Analysis of thermal performance and thermal stress using two-dimensional thermoelastic model for a 50 MWe external cylindrical solar receiver

Hao Zhou,Yuhang Zuo,Yawei Li,Mingxi Zhou 대한기계학회 2021 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.35 No.10

The thermal stress arisen from highly inhomogeneous solar radiation and temperature distribution during operation is mainly responsible for the failure of the central receiver. In the present study, the analytical approximation method, finite volume method and 2D thermoelastic analytical approach were used in combination to obtain the thermal characteristics of a 50 MWe external cylindrical receiver. The results demonstrated that the direct normal irradiance and tube surface absorptivity significantly affected the thermal stress. The axial distribution of the equivalent thermal stress at θ = 0° consisted with the surface solar flux distribution, and the maximum equivalent stress was underestimated by 30.0 % with the homogeneous surface solar flux distribution. Compared with molten salt flowing into the receiver from the south, the maximum equivalent stress and maximum wall temperature of molten salt flowing from the north are 16.3 % higher and 8.1 % lower, respectively.

Cold-induced ginsenosides accumulation is associated with the alteration in DNA methylation and relative gene expression in perennial American ginseng (Panax quinquefolius L.) along with its plant growth and development process

Mengzhen Hao,Yuhang Zhou,Jinhui Zhou,Min Zhang,Kangjiao Yan,Sheng Jiang,Wenshui Wang,Xiaoping Peng,San Zhou 고려인삼학회 2020 Journal of Ginseng Research Vol.44 No.5

Background: Ginsenosides accumulation responses to temperature are critical to quality formation in cold-dependent American ginseng. However, the studies on cold requirement mechanism relevant to ginsenosides have been limited in this species. Methods: Two experiments were carried out: one was a multivariate linear regression analysis between the ginsenosides accumulation and the environmental conditions of American ginseng from different sites of China and the other was a synchronous determination of ginsenosides accumulation, overall DNA methylation, and relative gene expression in different tissues during different developmental stages of American ginseng after experiencing different cold exposure duration treatments. Results: Results showed that the variation of the contents as well as the yields of total and individual ginsenosides Rg1, Re, and Rb1 in the roots were closely associated with environmental temperature conditions which implied that the cold environment plays a decisive role in the ginsenoside accumulation of American ginseng. Further results showed that there is a cyclically reversible dynamism between methylation and demethylation of DNA in the perennial American ginseng in response to temperature seasonality. And sufficient cold exposure duration in winter caused sufficient DNA demethylation in tender leaves in early spring and then accompanied the high expression of flowering gene PqFT in flowering stages and ginsenosides biosynthesis gene PqDDS in green berry stages successively, and finally, maximum ginsenosides accumulation occurred in the roots of American ginseng. Conclusion: We, therefore, hypothesized that cold-induced DNA methylation changes might regulate relative gene expression involving both plant development and plant secondary metabolites in such cold-dependent perennial plant species.

Current Status of Serum Insulin and C-Peptide Measurement in Clinical Laboratories: Experience from 94 Laboratories in China

Zhou Weiyan,Deng Yuhang,Zhao Haijian,Zhang Chuanbao 대한진단검사의학회 2022 Annals of Laboratory Medicine Vol.42 No.4

Background: Accurate measurements of serum insulin and C-peptide are needed for the therapy and classification of diabetes. This study investigated the status of serum insulin and C-peptide measurements in China by analyzing the results of five pooled serum samples measured in 94 laboratories. Methods: Patient serum samples were pooled into five groups according to insulin and C-peptide concentrations and measured in 94 laboratories using different measurement systems. The inter- and intra-laboratory %CV as well as inter- and intra-measurement system %CV were calculated to assess the status of insulin and C-peptide measurements. To verify whether the disagreement between laboratories was due to different calibrators, as reported in previous studies, one low-level and one high-level sample extracted from the five pooled serum samples were used to recalibrate clinical measurement systems. Results: The mean intra-laboratory, intra-measurement system, inter-laboratory, and inter-measurement system %CVs were 2.7%, 4.8%, 21.8%, and 22.4%, respectively, for insulin and 2.3%, 6.7%, 16.4%, and 24.5%, respectively, for C-peptide. The inter- and intra-laboratory %CVs for insulin decreased with increasing concentration. After recalibration with low- and high-level samples, the mean inter-measurement %CV decreased from 22.4% to 17.2% for insulin and from 24.5% to 5.7% for C-peptide. Conclusions: The intra-laboratory and intra-measurement system imprecision values are satisfactory for serum insulin and C-peptide measurements. However, the results from laboratories using different measurement systems were not comparable, and there is still much work needed to achieve the standardization or harmonization of serum insulin and C-peptide measurements.

Quantitative Characterization Method for Rock Surface Roughness with Different Scale Fluctuation

Yuhang Guo,Chuanqing Zhang,Hang Xiang,Guojian Cui,Fanzhen Meng,Hui Zhou 대한토목학회 2022 KSCE Journal of Civil Engineering Vol.26 No.4

Quantitative characterization of the surface roughness plays a vital role in the field of rock mechanics. The objectives of this study were to propose a new index that can describe the various morphological characteristics with different scale fluctuation. The power spectral density (PSD) parameters and conventional statistical parameters were used to analyze the roughness of meso-scale grind surfaces, intermediate-scale synthesis surfaces, and macro-scale shear surfaces. The results showed that the PSD parameters (slope k, intercept b, spectral moment λ0, and spectral shape parameters ω1 and ω2) and conventional statistical parameters(RMS and Z2) have evident uniqueness and uniformity in characterizing the roughness with different scale fluctuation. It is necessary to appropriately use the correct parameters for classifying and quantifying the roughness. For this purpose, a new characterization index SLAwas proposed based on the spectral shape parameter ω1, spectral moment λ0, slope k, and angle fractal index C.

PMN-PT Single Crystal for Endoscopic Ultrasound 2D Array Application

Yuhang Zhu,Huageng Liang,Benpeng Zhu,Dan Zhou,Xiaofei Yang 대한금속·재료학회 2017 ELECTRONIC MATERIALS LETTERS Vol.13 No.2

Based on lead magnesium niobate-lead titanate single crystal, a 24 × 24row-column addressing endoscopic two-dimensional array has beensuccessfully fabricated using novel flanged electrodes and “semi-kerf”technologies. Each row/column array element was measured to have anelectromechanical coupling coefficient of 0.81, a center frequency of5MHz, and a fractional bandwidth of approximately 88% at −6 dB. Ofparticular significance was that the lead magnesium niobate-lead titanateelement exhibits much higher sensitivity compared with lead zirconatetitanate-based 2D arrays with similar operational frequency and elementarea. According to the Field II simulated results, although the obtainedbeamwidth at −6 dB was a little inferior to that of the fully sampled 24 × 24two-dimensional array, it is believed that the beamwidth can be improved byappropriately increasing the element number. These results demonstratedthat the lead magnesium niobate-lead titanate single-crystal 2D array is apromising candidate for real-time three-dimensional endoscopic ultrasoundimaging.

An Accurate Isotope Dilution Liquid Chromatography-Tandem Mass Spectrometry Method for Serum C-Peptide and Its Use in Harmonization in China

Deng Yuhang,Zhang Chao,Wang Jing,Zeng Jie,Zhang Jiangtao,Zhang Tianjiao,Zhao Haijian,Zhou Weiyan,Zhang Chuanbao 대한진단검사의학회 2023 Annals of Laboratory Medicine Vol.43 No.4

Background: Serum C-peptide results from various routine methods used in China are highly variable, warranting well-performing methods to serve as an accuracy base to improve the harmonization of C-peptide measurements in China. We developed an accurate isotope dilution liquid chromatography-tandem mass spectrometry (ID-LC–MS/MS) method for serum C-peptide measurement and explored its use in harmonization. Methods: After protein precipitation with ZnSO4 solution, C-peptide was extracted from serum samples by anion-exchange solid-phase extraction and quantified by ID-LC–MS/MS in positive ion mode. The precision and analytical recovery of the ID-LC–MS/MS method were assessed. Seventy-six serum samples were analyzed using the ID-LC–MS/MS method and six routine immunoassays. Ordinary linear regression (OLR) and Bland-Altman (BA) analyses were conducted to evaluate the relationship between the ID-LC–MS/MS method and routine immunoassays. Five serum pool samples assigned using the ID-LC–MS/MS method were used to recalibrate the routine assays. OLR and BA analyses were re-conducted after recalibration. Results: The within-run, between-run, and total precision for the ID-LC–MS/MS method at four concentrations were 1.0%–2.1%, 0.6%–1.2%, and 1.3%–2.2%, respectively. The analytical recoveries for the ID-LC–MS/MS method at three concentrations were 100.3%–100.7%, 100.4%–101.0%, and 99.6%–100.7%. The developed method and the immunoassays were strongly correlated, with all R2 >0.98. The comparability among the immunoassays was substantially improved after recalibration. Conclusions: The performance of the ID-LC–MS/MS method was carefully validated, and this method can be used to improve the harmonization of serum C-peptide measurements in China.

Commutability Assessment of Processed Human Plasma Samples for Normetanephrine and Metanephrine Measurements Based on the Candidate Reference Measurement Procedure

Deng Yuhang,Liu Qingxiang,Liu Zhenni,Zhao Haijian,Zhou Weiyan,Zhang Chuanbao 대한진단검사의학회 2022 Annals of Laboratory Medicine Vol.42 No.5

Background: To identify candidate external quality assessment (EQA) materials for normetanephrine and metanephrine measurements, we assessed the commutability of eight processed human plasma samples. The agreement between routine assays and the candidate reference measurement procedure (cRMP) was also evaluated. Methods: Fifty-three clinical samples and eight processed plasma samples were prepared. The processed samples included pooled and individual plasma samples spiked with pure normetanephrine and metanephrine and non-spiked pooled and individual plasma samples. The clinical and processed samples were subjected to four routine isotope dilution tandem mass spectrometry assays and cRMP. Commutability was assessed based on two approaches recommended by the CLSI and International Federation of Clinical Chemistry (IFCC). Passing–Bablok regression and Bland–Altman analysis were used to evaluate the agreement between the routine assays and cRMP. Results: The commutability results of the CLSI approach were better than those of the IFCC approach. For the CLSI approach, spiked individual plasma samples and spiked high-concentration pooled plasma samples were commutable for all routine assays for both analytes. The non-spiked pooled plasma sample was commutable for two out of four routine assays for metanephrine and three out of four routine assays for normetanephrine. The agreement between the routine assays and the cRMP was satisfactory, except for one routine assay showing significant bias. Conclusions: High-concentration spiked pooled plasma samples and spiked individual plasma samples are candidate EQA materials for normetanephrine and metanephrine measurements.

SET/PP2A signaling regulates macrophage positioning in hypoxic tumor regions by amplifying chemotactic responses

Zhang Shaolong,Zhou Jingping,Shang Pengzhao,Zhao Guomeng,Wang Anlei,Mao Jinlei,Tao Yuhang,Chen Ziyi,Wang Xuehao,Guo Changying 생화학분자생물학회 2022 Experimental and molecular medicine Vol.54 No.-

Tumor-associated macrophages (TAMs) are one of the main cellular components in the tumor microenvironment (TME). In many types of solid tumors, TAMs tend to accumulate in hypoxic areas and are intimately related to poor patient prognosis. However, the underlying mechanisms by which TAMs infiltrate hypoxic tumor regions remain unclear. In this study, we report that genetic deletion of SE translocation (SET) in myeloid cells inhibited the entry of TAMs into the hypoxic tumor region and abated their proangiogenic and immunosuppressive functions, ultimately inhibiting tumor growth. Mechanistically, in response to hypoxic tumor supernatant stimulation, SET in macrophages shuttled between the nucleus and cytoplasm via the PKC-CK2α signaling axis. Cytoplasmic retention of SET increased ERK and P38 signaling by inhibiting PP2A, which promoted TAM migration into the hypoxic area and polarization toward the M2 phenotype. Therefore, we conclude that SET modulates tumor immunity by acting as a key regulator of macrophage positioning and function in the tumor.

Effects of different dietary fats on biological characteristics of Coccinella septempunctata L

Cheng Ying,Zhou Yuhang,Li Fengliang 한국응용곤충학회 2024 Journal of Asia-Pacific Entomology Vol.27 No.2

The study aims to provide a basis for the large-scale artificial breeding of Coccinella septempunctata, the composition of an artificial diet for the ladybird was optimised by adding different fats to the diet. The effects of different dietary fats on the biology of ladybirds were evaluated by supplementing artificial diets with fats. The results show that the coconut, palm, perilla, linseed, lard and sesame oils should not be added to the artificial diet of ladybird larvae because of deleterious effects on ladybirds. The addition of 6 g olive oil (3 % of diet weight) improved larvae survival rate, and the addition of 4 g beef tallow (2 % of diet weight) increased ladybird pu pation and emergence rates. In adult stage, the addition of 4 g coconut oil (2 % of diet weight) improved survival rates. Whereas 2–4 g olive oil (1–2 % of diet weight), 2–6 g lard (1–3 % of diet weight) and 6 g beef tallow oil (3 % of diet weight) improved oviposition and hatchability. In conclusion, the demand for fats is different in the larval and adult stages of the C. septempunctata. The findings of this study provide a valuable reference for the addition of exogenous fats to the ladybird artificial diet.

Geometry and Mechanical Behaviour of Radially Retractable Roof Structures During the Movement Process

Jianguo Cai,Yuhang Zhou,Yifeng Zhu,Yixiang Xu,Jin Zhang 한국강구조학회 2016 International Journal of Steel Structures Vol.16 No.3

In this paper, the kinematic characteristic of the radially retractable roof structure was firstly discussed and the motion boundary of the system was also studied. The results show that the diameter of the outer boundary of the system increases firstly and then decreases when the roof is open. Moreover, the numerical study of the structural behavior of the retractable roof with radial foldable bars and circumferential foldable bars was carried out, respectively. It can be found the latter one has a better structural behavior. Then the mechanical behaivor of the system during the motion was also investigated. Finally, a loop linkage based on a special scissor-like element was proposed to support the retractable roof.