Backward scattering of laser plasma interactions from hundreds-of-joules broadband laser on thick target

The use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions(LPIs).In this study,several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser facility.Through direct comparison with LPI results for a traditional narrowband laser,the actual LPI-suppression effect of the broadband laser is shown.The broadband laser had a clear suppressive effect on both back-stimulated Raman scattering and back-stimulated Brillouin scattering at laser intensities below 1×10^(15) W cm^(−2).An abnormal hot-electron phenomenon is also investigated,using targets of different thicknesses.

Machine learning for parameters diagnosis of spark discharge by electro-acoustic signal

Discharge plasma parameter measurement is a key focus in low-temperature plasma research.Traditional diagnostics often require costly equipment,whereas electro-acoustic signals provide a rich,non-invasive,and less complex source of discharge information.This study harnesses machine learning to decode these signals.It establishes links between electro-acoustic signals and gas discharge parameters,such as power and distance,thus streamlining the prediction process.By building a spark discharge platform to collect electro-acoustic signals and implementing a series of acoustic signal processing techniques,the Mel-Frequency Cepstral Coefficients(MFCCs)of the acoustic signals are extracted to construct the predictors.Three machine learning models(Linear Regression,k-Nearest Neighbors,and Random Forest)are introduced and applied to the predictors to achieve real-time rapid diagnostic measurement of typical spark discharge power and discharge distance.All models display impressive performance in prediction precision and fitting abilities.Among them,the k-Nearest Neighbors model shows the best performance on discharge power prediction with the lowest mean square error(MSE=0.00571)and the highest R-squared value(R^(2)=0.93877).The experimental results show that the relationship between the electro-acoustic signal and the gas discharge power and distance can be effectively constructed based on the machine learning algorithm,which provides a new idea and basis for the online monitoring and real-time diagnosis of plasma parameters.

Incidence,Risk Factors,and Prognosis of Patients with Hepatocellular Carcinoma and Brain Metastases

Objective Brain metastases significantly impact the clinical course of patients with hepatocellular carcinoma(HCC).This study aimed to examine the age-related incidence,demographics,and survival of patients with HCC and brain metastases.Methods Data of HCC patients from 2010 to 2015 in the Surveillance,Epidemiology,and End Results(SEER)Registry were screened for the presence of brain metastases.They were stratified by age and ethnicity.Multivariable logistic and Cox regression analyses were used to identify factors associated with brain metastases and those with overall survival(OS)and liver cancer-specific survival(CSS),respectively.Results A total of 141 HCC patients presenting with brain metastases were identified,accounting for 0.35% of all HCC patients and 2.37% of patients with metastatic disease.Among all HCC patients,the incidence rate was the highest among patients aged 30-49 years old(0.47%).Ethnicity was not associated with the presence of brain metastases at the time of HCC diagnosis.However,African-American patients presented with a significantly lower disease-specific survival[median time:1 month;interquartile range(IQR):0-3.0 months].Initial lung or bone metastasis was independently associated with an increased risk of the presence of brain metastases[odds ratio(OR):12.62,95% confidence interval(CI):8.40-18.97]but was not associated with a worse OS or CSS among those with brain metastases.Conclusion This study identified the age-related incidence and risk factors of brain metastases in HCC patients.These results may contribute to the consideration of brain screening among patients with initial metastatic HCC with lung or bone metastases,and influence the counseling of this patient population regarding their prognosis.

Direct observation of shock-induced phase transformation in polycrystalline iron via in situ x-ray diffraction

Phase transition of polycrystalline iron compressed along the Hugoniot is studied by combining laser-driven shock with in situ x-ray diffraction technique.It is suggested that polycrystalline iron changes from an initial body-centered cubic structure to a hexagonal close-packed structure with increasing pressure(i.e.,a phase transition fromαtoε).The relationship between density and pressure for polycrystalline iron obtained from the present experiments is found to be in good agreement with the gas-gun Hugoniot data.Our results show that experiments with samples at lower temperatures under static loading,such as in a diamond anvil cell,lead to higher densities measured than those found under dynamic loading.This means that extrapolating results of static experiments may not predict the dynamic responses of materials accurately.In addition,neither the face-centered cubic structure seen in previous molecular-dynamics simulations or twophase coexistence are found within our experimental pressure range.

Spectral characteristics of laser-plasma instabilities with a broadband laser

Recent experimental progresses regarding broadband laser-plasma instabilities(LPIs)show that a 0.6%laser bandwidth can reduce backscatters of the stimulated Brillouin scattering(SBS)and the stimulated Raman scattering(SRS)at normal incidence[Phys.Rev.Lett.132035102(2024)].In this paper,we present a further discussion of the spectral distributions of the scatters developed by broadband LPIs,in addition to a brief validation of the effectiveness of bandwidth on LPIs mitigation at oblique incidence.SBS backscatter has a small redshift in the broadband case contrary to the blueshift with narrowband laser,which may be explained by the self-cross beam energy transfer between the various frequency components within the bandwidth.SRS backscatter spectrum presents a peak at a longer wavelength in the broadband case compared to the short one in the narrowband case,which is possibly attributed to the mitigation effect of bandwidth on filaments at underdense plasmas.The three-halves harmonic emission(3ω/2)has a one-peak spectral distribution under the broadband condition,which is different from the two-peak distribution under the narrowband condition,and may be related to the spectral mixing of different frequency components within the bandwidth if the main sources of the two are both two-plasmon decays.

机械共混法制备改性多层氧化石墨烯/天然橡胶复合材料及其性能

采用含硫硅烷偶联剂(双-(γ-三乙氧基硅基丙基)四硫化物,Si69)改性多层氧化石墨烯(MGO),制备出改性多层氧化石墨烯(SMGO),并采用红外光谱、紫外光谱、扫描电镜对其进行表征分析。进一步利用机械共混法制备出SMGO/NR复合材料,研究了复合材料的力学性能、动态内耗性能,并与MGO/NR复合材料进行对比。结果表明,Si69成功接枝到MGO上;相比纯胶,当添加2phr SMGO时,复合材料的拉伸性能提高57%,tanδ值降低21.4%。

Hexagonal boron nitride adsorbent: Synthesis, performance tailoring and applications

Hexagonal boron nitride(h-BN),with unique structural and properties,has shown enormous potentitoward variety of possible applications.By virtue of partially-ionic character of BN chemical bonds anusually large specific surface area,h-BN-related nanostructures exhibit appealing adsorption propertiewhich can be widely applied for separation and purification towards energy and environment treatmenIn this review,recent progress in designing h-BN micro,nano-structure,controlled synthesis,performancoptimizing as well as energy and environment-related adsorption applications are summarized.Strategieto tailor the h-BN can be classified as morphology control,element doping,defect control and surfacmodification,focusing on how to optimize the adsorption performance.In order to insight the intrinsimechanism of tuning strategies for property optimization,the significant adsorption applications of h-Btowards hydrogen storage,CO2 capture,pollutants removal from water and adsorption desulfurization arpresented.

CO selective methanation in hydrogen-rich gas mixtures over carbon nanotube supported Ru-based catalysts

Series of carbon nanotube supported Ru-based catalysts were prepared by impregnation method and applied successfully for complete removal of CO by CO selective methanation from H2-rich gas stream conducted in a fixed-bed quartz tubular reactor at ambient pressure. It was found that the metal promoter, reduction temperature and metal loading affected the catalytic properties significantly. The most excellent performance was presented by 30 wt% Ru-Zr/CNTs catalyst reduced at 350 ℃. Since it decreased CO concentration to below 10 ppm from 12000 ppm by CO selective methanation at the temperature range of 180-240 ℃, and kept CO selectivity higher than 85% at the temperature below 200 ℃. Characterization using XRD, TEM, H2-TPR and XPS suggests that Zr modification of Ru/CNTs results in the weakening of the interaction between Ru and CNTs, a higher Ru dispersion and the oxidization of surface Ru. Amorphous and high dispersed Ru particles with small size were obtained for 30 wt% Ru-Zr/CNTs catalyst reduced at 350 ℃, leading to excellent catalytic performance in CO selective methanation.

Determination of Surface Roughness in Wire and Arc Additive Manufacturing Based on Laser Vision Sensing

Wire and arc additive manufacturing(WAAM) shows a great promise for fabricating fully dense metal parts by means of melting materials in layers using a welding heat source. However, due to a large layer height produced in WAAM, an unsatisfactory surface roughness of parts processed by this technology has been a key issue. A methodology based on laser vision sensing is proposed to quantitatively calculate the surface roughness of parts deposited by WAAM.Calibrations for a camera and a laser plane of the optical system are presented. The reconstruction precision of the laser vision system is verified by a standard workpiece. Additionally, this determination approach is utilized to calculate the surface roughness of a multi-layer single-pass thin-walled part. The results indicate that the optical measurement approach based on the laser vision sensing is a simple and effective way to characterize the surface roughness of parts deposited by WAAM. The maximum absolute error is less than 0.15 mm. The proposed research provides the foundation for surface roughness optimization with different process parameters.

Spontaneous rupture of hepatocellular carcinoma: a retrospective study of 87 patients in a teaching hospital

Objective: The aim of the study was to review the management of ruptured hepatocellular carcinoma (HCC) in a single teaching hospital over 13-year period; to determine the prognostic factor of in-hospital mortality and evaluate the safety and efficacy of liver resection. Methods: A retrospective collection of medical records of 87 patients with spontaneous ruptured HCC was carried out. The 28 patients underwent emergency intervention including transarterial chemoembolization (TACE) and laparotomy with/without liver resection. Conservative treatment was performed in 59 patients and 16 of which underwent delayed hepatectomy or TACE. Results: The overall in-hospital mortality and median survival time was 54% and 22 days respectively. Albumin level (OR = 0.874, 95% CI: 0.778-0.973, P = 0.024), number of tumors (OR = 5.011, 95% CI: 1.015-24.750, P = 0.048) and laparotomy (OR = 0.069, 95% CI: 0.012-0.406, P = 0.003) were all independent factors affecting overall in-hospital mortality, but for patients undergone laparotomy, only total bilirubin level (OR = 1.138, 95% CI: 1.024-1.264, P = 0.016) was independent factor affecting overall in-hospital mortality. Age, total bilirubin level, maximum tumor size, number of tumors, portal vein tumor thrombosis and extra-hepatic metastasis were all significantly different between groups with laparotomy and without. There were no significant differences between emergency and delayed liver resection groups in in-hospital mortality (0 vs. 0), median survival time (788 vs. 750 days respectively) as well as 1-year and 3-year survival rates (66.7%, 44.4% vs. 70%, 30%, respectively) (P = 0.763, log-rank test). Conclusion: Both underlying chronic liver disease and tumor stage can affect the in-hospital mortality, but for patients undergone laparotomy, only total bilirubin level is independent factor. Surgeons are more prone to choose patients with younger age, better liver function and earlier tumor stage to do surgery. In well selected patients, both emergency and delayed liver resections are safe and could achieve prolonged survival.

Whole exome sequencing identifies an AMBN missense mutation causing severe autosomal-dominant amelogenesis imperfecta and dentin disorders

Tooth development is a complex process that involves precise and time-dependent orchestration of multiple genetic, molecular,and cellular interactions. Ameloblastin(AMBN, also named "amelin" or "sheathlin") is the second most abundant enamel matrix protein known to have a key role in amelogenesis. Amelogenesis imperfecta(AI [MIM: 104500]) refers to a genetically and phenotypically heterogeneous group of conditions characterized by inherited developmental enamel defects. The hereditary dentin disorders comprise a variety of autosomal-dominant genetic symptoms characterized by abnormal dentin structure affecting either the primary or both the primary and secondary teeth. The vital role of Ambn in amelogenesis has been confirmed experimentally using mouse models. Only two cases have been reported of mutations of AMBN associated with non-syndromic human AI. However, no AMBN missense mutations have been reported to be associated with both human AI and dentin disorders.We recruited one kindred with autosomal-dominant amelogenesis imperfecta(ADAI) and dentinogenesis imperfecta/dysplasia characterized by generalized severe enamel and dentin defects. Whole exome sequencing of the proband identified a novel heterozygous C-T point mutation at nucleotide position 1069 of the AMBN gene, causing a Pro to Ser mutation at the conserved amino acid position 357 of the protein. Exfoliated third molar teeth from the affected family members were found to have enamel and dentin of lower mineral density than control teeth, with thinner and easily fractured enamel, short and thick roots, and pulp obliteration. This study demonstrates, for the first time, that an AMBN missense mutation causes non-syndromic human AI and dentin disorders.

Research on Simulation Methods of Electric Field Intensity on Surface of 10 kV Cable Joint

The electric field intensity (EFI) is important characteristic quantity for evaluating the internal insulation state of cable joints. Based on finite element method, this paper proposes two EFI research methods, field-circuit coupling method and equivalent circuit method. The average EFI of the inner surface of the outer semi-conducting shield can be calculated from the current in the measuring circuit. The relative error between these two methods is about 15%, which roughly proves the consistency of the two methods. Further practical application research enables online monitoring of cable joints.

Rupture of hepatocellular carcinoma following transarterial embolization/chemoembolization: two cases report and systematic review

Objective: Rupture of hepatocellular carcinoma (HCC) following transarterial embolization/chemoembolization (TAE/TACE) is a rare but life-threatening complication. The aim of the study was to explore the incidence, risk factors, clinical characteristics, treatment, and outcomes of this complication. Methods: We described two cases and reviewed all cases of ruptured HCC after TAE/TACE reported in the literature. Results: Our search yielded 32 cases of ruptured HCC after TAE/TACE. The overall incidences were 0.45% per patient and 0.21% per session. The mean age of the patients was 57.4 years (range 28-90 years, n=26, No. of cases with available information). Males accounted for 81% of cases (21/26). The 50% of the cases had histories of primary hypertension, diabetes or peripheral artery disease (6/12). Mean diameter of the tumors was 11.4 cm (range 3-20 cm, n=27). The 100% of cases had superficial or exophytic tumors (23/23). Portal vein thrombosis was presented in 61.5% of patients (8/13). The median interval between TAE/TACE and rupture was 2 days (range 0 hour-30 days, n=31). Management choices included emergency TAE, surgery, and conservative treatment. The overall median survival time was 7 days (n=19). Conclusion: Rupture of HCC following TAE/TACE is relatively rare but potentially life-threatening. The management is difficult and prognosis is poor. Large tumor size, superficial or exophytic tumors as well as portal vein thrombosis and comorbidities such as primary hypertension, diabetes or peripheral artery disease may be predisposing factors for rupture.

Status and Development Strategies of Grassland Agriculture: A Case Study of Dafang County

In order to better promote the development of grassland husbandry in the Bijie experimental area and promote industrial poverty alleviation and rural revitalization strategies,the development status of grassland agriculture in developed countries( USA,Netherlands and France) and China is summarized. By learning from the successful experience of grassland agricultural development at home and abroad,combined with the survey results of grassland agriculture in Dafang County of Bijie experimental area,the development of grassland agriculture in Dafang County of Bijie experimental area is analyzed,and corresponding development strategies are put forward.

Glucose Metabolic Alteration of Cerebral Cortical Subareas in Rats with Renal Ischemia/Reperfusion Based on Small-Animal Positron Emission Tomography

Objective:To investigate glucose metabolic alterations in cerebral cortical subareas using ^(18)F-labeled glucose derivative fluorodeoxyglucose(FDG)micro-positron emission tomography(PET)scanning in a rat renal ischemia/reperfusion(RIR)model.Methods:Small-animal PET imaging in vivo was performed with ^(18)F-labeled FDG as a PET tracer to identify glucose metabolic alterations in cerebral cortical subregions using a rat model of RIR.Results:We found that the average standardized uptake value(SUV_(average))of the cerebral cortical subareas in the RIR group was significantly increased compared to the sham group(P<0.05).We also found that glucose uptake in different cortical subregions including the left auditory cortex,right medial prefrontal cortex,right para cortex,left retrosplenial cortex,right retrosplenial cortex,and right visual cortex was significantly increased in the RIR group(P<0.05),but there was no significant difference in the SUV_(avcrage) of right auditory cortex,left medial prefrontal cortex,left para cortex,and left visual cortex between the two groups.Conclusion:The ^(18)F-FDG PET data suggests that RIR causes a profound shift in the metabolic machinery of cerebral cortex subregions.

Specific Patterns of Spinal Metabolite Ratio Underlying a-Me-5-HTevoked Pruritus Compared with Compound 48/80 Based on Proton Nuclear Magnetic Resonance Spectroscopy

Summary:Mechanisms of pruritus are implicated in the dysregulation of the metabolites in the spinal cord.We investigated pruritus behavioral testing in three groups of young adult male C57B1/6 mice,including one group treated with normal saline,while the other groups intradermally injected with a-Me-5-HT(histamine-independent pruritogen),compound 48/80(histaminedependent pruritogen)at the nape skin of the neck,respectively.Proton nuclear magnetic resonance spectroscopy(MRS)was used to compare spinal metabolites from the vertebral cervical among three groups,and to study the association of spinal metabolite ratio and pruritus intensity.The MRS-measured N-acetylaspartate-to-myoinositol ratio(NAA/Ins)was significantly correlated with the number of scratches between normal saline group and 48/80 group or a-Me-5-HT group(both P<0.0001),indicating that NAA/Ins may be a robust surrogate marker of histamine-independent/dependent pruritogen.There was significant difference in Glu/Ins between normal saline group and 48/80 group(P=0.017),indicating that Glu/Ins may be a surrogate marker of histamine-dependent pruritogen,while GABA/Ins was highly significantly different between normal saline group and a-Me-5-HT group(P=0.008),suggesting that GABA/Ins may be a surrogate marker of histamineindependent pruritogen.MRS may reflect the extent of pruritus intensity elicited by a-Me-5-HT and compound 48/80 with sensitivity similar to the number of scratches,and above potential markers need to be further validated in pre-clinical and clinical treatment trials.

Engineering Dual Oxygen Simultaneously Modified Boron Nitride for Boosting Adsorptive Desulfurization of Fuel

Oxygen atoms usually co-exist in the lattice of hexagonal boron nitride(h-BN). The understanding of interactions between the oxygen atoms and the adsorbate, however, is still ambiguous on improving adsorptive desulfurization performance. Herein, simultaneously oxygen atom-scale interior substitution and edge hydroxylation in BN structure were constructed via a polymer-based synthetic strategy.Experimental results indicated that the dual oxygen modified BN(BN–2O) exhibited an impressively increased adsorptive capacity about 12% higher than that of the edge hydroxylated BN(BN–OH) fabricated via a traditional method. The dibenzothiophene(DBT) was investigated to undergo multimolecular layer type coverage on the BN–2O uneven surface via π–π interaction, which was enhanced by the increased oxygen doping at the edges of BN–2O. The density functional theory calculations also unveiled that the oxygen atoms confined in BN interior structure could polarize the adsorbate, thereby resulting in a dipole interaction between the adsorbate and BN–2O. This effect endowed BN–2O with the ability to selectively adsorb DBT from the aromatic-rich fuel, thereafter leading to an impressive prospect for the adsorptive desulfurization performance of the fuel. The adsorptive result was in good accordance with Freundlich and pseudo-second-order adsorption kinetics model results. Therefore, the designing of a polymer-based strategy could be also extended to other heteroatom doping systems to enhance adsorptive performance.

Enhancing the cycling stability of Na-ion batteries by bonding MoS2 on assembled carbon-based materials

Room temperature Na-ion batteries(SIBs) show great potential for use as renewable energy storage systems.However, the large-scale application of SIBs has been hindered by the lack of an ideal SIBs anode material. We synthesized MoS2 on carbonized graphene-chitosan(G-C) using the hydrothermal method. The strong interaction between the MoS2 and the G-C greatly improved the electron transport rate and maintained the structural stability of the electrode, which lead to both an excellent rate capability and long cycle stability. The G-C monolith was proven to enhance the electrical conductivity of the composites and served as a matrix for uniformly dispersing active MoS2 nanosheets(NSs), as well as being a buffer material to adapt to changes in volume during the cycle.Serving as an anode material for SIBs, the MoS2-G-C electrode showed good cycling stability(527.3mAh g-1 at100 m A g-1 after 200 cycles), excellent rate capability, and a long cycle life(439.1 m Ah g-1 at 1 A g-1 after 200 cycles).

Nonlinear Switching Transient Field Simulation of Cable Joint without Residual Charge

The analysis of the impulse voltage on the internal electric field of the cable joint plays a key role in studying the breakdown of the joint. Based on the finite element method, a three-dimensional electromagnetic field simulation model of the cable joint is established in this paper. Simulation results show that the voltage at the head of the cable joint reaches about twice the impulse voltage. The increase of the conductivity of semi-conductive material also leads to the increase of electric field intensity. Then, several points and curves at different positions are selected for further analysis in this paper. Among them, the electric field distortion at the edge of the high voltage shield is the most serious and the electric field in the air gap is the least.

Secure Communications for Two-Way Relay Networks Via Relay Chatting

In this paper, we investigate a two-way relay network consisting of two sources, multiple cooperative relays and an eavesdropper. To enhance secure communications, a new relay chatting based on transmission scheme is proposed. Specifically, the proposed scheme selects a best relay that maximize the sum mutual information among the sources to forward the sources’ signals using an amplify-and-forward protocol, and the remaining relays transmit interference signals to confuse the eavesdropper via distributed beam forming. It can be found that the proposed scheme with relay chatting does not require the knowledge of the eavesdropper’s channel, and outperforms the joint relay and jammer selection scheme, which introduces the interference into the sources. Numerical results show that the secrecy outage probability of the proposed scheme converges to zero as the transmit power increases.