Investigation of Quench Sensitivity and Microstructure Evolution During Isothermal Treatment in 2195 Al–Li Alloy

Zhiwu Zhang,Youping Yi,Wen You,Shiquan Huang,Yonglin Guo,Hailin He 대한금속·재료학회 2022 METALS AND MATERIALS International Vol.28 No.6

To investigate the quenching sensitivity of the 2195 Al–Li alloy rolled sheet and guide the design of the quenching process,the time–temperature-property (TTP) curves of this material were researched through interrupted quenching experiments. The differential scanning calorimetry (DSC) and transmission electron microscope (TEM) were used to characterize theevolution of precipitates during isothermal treatment. The results of this essay demonstrated that the nose temperature of 2195Al–Li alloy is around 370 °C and the temperature range of quenching sensitivity is 340 °C to 400 °C. The microstructureobservation revealed that the T1particles precipitate and grow rapidly at the temperature from 340 to 400 °C, which is dueto the high nucleation rate of phase and fast solute diffusion kinetics, especially at the nose temperature. The needle-shapedθ′/θ″ and T1particles grow up quickly as the isothermal preservation time prolonged, leading to the decrease of the supersaturatedsolid solution of the matrix. This will reduce the number of the age-induced precipitate and weaken the subsequentage hardening effect. Therefore, the rate of cooling should be increased in the quenching sensitivity range (340–400 °C) toinhibit the precipitation of the second phase and obtain excellent mechanical properties. While in other temperature ranges,the cooling rate should be decreased appropriately to reduce residual stress. The appropriate average cooling rate is recommendedto be around 13 °C s−1 at the temperature from 340 to 400 °C.

Spatial analysis of tuberculosis treatment outcomes in Shanghai: implications for tuberculosis control

Zhang Jing,Shen Xin,Yang Chongguang,Chen Yue,Guo Juntao,Wang Decheng,Zhang Jun,Lynn Henry,Hu Yi,Pan Qichao,Zhang Zhijie 한국역학회 2022 Epidemiology and Health Vol.44 No.-

OBJECTIVES: Tuberculosis (TB) treatment outcomes are a key indicator in the assessment of TB control programs. We aimed to identify spatial factors associated with TB treatment outcomes, and to provide additional insights into TB control from a geographical perspective.METHODS: We collected data from the electronic TB surveillance system in Shanghai, China and included pulmonary TB patients registered from January 1, 2009 to December 31, 2016. We examined the associations of physical accessibility to hospitals, an autoregression term, and random hospital effects with treatment outcomes in logistic regression models after adjusting for demographic, clinical, and treatment factors.RESULTS: Of the 53,475 pulmonary TB patients, 49,002 (91.6%) had successful treatment outcomes. The success rate increased from 89.3% in 2009 to 94.4% in 2016. The successful treatment outcome rate varied among hospitals from 78.6% to 97.8%, and there were 12 spatial clusters of poor treatment outcomes during the 8-year study period. The best-fit model incorporated spatial factors. Both the random hospital effects and autoregression terms had significant impacts on TB treatment outcomes, ranking 6th and 10th, respectively, in terms of statistical importance among 14 factors. The number of bus stations around the home was the least important variable in the model.CONCLUSIONS: Spatial autocorrelation and hospital effects were associated with TB treatment outcomes in Shanghai. In highly-integrated cities like Shanghai, physical accessibility was not related to treatment outcomes. Governments need to pay more attention to the mobility of patients and different success rates of treatment among hospitals.

A 32.2 GHz Full Adder Designed with TLE Method in a InP DHBT Technology

Yi Zhang,Xiaopeng Li,Youtao Zhang,Yufeng Guo,Ying Zhang,Hao Gao 대한전자공학회 2021 Journal of semiconductor technology and science Vol.21 No.6

Ultra-high-speed full adder is the bottleneck in a tens of GHz Direct digital synthesizer (DDS). In this paper, a 32.2 GHz, 1bit full adder in a 0.7 μm InP double hetero-junction bipolar transistor (DHBT) technology is presented. In such a high-speed circuit, signal integrity is a crucial issue. Therefore, a transmission line equivalent (TLE) method is proposed. With the TLE method, the design of the full adder could be simplified with good accuracy. The synchronous latch is combined with adding operation to improve the calculation speed. A single-level parallel-gated circuit is designed using majority decision algorithm to reduce power consumption. Measurement results show that the maximum clock frequency of the full adder is 32.2-GHz, and the overall power consumption is 350 mW. The full adder is successfully adopted in a 17 GHz, 8 bit DDS which can synthesize sin-wave outputs from 66.41 MHz to 8.5 GHz in 66.41 MHz steps with an average Spurious-Free Dynamic Range (SFDR) of -18.1 dBc.

Cytotoxic activity and probable apoptotic effect of Sph2, a sphigomyelinase hemolysin from Leptospira interrogans strain Lai

( Yi Xuan Zhang ),( Yan Geng ),( Jun Wei Yang ),( Xiao Kui Guo ),( Guo Ping Zhao ) 생화학분자생물학회 2008 BMB Reports Vol.41 No.2

A 2 GS/s, 6-bit DAC for UWB Applications In 0.18 ㎛ CMOS Technology

Yi Zhang,Zhonghua Liu,Changchun Zhang,Yufeng Guo,Ying Zhang,Xiaopeng Li,Youtao Zhang,Hao Gao 대한전자공학회 2019 Journal of semiconductor technology and science Vol.19 No.6

To satisfy higher and higher transmission rate and broadband requirement of modern communication, high-speed, low-resolution Digital-to-Analog Converters (DACs) becomes the key element. In this paper, the design of a 2 GS/s, 6 bit DAC without calibration for Ultra-wideband (UWB) applications, is presented. The DAC is based on current steering architecture and is segmented with 4 bit unary and 2 bit binary. To realize larger linear range and fast switching, the source degeneration switch is designed instead of the traditional differential switch. The DAC is designed and taped-out in SMIC 0.18 ㎜ CMOS technology and the area is 975 ㎛´ 775 ㎛. The wafer bonding measurement results shows that the DNL is 0.11 LSB, INL is 0.25 LSB. Under a clock frequency of 2 ㎓, the DAC can achieve a SFDR of 51 ㏈ for input signal of 6㎒, and a SFDR of 32.4 ㏈ for Nyquist input while the power consumption is 79 ㎽.

Enhancement of transglutaminase production in Streptomyces mobaraensis DSM 40587 by non-nutritional stress conditions: Effects of heat shock, alcohols, and salt treatments

Lili Zhang,Lanwei Zhang,Huaxi Yi,Ming Du,Yingchun Zhang,Xue Han,Zhen Feng,Jingyan Li,Yuehua Jiao,Yanhe Zhang,Chunfeng Guo 한국화학공학회 2012 Korean Journal of Chemical Engineering Vol.29 No.7

Stress-mediated bioprocess is a strategy designed to enhance biological target productivity. In this study,an attempt was made to enhance transglutaminase (TGase) production by Streptomyces mobaraensis by using different stress conditions including heat shock, alcohols and salt stress. Results showed that the effects of stress on TGase production depended on the type applied. For heat shock, TGase production (1.32 U/ml) was recorded maximum in the culture treated at 48 h post inoculation in water bath at 60 oC for 1 min. For alcohols treatment, the maximum activity of TGase (1.77 and 1.75 U/ml) was obtained when 3% methanol was added into the medium at 0 or 24 h of fermentation. However, a 3.5-fold increased production of TGase (3.8 U/ml) was observed in the medium supplemented with 0.2mol/l MgCl2 compared with the basic medium at the beginning of fermentation. In conclusion, TGase production from S. mobaraensis was improved by heat shock, methanol and salt stress treatments, MgCl2 stress was the most effective.

Associations of TNF-RII rs1061622 With Post-Traumatic Stress Disorder and Their Interplays on Serum Lipids Levels in Adolescents

Ji Cheng Zhang,Jin Hua Wang,Jun Yi Liu,Qi Wei Guo,Jia Lin,Yi Lin Shen,Ke Xin Jia,Jia Jing Cai,Guo Ming Su,Ding Zhi Fang 대한신경정신의학회 2023 PSYCHIATRY INVESTIGATION Vol.20 No.11

Objective To verify effects of rs1061622 at tumor necrosis factor-α receptor II (TNF-RII) gene (<i>TNF-RII</i>) on post-traumatic stress disorder (PTSD) and its interactive effects with PTSD on serum lipids levels in adolescents.Methods PTSD was measured by PTSD Checklist-Civilian Version (PCL-C) in 699 adolescent survivors at 6 months after Wenchuan earthquake in China. A polymerase chain reaction and restriction fragment length polymorphism assay were utilized for <i>TNF-RII</i> rs1061622 genotyping followed by verification using DNA sequencing. Serum triglycerides (TG), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), and low-density lipoprotein cholesterol were tested using routine methods.Results G (deoxyguanine) allele carriers had higher PCL-C scores than TT (deoxythymidine) homozygotes in female subjects. Female adolescents had higher PCL-C scores than male subjects in TT homozygotes. Predictors of PTSD prevalence and severity were different between G allele carriers and TT homozygotes. Subjects with PTSD had lower TG, TG/HDL-C, TC/HDL-C, and higher HDL-C than adolescents without PTSD in male G allele carriers. G allele carriers had higher TG/HDL-C and TC/HDL-C than TT homozygotes in male adolescents without PTSD, and lower TG and TG/HDL-C in male PTSD patients. G allele carriers had higher TG than TT homozygotes only in female adolescents without PTSD.Conclusion These results suggest reciprocal actions of <i>TNF-RII</i> rs1061622 with other factors on PTSD severity, interplays of <i>TNF-RII</i> rs1061622 with PTSD on serum lipid levels, and novel treatment strategies for PTSD and comorbidities of PTSD with hyperlipidemia among adolescents with different genetic backgrounds of <i>TNF-RII</i> rs1061622 after experiencing traumatic events.

Novel AgCl/Ag2SO3 Hybrids as a Visible-Light-driven Photocatalyst: Preparation, Characterization, and Degradation of Rhodamine-B and Methyl Orange

Xiang-Feng Wu,Yi-Jin Wang,Zuo-Lin Cao,Yan-Mei Feng,Hui Li,Chen-Xu Zhang,Jun-Zhang Su,Jia-Rui Zhang,Yi-Wei Wang,Kai-Yuan Wang,Guo-Wen Sun 대한화학회 2018 Bulletin of the Korean Chemical Society Vol.39 No.7

The novel AgCl/Ag2SO3 hybrids as an efficient photocatalyst had been fabricated by an in situ synthetic method. The correlations between the structure and the photocatalytic properties of the as-fabricated hybrids were analyzed. Experimental results exhibited that with increasing the amount of Ag2SO3, the degradation rate of the as-obtained samples was firstly increased and then decreased under the visible light irradiation. When the mass ratio of AgCl to Ag2SO3 was 1:2, in 30?min, it displayed the highest degradation rate of 99.2% for rhodamine-B, which was obviously higher than 46.1, 60.5, and 14.6% of pure AgCl, Ag2SO3, and TiO2 (P25), respectively. Similar results could be found in degradation of methyl orange. It had the maximum of 97.4% in 90?min, which was higher than 55.2, 48.7, and 12.7% of pure AgCl, Ag2SO3, and P25, respectively. Moreover, the as-prepared hybrids possessed the enhanced separation and transfer of photo-generated electron?hole pairs compared to the pure samples. In addition, the holes and superoxide radicals played the dominant role and the hydroxyl radicals played the secondary role during the process of photocatalytic degradation.

A Meta-Analysis of the Accuracy of Prostate Cancer Studies Which Use Magnetic Resonance Spectroscopy as a Diagnostic Tool

Peng Wang,You-min Guo,Min Liu,Yong-qian Qiang,Xiao-juan Guo,Yi-li Zhang,Xiao-Yi Duan,Qiu-Juan Zhang,Weifeng Liang 대한영상의학회 2008 Korean Journal of Radiology Vol.9 No.5

Objective: We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer studies which use magnetic resonance spectroscopy (MRS) as a diagnostic tool. Materials and Methods: Prospectively, independent, blind studies were selected from the Cochrane library, Pubmed, and other network databases. The criteria for inclusion and exclusion in this study referenced the criteria of diagnostic research published by the Cochrane center. The statistical analysis was adopted by using Meta-Test version 6.0. Using the homogeneity test, a statistical effect model was chosen to calculate different pooled weighted values of sensitivity, specificity, and the corresponding 95% confidence intervals (95% CI). The summary receiver operating characteristic (SROC) curves method was used to assess the results. Results: We chose two cut-off values (0.75 and 0.86) as the diagnostic criteria for discriminating between benign and malignant. In the first diagnostic criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI (expressed as area under curve [AUC]) were 0.82 (0.73, 0.89), 0.68 (0.58, 0.76), and 83.4% (74.97, 91.83). In the second criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI were 0.64 (0.55, 0.72), 0.86 (0.79, 0.91) and 82.7% (68.73, 96.68). Conclusion: As a new method in the diagnostic of prostate cancer, MRS has a better applied value compared to other common modalities. Ultimately, large scale RCT randomized controlled trial studies are necessary to assess its clinical value. Objective: We aimed to do a meta-analysis of the existing literature to assess the accuracy of prostate cancer studies which use magnetic resonance spectroscopy (MRS) as a diagnostic tool. Materials and Methods: Prospectively, independent, blind studies were selected from the Cochrane library, Pubmed, and other network databases. The criteria for inclusion and exclusion in this study referenced the criteria of diagnostic research published by the Cochrane center. The statistical analysis was adopted by using Meta-Test version 6.0. Using the homogeneity test, a statistical effect model was chosen to calculate different pooled weighted values of sensitivity, specificity, and the corresponding 95% confidence intervals (95% CI). The summary receiver operating characteristic (SROC) curves method was used to assess the results. Results: We chose two cut-off values (0.75 and 0.86) as the diagnostic criteria for discriminating between benign and malignant. In the first diagnostic criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI (expressed as area under curve [AUC]) were 0.82 (0.73, 0.89), 0.68 (0.58, 0.76), and 83.4% (74.97, 91.83). In the second criterion, the pooled weighted sensitivity, specificity, and corresponding 95% CI were 0.64 (0.55, 0.72), 0.86 (0.79, 0.91) and 82.7% (68.73, 96.68). Conclusion: As a new method in the diagnostic of prostate cancer, MRS has a better applied value compared to other common modalities. Ultimately, large scale RCT randomized controlled trial studies are necessary to assess its clinical value.

A New Control Strategy for a Three-Phase PWM Current-Source Rectifier in the Stationary Frame

Guo, Qiang,Liu, Heping,Zhang, Yi The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.4

This paper presents a novel power control strategy for PWM current-source rectifiers (CSRs) in the stationary frame based on the instantaneous power theory. In the proposed control strategy, a virtual resistance based on the capacitor voltage feedback is used to realize the active damping. In addition, the proportional resonant (PR) controller under the two-phase stationary coordinate is designed to track the ac reference current and to avoid the strong coupling brought about by the coordinate transformation. The limitations on improving steady-state performance of the PR controller is investigated and mitigated using a cascaded lead-lag compensator. In the z-domain, a straightforward procedure is developed to analyze and design the control-loop with the help of MATLAB/SISO software tools. In addition, robustness against parameter variations is analyzed. Finally, simulation and experimental results verify the proposed control scheme and design method.