversion quality.

Nanosecond pulsed laser cleaning is an indispensable green technology. A three-dimensional (3-D) finite element model (FEM) was used to predict the surface temperature during laser cleaning. Then, the macroscopic morphology of the FEM that was obtained was verified using digital ultra-depth-of-field microscopy (OM). Finally, the variation in the surface morphology with the maximum power density (F), x-axis spot overlap ratio (Ux), and y-axis spot overlap ratio (Uy) was determined using field-emission scanning electron microscopy (FE-SEM) and atomic force microscopy (AFM). The change in surface composition was analysed using X-ray photoelectron spectroscopy (XPS), and optical emission spectroscopy (OES) was used to monitor laser cleaning. Transmission electron microscopy (TEM) was used to analyse the surface secondary oxidation thickness. The original surface consisted of titanium oxides (Ti4+and Ti3+) and organics. The Ti0peak was enhanced, and the O content was reduced after laser cleaning. Therefore, the laser-cleaning effect was clear. The surface was smooth without cracks when the maximum power density and the spot overlap ratio were set to 31.85 MW/cm2and 80 %, respectively. A dense and uniformity oxide film, 29 nm thickness, was formed on the surface of TA15 titanium alloy after laser cleaning. Changes in F, Ux, and Uycaused noticeable changes in the Ti I and Ti II peaks in the OES spectra, which were used to monitor laser cleaning.

Fabricating TC4 coatings on the carbon fiber reinforced plastic (CFRP) substrate surface will contribute to increasing the applicability of CFRP materials in the aerospace industry. However, chemical metallurgical bonding between the TC4 alloy and CFRP is crucial during the manufacturing process. Here, we studied the effect of Al powder content on the microstructural characteristics and mechanical properties of the laser cladded TC4+AlSi10Mg composite coating on the CFRP surface. Furthermore, the relationship between laser process parameters, interfacial morphologies, and mechanical properties is established. The amount of CFRP decomposed increases with a rise in the AlSi10Mg powder content, while augmenting the penetration of the transition layer into the CFRP material. Moreover, the TC4 coating with 10wt.% AlSi10Mg is composed of α′ martensite, TiC, Ti3Al, and Ti3AlC. The average nano-hardness of the TC4 coating increases from 6.00 to 6.86 GPa when the AlSi10Mg content rises from 5% to 20%. Meanwhile, the maximum shear strength of the CFRP/TC4 interface is 26.8 MPa. Based on the experimental observations and theoretical analysis, the interface reaction mechanism of the laser cladded TC4+AlSi10Mg composite coating on the CFRP surface is: Ti(s)+C(s)→TiC(s), Al(1)+3Ti(s)→Ti3Al(s).

Duchenne muscular dystrophy (DMD) is a progressive disease characterized by skeletal muscle atrophy, respiratory failure, and cardiomyopathy. Our previous studies have shown that transplantation with allogeneic myogenic progenitor-derived exosomes (MPC-Exo) can improve cardiac function in X-linked muscular dystrophy (Mdx) mice. In the present study we explored the molecular mechanisms underlying this beneficial effect. We quantified gene expression in the hearts of two strains of Mdx mice (D2.B10-DmdMdx/J and Utrntm1Ked-DmdMdx/J). Two days after MPC-Exo or control treatment, we performed unbiased next-generation RNA-sequencing to identify differentially expressed genes (DEGs) in treated Mdx hearts. Venn diagrams show a set of 780 genes that were ≥2-fold upregulated, and a set of 878 genes that were ≥2-fold downregulated, in both Mdx strains following MPC-Exo treatment as compared with control. Gene ontology (GO) and protein-protein interaction (PPI) network analysis showed that these DEGs were involved in a variety of physiological processes and pathways with a complex connection. qRT-PCR was performed to verify the upregulated ATP2B4 and Bcl-2 expression, and downregulated IL-6, MAPK8 and Wnt5a expression in MPC-Exo-treated Mdx hearts. Western blot analysis verified the increased level of Bcl-2 and decreased level of IL-6 protein in MPC-Exo-treated Mdx hearts compared with control treatment, suggesting that anti-apoptotic and anti-inflammatory effects might be responsible for heart function improvement by MPC-Exo. Based on these findings, we believed that these DEGs might be therapeutic targets that can be explored to develop new strategies for treating DMD.

With the aim of improving the durability and safety, erosion time, and cost-effective of asphalt road, a composite of modified calcium sulfate whisker-styrene butadiene rubber modified asphalt (MCSW-SBRMA) was prepared viathermal doping. Firstly, stearic acid and titanate coupling agent (NDZ-201) were used as a modifier to transform calcium sulfate whisker (CSW) into MCSW viawet modification method at 60 °C and anhydrous ethanol as a dispersant. What is more, the optimum loading of modifier (a mixture of 25% stearic acid + 75% NDZ-201) was found to be at 2% to prepare MCSW. Subsequently, a composite of MCSW-SBRMA was prepared with different loading of MCSW (i.e. 2% to 8%) to enhance the softening point of asphalt. In this study, it was found that 4% of modifiers was the best composition to improve the MCSW-SBRMA properties as elucidated in the orthogonal experiment table L16(42). The effects of MCSW and SBR addition on several properties of asphalt were studied by multiple routine tests including penetration, segregation test, and so on. The results show that: 2% to 8% MCSW can increase the softening point of SBR modified asphalt (SBRMA) by 7% to 8%. 4% MCSW increased the PG of SBRMA from 64 to 70, which greatly improved the high temperature characteristics of asphalt. The 5 °C ductility of MCSW-SBRMA is greater than 100 cm, which greatly improves the low temperature performance of asphalt. Through the application of fluorescence microscopy (FM), Fourier transform infrared spectroscopy (FTIR), Scanning electron microscopy (SEM), and energy dispersive spectroscopy (SEM-EDS), it has been demonstrated that MCSW-SBR effectively alters asphalt in a highly uniform manner, with some MCSW still retaining large cross sections, thereby facilitating the dispersion of shear stress and enhancing the durability of asphalt.

Nickel-based materials have garnered considerable attention owing to their potential as affordable, effective, and durable catalysts for CO2hydrogenation. However, their propensity to favor methane production over more desirable methanol has posed a challenge. In this study, we endeavored to address this issue by synthesizing α-, β-, and γ-Ga2O3supported Ni catalysts through the wet impregnation method. Notably, Ni supported on the α-Ga2O3catalyst (referred to as 10Ni/α-Ga2O3) exhibited superior activity and methanol selectivity under typical CO2hydrogenation conditions (3 MPa and 260 °C), reaching ca. 80% methanol selectivity at 0.72% CO2conversion. This performance outpaced analogous counterparts utilizing β- and γ-Ga2O3supports, which is attributed to the abundance of strong basic sites inherent in α-Ga2O3. We unveiled the intricate mechanism governing CO2hydrogenation on 10Ni/α-Ga2O3catalysts through ex situ characterizations and in situ FTIR. Evidently, H2underwent dissociation over Ni nanoparticles. It spilts over onto the oxide support, while strong basic sites on the α-Ga2O3support facilitate the adsorption of CO2, forming bidentate carbonate as a key intermediate and subsequently hydrogenated to yield methanol. Our findings propose a promising avenue for developing cost-effective and highly efficient catalyst systems for methanol synthesis through CO2hydrogenation.

The digital twins process of equipment operation and maintenance involves massive data and complex business logic. Through data awareness of equipment and workshop environment. According to the characteristics of equipment operation and maintenance, the data characteristics and requirements are analysed, an equipment operation and maintenance management system based on the micro-service framework is proposed, a set of equipment operation and maintenance digital twins are designed and a general reference software architecture is designed and by checking the underlying in-heap pattern reduces high-impact portions of memory to provide accurate follow-up complex digital twins modelling provides the architectural foundation.

Laser welding was employed to join short carbon fiber reinforced polyphenylene sulfide (SCF/PPS) and TC4 alloy inexpensively and quickly. An excellent joint with a large interfacial bonding area was achieved, while the TC4 and the SCF/PPS were tightly joined under the sufficient temperature and pressure. The bubble defects formed easily at the joining interface due to the voids in the PPS resin, SCF/PPS volume shrinkage during the solidification stage, and the decomposition of the PPS resin, and these phenomena were significantly reduced by regulating and controlling welding parameters. As the laser power increased, the tensile shear load first increased and then decreased, which was attributed to the effects of the joining area, bubble defects and PPS decomposition. The maximum tensile shear load of 2052 N was achieved at the optimum laser power of 700 W due to the large interfacial joining area and absence of obvious decomposition. The joint fracture presented mixed fracture characteristics of cohesion and adhesion failures.

CF/PEEK composites were welded assisted by ultrasonic. The influence of vibration time and using of energy director (ED) to the joints were investigated in details. The joints had defect of incomplete fusion at the interface under short welding time without ED, and defects of cracks and voids appeared at the interface of carbon fiber and PEEK resin, which attributed to too much heat accumulation at the heat affected zone (HAZ). By using flat ED, joint with sound bonding was realized under vibration time of 0.9 s. The lap shear strength of joint can reach 28 MPa, and the joint fractured at the HAZ. The real-time temperature at interfaces were monitored. It is found that the heating rate can be accelerated by using flat ED, and the peak temperature was lowered. At last, the influence mechanism of processing parameter to the joint were discussed in details.

Restrictive cardiomyopathy (RCM) is a rare childhood cardiomyopathy that is a challenging diagnostic problem for clinicians. We describe a case of an 8-year-old girl with a 2-year history of shortness of breath on exertion. Electrocardiogram and echocardiography showed biatrial enlargement, while cardiac magnetic resonance showed biatrial dilation and normal pericardial thickness. Left and right heart catheterization revealed a left ventricular (LV) end-diastolic pressure (EDP) of 20 mmHg, right ventricular (RV) EDP of 13 mmHg, and pulmonary arterial systolic pressure of 51 mmHg. LV and RV pressure traces showed that LV and RV pressures moved concordantly with respiration, and that the systolic area index was 0.98. Cardiac catheterization data were therefore supportive of RCM. Next-generation sequencing identified a heterozygous variant of the troponin I gene (TNNI3; c.574C>T). Combining these findings led to a diagnosis of RCM. The patient’s parents chose conservative treatment, but at the 12-month follow-up she died of worsening heart failure and cerebral infarction. This case emphasizes the need for cardiac catheterization and genetic testing in RCM, and suggests that anticoagulants should be recommended to reduce the risk of thromboembolic events.

ABSTRACTBackground: Circulating tumor cells (CTCs) and microemboli (CTM) are attracting increasing attention in medical biology and clinical practice. However, the clinical relevance of CTCs in nasopharyngeal carcinoma (NPC) has not yet been ascertained, and no study has focused on the influence of Epstein-Barr virus (EBV) status on CTCs in NPC patients. These issues were therefore examined. Methods: Peripheral blood samples were prospectively obtained from 33 NPC patients before treatment. CTCs and CTM were captured using the Isolation by Size of Epithelial Tumor (ISET) method. Immunohistochemistry on CK5/6 (cytokeratin5/6) and P63, as well as in situ hybridization of EBERs (EBV-encoded RNAs) were used to validate the harvested tumor cells. Results: Out of 33 NPC patients, CTCs were detected in 22 cases (66.7%), and CTM were observed in 2 cases (6.1%). CTCs were presented in all stages of NPC patients but had no association with the TNM stages (all P > 0.05). The presence of CTCs appeared to correlate with EBV activation status. Among the total NPC patients, the EBV VCA-IgA levels in CTC-positive cases were higher than that in CTC-negative cases (negative vs. positive: 3.88 vs. 4.86, P = 0.016). A similar result was observed in the patients without distant metastasis (negative vs. positive: 3.76 vs. 4.95, P = 0.009). When the number of CTCs was considered, CTC counts were found to correlate with EBV VCA-IgA (R = 0.382, P = 0.041) and EBV DNA load (R = 0.396, P = 0.033) for all NPC patients as well as NPC patients without distant metastases. Conclusions: These findings strongly suggested detectable CTCs/CTM in all stages of NPC patients and support a positive correlation between CTCs and EBV activation in NPC patients.

Tungsten carbide thin films were deposited on silicon (100) substrates by DC reactive magnetron sputtering using CH4 as a carbon source. The microstructure, compressive stress, hardness and tribological behaviors showed great dependences on the rates of CH4 flow (FCH4). Increasing the FCH4 from 2 to 5 sccm, the film exhibited a phase transition from hexagonal-W2C to cubic-WC1-x. Further increasing the FCH4 larger than 10sccm, the film presented amorphous state. As the FCH4 increased, the Raman revealed that the films showed a graphitization trend, meanwhile, the surface of the films became smoother and smoother. The hardness of tungsten carbide films first increased, and then decreased after reaching the maximum 38.5GPa (FCH4=10 sccm). While the sample deposited at 15 sccm obtained the lowest wear rate (2.17×10-6 mm3/Nm) and low coefficient of friction (CoF, 0.24) and still maintained a high hardness of 32.1 GPa. The lowest wear rate could be ascribed to the highest ratio of H3/E2.

Y2O3 has a great application potential at reaction barrier coating of high-temperature composites due to its high thermodynamic stability and high melting point, and the phase structure stability at high temperature and structure dependent mechanical property are key parameters for this application. Y2O3 thin films were deposited on silicon (100) wafers by DC magnetron sputtering with various oxygen partial pressure and substrate bias, and then vacuum annealing at 1000°C was performed to investigate the phase structure stability. The microstructure, stress and hardness of as-deposited and annealed Y2O3 thin films were explored by X-ray diffraction, transmission electron microscope, and nanoindenter. The result showed that as-60 bias voltage was applied to substrate, cubic-c phase formed regardless of variation of oxygen partial pressure, and the cubic-c phase remains stability and crystallinity became better after annealing at 1000 °C.In addition, the hardness and modulus also just had minor changes as a function of oxygen partial pressure. As oxygen partial pressure was kept at 0.043 Pa, phase transition from cubic-c to monoclinic-b phase took place with increasing substrate bias, accompanying by the increment of hardness and modulus, and 1000 °Chigh-temperature annealing resulted in that as-deposited monoclinic-b phase transforms to cubic-c phase.

Niobium carbide films was deposited by direct current reactive magnetron sputtering on Si (001) substrates in discharging a mixture of CH4/Ar gas. The effects of growth temperature (Ts) and methane flow rate (FCH4) on the phase structure, composition, mechanical and tribological properties for NbCx films were explored. For the film grown at FCH4=6 sccm, a phase transition from cubic-NbC phase to hexagonal-Nb2C phases occurred with increasing the Ts; In contrast, when the film deposited at FCH4=16 sccm, only the cubic-NbC phase was observed at different Ts. The surface of all the films became rough with increasing the Ts. In addition, when the Ts increased from RT to 600 °C, the films exhibited the compressive stress and kept rising. While as the Ts > 600 °C, the stress partially relaxed both at FCH4=6 sccm and FCH4=16 sccm. The hardness (H) for sample grown at FCH4=6 sccm first increased up to a maximum value, and then decreased with increasing the Ts. And the films grown at FCH4=16 sccm kept decreasing with the maximum super-hard value of the filmsof 40.5 GPa at FCH4=6 sccm and 600 °C. The friction coefficient for the film obtained at FCH4=16 sccm was lower than that at FCH4=6 sccm, which might be due to the presence more carbon in the film grown at FCH4=16 sccm.

The cubic-NbN/NbCN multilayers with modulation periodicity (Λ) ranging from 4.2 to 39.1 nm were deposited on Si (100) substrate by reactive magnetron sputtering in a mixture of Ar and N2 gases. The Λ dependent structural, mechanical and tribological properties for resulting c-NbN/NbCN multilayers were explored. As Λ varied from 4.2 to 39.1 nm, all the films exhibited an obvious modulated structure. Increasing the Λ, the Nb (C,N)(111) peak in XRD gradually shifted to bigger angles and the peak intensity of NbN(111) became stronger. The stress for all multilayers was compressive ranging in between the stress for both NbN and NbCN single layers, and the stress value was stable with increasing Λ. The NbN layer was beneficial to relaxing the compressive stress which induced by NbCN layer. In addition, as Λ increases, the hardness (H) first increased, and then decreased after reaching a maximum value. The obvious enhancement in hardness for multilayers was observed, whose maximum value approaches 43.3 GPa when Λ = 8.4 nm, 37% larger than that obtained by the rule of mixture value. The friction coefficient values of NbN/NbCN multilayers ranging between 0.34 and 0.4 were much lower than that of NbN monolayer but higher than that of NbCN monolayer were.

The NbN/Ni coatings were deposited by co-sputtering on Si (100) substrates. The structure, hardness and tribological properties were characterized by X-ray diffraction (XRD), atomic force microscope (AFM), scanning electron microscopy (SEM), nanoindentation test and ball-on-disc tribometer. XRD revealed that the NbN/Ni coatings exhibited a NaCl-type NbN structure but no sign of any nickel phase. For the coatings with various nickel powers ranged from 20 W to 40 W, the shrinkage of the lattice parameter of NbN indicated that Ni atoms might be incorporated into the NbN lattice with a substitution of Nb atoms by the smaller Ni atoms. Further increasing of Ni powers, the degree of crystallinity of the coatings became worse. The NbN coating doped with a certan power of Ni (40 W) exhibited the best degree of crystallinity among all samples. It also displayed a maximum microhardness of 25 GPa combined with a better resistance to plastic deformation, which could attribute to the grain refinement and the solid solution strengthening. Tribilogical properties of NbN/Ni coatings were also found to be depentent on nickel powers significantly. For the pure NbN coating, the coefficient of friction (CoF) was 0.7 approximately, while it decreased to 0.54 when the power of Ni increased to 40 W. Simultaneously, the wear resistance of the NbN/Ni coatings was improved due to the spontaneous oxidation of the wear track surfaces caused by the addition of a certain amount of nickel to the niobium nitride coatings.

Based on previous work on lubricant hard HfCx film, the HfCxNyfilmswere deposited by sputtering from theHf target in a mixture of discharging N2,Ar and CH4, and the N content in films was accurately controlled by changing the N2 flow rate.Theintroduction of N into the films contributed to the presence of solid solution FCC-HfC(N) and FCC-HfNphase appeared at high N content in films. In addition, the a-C content in the filmsdecreasedwith increment ofN content in the films. In comparison with HfCx film, hardness of HfCxNy films were enhanced from 21 GPa to 25 GPa with N content rising to 6.8 at.% but then surplus N in the films impaired the hardness. The coefficient of friction and surface roughness for HfCxNy films increasedfrom 0.10 to 0.23 and 3.13 nm to 12.4 nm, respectively, with decreasing a-C content from 52.9 at.% to 46.3 at.%. However, the introduction of N into HfCxFilm improvedthe wear resistance of filmseffectively, and the specific friction rate for this HfCxNyfilm deposited at 8 sccm N2was only 6.17×10-7 mm3/Nm about half of that of HfCx film (1.09×10-6mm3/Nm).

Cubic δ-NbNfilm with (200) texture, hexagonalδ′-NbN films with a mixed (100)+(110) texture and (110) texture have been deposited on Si (100) substrate at-40, -160 and-200Vsubstrate bias, respectively. Vacuum heat treatments were performed to investigate the effects of annealing temperature on structural stability and hardness of δ-NbN and δ′-NbN films. The results show that for δ-NbN film and δ′-NbN films with a strong (110) texture,no phase transition occuredafter heat treatments.But for δ′-NbN films with a mixed (100)+(110) texture, phase transition from δ′-NbN to δ-NbNtook place, which can be ascribed to small lattice mismatch between δ′-NbN (100) and δ-NbN (111) and low phase transition barrier. In addition, the high substrate bias can improve the interface adhesion due to interface mixing resulting from high energy ions bombardment. Even after annealing at 900°C, the hardness for δ′-NbN deposited at-200V still remains 32GPa, which shows a potential application at the field of protect coatings.

High draft is an important procedure in the spinning which is a crucial step in textile engineering. Lei Binglin as a famous textile engineer invented Lei’s high draft in 1936 which not only made a contribution to modern China’s textile but also showed Chinese independent innovation to the world. So it is significant to research the role of Lei’s high draft in the process of spinning, the inheritance and innovation of high draft invention made by Lei Binglin and encourage given by country for Lei’s high draft. By analyzing all these aspects mentioned before, we would conclude the importance of Lei’s high draft in this thesis.

Zhejiang Sci-Tech University is a famous university of science and engineering in China which locates in Hangzhou of Zhejiang province. This university has more than 100-year history. It was named as Zhejiang Institute of Silk Engineering before which was famous for its textile engineering. In 1897, Lin Qi who was the governor of Hangzhou proposed to found an agricultural education institution in Hangzhou and then he founded the Sericulture Academy which was the predecessor of Zhejiang Sci-Tech University. From the Sericulture Academy to Zhejiang Sci-Tech University, textile education in this school gradually developed which was a typical sample of China.

The textile periodical in modern China recorded all aspects of textile industry on specific historical period which was an important way for us to learn the modern textile industry. Textile Industry was one of the modern textile periodicals. It was published by the alumni association of Textile College of Nantong Institute which was the first higher textile education in modern China. It was published for nearly ten years from April 1931 to June 1940. By researching information about Textile Industry, Textile College of Nantong Institute and its alumni association and articles about Lei’s high draft published on the Textile Industry, this thesis would conclude and summarize the importance of Textile Industry. By learning its importance on textile periodical, textile education and textile research, we could learn more information about modern textile history.

Oral cancer is the twelfth largest malignant tumor in the world. Oral cancer is prone to lymph node metastasis in the early stages of the disease, and lymph node metastasis will directly affect the treatment and survival rate. Therefore, whether the lymph node metastasis can be accurately evaluated is of great significance to the treatment and prognosis of patients.

Objective. The objective of this study is to determine the effect of whole-body vibration (WBV) exercise on the anticipatory delay of core muscles in nonspecific low back pain (NSLBP) patients. Methods. Forty participants with NSLBP were randomly divided into the WBV group and the control group. The sEMG signals of deltoid, erector spines (ES), multifidus (MF), rectus abdominis (RA), and transversus abdominus/internal oblique muscles (TrA/IO) were recorded before and after the intervention in the weight-shifting task. The relative activation time of each muscle was calculated. Results. In the WBV group, the relative activation time of bilateral MF and bilateral TrA/IO was significantly reduced on shoulder flexion (right MF: P=0.014; left MF: P=0.011; right TrA/IO: P=0.008; left TrA/IO: P=0.026). As for shoulder abduction, except for the left TrA/IO and the left RA, the relative activation time of other muscles was significantly reduced (right ES: P=0.001; left ES: P<0.001; right MF: P=0.001; left MF: P=0.009; right TrA/IO: P<0.001; right RA: P=0.001). In the control group, there was no significant difference in the relative activation time of each muscle before and after the intervention (P>0.05). Conclusions. WBV exercise can effectively alleviate the anticipatory delay of core muscles in NSLBP patients, but the long-term effects still need further study. This trial is registered with ChiCTR-TRC-13003708.