Effects of Aging Temperature on the Mechanical Properties and Precipitation Behavior of a Pre-strained Al–Cu–Mg–Ag Alloy

Jian Wang,Jingpei Xie,Zhiyi Liu,Aiqin Wang,Wenyan Wang 대한금속·재료학회 2023 METALS AND MATERIALS International Vol.29 No.2

In this work, effects of artificial aging temperature on the mechanical properties and precipitation behavior of a pre-strainedAl–Cu–Mg–Ag alloy were investigated by hardness and tensile tests, and quantitative transmission electron microscopeanalysis. Three aging conditions, a single aging at a high temperature (T8H), a single aging at a low temperature (T8L) andan interrupted aging at low temperature following under-aging at a higher temperature (T8I4), were compared. Based on thequantitative analysis of the strengthening phases, the evolution law of the average diameter, thickness and volume fractionof Ω plates with the aging time for a pre-stretched Al–Cu–Mg–Ag alloy aged at 190 °C/160 °C may be predicted by themodified equations. The precipitation behavior of Ω precipitates was confirmed by considering the coarsening kinetics ofthem. Results show that a higher aging temperature can increase the precipitation kinetics of Ω phase and inhibit the precipitationof θ′ phase. Thus, a new type of interrupted aging treatment, T8I4 (3.2% pre-stretch + 190 °C/1 h + 160 °C/10 h),was proposed to enhance the strength of the pre-stretched Al–Cu–Mg–Ag alloy.

Lowest Instrumented Vertebra at L3 Versus L4 in Posterior Fusion for Moderate Lenke 5C Type Adolescent Idiopathic Scoliosis: A Case-Match Radiological Study

Zhiyi Li,You Du,Yiwei Zhao,Guanfeng Lin,Haoran Zhang,Chenkai Li,Xiaohan Ye,Yang Yang,Shengru Wang,Jianguo Zhang 대한척추신경외과학회 2023 Neurospine Vol.20 No.4

Objective: To compare the radiological outcomes in Lenke 5C type patients whose lowest instrumented vertebra (LIV) was L3 or L4 in a case-match study. Methods: We conducted a retrospective case-match study and included 82 patients in the study. Radiological results before surgery, after surgery, and at last follow-up were recorded and analyzed in the L3 and L4 groups. Results: After matching the age, Risser’s sign, sex, and main Cobb, 41 pairs of patients were enrolled in our study. The total fusion segments in the L3 group (median [interquartile range]: 5.0 [6.0–5.0]) were shorter than those in the L4 group (6.0 [6.5–6.0]). The main curve was significantly corrected after surgery in both groups, and was comparable at the last followup between groups. In addition, according to the results of Fisher precision probability test, there was no significant difference of coronal or sagittal imbalance between the 2 groups at the 2-year follow-up. Conclusion: The correction in coronal and sagittal planes in L3 group and L4 group remains similar. On account of more motion segments, L3 could be an ideal choice as LIV in moderate Lenke 5C type AIS. Long-term follow-up is needed to evaluate the effect of larger compensatory lumbar-sacral curve when stopping at L3.

An I-Shaped Slot Grid Antenna Array with Substrate Integration and Enhanced Bandwidth

Zhiyi Li,Shengjie Wang,Fan Li,Lin Lin,Hongzheng Zeng 한국전자파학회JEES 2023 Journal of Electromagnetic Engineering and Science Vol.23 No.5

Optimization Design of an Ultra-Low Specific-Speed Centrifugal Pump Using Entropy Production Minimization and Taguchi Method

Cong Wang,Yongxue Zhang,Hucan Hou,Zhiyi Yuan,Ming Liu 한국유체기계학회 2020 International journal of fluid machinery and syste Vol.13 No.1

To improve the energy conversion efficiency and cavitation performance of the ultra-low specific-speed centrifugal pump (ULSSCP), the impeller-volute interaction has been studied. Blade outlet setting angle (β₂), wrap angle (φ), volute inlet width (b₃) and throat area (St) were addressed as the design parameters. The entropy production at 0.5 Q0 and NPSHc (critical net positive suction head) at 1.5 Q0 were selected as the target to characterize the energy loss and cavitation performance. The L9 (3⁴) orthogonal matrix was established via Taguchi method. Results show that the contribution ratio of φ on S/NS is the most vital, followed by b₃ and St, while the influence of β₂ is relatively small, and the design parameter combination with β₂=19°, φ=220°, b₃=12mm and St=190㎟ is the best choice for the lowest entropy production at 0.5Q0 and NPSHc. At last, the optimization design reduces the loss greatly before and after cavitation by alleviation of vortex generation and backflow intensity.

Pretreatment of Switchgrass with Electrolyzed Water and a Two-stage Method for Bioethanol Production

Xiaojuan Wang,Hao Feng,Zhiyi Li 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.3

In this study, switchgrass, which is a promising energy crop, was treated with two new pretreatment methods for the production of bioethanol. Acidic electrolyzed water (AEW) and alkaline electrolyzed water (ALEW) were first used as pretreatment catalysts at three temperatures (170,185, and 200oC) and 3 treatment times (5, 15, and 25 min). In the two-stage pretreatment, 1.0, 2.0 and 3.0% H2O2solutions were used to partially remove hemicellulose and lignin during the 1st stage at 50oC for 16, 24, or 32 h at a solid concentration of 5%. The supernatant of the 1st stage was used for hemicellulose precipitation. The remaining solids were subjected to a 2nd stage treatment with hot water at 121oC for 30 min in an autoclave at a solid concentration of 12.5%. In the electrolyzed water pretreatment,the highest glucose yield was achieved by pretreatment with ALEW at 200oC and 25 min, which resulted in the release of 23.8 g glucose from 100 g dry switchgrass. The hydrolyzate obtained from switchgrass pretreated with 3% H2O2 for 16 h followed by enzymatic hydrolysis was fermented using S. cerevisiae at 30oC for 96h without any concentration or detoxification steps. The final ethanol concentration was 11.8 g/L and the productive yield was 74% of the theoretical yield. A mass balance for the two-stage process showed that 12 g of ethanol was produced from 100 g dry switchgrass. In this study, switchgrass, which is a promising energy crop, was treated with two new pretreatment methods for the production of bioethanol. Acidic electrolyzed water (AEW) and alkaline electrolyzed water (ALEW) were first used as pretreatment catalysts at three temperatures (170,185, and 200oC) and 3 treatment times (5, 15, and 25 min). In the two-stage pretreatment, 1.0, 2.0 and 3.0% H2O2solutions were used to partially remove hemicellulose and lignin during the 1st stage at 50oC for 16, 24, or 32 h at a solid concentration of 5%. The supernatant of the 1st stage was used for hemicellulose precipitation. The remaining solids were subjected to a 2nd stage treatment with hot water at 121oC for 30 min in an autoclave at a solid concentration of 12.5%. In the electrolyzed water pretreatment,the highest glucose yield was achieved by pretreatment with ALEW at 200oC and 25 min, which resulted in the release of 23.8 g glucose from 100 g dry switchgrass. The hydrolyzate obtained from switchgrass pretreated with 3% H2O2 for 16 h followed by enzymatic hydrolysis was fermented using S. cerevisiae at 30oC for 96h without any concentration or detoxification steps. The final ethanol concentration was 11.8 g/L and the productive yield was 74% of the theoretical yield. A mass balance for the two-stage process showed that 12 g of ethanol was produced from 100 g dry switchgrass.

Transverse impact characteristics of a rubber pipe expansion joint

Yong Chen,Wang Yu,ZhiYi Zhang,Hongxing Hua 대한기계학회 2012 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.26 No.6

The transverse impact characteristics of a rubber pipe expansion joint are studied. A pair of joints assembled end to end with an inserted middle mass is tested on a drop shock testing machine. Based on the test results, an equivalent fixed-fixed beam model with polynomial stiffness and damping is applied to predict the transverse impact response and identify the nonlinear impact parameters. The least square residual between the computed and test results is defined to drive the identification optimization. The response surface methodology in combination with the generalized reduced gradient method is used to search the best matching coefficients. Final results show that the equivalent bending stiffness of the tested rubber expansion joint gradually decreases with the transverse deformation and is greatly influenced by its internal working pressure.

Bacterial Fruit Rot of Apricot Caused by Burkholderia cepacia in China

Fang, Yuan,Li, Bin,Wang, Fang,Liu, Baoping,Wu, Zhiyi,Su, Ting,Qiu, Wen,Xie, Guanlin The Korean Society of Plant Pathology 2009 Plant Pathology Journal Vol.25 No.4

An unreported disease of apricot was observed in orchards in Zhejiang province, China. Symptoms started as water soaked lesions on the fruit surface. Later, water-soaked areas developed and spread to the entire fruit, resulting in soft rot of the whole fruit. The causal organism isolated from symptomatic fruits was identified as Burkholderia cepacia based on its biochemical and physiological characteristics and confirmed by the cellular fatty acid composition and Biolog data as well as 16S rRNA gene sequence analysis. The bacterial isolates caused similar symptoms when inoculated onto fruits of apricot. In addition, European plum, Japanese plum, nectarine and kiwifruit were susceptible to the B. cepacia pathogen. However, the B. cepacia pathogen failed to cause any visible symptoms when it was inoculated onto 16 other fruits. This is the first report of a bacterial disease of apricot caused by B. cepacia in China.

Bacterial Fruit Rot of Apricot Caused by Burkholderia cepacia in China

Yuan Fang,Bin Li,Fang Wang,Baoping Liu,Zhiyi Wu,Ting Su,Wen Qiu,Guanlin Xie 한국식물병리학회 2009 Plant Pathology Journal Vol.25 No.4

An unreported disease of apricot was observed in orchards in Zhejiang province, China. Symptoms started as water soaked lesions on the fruit surface. Later, water-soaked areas developed and spread to the entire fruit, resulting in soft rot of the whole fruit. The causal organism isolated from symptomatic fruits was identified as Burkholderia cepacia based on its biochemical and physiological characteristics and confirmed by the cellular fatty acid composition and Biolog data as well as 16S rRNA gene sequence analysis. The bacterial isolates caused similar symptoms when inoculated onto fruits of apricot. In addition, European plum, Japanese plum, nectarine and kiwifruit were susceptible to the B. cepacia pathogen. However, the B. cepacia pathogen failed to cause any visible symptoms when it was inoculated onto 16 other fruits. This is the first report of a bacterial disease of apricot caused by B. cepacia in China.

Ginsenosides as dietary supplements with immunomodulatory effects: a review

Tang Ping,Liu Sitong,Zhang Junshun,Ai Zhiyi,Hu Yue,Cui Linlin,Zou Hongyang,Li Xia,Wang Yu,Nan Bo,Wang Yuhua 한국응용생명화학회 2024 Applied Biological Chemistry (Appl Biol Chem) Vol.67 No.-

Immune disorders have become one of the public health problems and imposes a serious economic and social burden worldwide. Ginsenosides, the main active constituents of ginseng, are regarded as a novel supplementary strategy for preventing and improving immune disorders and related diseases. This review summarized the recent research progress of ginsenosides in immunomodulation and proposed future directions to promote the development and application of ginsenosides. After critically reviewing the immunomodulatory potential of ginsenosides both in vitro and in vivo and even in clinical data of humans, we provided a perspective that ginsenosides regulated the immune system through activation of immune cells, cytokines, and signaling pathways such as MAPK, PI3K/ Akt, STAT, and AMPK, as well as positively affected immune organs, gut flora structure, and systemic inflammatory responses. However, the evidence for the safety and efficacy of ginsenosides is insufficient, and the immune pathways of ginsenosides remain incompletely characterized. We believe that this review will provide a valuable reference for further research on ginsenosides as dietary supplements with immunomodulatory effects.

Atorvastatin regulates the migration and invasion of prostate cancer through the epithelial-mesenchymal transformation and matrix metalloproteinase pathways

Zhanmeng Zhu,Yin Cao,Lingyun Liu,Zhiyi Zhao,Hongyu Yin,Hongliang Wang 대한비뇨의학회 2022 Investigative and Clinical Urology Vol.63 No.3

Purpose: Our purpose was to verify the effects of atorvastatin (ATO) on prostate cancer (PCa) proliferation, apoptosis, invasion, and metastasis and to further explore the drug’s mechanism of action. Materials and Methods: We used cell counting kit-8 (CCK8) and clone formation experiments to study the effect of ATO on the proliferation of PC3 cells. Flow cytometry and Hoechst 33342 staining were used to detect cell apoptosis. Cell migration and invasion were detected through wound healing experiments and transwell experiments. Western blotting was applied to detect apoptosis-related proteins (BAX, Bcl-2, PARP, and Caspase-3), epithelial-mesenchymal transformation (EMT) proteins, and matrix metalloproteinase (MMP) expression. A mouse xenograft tumor model was established, and tumor volume and weight were determined. The expression levels of the above-mentioned proteins were determined through western blot. Results: ATO inhibited PC-3 cell proliferation and promoted cell apoptosis in a dose-dependent manner. ATO significantly up-regulated the expression of BAX, PARP, and Caspase-3 and inhibited the expression of Bcl-2. Wound healing and transwell experiments showed that ATO inhibited invasion and metastasis in PC-3 cells, possibly because ATO could inhibit the EMT and the expression of MMPs in PC-3 cells. Studies in nude mice showed that ATO significantly reduced tumor volume and weight; the expression levels of related proteins were consistent with the in vitro results. Conclusions: ATO inhibits the occurrence and development of PCa and regulates the migration and invasion of PCa cells by inhibiting the EMT and MMPs.