Compact intense electron-beam accelerators based on high energy density liquid pulse forming lines

This paper provides a review of the compact intense electron-beam accelerators (IEBAs) based on liquid pulse forming lines (PFLs) that havebeen developed at the National University of Defense Technology (NUDT) in China. The history and roadmap of the compact IEBAs used todrive high-power microwave (HPM) devices at NUDT are reviewed. The properties of both de-ionized water and glycerin as energy storagemedia are presented. Research into the breakdown properties of liquid dielectrics and the desire to maximize energy storage have resulted in theinvention of several coaxial PFLs with different electromagnetic structures, which are detailed in this paper. These high energy density liquidPFLs have been used to increase the performance of IEBA subsystems, based on which the SPARK (Single Pulse Accelerator with spark gaps)and HEART (High Energy-density Accelerator with Repetitive Transformer) series of IEBAs were constructed. This paper also discusses howthese compact IEBAs have been used to drive typical HPM devices and concludes by summarizing the associated achievements and theconclusions that can be drawn from the results.

An early screening model of pulse detection technology for hepatic steatosis

Background The increasing prevalence of hepatic steatosis presents a considerable challenge to public health.There is a critical need for the development of novel preventive and screening strategies for this condition.Thisstudy evaluated the potential applications of wrist pulse detection technology for the early detection of liverdiseases.The pulse time-domain features of a medical exam population with and without hepatic steatosis wereassessed to develop a screening model for this disease.Methods Participants were consecutively recruited from March 2021 to March 2022 in the medical examinationcenters of the Yueyang Hospital of Integrated Traditional Chinese and Western Medicine and the Shanghai Municipal Hospital of Traditional Chinese Medicine.Clinical data from 255 participants,including general information(sex,age,and body mass index),and data related to glucose and blood lipids(fasting plasma glucose,triglyceride,total cholesterol,high-density lipoprotein,and low-density lipoprotein levels)were collected.Wrist pulse signalswere acquired using a pulse detection device,and the pulse time-domain features,including t_(1),t_(4),t_(5),T,w_(1),w_(2),h_(2)/h_(1),h_(3)/h_(1),and h5/h_(1) were extracted.Participants were assigned to hepatic steatosis and non-hepatic steatosisgroups according to their abdominal ultrasound examination results.Their clinical data and pulse time-domainfeatures were compared using chi-square and parametric or non-parametric statistical methods.Three datasetswere used to construct screening models for hepatic steatosis based on the random forest algorithm.The datasetsfor modeling were defined as Dataset 1,containing blood glucose and lipid data and general information;Dataset2,containing time-domain features and general information;Dataset 3,containing time-domain features,bloodglucose and lipid data,and general information.The evaluation metrics,accuracy,precision,recall,F1-score,andareas under the receiver operating characteristic curve(AUC)were compared for each model.Results The time-domain features of the two groups differed significantly.The t_(1),t_(4),t_(5),T,h_(2)/h_(1),h_(3)/h_(1),w_(1),and w_(2) features were higher in the hepatic steatosis group than in the non-hepatic steatosis group(P<0.05),while the h5/h_(1) features were lower in the hepatic steatosis group than in the non-hepatic steatosis group(P<0.05).The screening models for hepatic steatosis based on both time-domain features and blood glucose andlipid data outperformed those based on time-domain features or blood markers alone.The accuracy,precision,recall,F1-score,and AUC of the combined model were 81.18%,80.56%,76.32%,79%,and 87.79%,respectively.These proportions were 1.57%,1.86%,1.76%,2%,and 3.54%higher,respectively,than those of the model basedon time-domain features alone and 3.14%,4.2%,2.64%,4%,and 6.47%higher,respectively,than those of themodel based on blood glucose and lipid alone.Conclusion The early screening model for hepatic steatosis using datasets that included pulse time-domainfeatures achieved better performance.The findings suggest that pulse detection technology could be used toinform the development of a mobile medical device or remote home monitoring system to test for hepatitissteatosis.

Comparative study of objective visual quality between FS-LASIK and SMART in myopia

AIM:To compare the changes in the objective visual quality of patients with low and moderate myopia postoperatively after transepithelial photorefractive keratectomy using the smart pulse technology(SMART)and femtosecond laser in situ keratomileusis(FS-LASIK).METHODS:Corneal higher-order aberrations(HOAs),horizontal coma,vertical coma and spherical aberration were measured using Pentacam,and cutoff for modulation transfer function(MTF cutoff),objective scatter index(OSI)and Strehl ratio(SR)was measured using an optical quality analysis system(OQAS-II),before and after operation at 1,3,and 6 mo,and data were analyzed by repeated measurement two-way analysis of variance.RESULTS:The difference in uncorrected distance visual acuity between SMART and FS-LASIK was statistically significant only 1 wk postoperatively.Approximately 86.36%and 80.69%of patients with spherical equivalent(SE)in±0.50 D were observed in the SMART and FS-LASIK groups,respectively.No significant difference was observed in SE between the two groups(P=0.509).The HOAs increased postoperatively compared with those before surgery in both groups(P<0.05).No significant difference in HOA,corneal horizontal coma,spherical aberration,ΔHOA,Δhorizontal coma,andΔspherical aberration were observed between the two group(P>0.05).Corneal vertical coma andΔcorneal vertical coma in the FS-LASIK group were higher than those in the SMART group(P<0.05).The OSI of both groups at 1 mo after surgery was higher than that before surgery(P<0.05).At 3 and 6 mo postoperatively,the OSI in the FS-LASIK group was slightly higher than that in the SMART group(P=0.040 and 0.047,respectively).At 6 mo after surgery,the MTF cutoff was statistically significant different between the two groups(P=0.026).No significant difference in SR between the FS-LASIK and SMART groups was observed at 1,3,and 6 mo postoperatively(P>0.05).CONCLUSION:The HOAs increase and visual quality is delayed in both groups postoperatively,and the long-term objective visual quality after SMART is slightly better than that after FS-LASIK.

Measurements ofthe 197Au(n, γ) crosssectionupto100keV at the CSNSBack-nfacility

The neutron capture cross section of 197 Au was measured using the time-of-flight(TOF)technique at the Back-n facility of the China Spallation Neutron Source(CSNS)in the 1 eV to 100 keV range.Prompt c-rays originating from neutron-induced capture events were detected by four C_(6)D_(6) liquid scintillator detectors.Pulse height weighting technology(PHWT)was used to analyze the data.The results are in good agreement with ENDF/B-VIII.0,CENDL-3.1,and other evaluated libraries in the resonance region,and in agreement with both n TOF and GELINA experimental data in the 5–100 keV range.Finally,the resonance peaks in the energy range from 1eV to 1 keV were fitted by the SAMMY R-matrix code.

Yb-doped passively mode-locked fiber laser with Bi_2Te_3-deposited

In this study we present an all-normal-dispersion Yb-doped fiber laser passively mode-locked with topological insulator（Bi2Te3） saturable absorber. The saturable absorber device is fabricated by depositing Bi2Te3 on a tapered fiber through using pulsed laser deposition（PLD） technology, which can give rise to less non-saturable losses than most of the solution processing methods. Owing to the long interaction length, Bi2Te3 is not exposed to high optical power, which allows the saturable absorber device to work in a high power regime. The modulation depth of this kind of saturable absorber is measured to be 10%. By combining the saturable absorber device with Yb-doped fiber laser, a mode-locked pulse operating at a repetition rate of 19.8 MHz is achieved. The 3-d B spectral width and pulse duration are measured to be 1.245 nm and317 ps, respectively.

Zinc Oxide Surface Flashover Triggering of Pseudospark Switch

Accurate and reliable triggering is one of the most important issues with high power pseudospark switch, because it not only has an impact on the design of discharge chamber of switch, but also has an influence on the dynamic range of operation voltage, repetition frequencies and lifetime of switch. The unique feature of pseudospark switch is its hollow cathode geometry. The hollow cathode effect produced by the hollow cathode provides the protection of the switch for the triggering unit from erosion by high discharge plasma. In this paper, a zinc oxide (ZnO) surface flashover triggering is presented. This trigger unit possesses an excellent time delay (80 ns - 360 ns) and jitter (20 ns - 50 ns) at the switch voltage of 30 kV - 2 kV. The emitted plasma electron density is high enough to trigger switch reliably down to switch voltage of 440 V.

SmartSurf^(ACE)transepithelial photorefractive keratectomy with mitomycin C enhancement after small incision lenticule extraction

Background:To evaluate predictability,stability,efficacy,and safety of transepithelial photorefractive keratectomy(TPRK)using smart pulse technology(SPT)(SmartSurface procedure)of Schwind Amaris with mitomycin C for correction of post small incision lenticule extraction(SMILE)myopic residual refractive errors.Method:This study is a prospective,non-comparative case series conducted at a private eye centre in Ismailia,Egypt,on eyes with post-SMILE myopic residual refractive errors because of undercorrection or suction loss(suction loss occurred after the posterior lenticular cut and the creation of side-cuts;redocking was attempted,and the treatment was completed in the same session with the same parameters)with myopia or myopic astigmatism.The patients were followed up post-SMILE for six months before the SmartSurface procedure,and then they were followed up for one year after that.TPRK were performed using Amaris excimer laser at 500 kHz.The main outcomes included refractive predictability,stability,efficacy,safety and any reported complications.Results:This study included 68 eyes of 40 patients out of 1920 total eyes(3.5%)with post-SMILE technique myopic residual refractive errors.The average duration between the SMILE surgery and TPRK was 6.7±0.4 months(range 6 to 8 months).The mean refractive spherical equivalent(SE)was within±0.50 D of plano correction in 100%of the eyes at 12 months post-TPRK.Astigmatism of<0.50 D was achieved in 100%of the eyes.The mean of the residual SE error showed statistically significant improvement from preoperative−1.42±0.52 D to 0.23±0.10 D(P<0.0001).Uncorrected distance visual acuity(UDVA)(measured by Snellen’s chart and averaged in logMAR units)was improved significantly to 0.1±0.07(P<0.0001).UDVA was 0.2 logMAR or better in 100%of the eyes,0.1 logMAR or better in 91.2%of the eyes,and 0.0 logMAR in 20.6%of the eyes.Corrected distance visual acuity(CDVA)remained unchanged in 79.4%of eyes.14.7%of eyes gained one line of CDVA(Snellen).5.9%of eyes gained two lines of CDVA(Snellen).Conclusion:Transepithelial photorefractive keratectomy using smart pulse technology with mitomycin C enhancement after SMILE is a safe,predictable,stable,and effective technique.