38 results on '"Zhang, Yajie"'
Search Results
2. An Exploration of Registered Dietitian Accreditation System Development in China
- Author
-
Zhang, Yajie, Wang, Xiaoli, Liu, Ya, Shen, Xiuhua, Xiao, Rong, Zhu, Huilian, Zeng, Guo, Cai, Wei, Ma, Aiguo, and Yang, Yuexin
- Subjects
China ,Marital Status ,Universities ,Humans ,Internship and Residency ,General Medicine ,Education - Abstract
The registered dietitian system started late in China, and since 2014 a working committee of registered dietitians has been formed by the Chinese Nutrition Society to establish a national accreditation system in accordance with the international standard academic and internship requirements. The data from the certification examinations and registrations were collected and analyzed. 8,328 registered dietitians were included in the study, with 5,673 registered dietitians (RD) and 2,655 registered dietetic technicians (DTR). Among them, 45.27% of RDs have master degree or above, and 66.44% of DTRs have bachelor or above. 53.25% RDs work in medical institutions, 14.77% in colleges and universities, and 14.56% in enterprises; 48.21% DTRs work in the medical institutions, 30.28% in enterprises, and 7.34% in the community. Although six years of work has initially established a foundation of standardized registered dietitian accreditation system, the problems of limited resources for academic education and the lack of legislative protection for the profession remain prominent.
- Published
- 2022
3. Additional file 3 of Uncertainties of soil organic carbon stock estimation caused by paleoclimate and human footprint on the Qinghai Plateau
- Author
-
Liu, Xia, Zhou, Tao, Shi, Peijun, Zhang, Yajie, Luo, Hui, Yu, Peixin, Xu, Yixin, Zhou, Peifang, and Zhang, Jingzhou
- Subjects
GeneralLiterature_REFERENCE(e.g.,dictionaries,encyclopedias,glossaries) - Abstract
Additional file 3. List of 58 published papers from which the data used in this study were derived.
- Published
- 2022
- Full Text
- View/download PDF
4. Additional file 1 of Uncertainties of soil organic carbon stock estimation caused by paleoclimate and human footprint on the Qinghai Plateau
- Author
-
Liu, Xia, Zhou, Tao, Shi, Peijun, Zhang, Yajie, Luo, Hui, Yu, Peixin, Xu, Yixin, Zhou, Peifang, and Zhang, Jingzhou
- Subjects
Data_FILES - Abstract
Additional file 1. Supplemental figures and tables.
- Published
- 2022
- Full Text
- View/download PDF
5. Additional file 4 of Uncertainties of soil organic carbon stock estimation caused by paleoclimate and human footprint on the Qinghai Plateau
- Author
-
Liu, Xia, Zhou, Tao, Shi, Peijun, Zhang, Yajie, Luo, Hui, Yu, Peixin, Xu, Yixin, Zhou, Peifang, and Zhang, Jingzhou
- Abstract
Additional file 4. Supplementary environmental data description.
- Published
- 2022
- Full Text
- View/download PDF
6. Jing-an oral liquid alleviates Tourette syndrome via the NMDAR/MAPK/CREB pathway in vivo and in vitro
- Author
-
Xi, Leying, Ji, Xixi, Ji, Wenxiu, Yang, Yue’e, Zhang, Yajie, and Long, Hongyan
- Abstract
Jing-an oral liquid (JA) is a Chinese herbal formula used in the treatment of Tourette syndrome (TS); however, its mechanism is unclear. To investigate the effects of JA on amino acid neurotransmitters and microglia activation in vivo and in vitro. Sixty male Sprague–Dawley rats were divided into a control group and 5 TS groups. TS was induced in rats with intraperitoneal injection of 1-(2,5-dimethoxy-4-iodophenyl)-2-aminopropane (1 mg/kg) and in BV2 cells with lipopolysaccharide. Control and model rats were administered saline, whereas treatment groups were administered JA (5.18, 10.36, or 20.72 g/kg) or tiapride (a benzamide, 23.5 mg/kg) by gavage once daily for 21 days. Stereotypic behaviour was tested. The levels of N-methyl-d-aspartate receptor (NMDAR)/mitogen-activated protein kinase/cAMP response element-binding protein (CREB)-related proteins in striatum and BV2 cells were measured via western blots. CD11b and IBa1 levels were also measured. Ultra-high-performance liquid-chromatography was used to determine γ-aminobutyric acid (GABA), glutamic acid (Glu), and aspartic acid (ASP) levels. JA markedly alleviated the stereotype behaviour (25.92 ± 0.35 to 13.78 ± 0.47) in rats. It also increased NMDAR1 (0.48 ± 0.09 to 0.67 ± 0.08; 0.54 ± 0.07 to 1.19 ± 0.18) expression and down-regulated the expression of p-ERK, p-JNK, p-P38, and p-CREB in BV2 cells and rat striatum. Additionally, Glu, ASP, GABA, CD11b, and IBa1 levels were significantly decreased by JA. JA suppressed microglia activation and regulated the levels of amino acid neurotransmitters, indicating that it could be a promising therapeutic agent for TS.
- Published
- 2022
- Full Text
- View/download PDF
7. Additional file 1 of Exosomal circLPAR1 functions in colorectal cancer diagnosis and tumorigenesis through suppressing BRD4 via METTL3���eIF3h interaction
- Author
-
Zheng, Rui, Zhang, Ke, Tan, Shanyue, Gao, Fang, Zhang, Yajie, Xu, Wenxia, Wang, Huabin, Gu, Dongying, Zhu, Lingjun, Li, Shuwei, Chu, Haiyan, Zhang, Zhengdong, Liu, Lingxiang, Du, Mulong, and Wang, Meilin
- Abstract
Additional file 1: Supplementary Materials and Methods. Table S1. Demographic and clinical characteristics of the subjects who participated in RNA-Seq and proteogenomic analysis. Table S2. Five differentially expressed circRNAs and significant fold changes. Table S3. Demographic and clinical characteristics of the subjects in FISH analysis. Table S4. Demographic and clinical characteristics of subjects with colorectal cancer and cancer-free controls. Table S5. Characteristics of patients with other types of cancer. Table S6. Demographic and clinical characteristics of the colorectal cancer patients before and after operation. Table S7. Characterization of circLPAR1-binding proteins. Table S8. The correlation between protein and its parental gene expression and prediction of RNA binding ability. Table S9. Sequences of circLPAR1 used for FISH analysis in the study. Table S10. Sequences of primers used for RT-qPCR in the study. Figure S1. The expression of circRNAs detected by RT-qPCR. Figure S2. The expression of circLPAR1 in CRC cells treated with actinomycin D and colorectal tumors. Figure S3. Characterization of exosomes derived from human plasma. Figure S4. The expression of traditional clinical biomarkers in plasma. Figure S5. ROC curve analysis of exosomal circLPAR1 and traditional clinical biomarkers in human plasma. Figure S6. Fluorescence observation of colorectal cancer cells after incubation with PKH67-labelled exosomes or non-exosomes. Figure S7. Fluorescence observation of colorectal cancer cells incubation with PKH67-labelled exosomes pretreated with cytochalasin D. Figure S8. The expression of circLPAR1 in exosomes derived from colorectal cancer cells. Figure S9. The effect of exosomal circLPAR1 on invasion and migration abilities of HCT116 cells. Figure S10. The effect of circLPAR1 overexpression on colorectal cancer cellular phenotypes. Figure S11. The cellular localization of circLPAR1 in colorectal cancer cells. Figure S12. MS2-CP-Flag was pulled down by anti-flag and evaluated by Western blot. Figure S13. The proteomic analysis showing 23 proteins levels based on 25 paired colorectal cancer tissues. Figure S14. Mass spectrometry analysis identification of eIF3h. Figure S15. The effect of BRD4 regulation by circLPAR1 on colorectal cancer cellular phenotype. Figure S16. The enrichment of miR-762 in the complex with MS2-CP-Flag. Figure S17. Effect of exosomal circLPAR1 on colorectal cancer progression in vivo.
- Published
- 2022
- Full Text
- View/download PDF
8. Additional file 1 of Effects of pre-operative enteral immunonutrition for esophageal cancer patients treated with neoadjuvant chemoradiotherapy: protocol for a multicenter randomized controlled trial (point trial, pre-operative immunonutrition therapy)
- Author
-
Cao, Yuqin, Han, Dingpei, Yang, Su, Shi, Yongmei, Zhao, Shengguang, Jin, Qianwen, Li, Jian, Li, Chengqiang, Zhang, Yajie, Shen, Weiyu, He, Jinxian, Wang, Mingsong, Ji, Guangyu, Li, Zhigang, He, Yi, Chen, Qixun, Wei, Weitian, Chen, Chun, Gong, Xian, Wang, Jinyi, Tan, Lijie, Wang, Hao, and Li, Hecheng
- Abstract
Additional file1: Table S1. Time schedule of enrolment, interventions, and assessments.
- Published
- 2022
- Full Text
- View/download PDF
9. A Frame Level Feature Aggregation Method for Video target Detection
- Author
-
Wang Xinyue, Liu Bo, Zhang Bin, Hou Shuai, Chen Wenbo, Zhang Yajie, Chen Liu, Liu Wenfeng, Li Wei, Wang Jiayi, and Guo Jun
- Subjects
Pixel ,Computer science ,business.industry ,Motion blur ,Cosine similarity ,ComputingMethodologies_IMAGEPROCESSINGANDCOMPUTERVISION ,Optical flow ,Robustness (computer science) ,Computer Science::Multimedia ,Weight distribution ,Computer vision ,Artificial intelligence ,Zoom ,business ,Scaling - Abstract
The invention provides a frame level feature aggregation method for video target detection, and relates to the technical field of computer vision. The invention provides a frame-level feature aggregation method for video target detection. The method comprises the following steps: firstly, extracting deep features from a single-frame image through a feature network; extracting an inter-frame optical flow by using an optical flow network FlowNet; aligning the frame-level features of the adjacent frames to the current frame based on the optical flow to realize frame-level feature propagation; finally, calculating the scaling cosine similarity weight through the mapping network and the weight scaling network, and using the scaling cosine similarity weight to aggregate the multi-frame featuresto generate the aggregated features. According to the frame-level feature aggregation method for video target detection provided by the invention, the weight distribution is more reasonable, and the aggregated features are input into the video target detection network, so that video detection in complex scenes such as motion blur, low pixels, lens zooming and shielding can have a better detectioneffect and robustness.
- Published
- 2021
10. Additional file 2 of Epidemiological and clinical characteristics of respiratory viruses in 4403 pediatric patients from multiple hospitals in Guangdong, China
- Author
-
Zhang, Yajie, Qiao, Lin, Yao, Jinxiu, Yu, Nan, Mu, Xiaoping, Huang, Shengqi, Hu, Bo, Li, Weixuan, Qiu, Feng, Zeng, Fangyin, Chen, Cong, Zhou, Yuqiu, Zhang, Bashan, Cai, Tian, Wang, Weijia, Wu, Xianjin, Zhou, Yiwen, Wang, Guochang, Situ, Bo, Lan, Shuling, Li, Na, Li, Xiu, Li, Zihua, Li, Xin, Wang, Congrong, Yang, Chao, Feng, Pingfeng, Wang, Hongxia, Zhu, Sijing, Xiong, Yufeng, Luo, Min, Shen, Wenjuan, Hu, Xiumei, and Zheng, Lei
- Subjects
viruses - Abstract
Additional file 2: Clinical Indicators and Clinical Symptoms Associated with Respiratory Viruses Negative.
- Published
- 2021
- Full Text
- View/download PDF
11. sj-pdf-1-jcb-10.1177_0271678X211028816 - Supplemental material for Endovascular administration of magnetized nanocarriers targeting brain delivery after stroke
- Author
-
Grayston, Alba, Zhang, Yajie, Garcia-Gabilondo, Miguel, Arrúe, Mercedes, Martin, Abraham, Kopcansky, Peter, Timko, Milan, Kovac, Jozef, Strbak, Oliver, Castellote, Laura, Belloli, Sara, Moresco, Rosa M, Picchio, Maria, Roig, Anna, and Rosell, Anna
- Subjects
110320 Radiology and Organ Imaging ,FOS: Clinical medicine ,FOS: Biological sciences ,Medicine ,Cell Biology ,110305 Emergency Medicine ,110306 Endocrinology ,Biochemistry ,69999 Biological Sciences not elsewhere classified ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-pdf-1-jcb-10.1177_0271678X211028816 for Endovascular administration of magnetized nanocarriers targeting brain delivery after stroke by Alba Grayston, Yajie Zhang, Miguel Garcia-Gabilondo, Mercedes Arrúe, Abraham Martin, Peter Kopcansky, Milan Timko, Jozef Kovac, Oliver Strbak, Laura Castellote, Sara Belloli, Rosa M Moresco, Maria Picchio, Anna Roig and Anna Rosell in Journal of Cerebral Blood Flow & Metabolism
- Published
- 2021
- Full Text
- View/download PDF
12. sj-pdf-1-jcb-10.1177_0271678X211028816 - Supplemental material for Endovascular administration of magnetized nanocarriers targeting brain delivery after stroke
- Author
-
Grayston, Alba, Zhang, Yajie, Garcia-Gabilondo, Miguel, Arrúe, Mercedes, Martin, Abraham, Kopcansky, Peter, Timko, Milan, Kovac, Jozef, Strbak, Oliver, Castellote, Laura, Belloli, Sara, Moresco, Rosa M, Picchio, Maria, Roig, Anna, and Rosell, Anna
- Subjects
110320 Radiology and Organ Imaging ,FOS: Clinical medicine ,FOS: Biological sciences ,Medicine ,Cell Biology ,110305 Emergency Medicine ,110306 Endocrinology ,Biochemistry ,69999 Biological Sciences not elsewhere classified ,110904 Neurology and Neuromuscular Diseases ,Neuroscience - Abstract
Supplemental material, sj-pdf-1-jcb-10.1177_0271678X211028816 for Endovascular administration of magnetized nanocarriers targeting brain delivery after stroke by Alba Grayston, Yajie Zhang, Miguel Garcia-Gabilondo, Mercedes Arrúe, Abraham Martin, Peter Kopcansky, Milan Timko, Jozef Kovac, Oliver Strbak, Laura Castellote, Sara Belloli, Rosa M Moresco, Maria Picchio, Anna Roig and Anna Rosell in Journal of Cerebral Blood Flow & Metabolism
- Published
- 2021
- Full Text
- View/download PDF
13. Study on the Accommodation Ability and Development Demand with High Proportion Renewable Energy Integrated into Grid in China
- Author
-
Zhang Yuqiong, Zhang Yajie, Zhao Qiang, and Chen Ziwei
- Subjects
Electricity generation ,business.industry ,Production (economics) ,Environmental science ,Power grid ,Environmental economics ,Energy structure ,China ,Grid ,business ,Accommodation ,Renewable energy - Abstract
In recent years, China's renewable energy has grown rapidly and continuously, and its proportion in the power grid has been increasing gradually to enter a large-scale development stage. This paper constructs a scientific and reasonable grid development scenario under the assumption that China's high proportion of renewable energy have been integrated into grid in 2030. Use production simulation technology to verify the feasibility of development scenario, and propose reasonable suggestions to provide decision-making reference for the development and utilization of renewable energy and energy structure in China.
- Published
- 2020
14. TPGS modified reduced bovine serum albumin nanoparticles as a lipophilic anticancer drug carrier for overcoming multidrug resistance
- Author
-
Xinru You, Chunli Zheng, Liang Ge, Zhang Yajie, Jiabi Zhu, Fangcheng Chen, Jianping Liu, Vishva Shah, Fujuan Cai, and Jun Wu
- Subjects
Drug ,Materials science ,Carrier system ,media_common.quotation_subject ,Biomedical Engineering ,02 engineering and technology ,Polyethylene glycol ,010402 general chemistry ,01 natural sciences ,chemistry.chemical_compound ,In vivo ,Zeta potential ,General Materials Science ,Bovine serum albumin ,Cytotoxicity ,media_common ,biology ,General Chemistry ,General Medicine ,021001 nanoscience & nanotechnology ,0104 chemical sciences ,Biochemistry ,chemistry ,Biophysics ,biology.protein ,0210 nano-technology ,Conjugate - Abstract
In this study, a novel protein–polymer conjugate, D-α-tocopheryl polyethylene glycol succinate modified reduced bovine serum albumin (TPGS–Re-BSA, TRB), was synthesized for lipophilic anticancer drug delivery, and its unique ability to overcome drug resistance was explored. This conjugate was extensively characterized for its chemical structure, average molecular weight, secondary structure, degree of substitution, hydrophobicity, particle size and zeta potential. PTX-loaded nanoparticles (NPs) with diameters of 170–370 nm and drug loading efficiency of up to 13.62% were successfully prepared by the dialysis method. These drug-loaded NPs were found to exhibit a sustained release of PTX at pH 7.4, 6.5 and 5.5. Moreover, great anti-tumor activity in drug sensitive MCF-7 cells was observed in the in vitro anti-tumor studies. In particular, enhanced cytotoxicity and PTX-induced apoptosis were observed in the drug-resistant MCF-7/ADR cells compared to the Taxol and PTX-loaded BSA NPs. This could be attributed to the significant inhibition of P-gp activity and reduced ATP levels due to the presence of TRB NPs. Lastly, in vivo tumor inhibition assay verified the higher efficacy of TRB NPs. Overall, the results suggest that this TRB NPs could provide an effective carrier system for the delivery of anticancer agents.
- Published
- 2020
15. Multimodal Nanocapsules for Brain Repair and Imaging after Stroke
- Author
-
Roig Serra, Anna and Zhang, Yajie
- Abstract
According to the World Health Organization, 15 million persons suffer a stroke worldwide each year. However, the only available treatment is the acute thrombolytic therapy (pharmacological or mechanical) which is being administered to less than 10% of stroke patients due to strict selection criteria. In contrast, neuro-repair treatments could offer the opportunity to include most stroke patients by extending the therapeutic time window. Novel polymeric magnetic nanocapsules could achieve brain tissue imaging and repair in the context of an ischemic event by delivering therapeutic growth factors into the peri-infracted area. I will present some chemical routes to attain theranostic nanocapsules that incorporate multimodal capacities - MRI, fluorescence at different emitting wavelengths (blue and NIR) and 89Zr-radiolabeling for positron emission tomography (PET) imaging [1,2]. Then I will show preliminary results on how growth factors, secreted by endothelial progenitor cells with proved potential to induce tissue repair [3], can be encapsulated in the nanocapsules and can be grafted into mouse brains by an external magnetic field [4,5]. We expect that in the future our approach will provide an advanced therapy that could be translated to a clinical stage as noninvasive, safe and available to most stroke patients.
- Published
- 2020
16. Multimodal Imaging PLGA Nanocapsules as Protein Carrier for Potential Neurorepair in Ischemic Brain
- Author
-
Zhang, Yajie, Roig i Serra, Anna, Rosell Novel, Anna, and Sebastián Pérez, Rosa M.
- Subjects
Drug delivery carriers ,Medical imaging techniques ,Ciències Experimentals ,Bionanomaterials ,Bionanomateriales ,Administracion de farmacos ,Administracio de farmacs ,Tecniques d'imatge medica ,Tecnicas de imagen medica - Abstract
Els avenços en sistemes nanoparticulats capaços de proporcionar les funcionalitats necessàries a les noves nanomedicines i oferir la possibilitat de combinar la detecció no invasiva de malalties amb tractaments individualitzats estan convertint en realitat la medicina personalitzada. A més, els progressos en teranòstica estan configurant el desenvolupament de l’ administració de fàrmacs guiats per imatge que milloren l’eficiència en el tractament, visualitzant les seves biodistribucions, efectes sobre les dianes moleculars i cel·lulars específiques i els efectes terapèutics corresponents. Aquesta tesi té com a finalitat el disseny i síntesis de nano-biomaterials teranòstics dirigits a la neuroreparació en el context d’un ictus isquèmic per tal d’estimular l’angiogènesi en la zona d’afectació. Per aconseguir-ho, s’han encapsultat factors de creixement secretats per cèl·lules progenitores endotelials (EPCs-secretoma), amb potencial demostrat per induir angiogènesi, en nanocàpsules magnètiques biocompatibles i biodegradables de poli (D, L àcid co-glicòlic) (PLGA). D’altra banda, les càpsules de PLGA s’han funcionalitzat amb diversos agents de contrast permetent tant la retenció magnètica com la seva visualització in vitro o in vivo. Els principals objectius aconseguits en aquesta tesi són: 1) optimització de nanocàpsules magnètiques de PLGA per afavorir la seva retenció en la zona a tractar i l’encapsulació i alliberament controlats de proteïnes terapèutiques; 2) funcionalització modular de les nanocàpsules amb agents de contrast per: ressonància magnètica d’imatge, fluorescència a quatre longituds d’ona diferents i tomografia d’emissió de positrons i 3) noves aproximacions per millorar l’acumulació cerebral de les nanocàpsules en ratolins i augmentar-ne la càrrega del secretoma encapsulat en les mateixes. El desarrollo de sistemas nanoparticulados capaces de proporcionar las funcionalidades necesarias a las nuevas nanomedicinas ofreciendo la posibilidad de combinar la detección no invasiva de enfermedades con tratamientos individualizados están convirtiendo en realidad la medicina personalizada. Además, los progresos en teranóstica están configurando el progreso de la administración de fármacos guiados por imagen que mejoran la eficiencia del tratamiento visualizando su biodistribución, el efecto sobre las dianas moleculares y celulares específicas y los efectos terapéuticos correspondientes. Esta tesis tiene como finalidad el diseño y la síntesis de nano-biomateriales teranósticos dirigidos a la neuroreparación en el contexto de un ictus isquémico con el objetivo de estimular la angiogénesis en la zona de afectación. Para ello, se han encapsulado factores de crecimiento secretados por las células progenitoras endoteliales (EPCs-secretoma), con demostrado potencial para inducir angiogénesis, en nanocápsulas magnéticas biocompatibles y biodegradables de poli (D, L ácido co-glicólico) (PLGA). Por otra parte, las cápsulas de PLGA se han funcionalizado con varios agentes de contraste permitiendo tanto la retención magnética como su visualización in vitro o in vivo. Los principales objetivos conseguidos en esta tesis son: 1) optimización de nanocápsulas magnéticas de PLGA para favorecer su retención en la zona a tratar y la encapsulación y liberación controlados de proteínas terapéuticas; 2) funcionalización modular de las nanocápsulas con agentes de contraste para: resonancia magnética de imagen, fluorescencia a cuatro longitudes de onda diferentes i tomografía de emisión de positrones y 3) nuevas aproximaciones para mejorar la acumulación cerebral de las nanocápsulas en ratones y aumentar la carga de secretoma encapsulado en las mismas. Advancements in nanoparticulated systems capable of providing the necessary functionalities to new nanomedicines and offering the possibility to combine non-invasive disease detection with individualized treatments are facilitating personalized medicine to become a reality. Besides, the progress in theranostics is shaping the development of image-guided drug delivery improving the efficiency of pharmaceuticals by visualizing their biodistributions, effects on specific molecular and cellular targets, and the corresponding therapeutic effects. This thesis is devoted to engineering theranostic magnetic nano-biomaterials to address neurorepair in the context of an ischemic stroke by enhancing local angiogenesis. Growth factors secreted by endothelial progenitor cells (EPCs-secretome), with proved potential to induce angiogenesis, were encapsulated into magnetic poly(D,L lactic co glycolic acid) (PLGA) nanocapsules. Additionally, this PLGA-drug delivery system was functionalized with versatile imaging reporters allowing magnetic retention and in vitro/in vivo product tracking. The main accomplished objectives of the thesis are: 1) optimization of PLGA nanocapsules for magnetically targeted delivery and controlled encapsulation and release of proteins, 2) modular functionalization of PLGA nanocapsules with versatile imaging reporters: magnetic resonance imaging, fluorescence at four different wavelengths and positron emission tomography and 3) improved approaches to enhance mice brain accumulation of the nanocapsules and to increase EPCs-secretome loading. Universitat Autònoma de Barcelona. Programa de Doctorat en Ciència de Materials
- Published
- 2020
17. Subcritical water extraction of bioactive components from ginseng roots ( Panax ginseng C.A. Mey)
- Author
-
Ying Ying, Ahmed Aboueloyoun Taha, Li Xiaoping, Yu Zhang, Xiaoyuan Chen, Chao Ma, and Zhang Yajie
- Subjects
Ethanol ,Antioxidant ,Chromatography ,medicine.medical_treatment ,010401 analytical chemistry ,Extraction (chemistry) ,Water extraction ,04 agricultural and veterinary sciences ,040401 food science ,01 natural sciences ,0104 chemical sciences ,Solvent ,chemistry.chemical_compound ,Ginseng ,Hydrolysis ,0404 agricultural biotechnology ,chemistry ,medicine ,Sugar ,Agronomy and Crop Science - Abstract
The feasibility of applying subcritical water extraction (SWE), which is considered to be an environmentally friendly and efficient extraction technology for the extraction of bioactive components from ginseng roots, was evaluated by comparing it with conventional water (WE) and ethanol (EE) extraction methods SWE was conducted at different temperatures ranging from 120 to 200 °C, and WE and EE were performed by solid–liquid heating extraction methods using water or 70% (v/v) aqueous ethanol as a solvent, respectively. SWE showed significantly and markedly higher extraction yields of total sugar (TS), total protein (TPro), phenolic components (TP), and more potent antioxidant activities than WE and EE. The optimized temperature for TS, TP, and antioxidant activities was 200 °C, and that for TPro was 180 °C. Although vanillin–perchloric acid colorimetric quantification showed that SWE yielded more total ginsenosides (TG) than WE and EE, ultrafast liquid chromatography tandem mass spectroscopy (UFLC–MS/MS) analysis revealed that SWE induced extensive hydrolysis of the ginsenosides, except for Rg2. At 160 °C, SWE yielded 9.7- and 6.2-fold more Rg2 than WE and EE, respectively. In comparison, the extraction yields of R1, Rb1, Rb2, Rb3, Rc, Rd, Re, Rg1, and Ro decreased significantly with the increase of SWE temperature. These findings suggested that SWE is a promising environmentally friendly and efficient technology for extracting bioactive polysaccharides, proteins, TP, and Rg2 from ginseng roots, but it has potency to induce extensive hydrolysis of ginsenosides, such as Rb1 and Re.
- Published
- 2018
18. Contamination characteristics of trace metals in dust from different levels of roads of a heavily air-polluted city in north China
- Author
-
Zhang Yajie, Wang Mengmeng, Mohai Shen, Guangxuan Yan, Qiaoying Chen, Xin Zhang, Xiaoying Wang, Tianfang Yang, Zhiguo Cao, Shihua Wang, Jianhui Sun, Leicheng Zhao, and Zi-Yang Zhang
- Subjects
Road dust ,China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,North china ,010501 environmental sciences ,Risk Assessment ,01 natural sciences ,Arsenic ,Geochemistry and Petrology ,Metals, Heavy ,Humans ,Environmental Chemistry ,Cities ,Particle Size ,0105 earth and related environmental sciences ,General Environmental Science ,Water Science and Technology ,Health risk assessment ,Dust ,General Medicine ,Contamination ,Trace Elements ,Trace (semiology) ,Environmental chemistry ,Environmental science ,Environmental Monitoring - Abstract
Concentrations of eight trace metals (TMs) in road dust (RD) (particles 25 μm) from urban areas of Xinxiang, China, were determined by inductively coupled plasma mass spectrometry. The geometric mean concentrations of Zn, Mn, Pb, As, Cu, Cr, Ni and Cd were 489, 350, 114, 101, 60.0, 39.7, 31.6, and 5.1 mg kg
- Published
- 2018
19. Design and Analysis of PCB Transformer in Direct Current Distribution Network
- Author
-
Ma Tao, Zhang Yusen, Hou Lei, Sun Zhen, Zhang Yajie, and Zhang Maopeng
- Subjects
History ,Distribution networks ,business.industry ,Computer science ,Direct current ,Electrical engineering ,business ,Computer Science Applications ,Education ,Transformer (machine learning model) - Abstract
In order to accurately calculate the leakage inductance of the PCB transformer and improve the reliability of the PCB transformer, a PCB transformer is designed and analyzed in this article. Firstly, the magnetic core and winding design of the PCB transformer are studied in this paper, and the leakage magnetic field and temperature field of the PCB transformer are calculated by using the finite element software. Finally, experiments were performed on the leakage magnetic field and temperature of the PCB transformer to verify the correctness of the proposed scheme.
- Published
- 2021
20. RESEARCH ON PRIVACY PROTECTION TECHNOLOGY BASED ON IOT
- Author
-
Zhang Yajie.
- Subjects
business.industry ,Privacy software ,Computer science ,Privacy protection ,Internet privacy ,Internet of Things ,business ,Computer security ,computer.software_genre ,computer - Published
- 2017
21. PAH contamination in road dust from a moderate city in North China: The significant role of traffic emission
- Author
-
Jinglan Feng, Yuesi Wang, Zhiguo Cao, Leicheng Zhao, Zhang Yajie, Guangxuan Yan, Mohai Shen, Xin Zhang, Yumeng Shi, Shihua Wang, and Xuefeng Wang
- Subjects
Road dust ,010504 meteorology & atmospheric sciences ,Health, Toxicology and Mutagenesis ,Ecological Modeling ,Environmental engineering ,North china ,Traffic emission ,010501 environmental sciences ,Contamination ,01 natural sciences ,Pollution ,Human exposure ,Environmental chemistry ,polycyclic compounds ,Environmental science ,0105 earth and related environmental sciences - Abstract
To investigate the contamination level, distribution, possible source, and human exposure risk of polycyclic aromatic hydrocarbons (PAHs) in the urban traffic environment, 15 PAHs were measured in 34 road dust samples (particle size < 25 μm) collected from three grades of roads and park paths in Xinxiang, China. ΣPAHs concentrations ranged from 311 to 21200 ng g−1, with a mean of 5890 ng g−1 and decreased in the following order: main roads (7650 ng g−1) > collector streets (7410 ng g−1) > bypasses (2970 ng g−1) > park paths (1570 ng g−1), indicating that significant positive correlation existed between PAH contamination and traffic density. PAHs in all samples were dominantly composed of 4-ring PAHs, accounting for 44.8% of the total. Pyrene, fluoranthene, and chrysene were the predominant individual components and accounted for 14.7% (1.2–19.2%), 12.9% (3.3–20.3%), and 11.0% (2.5–18.6%) of ΣPAHs, respectively. The specific isomer ratios indicated that traffic emission was the dominant source of PAHs in road dust. The incremental lifetime cancer risk values showed that cancer risk from exposure to road dust–borne PAHs was acceptable for local residents in Xinxiang.
- Published
- 2017
22. Influence of Air Pollution on Inhalation and Dermal Exposure of Human to Organophosphate Flame Retardants: A Case Study During a Prolonged Haze Episode
- Author
-
Zhiguo Cao, Jianye Jie, Li Changhe, Xiaotu Liu, Ren Meihui, Zhang Yacai, Wang Zhiyu, Mohai Shen, Zhang Yajie, Leicheng Zhao, and Qingwei Bu
- Subjects
Pollution ,China ,Haze ,media_common.quotation_subject ,Air pollution ,Absorption (skin) ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Dermal exposure ,chemistry.chemical_compound ,Air Pollution ,medicine ,Environmental Chemistry ,Humans ,Air quality index ,0105 earth and related environmental sciences ,media_common ,Flame Retardants ,integumentary system ,Inhalation ,Organophosphate ,Dust ,General Chemistry ,Organophosphates ,chemistry ,Environmental chemistry ,Air Pollution, Indoor ,Environmental science - Abstract
The health impact of haze is of great concern, but few studies have explored its influence on human inhalation and dermal exposure to trace pollutants. Size-segregated atmospheric particles ( n = 72) and forehead wipe samples ( n = 80) from undergraduates were collected in Xinxiang, China, during a prolonged haze episode and analyzed for 10 organophosphate flame retardants (OPFRs). ∑TCPP and TCEP were the most abundant OPFR substances in all samples. The arithmetic mean particle-bound and forehead OPFR concentrations under a heavy pollution condition (air quality index (AQI), 350-550) were 41.9 ng/m3 (∑8OPFRs) and 7.4 μg/m2 (∑6OPFRs), respectively, apparently greater than the values observed under a light pollution condition (AQI, 60-90) (19.5 ng/m3 and 3.9 μg/m2, respectively). Meteorological conditions played distinctive roles in affecting the OPFR occurrence in atmospheric particles (statistically significant for TCEP and ∑TCPP) and forehead wipes (excluding TPHP), implying that OPFR exposure through inhalation and dermal absorption was synchronously influenced by air quality, and OPFRs on the forehead may be mainly absorbed from the air. Inhalation contributed dominantly to the total OPFR exposure dose for humans when using the relative absorption method to assess dermal exposure, while according to the permeability coefficient method, dermal exposure was much more significant than inhalation. The results of this study indicate that OPFR exposure should attract particular concern in regions with heavy air pollution.
- Published
- 2019
23. PET/NIRF/MRI Triple Functional PLGA-based Nanocapsules as Protein
- Author
-
Zhang, Yajie and Roig Serra, Anna
- Published
- 2019
24. MRI/Photoluminescence Dual-Modal Imaging Magnetic PLGA Nanocapsules for Theranostics
- Author
-
Zhang, Yajie, García-Gabilondo, Miguel, Rosell Novel, Anna, Roig i Serra, Anna, Universitat Autònoma de Barcelona, Ministerio de Ciencia, Innovación y Universidades (España), Generalitat de Catalunya, Instituto de Salud Carlos III, and European Commission
- Subjects
theranostics ,Photoluminescence ,Materials science ,Biocompatibility ,Pharmaceutical Science ,multimodal imaging ,Nanotechnology ,02 engineering and technology ,010402 general chemistry ,behavioral disciplines and activities ,01 natural sciences ,Article ,Nanocapsules ,drug delivery systems ,Magnetic targeting ,chemistry.chemical_compound ,Magnetic resonance imaging ,Multimodal imaging ,mental disorders ,magnetic resonance imaging ,chemistry.chemical_classification ,technology, industry, and agriculture ,Polymer ,PLGA nanocapsules ,Theranostics ,021001 nanoscience & nanotechnology ,Drug delivery systems ,0104 chemical sciences ,Polyester ,PLGA ,magnetic targeting ,chemistry ,Drug delivery ,PEGylation ,photoluminescence ,0210 nano-technology - Abstract
Developing multifunctional and biocompatible drug delivery nanoplatforms that integrate high drug loads and multiple imaging modalities avoiding cross-interferences is extremely challenging. Here we report on the successful chemical reaction of the high quantum yield biodegradable and photoluminescent polyester (BPLP) with the poly(lactic-co-glycolic acid) (PLGA) polymer to fabricate biocompatible photoluminescent nanocapsules (NCs). Furthermore, we transform the PLGA-BPLP NCs into a magnetic resonance (MR)/photoluminescence dual-modal imaging theranostic platform by incorporating superparamagnetic iron oxide nanoparticles (SPIONs) into the polymeric shell. In vitro phantoms confirmed the excellent MRI-r2 relaxivity values of the NCs whilst the cellular uptake of these NCs was clearly observed by fluorescence optical imaging. Besides, the NCs (mean size ~270 nm) were loaded with ~1 wt% of a model protein (BSA) and their PEGylation provided a more hydrophilic surface. The NCs show biocompatibility in vitro, as hCMEC/D3 endothelial cells viability was not affected for particle concentration up to 500 μg/mL. Interestingly, NCs decorated with SPIONs can be exploited for magnetic guiding and retention., This work was partially supported by the Spanish Ministry of Science, Innovation and Universities through the grants PCIN-2017-090, RTI2018-096273-B-I00, CTQ2017-87637-R, SAF2017-87670-R, SEV-2015-0496 and MDM-2017-0720 and by the Generalitat de Catalunya grants (2017SGR765 & 2017SGR1427). Yajie Zhang was supported by the China Scholarship Council (CSC). The Acciones Complementarias program from the Instituto de Salud Carlos III, Spain, co-financed by the European Regional Development Fund (AC17/00004 grant) as part of the MAGBBRIS project (Euronanomed III 8th joint call), and the RETICS INVICTUS RD16/0019/0021 were acknowledged. Miguel Servet program (CPII15/00003) from Fondo de Investigaciones Sanitarias-Instituto de Salud Carlos III and ERDF, supported A. Roig research contract.
- Published
- 2019
25. A planning method for integrated energy station of energy internet
- Author
-
Zhao Qiang, Zhang Yuqiong, Liu Yuan, Yang Jun, Wu Fuzhang, Zhang Yajie, and Zhu Xu
- Subjects
Operations research ,Power station ,business.industry ,Computer science ,020209 energy ,02 engineering and technology ,Rational planning model ,Computer Science::Robotics ,Electricity generation ,Planning method ,0202 electrical engineering, electronic engineering, information engineering ,Energy transformation ,The Internet ,business ,Voronoi diagram ,Energy (signal processing) - Abstract
To realize the rational planning of integrated energy stations, this paper introduce a planning method for integrated energy station which based on multiple energy system's basic planning. This planning method contains the approach which based on C-means algorithm for forecasting users' daily energy load, the approach which based on Voronoi diagram for locating new multiple power stations and the planning model which aims to reduce the annual cost (includs the costs of equipments, operation, maintenance and fuels) of the power stations for power stations' planning. The steps of locating and station planning are all included in this method. This paper solves the model with actual data. By comparing the planning results, the feasibility of the method and the economy of the integrated energy system are verified.
- Published
- 2017
26. Classification of the Different Thickness of the Oil Film Based on Wavelet Transform Spectrum Information
- Author
-
Cui Jianyong, Song Dongmei, Chen Shouchang, Ma Yi, Zhang Yajie, Liu Bin, and Shen Chen
- Subjects
Engineering ,business.industry ,Noise (signal processing) ,Continuous spectrum ,Wavelet transform ,Hyperspectral imaging ,General Medicine ,Wavelength ,Wavelet ,Optics ,Transformation (function) ,Range (statistics) ,business ,Remote sensing - Abstract
The detection of different thickness of spilled oil film is internationally recognized as one of the difficult problems. Hyperspectral remote sensing data can provide continuous spectrum, and be beneficial for the identification of oil film. The traditional detection method failed to make full use of different spectral characteristics of the oil film, so is unable to improving the identification precision of them. By deep digging the time-frequency information based on the wavelet transform, we can enhance the difference of the spectral characteristic between thick and thin oil film, so that we can find sensitive wavelength location of them. High frequency coefficient of wavelet transformation is able to indicating the sensitive spectral range of different thickness of oil film, and low frequency coefficient information is available for eliminating the noise of the image, consequently, enhancing the contrast between the categories. Based on this, this paper proposed a new method for classification of the various thickness of oil film based on wavelet transform spectrum information. Firstly, we extracted the sensitive wave bands of different thickness of oil film based on the analysis of the singularity of the high frequency wavelet coefficient curve. Secondly, we regenerated the new low-frequency wavelet coefficients image of sensitive bands which are regarded as sensitive bands in term of the analysis on the high frequency wavelet coefficients curve. Finally, we conducted the classification of the different thickness of oil spill film based on the new low-frequency wavelet coefficients image. The experiment has gotten good effect with Hyperspectral data obtained airborne from oil spill accident happening in Dalian in Bohai Sea on July 16, 2010.
- Published
- 2015
- Full Text
- View/download PDF
27. Preliminary assessment on exposure of four typical populations to potentially toxic metals by means of skin wipes under the influence of haze pollution
- Author
-
Tianfang Yang, Guangxuan Yan, Qingwei Bu, Xin Zhang, Zhiguo Cao, Qiaoying Chen, Yunqing Pi, Dong Wenjing, Zhang Yajie, Benye Xi, and Wang Mengmeng
- Subjects
Adult ,Male ,China ,Environmental Engineering ,010504 meteorology & atmospheric sciences ,010501 environmental sciences ,01 natural sciences ,Dermal exposure ,Risk Assessment ,Air pollutants ,Environmental health ,Metals, Heavy ,Occupational Exposure ,Environmental Chemistry ,Humans ,Child ,Waste Management and Disposal ,0105 earth and related environmental sciences ,Exposure assessment ,Skin ,Air Pollutants ,Gender variation ,Environmental exposure ,Environmental Exposure ,Contamination ,Pollution ,Environmental chemistry ,Haze pollution ,Environmental science ,Female ,Occupational exposure ,Environmental Monitoring - Abstract
To investigate the exposure risk of human beings to nine potentially toxic metals (PTMs), namely, Cu, Cr, Zn, As, Cd, Pb, Ni, Mn, and Co, skin wipe samples were collected from four types of populations, namely, children, undergraduates, security guards, and professional drivers, under different haze pollution levels in Xinxiang, China by using Ghost wipes. The Ghost wipes were quantitatively analyzed by inductively coupled plasma mass spectrometry (ICP-MS) after microwave digestion. Generally, Zn (ND-1350μg/m2 for undergraduates, ND-2660μg/m2 for security guards, ND-2460μg/m2 for children, and ND-2530μg/m2 for professional drivers) showed the highest concentration among the four populations, followed by Cu (0.02-83.4μg/m2 for undergraduates, ND-70.2μg/m2 for security guards, 23.2-487μg/m2 for children, and ND-116μg/m2 for professional drivers). As (ND-5.7μg/m2 for undergraduates, ND-2.3μg/m2 for security guards, ND-21.1μg/m2 for children, and ND-11.0μg/m2 for professional drivers) and Co (ND-6.0μg/m2 for undergraduates, ND-7.9μg/m2 for security guards, ND-13.4μg/m2 for children, and ND-2.1μg/m2 for professional drivers) showed the lowest concentrations in all populations. Remarkable differences were found among the four populations and PTM levels decreased in the following order: children, professional drivers, security guards, and undergraduates. Gender variation was discovered for undergraduates and children. Generally, PTM contamination in skin wipes collected during a light haze pollution level was generally higher than that during a heavy haze pollution level, but PTM contamination was comparable between the two haze pollution levels for children. Non-carcinogenic exposure risks to As, Cd, and Pb for all populations were higher than those for the other six elements but all of them were within the acceptable safety threshold, indicating no apparent non-carcinogenic risk.
- Published
- 2017
28. Towards Energy - Efficient Qos-Aware Online Stream Data Processing for Internet of Things
- Author
-
Zhang, Yajie
- Subjects
IoT ,Statistics ,Edge Computing ,Data Stream Processing - Abstract
Online data stream processing in Internet of Things (IoT) systems is an emerging paradigm that allows users to use resource-constrained IoT devices with the back- end of resourceful machines to process the data collected from the physical world in a real-time manner. The huge amount of generated sensor data can produce value- added information with different purposes for several applications. Techniques to pro- mote knowledge discovery from the raw data allow fully exploiting the potential usage of wide spread sensors in the IoT. In this context, using the energy of the resource- constrained IoT devices in an efficient way is a major concern. However, the appli- cation of QoS requirements should not be ignored to achieve the purpose of energy saving at any cost. In this thesis, we propose a framework that combines online stream data processing with adaptive system control to address both needs. The online algo- rithms are based on statistical methods to meet the needs of stream data processing. The result of the algorithms are then used to dynamically control the system behaviour to meet the needs of energy-saving. Simulation results show the effectiveness of our proposed framework.
- Published
- 2017
29. Dang Gui Bu Xue Tang ameliorates coronary artery ligation-induced myocardial ischemia in rats
- Author
-
Zhang Yajie, Ma Chunhua, Long Hongyan, He Xiaoli, Zhu Weina, and Ruan Jie
- Subjects
0301 basic medicine ,medicine.medical_specialty ,p38 mitogen-activated protein kinases ,Myocardial Ischemia ,IκB kinase ,Proinflammatory cytokine ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,Electrocardiography ,0302 clinical medicine ,Internal medicine ,Lactate dehydrogenase ,Malondialdehyde ,medicine ,Animals ,Creatine Kinase, MB Form ,Myocardial infarction ,Ligation ,Chromatography, High Pressure Liquid ,Pharmacology ,biology ,L-Lactate Dehydrogenase ,business.industry ,Kinase ,Superoxide Dismutase ,Myocardium ,Angelica sinensis ,General Medicine ,medicine.disease ,Catalase ,Coronary Vessels ,Glutathione ,030104 developmental biology ,Endocrinology ,chemistry ,030220 oncology & carcinogenesis ,biology.protein ,Cytokines ,Creatine kinase ,Mitogen-Activated Protein Kinases ,business ,Drugs, Chinese Herbal - Abstract
Dang The present study was designed to investigate cardioprotective effects of Dang Gui Bu Xue Tang (DGBUT) on coronary artery ligation-induced myocardial ischemia. Myocardial ischemia (MI) model was induced in SD rats by surgical ligation of the left anterior descending coronary artery. ST segment elevation of Electrocardiograph (ECG) infarct size, levels of lactate dehydrogenase (LDH), creatine kinase (CK), glutathione (GSH) and catalase (CAT), catalase (SOD), malondialdehyde (MDA), and inflammatory cytokines and phosphorylation of extracellular signal-regulated kinase (ERK) 1/2, p38, c-Jun NH2 terminal kinases (JNK), nuclear factor (NF)-κBp65, inhibitory kappa B (IκB) α, IκB kinase (IKK) α and IKKβ were evaluated in rats treated with or without DGBUT. DGBUT treatment significantly reduced the elevation of the ST segment of ECG, the myocardial infarct size of MI. The level of LDH, CK and MDA were suppressed, the contents of SOD, GSH and CAT were enhanced with DGBUT. The elevated concentration of inflammatory cytokines tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β) and IL-6 in MI rats were effectively reversed by the DGBUT administration. Also, highly expressed p-JNK, p-ERK, p-p38, p-NF-κBp65, p-IκBα, p-IKKα and p-IKKβ in MI rats were restored respectively by DGBUT treatment. The protective effect of DGBUT against MI injury might be associated with MAPK/NF-кB pathway.
- Published
- 2016
30. Antihyperuricemic effect of liquiritigenin in potassium oxonate-induced hyperuricemic rats
- Author
-
Zhu Weina, Ruan Jie, Wu Suling, Zhang Yajie, and Long Hongyan
- Subjects
0301 basic medicine ,Male ,medicine.medical_specialty ,Necrosis ,Potassium ,Allopurinol ,chemistry.chemical_element ,Hyperuricemia ,Gout Suppressants ,Rats, Sprague-Dawley ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Internal medicine ,medicine ,Animals ,Pharmacology ,Kidney ,Dose-Response Relationship, Drug ,Chemistry ,Inflammasome ,General Medicine ,Rats ,Uric Acid ,IκBα ,Oxonic Acid ,030104 developmental biology ,medicine.anatomical_structure ,Endocrinology ,Treatment Outcome ,Flavanones ,Uric acid ,Female ,medicine.symptom ,Liquiritigenin ,030217 neurology & neurosurgery ,medicine.drug - Abstract
The aim is to investigate the anti-hyperuricemic and renal protective effects of liquiritigenin in potassium oxonate-induced hyperuricemic rats. Hyperuricemia in rats was induced were induced with potassium oxonate (250mg/kg) intragastrically for 7 days, and liquiritigenin (20, 40mg/kg) and allopurinol (5mg/kg) were daily administrated to the rats orally 1h after the potassium oxonate exposure. Liquiritigenin significantly reversed the elevated productions of uric acid in serum and urine and pro-inflammation cytokines in serum and kidney, which shown that liquiritigenin has renal protective effects. Histological study shows that liquiritigenin inhibited severe necrosis and inflammatory cell infiltration in potassium oxonate-treated rats. Furthermore, liquiritigenin mediated the activities of aquaporins 4 (AQP4), and regulated the activation of NF-κB p65 and the degradation of IκBα. Finally, significant increases of nod-like receptor protein 3 (NLRP3) inflammasome, apoptosis-associated speck-like protein adaptor (ASC) adaptor and cleaved caspased-1 were restored by liquiritigenin. Therefore, liquiritigenin might improve renal inflammation by suppressing renal AQP4/NF-κB/IκBα and NLRP3 inflammasome activation in hyperuricemic rats.
- Published
- 2016
31. Evaluation of maritime emergency rescue capability based on network analysis
- Author
-
Ma Yijia, Liu Shengjing, Zhang Yajie, Pang Haixiang, and Mao Tianyu
- Subjects
Computer science ,medicine ,Medical emergency ,Emergency rescue ,medicine.disease ,Network analysis - Published
- 2017
32. The thoracic procedures of robotic-assisted Ivor-Lewis esophagectomy
- Author
-
Xiang Jie, Jin Runsen, Zhang Yajie, Han Dingpei, and Li Hecheng
- Subjects
medicine.medical_specialty ,Robotic assisted ,business.industry ,General surgery ,Materials Chemistry ,medicine ,Ivor lewis ,business - Published
- 2017
33. Research of Electro-Hydraulic Camless Valvetrain System Based on AMESim
- Author
-
Zhang Yajie, Chu Chuanchuan, and Du Aimin
- Subjects
Controllability ,Valvetrain ,Internal combustion engine ,Computer science ,ComputerApplications_COMPUTERSINOTHERSYSTEMS ,computer.software_genre ,Electro hydraulic ,computer ,Automotive engineering ,System model ,Whole systems ,Simulation software ,Petrol engine - Abstract
Aiming at the application of Electro-hydraulic Camless Valve train system in Internal Combustion Engine, this paper completes the structure design of Electro-hydraulic Camless Valve train system and determines parameters of the whole system combining the parameters of a gasoline engine. Based on AMESim simulation software platform this paper completes the simulation and analysis of the system model. The simulation results indicate that the system shows great controllability and feasibility. And the influential factors of the system which are studied are the theoretical groundwork of the application of Electro-hydraulic Camless Valve train system in Internal Combustion Engine.
- Published
- 2014
34. Effects of the compatibilizer PP-g-GMA on morphology and mechanical properties of PP/PC blends
- Author
-
Zhang Xiaomin, Zhang Yajie, Yin Zhihui, and Yin Jinghua
- Subjects
Polypropylene ,Glycidyl methacrylate ,Morphology (linguistics) ,Materials science ,Polymers and Plastics ,Scanning electron microscope ,Organic Chemistry ,Concentration effect ,chemistry.chemical_compound ,Differential scanning calorimetry ,chemistry ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Polymer blend ,Composite material ,Polycarbonate - Abstract
Effects of the compatibilizer polypropylene grafted with glycidyl methacrylate(PP-g-GMA) on the morphology, thermal, rheological and mechanical properties of polypropylene and polycarbonate blends (PP/PC) were studied. It was found that the addition of PP-g-GMA significantly changed their morphology. The mean size of domains reduced from 20 μm to less than 5 μm. The dispersed domain size is also strongly dependent upon the content of PP-g-GMA. The interfacial tension of PP/PC/PP-g-GMA (50/30/20) is only about one-tenth of PP/PC (70/30). The crystallization temperature of PP in PP/PC/PP-g-GMA is 5–8°C higher than that of PP in PP/PC blends. Characterization studies based on mechanical properties, differential scanning calorimetry, rheology and morphological evidence obtained by using scanning electron microscopy support the hypothesis that an in-situ copolymer PP-g-PC was formed during the blending process.
- Published
- 1998
35. Critical Surface Tension of Acrylamide-Grafted Polypropylene Copolymer by the Contact Angle Method
- Author
-
Yin Jnghua, Yin Zhihui, and Zhang Yajie
- Subjects
Polypropylene ,Materials science ,Polymers and Plastics ,General Chemical Engineering ,Materials Science (miscellaneous) ,Organic solvent ,Analytical chemistry ,Critical surface ,Contact angle ,Surface tension ,chemistry.chemical_compound ,chemistry ,Acrylamide ,Polymer chemistry ,Materials Chemistry ,Copolymer ,Polar - Abstract
The contact angles θ of polar liquids on PP-g-AM copolymer (AM content 0.19, 0.26, and 0.37 wt%) were measured. The critical surface tension γC of PP-g-AM films were evaluated by the Zisman plot (cos θ versus-γl), the Young-Dupre-Good-Girifalco plot (1 + cos θ) versus 1/γ0.5 l, and the log(1 + cos θ) versus log-γl plot. The-γl values estimated by the plot log(1 + cos θ) versus log-γl were smaller than those obtained by the other plots.
- Published
- 1997
36. Morphological, thermal, and mechanical properties of polypropylene/polycarbonate blend
- Author
-
Yin Jinghua, Yin Zhihui, Zhang Xiaomin, and Zhang Yajie
- Subjects
Polypropylene ,chemistry.chemical_classification ,Glycidyl methacrylate ,Materials science ,Polymers and Plastics ,Plastics extrusion ,Concentration effect ,General Chemistry ,Compatibilization ,Polymer ,Surfaces, Coatings and Films ,law.invention ,chemistry.chemical_compound ,chemistry ,law ,visual_art ,Materials Chemistry ,visual_art.visual_art_medium ,Polycarbonate ,Composite material ,Crystallization - Abstract
This work deals with the effect of compatibilizer on the morphological, thermal, rheological, and mechanical properties of polypropylene/polycarbonate (PP/ PC) blends. The blends, containing between 0 to 30 vol % of polycarbonate and a compatibilizer, were prepared by means of a twin-screw extruder. The compatibilizer was produced by grafting glycidyl methacrylate (GMA) onto polypropylene in the molten state. Blend morphologies were controlled by adding PP-g-GMA as compatibilizer during melt processing, thus changing dispersion and interfacial adhesion of the polycarbonate phase. With PP-g-GMA, volume fractions increased from 2.5 to 20, and much finer dispersions of discrete polycarbonate phase with average domain sizes decreased from 35 to 3 mu m were obtained. The WAXD spectra showed that the crystal structure of neat PP was different from that in blends. The DSC results suggested that the degree of crystallization of PP in blends decreased as PC content and compatibilizer increased. The mechanical properties significantly changed after addition of PP-g-GMA. (C) 1997 John Wiley & Sons, Inc.
- Published
- 1997
37. Effect of reaction-induced phase separation on dielectric properties of epoxy resin modified with rubber
- Author
-
Zhang Yajie, Zhang Guanghua, Chen Shoutian, and Wang Desheng
- Subjects
Permittivity ,Diglycidyl ether ,Materials science ,Scanning electron microscope ,Epoxy ,Dielectric ,chemistry.chemical_compound ,Natural rubber ,chemistry ,visual_art ,Phase (matter) ,visual_art.visual_art_medium ,Dielectric loss ,Composite material - Abstract
The phase separation and polymerization took place during the curing process of the epoxy resin system, which consisted of diglycidyl ether of bisphenol A and a novel liquid rubber QR. The phase structure development was investigated by scanning electron microscopy (SEM). SEM revealed that the spherical rubber domain was dispersed randomly in the cured epoxy resin matrix. The domain size changed with the content of the modified rubber QR in the system. The higher the QR content, the larger was the spherical domain. Therefore, dielectric loss (tan/spl delta/), dielectric constant (/spl epsiv//sub r/) and volume resistivity (/spl rho//sub v/) of the cured resin were changed by different polarizations, especially interface polarization, which is introduced by the second rubber phase.
- Published
- 2002
38. Distribution regularity of breakdown field strength of high voltage ceramic capacitor
- Author
-
Zhang Yajie, Liu Bin, Chen Wei, and Chen Shoutian
- Subjects
Permittivity ,Materials science ,Electrical breakdown ,Field strength ,High voltage ,law.invention ,Capacitor ,law ,visual_art ,visual_art.visual_art_medium ,Electronic engineering ,Ceramic ,Composite material ,Ceramic capacitor ,Weibull distribution - Abstract
Electrical breakdown tests on high voltage ceramic capacitors, whose ceramic disks were in two kind of geometry, were carried out under various rates of voltage rise. It was shown that the breakdown field strength of samples in the same form displayed a Weibull distribution for the same rate of voltage rise. With increasing rate, the slope and character strength of the Weibull line improved in the flat samples, but was unchanged in concave samples. In the mean time, the mechanical strength of the ceramic material used in the capacitor was examined and obeyed the Weibull distribution. The Weibull line slope of mechanical strength was nearly same as that of the breakdown strength of concave samples. We concluded that the alternative breakdown of high permittivity ceramic happens when the degree of discharge at weak points exceeds some certain amount. The weak points are the voids and cracks contained in the ceramic, and the discharge at those weak points and electric-mechanical stress seem to be the main sources of electrical breakdown.
- Published
- 2002
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.