Geometric Accuracy and Energy Absorption Characteristics of 3D Printed Continuous Ramie Fiber Reinforced Thin-Walled Composite Structures

The application of continuous natural fibers as reinforcement in composite thin-walled structures offers a feasible approach to achieve light weight and high strength while remaining environmentally friendly.In addition,additive manufacturing technology provides a favorable process foundation for its realization.In this study,the printability and energy absorption properties of 3D printed continuous fiber reinforced thin-walled structures with different configurations were investigated.The results suggested that a low printing speed and a proper layer thickness would mitigate the printing defects within the structures.The printing geometry accuracy of the structures could be further improved by rounding the sharp corners with appropriate radii.This study successfully fabricated structures with vari-ous configurations characterized by high geometric accuracy through printing parameters optimization and path smoothing.Moreover,the compressive property and energy absorption characteristics of the structures under quasi-static axial compression were evaluated and compared.It was found that all studied thin-walled structures exhibited progressive folding deformation patterns during compression.In particular,energy absorption process was achieved through the combined damage modes of plastic deformation,fiber pullout and delamination.Furthermore,the com-parison results showed that the hexagonal structure exhibited the best energy absorption performance.The study revealed the structure-mechanical property relationship of 3D printed continuous fiber reinforced composite thin-walled structures through the analysis of multiscale failure characteristics and load response,which is valuable for broadening their applications.

An 80-GHz DCO utilizing improved SC ladder and promoted DCTL-based hybrid tuning banks

An 80-GHz DCO based on modified hybrid tuning banks is introduced in this paper.To achieve sub-MHz frequency res-olution with reduced circuit complexity,the improved circuit topology replaces the conventional circuit topology with two binary-weighted SC cells,enabling eight SC-cell-based improved SC ladders to achieve the same fine-tuning steps as twelve SC-cell-based conventional SC ladders.To achieve lower phase noise and smaller chip size,the promoted binary-weighted digi-tally controlled transmission lines(DCTLs)are used to implement the coarse and medium tuning banks of the DCO.Compared to the conventional thermometer-coded DCTLs,control bits of the proposed DCTLs are reduced from 30 to 8,and the total length is reduced by 34.3%(from 122.76 to 80.66μm).Fabricated in 40-nm CMOS,the DCO demonstrated in this work fea-tures a small fine-tuning step(483 kHz),a high oscillation frequency(79-85 GHz),and a smaller chip size(0.017 mm^(2)).Com-pared to previous work,the modified DCO exhibits an excellent figure of merit with an area(FoMA)of-198 dBc/Hz.

Effective inhibition of anomalous grain coarsening in cast AZ91 alloys during fast cooling via nanoparticle addition

In this work, the effects of Ti CN and γ-Al_(2)O_(3) nanoparticle(NP) addition on the microstructural evolution of cast AZ91 alloys at the cooling rate ranging from 15 to 120 K/s have been systematically investigated. Experimental results reveal that grain coarsening occurs in cast AZ91 alloys when the cooling rate exceeds 90 K/s, while it can be effectively inhibited upon addition of NPs. The marked inhibition effect may originate from the formation of Ti CN or γ-Al_(2)O_(3) NP-induced undercooling zone ahead of solid/liquid(S/L) front of α-Mg, which not only can restrict grain growth effectively, but also can reactivate the native nucleants that are inactive in AZ91 melts to participate in nucleation events. And if possessing high nucleation potency, NPs can also promote further nucleation events and lead to significant grain refinement. An analytical model has been established to quantitatively account for the restriction effect of NPs on grain growth. The present work may shed a new light on the grain coarsening of cast alloys during fast cooling and provide an effective approach to circumvent it.

Treatment and prevention of diabetes complicated with non-alcoholic fatty liver disease by integrated traditional Chinese and Western medicine

Today’s social economy and science and technology levels are developing rapidly.Type 2 diabetes mellitus(T2DM)is increasing in incidence,and T2DM promotes non-alcoholic fatty liver disease(NAFLD)through some mechanisms.The pathogenesis of T2DM and NAFLD is interconnected,interacted with,and promoted.While increasing the economic burden on patients,it also affects the quality and life of patients themselves.In the world,the current treatment methods include exercise and diet control,drugs(including sugar reduction,lipid-lowering drugs,etc.),weight loss surgery,etc.,but currently,researching drugs can only control the progress of the disease.At present,there is no drug for T2DM combined with NAFLD treatment.Therefore,it is necessary to find and study effective drugs for NAFLD.Based on the principle of“syndrome differentiation,”traditional Chinese medicine(TCM)played an important role in treating this disease.The theory of TCM believes that the cause of NAFLD is mostly diet disorders and imbalances in daily life,leading to liver Qi stagnation,spleen dysfunction,and liver and kidney deficiency,producing phlegm and stasis.During the treatment process,we must pay attention to the goal of phlegm turbidity,but also pay attention to the source of phlegm turbidity,strengthen the spleen and stomach,nourish the liver and kidney,and restore the physiological function of the body.The ingredients of Chinese medicine extracts have the effects of antagonist oxidation stress,protecting liver cells,improving fibrous soluble systems,and promoting lipid metabolism,thereby reducing inflammatory factors to release damage to liver cells.By combining the diagnosis of TCM syndromes with Western medical disease diagnosis,the model of disease diagnosis combined with syndrome differentiation can compensate for some of the limitations of TCM’s sole reliance on syndrome differentiation,allowing for a better grasp of the disease.In treatment,a dual approach using traditional Chinese and Western medicine can enhance efficacy and reduce toxicity,leveraging both complementary strengths.Chinese medicine explains its treatment of NAFLD from a macro and micro level,providing a safer and more effective method for treating the disease.

The Distribution of Sedimentary Organic Matter and Implication of Its Transfer from Changjiang Estuary to Hangzhou Bay, China

In this study, a comparison was made between the Changjiang Estuary and the Hanghzou Bay, in terms of the sources and diagenesis of the sedimentary organic matter (OM). To achieve this purpose, surface sediments from the estuary and bay were analyzed for lignin-derived phenols, stable carbon isotope and TOC/TN (total organic carbon/total nitrogen) molar ratio. The signal of land-derived OM decreased, and the vanillic acid to vanillin ratio, (Ad/Al)v, increased with increasing distance from the Changjiang Estuary and the Hangzhou Bay. These results corresponded with the contribution of the terrigenous OM from the rivers to the coastal zone, and the predominance of marine OM farther offshore, and that the land-derived OM underwent decomposition during transport along the estuary and bay. It should be noted that besides the Qiantang River, Hangzhou Bay is also receiving more than half of its materials from Changjiang Estuary, which flows into the Hangzhou Bay at the north, and leaves via the southern part of the bay. This important aspect of the hydrological cycle in Hangzhou Bay corresponded to higher Λ (total lignin in mg/100 mg OC), higher TOC and C/N ratios and more elevated (Ad/Al)v and (Ad/Al)s values in the bay than the Changjiang Estuary, thus, rendering the bay as a site for the accumulation and rapid cycling of terrigenous OM.

A Review of Heat Shock Proteins Research on Bemisia tabaci

Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) is the most destructive invasive pests in agricultural production and has a high tolerance to heat. Heat shock proteins play an essential role in life activities such as growth and development, reproduction and diapause of B. tabaci. At the same time, they are also crucial in resisting adverse environments and in adaptive evolution. The expression of heat shock protein in B. tabaci is not only related to temperature, but also to the tolerance of the environment. After receiving external stimuli, the expression level can be increased or decreased to maintain the stability of cells in vivo. This paper reviews the classification, biological characteristics, biological functions, and research status of HSPs in recent years. This mini-review will provide helpful information related to the use of heat shock proteins to study the occurrence and damage of B. tabaci. This has important theoretical and practical significance for revealing Hsps in explaining the population expansion mechanism of B. tabaci invasion and predicting population dynamics.

Application of 3D Electrical Resistivity Tomography for Diagnosing Leakage in Earth Rock-Fill Dam

The leakage occurs during operation of the dam in Liuhuanggou reservoir. It’s a threat to the safety of the people’s lives and property in downstream. In order to eliminate the hidden danger of reservoir, ensure the safety of the dam, play better the function of flood control and water storage of the reservoir etc., we apply the 3D electrical resistivity tomography detecting technology and volume rendering image processing technology, make the measurement in field, process the data and combine the field survey to find out the leakage channels inside the dam. The results show that the 3D resistivity images appear the low resistivity zone corresponding with the leakage channels. There are two main leakage channels that come from different location inside the dam. It is feasible to diagnose the leakage in earth rock-fill dam by applying 3D electrical resistivity tomography.

镁含量对铸造低锌含量Al-xMg-3Zn-1Cu合金的显微组织与力学性能的影响

研究镁含量对铸造低Zn含量Al−xMg−3Zn−1Cu(x=3~5,质量分数,%)合金的显微组织与力学性能的影响。随着Mg含量的增加,铸态合金的晶粒因为增强的生长抑制效应而得到细化,当Mg含量超过4%时,η-Mg(AlZnCu)_(2)相和S-Al_(2)CuMg相的形成受到抑制,而T-Mg_(32)(AlZnCu)_(49)相的形成得到促进。镁含量的增加通过增加共晶相尺寸的方式阻碍合金的固溶动力学,但合金的时效硬化却会因为析出动力学的加快和析出物数量密度的提升而加速。铸态、固溶态和峰时效态合金的屈服强度和抗拉强度均随着Mg含量的增加而增加,而合金的伸长率则随着Mg含量的增加而降低。峰时效Al−5Mg−3Zn−1Cu合金的抗拉强度和伸长率分别超过500 MPa和5%。峰时效合金最主要的强化机制是析出强化,这是通过T′析出物实现的,且随着镁含量的增加而得到加强。

Enhanced mechanical properties and degradation rate of Mg-Ni-Y alloy by introducing LPSO phase for degradable fracturing ball applications

In this work,as-cast Mg-Ni-Y alloys were proposed to develop a feasible material for fracturing balls,and their mechanical performance and corrosion behavior were systematically investigated.Long period stacking order(LPSO)phase was firstly introduced to improve both the mechanical properties and degradation rate of magnesium alloys.With the increase of LPSO phase,the compressive strength was improved significantly,while the elongation of the alloys decreased owing to the relatively brittle nature of LPSO phase.Due to the higher corrosion potential of LPSO phase,the LPSO phase can accelerate the corrosion process by providing more micro-couples.However,the LPSO phase would serve as the corrosion barrier between the corrosion medium and the matrix when the contents of LPSO phase are too high in Mg92.5Ni3Y4.5 and Mg87.5Ni5Y7.5 alloys.As-cast Mg97.5Ni1Y1.5 alloy with satisfactory mechanical properties and rapid degradation rate was successfully developed,exhibiting a high degradation rate of 6675 mm/a(93℃)in 3 wt.%KCl solution and a favorable ultimate compressive strength of 410 MPa.The degradation rate of Mg97.5Ni1Y1.5 alloy is 2-5 times of the current commercial magnesium alloy fracturing materials.

Patients with advanced primary hepatocellular carcinoma treated by melatonin and transcatheter arterial chemoembolization: a prospective study

Objective: To observe the clinical efficacy of tran-scatheter arterial chemoembolization (TACE) andTACE+MLT (melatonin) on inoperable advancedprimary hepatocellular carcinoma.Methods: From January 1997 to January 1998, onehundred patients with inoperable advanced primaryhepatocellular carcinoma were treated separately byTACE (50) and TACE+MLT (20 mg/d at 8:00PM orally, 7 days before TACE) (50).Results: The effective rates (WHO standards) ofTACE and TACE+MLT were 16% and 28% respec-tively (P【0.05). After TACE or TACE+MLT,the resection rate at two-stage of TACE was 4% or14% (P【0. 01). The 0.5-, 1- and 2-year survivalrates in the TACE group were 82%, 54% and 26%respectively; in the TACE+MLT group 100%, 68%and 40% respectively. The results were significantlybetter in the TACE+MLT group than in the TACEgroup. MLT could protect liver function from thedamage caused by TACE. The IL-2 levels of all pa-tients significantly increased, whereas sIL-2R expres-sions decreased after TACE+MLT as compared withthe TACE group (P【0.01).Conclusions: With definite protection and treatmenteffect on the liver function damage caused by TACE,MLT can enhance the immunological activities of pa-tients. It also can improve the effect of TACE by in-creasing the survival and resection rate after two-stage operation.

Spectral matching algorithm based on nonsubsampled contourlet transform and scale-invariant feature transform

A new spectral matching algorithm is proposed by using nonsubsampled contourlet transform and scale-invariant feature transform.The nonsubsampled contourlet transform is used to decompose an image into a low frequency image and several high frequency images,and the scale-invariant feature transform is employed to extract feature points from the low frequency image.A proximity matrix is constructed for the feature points of two related images.By singular value decomposition of the proximity matrix,a matching matrix(or matching result) reflecting the matching degree among feature points is obtained.Experimental results indicate that the proposed algorithm can reduce time complexity and possess a higher accuracy.

A multi-channel chemical sensor and its application in detecting hydrothermal vents

There are well-established chemical and turbidity anomalies in the plumes occurring vicinity of hydrothermal vents, which are used to indicate their existence and locations. We here develop a small, accurate multi-channel chemical sensor to detect such anomalies which can be used in deep-sea at depths of more than 4 000 m. The design allowed five all-solid-state electrodes to be mounted on it and each (apart from one reference electrode) could be changed according to chemicals to be measured. Two experiments were conducted using the chemical sensors. The first was a shallow-sea trial which included sample measurements and in situ monitoring. pH, Eh, CO3^2- and SO4^2- electrodes were utilized to demonstrate that the chemical sensor was accurate and stable outside the laboratory. In the second experiment, the chemical sensor was integrated with pH, Eh, CO3^2- and H2S electrodes, and was used in 29 scans of the seabed along the Southwest Indian Ridge (SWIR) to detect hydrothermal vents, from which 27 sets of valid data were obtained. Hydrothermal vents were identified by analyzing the chemical anomalies, the primary judging criteria were decreasing voltages of Eh and H2S, matched by increasing voltages of pH and CO3^2- . We proposed that simultaneous detection of changes in these parameters will indicate a hydrothermal vent. Amongst the 27 valid sets of data, five potential hydrothermal vents were targeted using the proposed method. We suggest that our sensors could be widely employed by marine scientists.

A Novel Protein Found in Selenium-rich Silkworm Pupas

A novel protein was isolated and characterized in selenium-rich silkworm pupas. The peptide mass fingerprint of the protein was found to be new. Partial amino acid sequencing also confirmed to be a new protein. The novel protein had a molecular mass of about 80 kDa in the SDS-PAGE.

Synthesis and superconductivity in yttrium superhydrides under high pressure

Flourishing rare earth superhydrides are a class of recently discovered materials that exhibit near-room-temperature superconductivity at high pressures,ushering in a new era of superconductivity research at high pressures.Yttrium superhydrides drew the most attention among these superhydrides due to their abundance of stoichiometries and excellent superconductivities.Here,we carried out a comprehensive study of yttrium superhydrides in a wide pressure range of 140 GPa-300 GPa.We successfully synthesized a series of superhydrides with the compositions of YH_(4),YH_(6),YH_(7),and YH_(9),and reported superconducting transition temperatures of 82 K at 167 GPa,218 K at 165 GPa,29 K at 162 GPa,and230 K at 300 GPa,respectively,as evidenced by sharp drops in resistance.The structure and superconductivity of YH_(4) were taken as a representative example and were also examined using x-ray diffraction measurements and the superconductivity suppression under external magnetic fields,respectively.Clathrate YH_(10),a candidate for room-temperature superconductor,was not synthesized within the study pressure and temperature ranges of up to 300 GPa and 2000 K.The current study established a detailed foundation for future research into room-temperature superconductors in polynary yttrium-based superhydrides.

Application Study on Rigidity Correlation Method for Density Inversion of Rockfill

Based on the theoretical model of rigidity correlation method, the study on application was carried out with Chinese Liyuan face rockfill dam as example. The linear relation equations between the rockfill rigidity and density measured by pit method were established, and the regression performance and accuracy of rigidity correlation method were analyzed by calculating the inversion values of density. The results show that the regression equations of rigidity correlation method are high significant so as to work out the rockfill density precisely;rigidity correlation method is used for density inversion of rockfill with minor error and namely high accuracy, which is proper with satisfactory results.

Exploring the effect of Radix Bupleuri(Bupleurum chinense DC)on nonalcoholic fatty liver disease based on network pharmacology

Objective:To investigate the main effects of Radix Bupleuri(Chinese name called Chai Hu)in the prevention and improvement of nonalcoholic fatty liver disease using network pharmacology techniques.Methods:We used theTraditional Chinese Medicine Systematic Pharmacologydatabase to query the main active ingredients of Radix Bupleuri;used theDisGenet database,Treatment Target Database,and DrugBank Database to screen the targets of nonalcoholic fatty liver disease;used the matchingtraditional Chinese medicine-disease targets to build the traditional Chinese medicine-component-target network system using Cytoscape software;used STRING software to build the protein protein interactionsystem and visualized the data;DAVID database was used forgene ontologyfunctional enrichment study andKyoto Encyclopedia of Genes and Genomespathway study.Results:Twelve major functional components and 175 targets have been obtained for the prevention and alleviation of nonalcoholic fatty liver disease in Radix Bupleuri;network pharmacology also confirmed the maximum degree value of kaempferol,the main active component of Radix Bupleuri;geneontologyfunctional enrichment analysis obtained the top 10 entries ofbiological process,cellular component,molecular functionand Kyoto Encyclopedia of Genes and Genomespathway analysis obtained the top 30 entries of the signalling pathway.Conclusion:Radix Bupleuri may use Fluid shear stress and atherosclerosis,Cancer,Advanced glycation end-(receptor of advanced glycation,interleukin 17,Hepatitis B,Toxoplasmosis,Relaxin,andtumor necrosis factorsignalling pathway to regulate the inflammatory response of interleukin6,tumor necrosis factor,and prostaglandin endoperoxide synthase2targets and reduce extracellular matrix deposition to improve the therapeutic effect of Nonalcoholic fatty liver disease.And the active ingredient of traditional Chinese medicine Radix Bupleuri,kaempferol,may also play a significant role in this.

Liver resection versus liver transplantation for hepatocellular carcinoma within the Milan criteria based on estimated microvascular invasion risks

Background:Preoperative prediction of microvascular invasion(MVI)in hepatocellular carcinoma(HCC)may optimize individualized treatment decision-making.This study aimed to investigate the prognostic differences between HCC patients undergoing liver resection(LR)and liver transplantation(LT)based on predicted MVI risks.Methods:We analysed 905 patients who underwent LR,including 524 who underwent anatomical resection(AR)and 117 who underwent LT for HCC within the Milan criteria using propensity score matching.A nomogram model was used to predict preoperative MVI risk.Results:The concordance indices of the nomogram for predicting MVI were 0.809 and 0.838 in patients undergoing LR and LT,respectively.Based on an optimal cut-off value of 200 points,the nomogram defined patients as high-or low-risk MVI groups.LT resulted in a lower 5-year recurrence rate and higher 5-year overall survival(OS)rate than LR among the high-risk patients(23.6%vs 73.2%,P<0.001;87.8%vs 48.1%,P<0.001)and low-risk patients(19.0%vs 45.7%,P<0.001;86.5%vs 70.0%,P=0.002).The hazard ratios(HRs)of LT vs LR for recurrence and OS were 0.18(95%confidence interval[CI],0.09–0.37)and 0.12(95%CI,0.04–0.37)among the high-risk patients and 0.37(95%CI,0.21–0.66)and 0.36(95%CI,0.17–0.78)among the low-risk patients.LT also provided a lower 5-year recurrence rate and higher 5-year OS rate than AR among the high-risk patients(24.8%vs 63.5%,P=0.001;86.7%vs 65.7%,P=0.004),with HRs of LT vs AR for recurrence and OS being 0.24(95%CI,0.11–0.53)and 0.17(95%CI,0.06–0.52),respectively.The 5-year recurrence and OS rates between patients undergoing LT and AR were not significantly different in the low-risk patients(19.4%vs 28.3%,P=0.129;85.7%vs 77.8%,P=0.161).Conclusions:LT was superior to LR for patients with HCC within the Milan criteria with a predicted high or low risk of MVI.No significant differences in prognosis were found between LT and AR in patients with a low risk of MVI.

Effects of light intensity and photoperiod on the growth and stress response of juvenile Nile tilapia(Oreochromis niloticus)in a recirculating aquaculture system

Light is an essential natural factor of fish growth and development.A light regime in indoor aquaculture is critical for sustainable fish production.This research aimed to investigate the effect of light intensity and photoperiod on the growth performance and stress response of Nile tilapia(Oreochromis niloticus),which is an important commercial species,in a recirculating aquaculture system(RAS).Fingerlings with an average weight of 5±0.9 g were randomly assigned to nine 1.5 m3 tanks with 145 fish in each tank,cultured under different light intensities(1000,2000,and 3000 lx)and photoperiods(12L:12D,18L:6D,24L:0D),and fed to apparent satiation twice a day for 160 days.The growth of tilapia subjected to 2000 lx was significantly better than that exposed to 1000 and 3000 lx(P<0.05)as indicated by the final weight(351.17±10.59 g),growth efficiency(0.77±0.26),specific growth rate(2.65%±0.21%per day)and feed conversion coefficient ratio(1.30±0.36).No significant difference was observed in the growth rate among different photoperiod groups(P>0.05).Light intensity and photoperiod manipulation did not cause a significant chronic stress response in tilapia.This study demonstrated that light intensity,especially at 2000 lx,and photoperiod manipulation could stimulate the growth of tilapia in the RAS and significantly affect economic profitability.This study also served as an important reference for tilapia indoor aquaculture.

Why Do Chinese Private Enterprises Seek Outward Foreign Direct Investment?

China is currently in a period of economic transformation and the reform of the factor market still lags behind that of the product market.This study explores the reasons causing China's private enterprise to expand abroad from the perspective of domestic factor market imperfection.Using data for Chinese listed firms between 2002 and 2020,it examines whether outward foreign direct investment(OFDI)has been undertaken by private enterprises as a response to domestic factor market imperfection.It finds that private enterprises located in regions with greater factor market imperfection have had a greater tendency to engage in OFDI.This effect has been more pronounced among firms with high productivity or high innovation capability,and among medium and small private enterprises.

Multi-Objective Optimization of Aluminum Alloy Electric Bus Frame Connectors for Enhanced Durability

The widespread adoption of aluminumalloy electric buses,known for their energy efficiency and eco-friendliness,faces a challenge due to the aluminum frame’s susceptibility to deformation compared to steel.This issue is further exacerbated by the stringent requirements imposed by the flammability and explosiveness of batteries,necessitating robust frame protection.Our study aims to optimize the connectors of aluminum alloy bus frames,emphasizing durability,energy efficiency,and safety.This research delves into Multi-Objective Coordinated Optimization(MCO)techniques for lightweight design in aluminum alloy bus body connectors.Our goal is to enhance lightweighting,reinforce energy absorption,and improve deformation resistance in connector components.Three typical aluminum alloy connectors were selected and a design optimization platform was built for their MCO using a variety of software and methods.Firstly,through three-point bending experiments and finite element analysis on three types of connector components,we identified optimized design parameters based on deformation patterns.Then,employing Optimal Latin hypercube design(OLHD),parametric modeling,and neural network approximation,we developed high-precision approximate models for the design parameters of each connector component,targeting energy absorption,mass,and logarithmic strain.Lastly,utilizing the Archive-based Micro Genetic Algorithm(AMGA),Multi-Objective Particle Swarm Optimization(MOPSO),and Non-dominated SortingGenetic Algorithm(NSGA2),we explored optimized design solutions for these joint components.Subsequently,we simulated joint assembly buckling during bus rollover crash scenarios to verify and analyze the optimized solutions in three-point bending simulations.Each joint component showcased a remarkable 30%–40%mass reduction while boosting energy absorption.Our design optimization method exhibits high efficiency and costeffectiveness.Leveraging contemporary automation technology,the design optimization platform developed in this study is poised to facilitate intelligent optimization of lightweight metal components in future applications.