A reusable planar triggered spark-gap switch batched-fabricated with PCB technology for medium- and low-voltage pulse power systems

Triggered spark-gap switch is a popular discharge switch for pulse power systems.Previous studies have focused on planarizing this switch using thin film techniques in order to meet the requirements of compact size in the systems.Such switches are one-shot due to electrodes being too thin to sufficiently resist spark-erosion.Additionally,these switches did not employ any structures in securing internal gas composition,resulting in inconsistent performance under harsh atmospheres.In this work,a novel planar triggered spark-gap switch(PTS)with a hermetically sealed cavity was batched-prepared with printed circuit board(PCB)technology,to achieve reusability with low cost.The proposed PTS was inspected by micro-computed tomography to ensure PCB techniques meet the requirements of machining precision.The results from electrical experiments demonstrated that PCB PTS were consistent and reusable with lifespan over 20 times.The calculated switch voltage and circuit current were consistent with those derived from real-world measurements.Finally,PCB PTS was used to introduce hexanitrostilbene(HNS)pellets in a pulse power system to verify its performance.

Roller Profile Online Measurement Based on Ultrasonic Circulation Pulse-echo Technology

In order to meet the high precision requirement of wide steel strip in industry field, a novel online measurement of roller profile based on sonic circulation and pulse-echo technology was introduced. All kinds of the factors influencing the accuracy of roller profile online measurement were analyzed in detail and error compensation analysis of system was accordingly presented. In order to reduce count error, field program gate array(FPGA) was introduced and a highprecision data acquisition system was designed based on digital phase-shift technology. Experiments indicate that the standard deviation of measure data was 7.27 μm, which showed the feasibility and validity of the proposed method, and realized the roll profile measurement with high precision.

Application of ARFI technology to explore the clinical study of Gandou Tang in treating liver fibrosis of wilson's disease with damp-heat accumulation

Objective:Acoustic radiation force impulse(ARFI)was applied to measure Shear wave velocity(SWV)of liver in patients with Wilson's disease(WD).To investigate the relationship between SWV and the serological indexes of liver fibrosis,such as type Ⅳ collagen(CⅣ),hyaluronic acid(HA),type Ⅲ procollagen peptide(PⅢNP),laminin(LN),APRI score(Asparate Aminotransfer to Platelet Ratio Index),and FIB-4 index(FIB-4 index).The clinical efficacy of GandouTang(GDT)in the treatment of liver fibrosis in WD with damp-heat internalization was also observed.Methods:80 cases of WD patients who met the inclusion criteria were randomly divided into the treatment group and the control group,with 40 cases in each group.The control group was treated with Sodium Dimercaptopropylsulfonate(DMPS)and the treatment group was additionally treated with the traditional Chinese medicine GDT.One course for 8 days,a total of 6 courses.The levels of SwV and four serological indicators of liver fibrosis(PⅢNP,HA,CⅣ,LN),APRI score and FIB-4 index were compared before and after treatment.Pearson correlation test was used to analyze the correlation between SWV and HA,CⅣ,LN,PⅢNP,APRI score and FIB-4 index.The effects of GDT on SWV,liver fiber,APRI and FIB-4 were evaluated according to the treatment plan.Results:①The SWV was positively correlated with FIB-4(r=0.83),APRI(r=0.82),HA(r=0.87),CⅣ(r=0.71),LN(r=0.85)and PINP(r=0.77).②Before treatment,there were no significant differences in SWV level,PⅢNP,HA,CⅣ,LN,APRI and FIB-4 levels between two groups(P>0.05).After treatment,the levels of PⅢNP,HA,LN,SWV,APRI and FIB-4 in both groups were significantly decreased(P<0.05,P<0.01),and the levels in the treatment group were lower than those in the control group.There were no significant specific changes in CⅣ level(P>0.05).Conclusion:SWV value can reflect the degree of WD liver fibrosis,and is positively correlated with HA,PⅢNP,CⅣ,LN,FIB-4 index and APRI score.On the basis of the treatment of protecting liver and expelling copper with western medicine,plus the treatment of traditional Chinese medicine GDT can effectively improve the degree of liver fibrosis in WD patients with damp-heat accumulation.

铝-镀锌钢板异种金属Pulsed DE-MIG熔钎焊方法研究

为精确控制焊接热输入,从而控制铝钢异种金属界面区金属间化合物生长,提出一种新型高效低热输入的脉冲旁路耦合电弧MIG焊(Pulsed DE-MIG)方法,用ER5356铝合金焊丝在镀锌钢板上利用平板堆焊实验对工艺参数进行优化.在焊丝总电流保持不变,不同的Pulsed DE-MIG焊接参数下焊接,结果表明随着旁路电流的增大,焊缝宽度显著变小,且焊缝堆高明显变高.采用OM、SEM、EDS等测试手段观察和分析连接界面区的微观组织,发现在连接界面区形成Fe2Al5、FeAl3金属间化合物层,且母材热输入大时,FeAl3析出得多,随着母材热输入的减小,FeAl3析出逐步减少直至FeAl3无析出.

Pulsed Eddy Current Non-destructive Testing and Evaluation:A Review

Pulsed eddy current （PEC） non-destructive test- ing and evaluation （NDT＆E） has been around for some time and it is still attracting extensive attention from researchers around the globe, which can be witnessed through the reports reviewed in this paper. Thanks to its richness of spectral components, various applications of this technique have been proposed and reported in the lit- erature covering both structural integrity inspection and material characterization in various industrial sectors. To support its development and for better understanding of the phenomena around the transient induced eddy currents, attempts for its modelling both analytically and numeri- cally have been made by researchers around the world. This review is an attempt to capture the state-of-the-art development and applications of PEC, especially in the last 15 years and it is not intended to be exhaustive. Future challenges and opportunities for PEC NDT＆E are also presented.

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.

FEATURES OF THYRISTOR COMMUTATORS OPERATION OF WELDING CURRENT UNDER PULSED-ARC WELDING

This article presents the special requirements and features of the thyristor commutators of the welding current.Advantages of pulsed - arc welding are described.Specificity of the thyristor commutators op- eration is presented. Semiconductor converter simulation allowing to create the engineering calculating techniques are considered.

Strong pulses from pulsar PSR J0034-0721

We present an analysis of strong single pulses from PSR J0034-0721. Our observations were made using the Urumqi 25-m radio telescope at a radio frequency of 1.54 GHz. A total of 353 strong pulses were detected during eight hours of observing, The signal-to-noise ratios of the detected pulses range from 5 to 11.5. The peak fluxes of those pulses are 17 to 39 times that of the average pulse peak. The cumulative distribution of the signal-to-noise ratios of these strong pulses has a rough power-law distribution with a slope of 4.4 q- 0.5. Ten of the strong pulses arrived approximately 23 to 40 ms earlier than the average profile peak. This suggests the possibility that there are two strong pulse-emitting regions.

Capillary Column Coated with Heptakis(2,3, 6-tri-O-octyl)-β-cyclodextrin Using Sol-gel Technology

Heptakis(2, 3, 6-tri-O-octyl)-β-cyclodextrin was coated onto the fused silica capillary by sol-gel technology. Column efficiency and column selectivity were studied. The results indicated that high ability of separation was acquired . Positional isomers of aromatic compounds were well separated.

4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-1,3,5-triazine modified carbon paste electrode for trace Cu(Ⅱ) determination by differential pulse volt-ammetry

A differential pulse voltammetric method was developed for the sensitive andselective determination of Cu(II) at 4-methoxy-2,6-bis(3,5-dimethylpyrazoyl)-l,3,5-triazine modifiedcarbon paste electrode in 0.05 mol/L KHC_8H_4O_4 solution (pH = 4.02). The oxidation peak of Cu(II)was observed at 0.065 V(vs Ag/AgCl) by scanning the potential in positive direction. The analysisprocedure consisted of an open circuit accumulation step in stirred sample solution. It was followedby medium exchange to a clean solution and subsequently an anodic potential scan was affected toobtain the voltammetric peak. The current was proportional to the concentration of the Cu(II) ion ina range of 1 X 10^(-7) -1 X 10^(-4) mol/L for 6 min accumulation; the most of metal ions did notinterfere with the determination. The developed method was applied to Cu (II) determination incoal-ash sample, the results agreed with that of atomic adsorption spectroscopy (AAS).

Verifying the Effects of an Education Program Leveraging Information Technology to Promote Cervical Cancer Screening in Women Aged 20 - 29—A One-Year Longitudinal Study

The purpose of this research is to implement an IT-based education program in order to promote cervical cancer screenings for women aged 20 - 29 years, as well as to examine the results of said program. This is a longitudinal/comparative study of two groups, one for which the program was implemented (the intervention group), and the other for which it was not (the control group). The program consisted of attending a health lecture and encouragement to be screened one month, six months, and one year later sent through IT-based methods. The target was unmarried women aged 20 - 29 who had neither previously given birth nor had been screened for cervical cancer in a period one year prior. They were divided into two groups, the intervention group (n = 142) and control group (n = 145). The effectiveness of the program was assessed via an initial survey and further surveys six months and one year later. Results were based on the Japanese version of the Health Belief Model Scale for Cervical Cancer and the Pap Smear Test (HBMSCCPST), knowledge scores in the categories of Healthy Lifestyles, Cervical Cancer, Cervical Cancer Screening, and screening behavior. A two-way ANOVA of the HBMSCCPST subscales and knowledge scores in the initial, six-month, and one-year surveys was performed, showing interaction in Cervical Cancer (p = 0.00). Main effects were observed in Cervical Cancer Screening (p = 0.00) and Healthy Lifestyles (p = 0.00). Regarding the amount of change from the initial survey, knowledge scores in the Cervical Cancer (p = 0.027) and Cervical Cancer Screening (p = 0.016) categories were significantly higher in the intervention group than in the control group. There was no significant difference in cervical cancer screening rates (p = 0.26) between the two groups. However, a small-degree effect size was observed for Benefits, Seriousness, and Susceptibility subscales in both examinees and non-examinees. Although the educational program of this study was effective in improving the knowledge of women in their twenties, there was little improvement in HBMSCCPST and it did not lead to the promotion of cervical cancer screening. In order to raise interest in cervical cancer screening, it is necessary to consider useful content to guide women to consult with healthcare professionals, a long-term population approach, and organizational structure of consultation.

DICP Symposium (I) on Catalysis: Future Directions of Catalysis Science and Technology October 16-18, 2003, Dalian, China

Introduction and Invitation DICP Symposium is a special series of interna-tional conference named after the Dalian Instituteof Chemical Physics (DICP). The DICP Symposiumwas founded with the purpose to promote the interna-tional communication and collaboration between theDICP and the international scientific community, to

3-Dimensional Body Measurement Technology

3 - dimensional body measurement technology, the basis of developing high technology in industry, accelerates digital development of aplparel industry. This paper briefly introduces the history of 3 - dimensional body measurement technology, and recounts the principle and primary structure of some types of 3 - dimensional automatic body measurement system. With this understanding, it discusses prospect of 3- dimensional CAD and virtual technology used in apparel industry.

The 4th International Exhibition on Refractories, Industrial Ceramics and Furnaces(RCF Expo'2003)Beijing, China, April 15-17, 2003In conjunction with China Refractories Seminar' 2003-Technology and Markets

Organizers and Sponsors: China Association of Refractories Industry The Chinese Society for Metals The Chinese Ceramic Society

Study on In-vitro Production Technology of Embryos from Young Dorper Sheep

This study was conducted to investigate the in-vitro production technology of embryos from young Dorper sheep, so as to provide technical support for the utilization of ovarian follicles in young Dorper sheep. Tests were conducted from the induction of Dorper sheep of 4 to 8 weeks old using follicle stimulating hormone(FSH) and pregnant horse serum(PMSG), collection of oocytes, in-vitro oocyte maturation-fertilization-zygote cultivation and 2-4-cell-stage fertilized ovum transfer. The results showed that 585 oocytes were collected from eight Dorper sheep at the age of 4 and 8 weeks, with an average of 73.13 oocytes/sheep. 346 of the 2-4-cell-stage fertilized eggs were obtained, whose cleavage rate was 59.15%. 77 in-vitro fertilized eggs at 2-4-cell stage were transplanted into 17 recipient sheep, seven of which were pregnant and gave birth to 13 "test-tube sheep" with a conception rate of 41.18%. It is indicated that the hormone induction technique, in-vitro oocyte maturation-fertilization-zygote cultivation technique and 2-4-cell-stage fertilized ovum transfer technique used in this study can serve as effective techniques for the in-vitro production of embryos from Dorper sheep of 4-8 weeks old.