Preliminary design and assessment of a heat pipe residual heat removal system for the reactor driven subcritical facility

Wenwen Zhang,Kaichao Sun,Chenglong Wang,Dalin Zhang,Wenxi Tian,Suizheng Qiu,G.H. Su 한국원자력학회 2021 Nuclear Engineering and Technology Vol.53 No.12

A heat pipe residual heat removal system is proposed to be incorporated into the reactor drivensubcritical (RDS) facility, which has been proposed by MIT Nuclear Reactor Laboratory for testing anddemonstrating the Fluoride-salt-cooled High-temperature Reactor (FHR). It aims to reduce the risk of thesystem operation after the shutdown of the facility. One of the main components of the system is an aircooled heat pipe heat exchanger. The alkali-metal high-temperature heat pipe was designed to meet theoperation temperature and residual heat removal requirement of the facility. The heat pipe modeldeveloped in the previous work was adopted to simulate the designed heat pipe and assess the heattransport capability. 3D numerical simulation of the subcritical facility active zone was performed by thecommercial CFD software STAR CCM þ to investigate the operation characteristics of this proposedsystem. The thermal resistance network of the heat pipe was built and incorporated into the CFD model. The nominal condition, partial loss of air flow accident and partial heat pipe failure accident weresimulated and analyzed. The results show that the residual heat removal system can provide sufficientcooling of the subcritical facility with a remarkable safety margin. The heat pipe can work under therecommended operation temperature range and the heat flux is below all thermal limits. The facilitypeak temperature is also lower than the safety limits

新时代高校培养好青年的路径探究

张雯雯(Wenwen Zhang),张泽琪(Zeqi Zhang),行国通(Guotong Xing) YIXIN 출판사 2024 教育教学研究论丛 Vol.2 No.3

青年是国家的希望,民族的未来。培养新时代好青年具有重大的意义,培养新时代好青年有利于高校青年自身素质提高、有利于青年勇于担当历史使命和推动民族复兴。因此高校应以培养新时代理想者、新时代担当者、新时代吃苦者和新时代奋斗者为目标和主要内容。但高校在培养青年过程中存在着诸多问题。为此,高校应形成协同发展的培育模式、建立结构完备的培育机制和健全网络培养体系。高校对新时代好青年的培育有助于增强中国青年的历史使命感和责任感,对党和国家未来的发展和社会主义建设起着重大而深远的意义。 Youth is the hope of a country and the future of a nation. Training good young people in the new era is of great significance, which is conducive to improving the quality of young people in colleges and universities, helping young people to take up the historical mission and promote national rejuvenation. Therefore, colleges and universities should take the training of the new era ideal, the new era of responsibility, the new era of hardship and the new era of strugglers as the goal and main content. But there are many problems in the process of training young people. Therefore, colleges and universities should form the cultivation mode of cooperative development, set up a well-structured cultivation mechanism and perfect network training system. The cultivation of good young people in colleges and universities in the new era helps to enhance the sense of historical mission and responsibility of Chinese youth, and plays a significant and far-reaching significance for the future development of the Party and the country and the construction of socialism.

miR-458b-5p regulates ovarian granulosa cells proliferation through Wnt/β‐catenin signaling pathway by targeting catenin beta-1

Wang Wenwen,Teng Jun,Han Xu,Zhang Shen,Zhang Qin,Tang Hui 아세아·태평양축산학회 2021 Animal Bioscience Vol.34 No.6

Objective: Ovarian follicular development, which dependent on the proliferation and differentiation of granulosa cells (GCs), is a complex biological process in which miRNA plays an important role. Our previous study showed that miR-458b-5p is associated with ovarian follicular development in chicken. The detailed function and molecular mechanism of miR-458b-5p in GCs is unclear. Methods: The luciferase reporter assay was used to verify the targeting relationship between miR-458b-5p and catenin beta-1 (CTNNB1), which is an important transcriptional regulatory factor of the Wnt/β-catenin pathway. The cell counting kit-8 (CCK-8) assay, flow cytometry with propidium iodide (PI) and annexin V-fluorescein isothiocyanate (FITC) labeling were applied to explore the effect of miR-458b-5p on proliferation, cell cycle and apoptosis of chicken GCs. Quantitative real-time polymerase chain reaction and Western blot were used to detect the mRNA and protein expression levels. Results: We demonstrated that the expression of miR-458b-5p and CTNNB1 showed the opposite relationship in GCs and theca cells of hierarchical follicles. The luciferase reporter assay confirmed that CTNNB1 is the direct target of miR-458b-5p. Using CCK-8 assay and flow cytometry with PI and Annexin V-FITC labeling, we observed that transfection with the miR-458b-5p mimics significantly reduced proliferation and has no effects on apoptosis of chicken GCs. In addition, miR-458b-5p decreased the mRNA and protein expression of CD44 molecule and matrix metallopeptidase 7, which are the downstream effectors of CTNNB1 in Wnt/β-Catenin pathway and play functional roles in cell proliferation. Conclusion: Taken together, the data indicate that miR-458b-5p regulates ovarian GCs proliferation through Wnt/β-catenin signaling pathway by targeting CTNNB1, suggesting that miR-458b-5p and its target gene CTNNB1 may potentially play a role in chicken ovarian follicular development. Objective: Ovarian follicular development, which dependent on the proliferation and differentiation of granulosa cells (GCs), is a complex biological process in which miRNA plays an important role. Our previous study showed that miR-458b-5p is associated with ovarian follicular development in chicken. The detailed function and molecular mechanism of miR-458b-5p in GCs is unclear.Methods: The luciferase reporter assay was used to verify the targeting relationship between miR-458b-5p and catenin beta-1 (<i><i>CTNNB1</i></i>), which is an important transcriptional regulatory factor of the Wnt/β-catenin pathway. The cell counting kit-8 (CCK-8) assay, flow cytometry with propidium iodide (PI) and annexin V-fluorescein isothiocyanate (FITC) labeling were applied to explore the effect of miR-458b-5p on proliferation, cell cycle and apoptosis of chicken GCs. Quantitative real-time polymerase chain reaction and Western blot were used to detect the mRNA and protein expression levels.Results: We demonstrated that the expression of miR-458b-5p and <i>CTNNB1</i> showed the opposite relationship in GCs and theca cells of hierarchical follicles. The luciferase reporter assay confirmed that <i>CTNNB1</i> is the direct target of miR-458b-5p. Using CCK-8 assay and flow cytometry with PI and Annexin V-FITC labeling, we observed that transfection with the miR-458b-5p mimics significantly reduced proliferation and has no effects on apoptosis of chicken GCs. In addition, miR-458b-5p decreased the mRNA and protein expression of CD44 molecule and matrix metallopeptidase 7, which are the downstream effectors of <i>CTNNB1</i> in Wnt/β-Catenin pathway and play functional roles in cell proliferation.Conclusion: Taken together, the data indicate that miR-458b-5p regulates ovarian GCs proliferation through Wnt/β-catenin signaling pathway by targeting <i>CTNNB1</i>, suggesting that miR-458b-5p and its target gene <i>CTNNB1</i> may potentially play a role in chicken ovarian follicular development.

Application of Improved Grid Search Algorithm on SVM for Classification of Tumor Gene

Li Wenwen,Xing Xiaoxue,Liu Fu,Zhang Yu 보안공학연구지원센터 2014 International Journal of Multimedia and Ubiquitous Vol.9 No.11

According to the merits and shortcomings of the traditional gridsearch algorithm in parameters optimization of support vector machine (SVM), an improved grid search algorithm is proposed. Dichotomous search algorithm is used to reduce target searching range. First, searching range is determined roughly, and a set of parameters are obtained. Then fine search is applied in reduction the range for searching, and searching the optimum parameters.Three kinds of famous tumor gene data set are used in the comparison experiments to validate the classification accuracy of principal component analysis (PCA)-SVM and kernel principal component analysis (KPCA)-SVM. Experiment results and data analysis shows that, comparing with traditional gridsearch algorithm, the proposed method has higher classification accuracy and less search time.

PVDF membrane with tea powder adhered for efficient separation of emulsified oil

Zhang Junshuang,Wu Yue,Xia Mengsheng,Yang Qijiang,Xu Qinyao,Feng Wenwen 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.10

Conventional oily wastewater treatment can remove slick oil and dispersed oil well, but it is difficult for it to remove emulsified oil. Nonetheless, the development of super wetting materials provides a key role in treating the emulsified oil, but there are some problems, such as expensive raw materials, complicated processes, as well as secondary pollution. In order to treat these problems, a brand-new oil/water separation membrane (TEA/PVDF membrane) was developed by combining the viscosity of sodium alginate (SA) and the filter tea powder (TEA) onto the surface of the polyvinylidene fluoride (PVDF) membrane by a vacuum pump. Furthermore, the underwater oleophobic angle reached 135o. Moreover, the oil-water separation experiments of oil-in-water emulsion utilizing TEA/PVDF membrane demonstrated excellent separation efficiency (99.6%) and good flux (254 L m−2 h−1 bar−1). Notably, upon ten cycles, the oil removal rate was still as high as 99.2%. Moreover, the TEA/PVDF membrane was able to separate oil-in-water emulsions in environments with strong acids, strong bases, and high salt concentrations, with a separation efficiency of over 95.9%. Such a novel oil/water separation membrane is economic, environmentally protective, and simple production process, which exhibits overwhelming potential in practical life for treating oily wastewater.

Isocryptotanshinone Induced Apoptosis and Activated MAPK Signaling in Human Breast Cancer MCF-7 Cells

Xuenong Zhang,Weiwei Luo,Wenwen Zhao,Jinjian Lu,Xiuping Chen 한국유방암학회 2015 Journal of breast cancer Vol.18 No.2

Purpose: Isocryptotanshinone (ICTS) is a natural bioactive product that is isolated from the roots of the widely used medical herb Salvia miltiorrhiza. However, few reports exist on the mechanisms underlying the therapeutic effects of ICTS. Here, we report that ICTS has anticancer activity and describe the mechanism underlying this effect. Methods: The antiproliferative effect of ICTS was determined using 3-(4,5-dimethyl-2-thiazolyl)-2,5- diphenyl-2-H-tetrazolium bromide (MTT) and clonogenic assays. The effect of ICTS on the cell cycle was measured using flow cytometry. Apoptosis was determined by Hoechst 33342 staining, DNA fragmentation assays, and Western blotting for apoptotic proteins. Finally, the effect of ICTS on mitogen-activated protein kinases (MAPKs) was determined by Western blotting. Results: ICTS significantly inhibited proliferation of MCF-7 and MDA-MB-231 human breast cancer cells, HepG2 human liver cancer cells, and A549 human lung cancer cells in vitro. Among the tested cell lines, MCF-7 cells showed the highest sensitivity to ICTS. ICTS significantly inhibited colony formation by MCF-7 cells. Furthermore, exposure of MCF-7 cells to ICTS induced cell cycle arrest at the G1 phase and decreased mitochondrial membrane potential. Hoechst 33342 staining and Western blot analysis for apoptotic proteins suggested that ICTS induced apoptosis in MCF-7 cells. In addition, ICTS activated MAPK signaling in MCF-7 cells by inducing time- and concentration-dependent phosphorylation of JNK, ERK, and p38 MAPK. Conclusion: Our results suggest that ICTS inhibited MCF-7 cell proliferation by inducing apoptosis and activating MAPK signaling pathways.

High-performance Zinc-Tin-Oxide thin film transistors based on environment friendly solution process

Qian Zhang,Guodong Xia,Lubin Li,Wenwen Xia,Hong-Yu Gong,Sumei Wang 한국물리학회 2019 Current Applied Physics Vol.19 No.2

Zinc-Tin-Oxide (ZTO) thin films were fabricated using a simple and eco-friendly sol-gel method and their application in thin film transistors (TFTs) was investigated. Annealing temperature has a crucial influence on the structure and electrical properties of sol-gel ZTO thin films. The ZTO thin films annealed at 300–600 °C revealed smooth and uniform surfaces with amorphous state, in addition, a high optical transparency over 90% of the ZTO films in the visible range was obtained. The electrical performance of ZTO TFTs showed obvious dependence on annealing temperature. The ZTO TFTs annealed at 500 °C showed a high carrier mobility of 5.9 cm2 /V, high on/off current ratio (Ion/off) of 106 -107 , and threshold voltage (Vth) of 1.03 V. To demonstrate the application of sol-gel ZTO films in low-power display fields, we also fabricated ZTO TFTs with a solution-processed high-permittivity (high-k) ZrTiOx dielectric layer. The ZTO/ZrTiOx TFTs showed high mobility of 17.9 cm2 /V and Ion/off of 105 -106 at a low operation voltage of 3 V, indicating that Indium-free ZTO thin films would be potential candidates for low cost, high performance oxide TFT devices.

Security Analysis of the Lightweight Cryptosystem TWINE in the Internet of Things

( Wei Li ),( Wenwen Zhang ),( Dawu Gu ),( Zhi Tao ),( Zhihong Zhou ),( Ya Liu ),( Zhiqiang Liu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.2

The TWINE is a new Generalized Feistel Structure (GFS) lightweight cryptosystem in the Internet of Things. It has 36 rounds and the key lengths support 80 bits and 128 bits, which are flexible to provide security for the RFID, smart cards and other highly-constrained devices. Due to the strong attacking ability, fast speed, simple implementation and other characteristics, the differential fault analysis has become an important method to evaluate the security of lightweight cryptosystems. On the basis of the 4-bit fault model and the differential analysis, we propose an effective differential fault attack on the TWINE cryptosystem. Mathematical analysis and simulating experiments show that the attack could recover its 80-bit and 128-bit secret keys by introducing 8 faulty ciphertexts and 18 faulty ciphertexts on average, respectively. The result in this study describes that the TWINE is vulnerable to differential fault analysis. It will be beneficial to the analysis of the same type of other iterated lightweight cryptosystems in the Internet of Things.

Effect of spiral spacing on axial compressive behavior of square reinforced concrete filled steel tube (RCFST) columns

Qiyun Qiao,Wenwen Zhang,Ben Mou,Wanlin Cao 국제구조공학회 2019 Steel and Composite Structures, An International J Vol.31 No.6

Spiral spacing effect on axial compressive behavior of reinforced concrete filled steel tube (RCFST) stub column is experimentally investigated in this paper. A total of twenty specimens including sixteen square RCFST columns and four benchmarked conventional square concrete filled steel tube (CFST) columns are fabricated and tested. Test variables include spiral spacing (spiral ratio) and concrete strength. The failure modes, load versus displacement curves, compressive rigidity, axial compressive strength, and ductility of the specimens are obtained and analyzed. Especially, the effect of spiral spacing on axial compressive strength and ductility is investigated and discussed in detail. Test results show that heavily arranged spirals considerably increase the ultimate compressive strength but lightly arranged spirals have no obvious effect on the ultimate strength. In practical design, the effect of spirals on RCFST column strength should be considered only when spirals are heavily arranged. Spiral spacing has a considerable effect on increasing the post-peak ductility of RCFST columns. Decreasing of the spiral spacing considerably increases the post-peak ductility of the RCFSTs. When the concrete strength increases, ultimate strength increases but the ductility decreases, due to the brittleness of the higher strength concrete. Arranging spirals, even with a rather small amount of spirals, is an economical and easy solution for improving the ductility of RCFST columns with highstrength concrete. Ultimate compressive strengths of the columns are calculated according to the codes EC4 (2004), GB 50936 (2014), AIJ (2008), and ACI 318 (2014). The ultimate strength of RCFST stub columns can be most precisely evaluated using standard GB 50936 (2014) considering the effect of spiral confinement on core concrete.

Regional Homogeneity Brain Alterations in Schizophrenia: An Activation Likelihood Estimation Meta-Analysis

Xiaolei Qiu,Wenwen Xu,Rongrong Zhang,Wei Yan,Wenying Ma,Shiping Xie,Min Zhou 대한신경정신의학회 2021 PSYCHIATRY INVESTIGATION Vol.18 No.8

Objective Resting state functional magnetic resonance imaging (rsfMRI) provides a lot of evidence for local abnormal brain activity in schizophrenia, but the results are not consistent. Our aim is to find out the consistent abnormal brain regions of the patients with schizophrenia by using regional homogeneity (ReHo), and indirectly understand the degree of brain damage of the patients with drug-naive first episode schizophrenia (Dn-FES) and chronic schizophrenia. Methods We performed the experiment by activation likelihood estimation (ALE) software to analysis the differences between people with schizophrenia group (all schizophrenia group and chronic schizophrenia group) and healthy controls. Results Thirteen functional imaging studies were included in quantitative meta-analysis. All schizophrenia group showed decreased ReHo in bilateral precentral gyrus (PreCG) and left middle occipital gyrus (MOG), and increased ReHo in bilateral superior frontal gyrus (SFG) and right insula. Chronic schizophrenia group showed decreased ReHo in bilateral MOG, right fusiform gyrus, left PreCG, left cerebellum, right precuneus, left medial frontal gyrus and left anterior cingulate cortex (ACC). No significant increased brain areas were found in patients with chronic schizophrenia. Conclusion Our findings suggest that patients with chronic schizophrenia have more extensive brain damage than FES, which may contribute to our understanding of the progressive pathophysiology of schizophrenia.