32 results on '"Jian Nie"'
Search Results
2. Optimization Of Secure Propagation Path Of New Media Short Video Based On Ant Colony Algorithm
- Author
-
Yuanyuan Dai, Qi Chen, and Jian Nie
- Published
- 2022
3. Research on Intelligent Operation and Maintenance System of Urban Rail Transit Vehicles Based on PHM Technology
- Author
-
Jian Nie, Qing Shi, and Yuanyuan Dai
- Published
- 2022
4. Stability of single-atomic-layer-height disconnections on (101¯2) twin boundary in Mg
- Author
-
Yuan Yue, Yu Zhang, and Jian Nie
- Subjects
Materials science ,Plane (geometry) ,Mechanical Engineering ,Metals and Alloys ,Stacking ,Geometry ,Condensed Matter Physics ,Fault (power engineering) ,Stability (probability) ,Mechanics of Materials ,General Materials Science ,Disconnection ,Crystal twinning ,Layer (electronics) ,Stacking fault - Abstract
Four different configurations of single-atomic-layer-height disconnections on ( 10 1 ¯ 2 ) twin boundary in magnesium are investigated using molecular dynamics simulations. It is found that a prismatic-basal (PB) single-atomic-layer-height disconnection is more stable than a basal-prismatic (BP) single-atomic-layer-height disconnection when each of them is connected with an I1 stacking fault associated with a stacking sequence change of BA B CB. In contrast, a BP single-atomic-layer-height disconnection is more stable than a PB single-atomic-layer-height disconnection when each of them is connected with an I1 fault associated with a stacking sequence change of AB A CA. A stable BP (or PB) single-atomic-layer-height disconnection can transform to a stable PB (or BP) single-atomic-layer-height disconnection when its step orientation changes with a change in the lying plane of the connected I1 fault.
- Published
- 2022
5. Test and Analysis of Hydroxyl Group in CVD Synthetic Silica Glass
- Author
-
Lei Wang, Zai Kui Xiang, Ya Nan Jia, Fei Xiang Liu, Chuan Dong Rao, Yu Fen Wang, and Lan Jian Nie
- Subjects
Glass structure ,Materials science ,Ir absorption ,Silica glass ,Chemical engineering ,Mechanics of Materials ,Group (periodic table) ,Impurity ,Mechanical Engineering ,Organic chemistry ,General Materials Science ,Spectral line - Abstract
Hydroxyl group, as one of the main impurities of CVD synthetic silica glass, affects glass structure and performance. IR absorption spectra of CVD synthetic silica glass prepared with different carrier gases, H2 and O2, shows different hydroxyl group distribution, it indicates that carrier gas has an important influence on hydroxyl group distribution. Combined the MAS-NMR testing results with the distribution results, the function of homogenization process has been discussed. The results indicate that: hydroxyl group distribution presents a parabolic figure when H2 is the carrier gas, while when O2 is the carrier gas, the distribution presents an inverse parabolic figure; During homogenization process, different structures of hydroxyl group acting with each other, leading to an average distribution of hydroxyl group.
- Published
- 2017
6. Laser Induced Damage in Fused Silica for 248 nm
- Author
-
Ya Nan Jia, Bo Fu, Hong Jie Wang, Lan Jian Nie, Zhu Feng Shao, and Hui Wang
- Subjects
Optics ,Materials science ,Mechanics of Materials ,business.industry ,law ,Mechanical Engineering ,General Materials Science ,business ,Focus (optics) ,Laser ,Sample (graphics) ,law.invention - Abstract
For the key-optical material, the laser induced damage character of fused silica is crucial for the application among the optical laser fitting. As the defect of each point of the silica sample is diverse, and the lasers focus point by point, we divided the sample block into three-dimensional structure for each laser-point to discuss the relationship between the LIDT of each points and the OH-content. The result shows that the LIDT of the center of the sample block is up to 10-11J/cm2 which is consistent after the treatment while the LIDT of border pieces is 9-10 J/cm2. The different temperature and the aggradation during the fusing process and the machine process caused the different OH content of different location of the sample.
- Published
- 2017
7. Microstructural Study on the Low Density SiO2 Soot Body
- Author
-
Ya Nan Jia, Fei Xiang Liu, Hui Wang, Lan Jian Nie, Lei Wang, and Zai Kui Xiang
- Subjects
Materials science ,Mechanical Engineering ,Mineralogy ,Microporous material ,medicine.disease_cause ,Microstructure ,Soot ,Amorphous solid ,Chemical engineering ,Mechanics of Materials ,Specific surface area ,Phase (matter) ,medicine ,General Materials Science ,Porosity ,Environmental scanning electron microscope - Abstract
Low density SiO2 soot body, with a certain strength and porosity, is an intermediate of silica glass prepared by the indirect synthetic method. The microstructures of SiO2 soot body have an important influence on the post-sintering process, such as micro-morphologies, pore structures and so on. These microstructures, including micro-morphologies, phase structure, hydroxyl structure, pore structure, pore size distribution and specific surface area, were studied by ESEM, XRD, FTIR, mercury intrusion method and nitrogen adsorption method. Experimental results indicate that, the low density SiO2 soot body is composed of amorphous nano-SiO2 particles with a particle diameter distribution of 100nm ~ 150nm. The pore structure of SiO2 soot body tends to be irregular and the pore shape contains cross-linked holes, through-holes and blind holes. The pore size distribution is wide and involves macropore, mesopore and micropore.
- Published
- 2017
8. Analyze of the Stress-Birefringence of the Fused Silica with Large Aperture
- Author
-
Lan Jian Nie, Xin Zhang, Yi Wang Bao, Hui Wang, Zhu Feng Shao, Jia Jia Wang, and Hong Jie Wang
- Subjects
Birefringence ,Materials science ,business.industry ,Manufacturing process ,Mechanical Engineering ,Polishing ,Large aperture ,Surface shape ,Laser ,law.invention ,Optics ,Mechanics of Materials ,law ,Homogeneity (physics) ,General Materials Science ,Thermal stability ,Composite material ,business - Abstract
Because of its excellent optical performance, photo-physical properties, thermal stability, the fused silica is widely used in laser and aerospace industry. Fused silica can be made to the large-aperture lens for high power laser facilities or the windows for detecting devices. In order to meet the applications, the surface shape of the fused silica must be polished to better than 1/3λ(P-V). If the result of stress-birefringence is big, it is hard to control the surface shape. The permanent stress of a large-aperture fused silica was measured with digital stressmeter and analyzed from manufacturing process stand point.The forming reason and the removing way of different types of stresses were also analyzed in this article. The structure stress is the permanent one in all the types, which also affects the result and the morphology of optical homogeneity.
- Published
- 2017
9. Digital Twin-based Smart Building Management and Control Framework
- Author
-
Wei-sheng Xu, Jian Nie, Da-zhang Cheng, and You-ling Yu
- Subjects
business.industry ,Computer science ,Control (management) ,Big data ,Systems engineering ,Cloud computing ,Internet of Things ,business ,Building management ,Field (computer science) ,Management control system ,Building automation - Abstract
Digital Twin is a digitalization technology that combines various technologies such as cloud computing, Internet of Things, and big data to implement interaction between physical and virtual spaces. This article describes the application of digital-Twin in the field of building and proposes a digital twin-based intelligent building management framework to achieve a more proactive, efficient, convenient and environment-friendly management control method throughout the life cycle. Finally, three application scenarios are listed under the digital twin-based smart building framework.
- Published
- 2019
10. Cadmium accumulation and tolerance of Macleaya cordata: a newly potential plant for sustainable phytoremediation in Cd-contaminated soil
- Author
-
Guangming Zeng, Xiaofei Tan, Chao Gan, Wei Liu, Jieli Xie, Jian Nie, Yunguo Liu, Bohong Zheng, and Huan Liu
- Subjects
Chlorophyll ,0106 biological sciences ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,010501 environmental sciences ,Plant Roots ,01 natural sciences ,Superoxide dismutase ,Soil ,chemistry.chemical_compound ,Dry weight ,Papaveraceae ,Malondialdehyde ,Plant Cells ,Botany ,Soil Pollutants ,Environmental Chemistry ,Biomass ,0105 earth and related environmental sciences ,Cadmium ,Macleaya cordata ,biology ,food and beverages ,General Medicine ,biology.organism_classification ,Pollution ,Plant Leaves ,Phytoremediation ,Horticulture ,Biodegradation, Environmental ,chemistry ,Catalase ,biology.protein ,010606 plant biology & botany - Abstract
Heavy metal pollution is a major concern of the public due to their threats to the safety of food chains. A 60-day pot experiment was conducted using Macleaya cordata as plant material to investigate the phytoremediation potential and anti-oxidative responses of M. cordata under different Cd stress. Significant growth inhibition phenomenon and toxic symptoms were not detected in the experiment. The high biomass of the plant provided high accumulation capacity for Cd with an average dry weight of 3.6 g. The maximum extraction amount of Cd was 393 μg·plant(-1), suggesting that this species had potential for phytoremediation of Cd-contaminated soil. A slight increase of chlorophyll (CHL) content was observed in Cd10 treatment. The plant was confirmed to have relatively high tolerance to the Cd stress on the basis of tolerance indexes (TI), relative water content, and CHLa/CHLb ratio. M. cordata could maintain high level of superoxide dismutase (SOD) activity under Cd stress, indicating strong tolerance capacity for reactive oxygen species (ROS) in plant cells. Catalase (CAT) activity show a certain range of decline in the experiment compare to the control. And peroxidase (POD) activity in leaves changed irregularly when compared to the control. The malondialdehyde (MDA) content increased as Cd concentration elevated compared to the control. In addition, as an inedible crop with relatively high economic value, M. cordata have shown the advantage of high biomass and high tolerance under Cd stress, which can provide a new plant resource for sustainable phytoremediation.
- Published
- 2016
11. The optimal timing of laparoscopic cholecystectomy in patients with mild gallstone pancreatitis
- Author
-
Wen-feng Huang, Kai Wang, Jian Nie, Xiao-fang Wang, Fu-ping Zhong, and Xue-qin Tan
- Subjects
medicine.medical_specialty ,Endoscopic retrograde cholangiopancreatography ,medicine.diagnostic_test ,business.industry ,medicine.medical_treatment ,MEDLINE ,General Medicine ,Cochrane Library ,medicine.disease ,Gastroenterology ,Confidence interval ,03 medical and health sciences ,0302 clinical medicine ,030220 oncology & carcinogenesis ,Meta-analysis ,Internal medicine ,Relative risk ,Medicine ,Pancreatitis ,Cholecystectomy ,030212 general & internal medicine ,business - Abstract
Background The optimal timing of laparoscopic cholecystectomy (LC) in patients with mild acute gallstone pancreatitis (MAGP) is controversial. The aim of this study was to systematically evaluate and compare the safety and efficacy of early laparoscopic cholecystectomy (ELC) and delayed laparoscopic cholecystectomy (DLC) in patients with MAGP. Methods A strict search was conducted of the electronic databases, including PubMed, MEDLINE Embase, the ISI Web of Science, and Cochrane Library for all relevant English literature and RevMan5.3 software for statistical analysis was used. Results A total of 19 studies comprising 2639 patients were included. There was no significant difference in intraoperative complications [risk ratio (RR) = 1.46; 95% confidence interval (CI) = 0.88-2.41; P = .14)], postoperative complications (RR = 0.81; 95% CI = 0.58-1.14; P = .23), rate of conversion to open cholecystectomy (RR = 1.00; 95% CI = 0.75-1.33; P = .99), operative time (MD = 1.60; 95% CI = -1.36-4.56; P = .29), and rate of readmission (RR = 0.63; 95% CI = 0.19-2.10; P = .45) between the ELC and DLC groups. However, the ELC group was significantly correlated with lower length of hospital stay (MD = -2.01; 95% CI = -3.15 to -0.87; P = .0006), fewer gallstone-related events rates (RR = 0.17; 95% CI = 0.07-0.44; P = .0003), and lower endoscopic retrograde cholangiopancreatography (ERCP) usage (RR = 0.83; 95% CI = 0.71-0.97; P = .02) compared with the DLC group. Conclusion Early laparoscopic cholecystectomy is safe and effective for patients with MAGP, but the indications and contraindications must be strictly controlled.
- Published
- 2019
12. The effects of P. aeruginosa ATCC 9027 and NTA on phytoextraction of Cd by ramie (Boehmeria nivea (L.) Gaud)
- Author
-
Xiaofei Tan, Guangming Zeng, Yunguo Liu, Weihua Xu, Hui Tang, Zhengjiang Jiang, Huan Liu, Jian Nie, Zhichao Sun, Wang Shufan, Bohong Zheng, Chao Gan, and Jieli Xie
- Subjects
Cadmium ,biology ,Chemistry ,Pseudomonas aeruginosa ,Inoculation ,General Chemical Engineering ,Nitrilotriacetic acid ,chemistry.chemical_element ,General Chemistry ,biology.organism_classification ,medicine.disease_cause ,Boehmeria ,Ramie ,Phytoremediation ,chemistry.chemical_compound ,Shoot ,medicine ,Food science - Abstract
In pot experiments, the effects of Pseudomonas aeruginosa ATCC 9027 and nitrilotriacetic acid (NTA) on Cd phytoextraction from contaminated soil by Boehmeria nivea (L.) Gaud (ramie) was investigated. Ramie was grown in a sandy soil in the presence of 30 mg kg−1 Cd and 50 mg kg−1 Cd, respectively. The experimental pots were amended with P. aeruginosa ATCC 9027 or NTA at different levels (5, 10 and 20 mmol kg−1) weekly. The results showed that the inoculation of P. aeruginosa ATCC 9027 alleviated the Cd-induced damages, resulting in promotion of ramie growth, improvement of antioxidative enzymes activities and increase of total Cd-uptake by ramie. By contrasting 30 and 50 mg kg−1 Cd treatments, the inoculation of P. aeruginosa ATCC 9027 increased accumulation in the roots ranging from 54% to 96% and 13% to 104% in 30 and 50 mg kg−1 Cd soils, respectively. The average accumulation of Cd with P. aeruginosa ATCC 9027 was about 1.95-fold (30 mg kg−1 Cd) and 1.54-fold (50 mg kg−1 Cd) compared to the corresponding NTA treatments. When added with NTA, the accumulation of Cd in the shoots of ramie was higher than the controls, but inhibition of plant growth and related enzyme activities were observed. The experimental results demonstrated that P. aeruginosa ATCC 9027 can greatly enhance phytoremediation efficiency. Besides, the results also indicated that P. aeruginosa ATCC 9027 was more effective than NTA to improve the efficiency of ramie under cadmium stress in practical applications.
- Published
- 2015
13. Mitigation mechanism of Cd-contaminated soils by different levels of exogenous low-molecular-weight organic acids and Phytolacca americana
- Author
-
Jian Nie, Guangming Zeng, Bohong Zheng, Xiaofei Tan, Jieli Xie, Yunguo Liu, Huan Liu, Wang Shufan, Zhichao Sun, Dafei Wang, Wei Liu, Zhengjiang Jiang, and Chao Gan
- Subjects
Cadmium ,Antioxidant ,General Chemical Engineering ,medicine.medical_treatment ,Oxalic acid ,chemistry.chemical_element ,General Chemistry ,chemistry.chemical_compound ,Phytoremediation ,chemistry ,Biochemistry ,Shoot ,Phytolacca americana ,medicine ,Malic acid ,Food science ,Citric acid - Abstract
Phytolacca americana L. (pokeweed) is a promising plant for phytoremediation of cadmium (Cd)-contaminated soil, with its large biomass and fast growth rate. Pot experiments were conducted to investigate the effects of low-molecular-weight organic acids (LMWOA) at different levels (10, 20, 30, 40 mmol kg−1) on the growth, oxidative stress and antioxidant system of pokeweed. Their role in Cd transportation and accumulation and the ameliorating effects of Cd-induced oxidative stress were also studied. The results showed that the tolerance threshold of Cd stress for pokeweed was 50 mg kg−1 dw. Moreover, Cd transfer can be effectively enhanced from root to shoot by lower concentrations (10 and 20 mmol kg−1 dw) of organic acids. Cd adsorption of pokeweed was obviously increased (312.5%, 142.9%, 305.9% in leaves and 130.9%, 103.6%, 119.9% in roots, respectively) when 10 mmol kg−1 dw citric acid (CA), 20 mmol kg−1 dw malic acid (MA) and 10 mmol kg−1 dw oxalic acid (OA) were added to the Cd-contaminated soil. The cadmium transfer coefficient of pokeweed was found to be effectively improved by certain concentrations of LMWOA. In conclusion, this study provides an important reference for further application of the pokeweed to soil remediation.
- Published
- 2015
14. Analysis of the Surface Shape Effect on Optical Homogeneity Measurement of Large Calibre Optical Materials
- Author
-
Zhu Feng Shao, Ya Nan Jia, Lei Wang, and Lan Jian Nie
- Subjects
Fused quartz ,Wavefront ,Fizeau interferometer ,Materials science ,business.industry ,Mechanical Engineering ,Slicing ,law.invention ,Optics ,Machining ,Mechanics of Materials ,law ,Caliber ,Optical materials ,Homogeneity (physics) ,General Materials Science ,business - Abstract
Optical homogeneity is an important measurement of the optical materials, directly affects wavefront quality of the refractive optical system, changes the system wavefront aberration. As the traditional direct measurement method requires high precision surface shape machining for optical material (PV value < 0.1λ), it was gradually replaced by the method of Fizeau interferometer four step, which requires lower surface shape. This article used 600mm diameter Fizeau interferometer, a four step method tested the optical homogeneity of the same 500 mm diameter fused quartz material with a front surface shape respectively 3.719 λ and 0.427 λ (λ = 632.8nm). Comparison of the test results showed that the PV difference of optical homogeneity between the two was only 0.036 λ, △n inaccuracy was 10-7, and the homogeneity morphology matched exactly. To further analyze the factors affecting the optical homogeneity, the front surface shape of the other sample was sliced in a predetermined direction. This artical analyzed the effect of morphology upon the slicing line on optical homogeneity. The conclusion was that the direct affecting factor on optical homogeneity was the slope of surface morphology, rather than the overall PV value.
- Published
- 2014
15. Toxicity of chemotherapy regimens in advanced and metastatic pancreatic cancer therapy: A network meta-analysis
- Author
-
Wen-feng Huang, Ji-Hao Jiang, Jian Nie, Xiao-fang Wang, Ding-Wu Tan, and Yong Zhou
- Subjects
medicine.medical_specialty ,FOLFIRINOX ,Nausea ,medicine.medical_treatment ,Network Meta-Analysis ,Leucovorin ,Neutropenia ,Pharmacology ,Irinotecan ,Biochemistry ,Gastroenterology ,Tegafur ,Deoxycytidine ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Antineoplastic Combined Chemotherapy Protocols ,medicine ,Humans ,030212 general & internal medicine ,Molecular Biology ,Chemotherapy ,Leukopenia ,business.industry ,Cell Biology ,medicine.disease ,Gemcitabine ,Oxaliplatin ,Pancreatic Neoplasms ,Regimen ,030220 oncology & carcinogenesis ,Fluorouracil ,medicine.symptom ,business ,medicine.drug - Abstract
This network meta-analysis is adopted in order to compare the toxicity of different chemotherapy regimens in the treatment of advanced/metastatic pancreatic cancer (PC). Randomized controlled trials (RCTs) about different chemotherapy regimens for advanced/metastatic PC were included in this network meta-analysis using Cochrane Library and PubMed electronic databases. The network meta-analysis was performed to combine direct and indirect evidence in order to calculate the odd ratios (OR) and draw a surface under the cumulative ranking (SUCRA) curve. A total of 19 RCTs were enrolled in this network meta-analysis including 12 chemotherapy regimens (Gemcitabine, Gemcitabine + S-1 [tegafur], Gemcitabine + nab-paclitaxel, Gemcitabine + Capecitabine, Gemcitabine + Cisplatin, FOLFIRINOX [oxaliplatin + irinotecan + fluorouracil + leucovorin], Gemcitabine + oxaliplatin, Gemcitabine + irinotecan, Gemcitabine + Exatecan, Gemcitabine + pemetrexed, Gemcitabine + 5-FU, S-1). The incidence of anemia of Gemcitabine + Capecitabine regimen was higher compared with Gemcitabine regimen, Gemcitabine + pemetrexed regimen exhibited the highest incidence rates of anemia and neutropenia; while Gemcitabine + S-1, Gemcitabine + Cisplatin and FOLFIRINOX regimens exhibited the highest incidence rates of neutropenia. However, S-1 regimen exhibited lower incidence rates of leukopenia and thrombocytopenia. Moreover, the incidence rates of nausea/vomiting and rash of Gemcitabine + S-1 regimen were higher compared with Gemcitabine regimen, while Gemcitabine + Cisplatin regimen had the highest incidence rate of nausea/vomiting. This study demonstrated that the hematologic toxicity of S-1 regimen was the lowest, while Gemcitabine regimen exhibited the lowest incidence rate of non-hematologic toxicity, providing guidance for the treatment of advanced/metastatic PC.
- Published
- 2017
16. Study on Economic Efficiency Monitoring Model of Power Grid Enterprises
- Author
-
Jian-Fen Shen and Ming-Jian Nie
- Subjects
Finance ,Economic efficiency ,business.industry ,Business process ,020209 energy ,02 engineering and technology ,Environmental economics ,Purchasing ,Power (social and political) ,Work (electrical) ,Order (exchange) ,0202 electrical engineering, electronic engineering, information engineering ,Key (cryptography) ,Economics ,Electricity ,business - Abstract
Since 2015, China's economic downward pressure continues to increase. Facing a more complex internal and external environment, power grid enterprises are paying more attention to their business performance. Through the effective monitoring and prevention of potential risks in economic activities, the abnormality of indicators and risk source tracking can realize. It is helpful for the power grid enterprises to find the work short-board and remedy the situation, so as to effectively enhance the competitiveness of the enterprises and adapt them to the new normal. Here, we firstly studied the benefit decomposition analysis model of power purchasing and selling, we found out the key factors that affected the purchasing and sales electrical benefit. Then, in order to find the abnormality in the electricity business process and trace the reason, we constructed a risk monitoring model of electricity purchasing and selling. In addition, we selected key indicators to be the real-time monitoring objectives. At last, we suggested the power grids to put emphasis upon retail market monitoring.
- Published
- 2017
17. Design of Sharing Multimedia Teaching System in Practical Education of PE
- Author
-
Li Li and Jian Nie
- Subjects
Cooperative learning ,Engineering ,Computer supported cooperative learning ,Multimedia ,business.industry ,Teaching method ,Cognition ,General Medicine ,computer.software_genre ,Stadium ,Interactivity ,Teaching and learning center ,ComputingMilieux_COMPUTERSANDEDUCATION ,The Internet ,business ,computer - Abstract
We puts forward a cognition of movement in computer supported cooperative learning , designs a multimedia teaching system in a shared environment on sports, and achieves the "Teacher-Student-Multimedia" cooperative learning, the multi-media teaching gradually exhibits its superiority and interactivity. The teaching resources partly apply to the sharing teaching on internet; partly apply to stadium assisting teaching, which supplies better environment for the students’ self-learning as well as more information resources for the teachers.
- Published
- 2014
18. Accelerometer-Measured Physical Activity in Children and Adolescents at Altitudes over 3500 Meters: A Cross-Sectional Study in Tibet
- Author
-
Chaoqun Fan, Mei Wang, Zhi Yao, Jingjing Wang, Ming-jian Nie, Qiang Feng, Yan-feng Zhang, and Rui-zhe Sun
- Subjects
Male ,Adolescent ,Cross-sectional study ,Accident prevention ,plateau ,Health, Toxicology and Mutagenesis ,education ,Physical activity ,lcsh:Medicine ,physical activity ,Poison control ,Overweight ,Tibet ,Body weight ,Article ,03 medical and health sciences ,Sex Factors ,0302 clinical medicine ,children ,Accelerometry ,Ethnicity ,Humans ,Medicine ,adolescents ,030212 general & internal medicine ,Child ,Exercise ,business.industry ,Altitude ,lcsh:R ,Body Weight ,Significant difference ,Age Factors ,Public Health, Environmental and Occupational Health ,030229 sport sciences ,accelerometer ,Cross-Sectional Studies ,Female ,medicine.symptom ,Negative correlation ,business ,human activities ,Demography - Abstract
There is a scarcity of studies on the physical activity (PA) of children and adolescents who live at high altitudes. This study aimed to objectively assess PA of children and adolescents living in the Tibet at altitudes over 3500 m and to examine its difference by ethnicity, gender, age/grade, and body weight status groups. A sample of 397 students aged 9&ndash, 18 years were recruited from 7 schools in Lhasa, Tibet. PA was measured using accelerometers (ActiGraph GT3X) for seven consecutive days and moderate to vigorous PA (MVPA) was identified using the Evenson (2008) cut-points. Participant MVPA was 62.3 min/day, with 65.5 min/day during weekdays and 54.1 min/day on weekends. Indigenous Tibetans were more active than Hans, and boys had more MVPA than girls. Age had a significantly weak negative correlation with MVPA. There was no significant difference in MVPA between the non-overweight and overweight/obese groups. Overall, only 9.1% (13.8% in boys and 4.5% in girls) accumulated at least 60 min of MVPA per day. Compared to their counterparts in other regions, the daily MVPA of children and adolescents living on the Tibetan Plateau at altitudes over 3500 m was relatively high. However, the proportion of meeting the WHO&rsquo, s PA recommendations was extremely low.
- Published
- 2019
19. Effect of water content on corrosion inhibition behavior of self-assembled TDPA on aluminum alloy surface
- Author
-
De-jian Nie, Geng Chen, Hairen Wang, and Jun-e Qu
- Subjects
Auger electron spectroscopy ,Materials science ,Alloy ,Inorganic chemistry ,Metals and Alloys ,Infrared spectroscopy ,Self-assembled monolayer ,engineering.material ,Geotechnical Engineering and Engineering Geology ,Condensed Matter Physics ,Electrochemistry ,Corrosion ,Adsorption ,Materials Chemistry ,engineering ,Fourier transform infrared spectroscopy - Abstract
Self assembled monolayers (SAMs) of 1–tetradecylphosphonic acids (TDPA, CH 3 (CH 2 ) 13 P(O)(OH) 2 ) were formed on the 2024 aluminum alloy surface in TDPA-containing ethanol–water solutions with different water content. The adsorption and corrosion protection properties of the SAMs for 2024 alloy in 0.1 mol/L H 2 SO 4 solution were examined and characterized by potentiodynamic polarization, electrochemical impedance spectrum (EIS), Fourier transformed infrared spectroscopy (FTIR), Auger electron spectra (AES) and atomic force microscopy (AFM). FTIR and AES results show that the TDPA molecules were successfully adsorbed on the 2024 aluminum alloy surface, and the density of the SAMs increased with the increasing water content in the assembly solution. The results of electrochemical studies and corrosion morphologies observed by AFM show that a 4 h modification resulted in maximal inhibition efficiencyand the higher the water content in the assembly solution is, the better the inhibition performance of the SAMs can be achieved. The effect of water content in TDPA solutions on the performance of the SAMs is related to the hydration reaction of the metal surface.
- Published
- 2013
20. Self-assembling behavior of TDPA molecules on inhomogeneous surface of 2024 aluminum alloy
- Author
-
Cheng Liu, Hairen Wang, De-jian Nie, June Qu, and Geng Chen
- Subjects
Auger electron spectroscopy ,Chemistry ,Scanning electron microscope ,Alloy ,Intermetallic ,chemistry.chemical_element ,Surfaces and Interfaces ,General Chemistry ,engineering.material ,Condensed Matter Physics ,Copper ,Surfaces, Coatings and Films ,Contact angle ,Crystallography ,Adsorption ,Chemical engineering ,Aluminium ,Materials Chemistry ,engineering - Abstract
The self-assembling behavior of 1-tetradecylphosphonic acid (TDPA) molecules on the surfaces of 2024 aluminum alloys was studied with an emphasis on the different micro-structural regions of the alloy surface, specially the alloy matrix and the two main types of intermetallic particles, as well as how the adsorption was effected by changes in water content of the self-assembly solution. Surface characterization was undertaken with contact angle measurement, scanning electron microscopy and Auger electron spectroscopy (AES). The packing density of TDPA film on the alloy surface increased with the increasing water content of the self-assembly solution. It seemed that the micro-distribution of TDPA molecules was related to copper amount and the region with a higher surface copper concentration had a lower packing density of TDPA. Some pits were formed in the acidic self-assembly solutions and the exposed surfaces of the pits can quickly adsorb TDPA molecules with compactness comparative to the matrix surface. Different adsorption models of TDPA corresponding to different water content of the self-assembly solution were suggested based on the analysis of AES depth sputtering data. Copyright © 2013 John Wiley & Sons, Ltd.
- Published
- 2013
21. Preparation of Ni-P-Al2O3 Composite Film on Mild Steel with High Resistance to Corrosion and Wear
- Author
-
Jian Nie, Hiroki Sawada, Rongguang Wang, and Nan Wang
- Subjects
Mean diameter ,Materials science ,Mechanical Engineering ,Metallurgy ,Alloy ,Composite film ,engineering.material ,Condensed Matter Physics ,Corrosion ,High resistance ,Wear resistance ,Cross section (physics) ,Mechanics of Materials ,Plating ,engineering ,General Materials Science ,Composite material - Abstract
The Ni-P-Al2O3 composite film was coated on mild steel of SS400 with electroless plating method. In this process, different sizes of Al2O3 particles and different blended amounts of Al2O3 particles into the plating solution were applied. From the surface and cross section observation, it is known that the Al2O3 particles were uniformly dispersed in the Ni-P alloy. The highest corrosion resistance and the highest wear resistance of the Ni-P-Al2O3 composite film were obtained when adding Al2O3 particles with the mean diameter of 0.05μm into the plating solution at the blended amount of 1.0g/L.
- Published
- 2013
22. Preparation of High Purity Low Hydroxyl Synthetic Fused Silica Glass
- Author
-
Zai Kui Xiang, Yu Fen Wang, Xue Fu Song, and Lan Jian Nie
- Subjects
Materials science ,General Engineering ,respiratory system ,law.invention ,Amorphous solid ,chemistry.chemical_compound ,Hydrolysis ,Chemical engineering ,chemistry ,law ,Transmittance ,Silicon tetrachloride ,Organic chemistry ,Calcination ,Crystallization ,Hydrophobic silica ,Fumed silica - Abstract
High purity low hydroxyl synthetic fused silica glass was prepared by electric melting synthetic crystallized silica powders which were made by the process of hydrolysis, dehydration and calcination of high purity silicon tetrachloride obtained from the by-product of polysilicon production. The structure morphology and hydroxyl content of synthetic silica powders were characterized by XRD and IR, respectively. The experimental results suggest that the silica powders dried at 120°C are amorphous, and the amorphous silica powders are gradually transformed to alpha-cristobalite after sintered in 1250°C, but the crystallization peaks are very strong and sharp until the temperature reaches at 1400°C. The hydroxyl content of silica powders can be effectively reduced by heat-treatment at high temperature.the crystallized silica powders calcined at 1500°C have much lower hydroxyl content than the amorphous silica powders. The hydroxyl group content in the silica glass products melted synthetic pre-crystallized silica powders is 7.3ppm, which meets the requirements for full-spectrum (wavelength from 190nm to 3200nm) transmittance.
- Published
- 2011
23. Processing and properties of Mg–6Gd–1Zn–0.6Zr
- Author
-
Matthew Barnett, Young Bum Chun, Jian Nie, Nicole Stanford, Jie Geng, and Chris Huw John Davies
- Subjects
Materials science ,Mechanical Engineering ,media_common.quotation_subject ,Metallurgy ,Recrystallization (metallurgy) ,Slip (materials science) ,Condensed Matter Physics ,Asymmetry ,Precipitation hardening ,Mechanics of Materials ,Macle ,Hardening (metallurgy) ,General Materials Science ,Composite material ,Crystal twinning ,Tensile testing ,media_common - Abstract
A Mg–6Gd–1Zn–0.6Zr alloy has been mechanically tested in the aged and solution treated conditions. The plate showed negligible yield asymmetry in either the aged condition or the particle free condition. This has been attributed to the weak texture that develops during recrystallisation. It is proposed that a negligible yield asymmetry can be achieved with textures weaker than ∼ 5 times random intensity, and that it is not necessary to have a fully random texture, but simply a texture weak enough for basal slip to dominate the deformation in both tension and compression. The ageing treatment provided little strengthening in tension or compression, and this is because the precipitates do not possess the strongest hardening characteristic of coherent shearable particles, which is internal order.
- Published
- 2011
24. The relationship between microstructure and creep resistance in die-cast magnesium–rare earth alloys
- Author
-
Su-Ming Zhu, Mark Alan Easton, Mark A. Gibson, and Jian Nie
- Subjects
Materials science ,Magnesium ,Precipitation (chemistry) ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,Intermetallic ,chemistry.chemical_element ,Condensed Matter Physics ,Microstructure ,Superalloy ,Creep ,chemistry ,Mechanics of Materials ,General Materials Science ,Grain boundary ,Solid solution - Abstract
Die-cast Mg–La, Mg–Ce and Mg–Nd binary alloys varying in composition have been used to investigate creep resistance and its relation to microstructure. The remarkable differences in creep resistance observed in these alloys are shown to be related to different levels of rare earth (RE) solute supersaturated in the α-Mg matrix. The results seem to suggest that strengthening of the α-Mg matrix by solid solution and/or precipitation is more important than grain boundary reinforcement by intermetallic phases for the creep resistance of Mg–RE alloys.
- Published
- 2010
25. The 18R and 14H long-period stacking ordered structures in Mg–Y–Zn alloys
- Author
-
Yuman Zhu, Jian Nie, and Allan James Morton
- Subjects
Materials science ,Polymers and Plastics ,Hexagonal crystal system ,Metals and Alloys ,Stacking ,Crystal structure ,Electronic, Optical and Magnetic Materials ,Crystallography ,Electron diffraction ,Lattice (order) ,Long period ,Scanning transmission electron microscopy ,Ceramics and Composites ,Monoclinic crystal system - Abstract
The 18R and 14H long-period stacking ordered structures formed in Mg–Y–Zn alloys are examined systematically using electron diffraction and high-angle annular dark-field scanning transmission electron microscopy. In contrast to that reported in previous studies, the 18R structure is demonstrated to have an ordered base-centred monoclinic lattice, with Y and Zn atoms having an ordered arrangement in the closely packed planes. Furthermore, the composition of 18R is suggested to be Mg 10 Y 1 Zn 1 , instead of the Mg 12 Y 1 Zn 1 composition that is commonly accepted. The 14H structure is also ordered . It has a hexagonal unit cell; the ordered distribution of Y and Zn atoms in the unit cell is similar to that in the 18R and its composition is Mg 12 Y 1 Zn 1 . The 18R unit cell has three ABCA-type building blocks arranged in the same shear direction, while the 14H unit cell has two ABCA-type building blocks arranged in opposite shear directions.
- Published
- 2010
26. Characterisation of intermetallic phases in an Mg–Y–Ag–Zn casting alloy
- Author
-
Yuman Zhu, Jian Nie, and Allan James Morton
- Subjects
Materials science ,Transmission electron microscopy ,Phase (matter) ,Metallurgy ,Alloy ,engineering ,Intermetallic ,engineering.material ,Ingot ,Condensed Matter Physics ,Crystal twinning ,Microstructure ,Casting - Abstract
The addition of Ag to Mg–Y–Zn alloys provides these alloys with the ability to develop a strong age-hardening response. In this work, the as-cast microstructure of an age-hardenable Mg–6Y–2Ag–1Zn–0.6Zr (wt%) alloy processed by conventional ingot metallurgy has been investigated by a transmission electron microscopy. Three distinct intermetallic phases are detected in the as-cast microstructure, two of which are similar to those phases present in the as-cast Ag-free Mg–Y–Zn alloys. The third is a previously unreported intermetallic phase associated with the additional element of Ag. The crystal structure of this phase is determined as diamond-cubic structure (a = 1.59 ± 0.01 nm, ). The dispersed particles of this phase often have a substructure of twinning on { 111} planes.
- Published
- 2010
27. Thermodynamic analysis of the La–Mg–Ni bulk metallic glass system
- Author
-
Jian Nie, Li-Bing Liu, Zhan Jin, Ligang Zhang, Shan Jin, Hongqun Dong, and Fangui Meng
- Subjects
Ternary numeral system ,Chemistry ,Mechanical Engineering ,Metals and Alloys ,Intermetallic ,Thermodynamics ,Entropy of mixing ,law.invention ,Mechanics of Materials ,law ,Phase (matter) ,Materials Chemistry ,Crystallization ,Ternary operation ,CALPHAD ,Phase diagram - Abstract
Phase equilibria of the La–Mg–Ni system have been analyzed and a complete thermodynamic description is obtained. The thermodynamic descriptions of the three binary systems are taken from the literature. Most of the binary intermetallic phases, except La2Mg17, LaNi3, and La2Ni7_L, are assumed to have zero solubility in the ternary system. Based on the experimental data, seven stable ternary intermetallic phases were taken into consideration in this system. Among them, two ternary compounds were treated as semi-stoichiometric compounds based on the ternary experimental results. The rest were treated as stoichiometric compounds. The calculated phase equilibria were in agreement with the available experimental data. Moreover, with the help of the optimized parameters, the composition dependencies of glass formation ability in the La–Mg–Ni system were predicted by searching local minima of driving forces for crystallization, and the prediction of glass formation ability agrees with the experimental results.
- Published
- 2010
28. Characterization of planar features in Mg–Y–Zn alloys
- Author
-
Matthew Weyland, Allan James Morton, Yuman Zhu, and Jian Nie
- Subjects
Materials science ,Polymers and Plastics ,Condensed matter physics ,Metals and Alloys ,Stacking ,Microstructure ,Electronic, Optical and Magnetic Materials ,Crystallography ,Transmission electron microscopy ,Stacking-fault energy ,Scanning transmission electron microscopy ,Ceramics and Composites ,Partial dislocations ,Dislocation ,Stacking fault - Abstract
The planar features in a Mg–8Y–2Zn–0.6Zr (wt.%) alloy solution-treated at 500 °C for 1 h have been examined using conventional transmission electron microscopy and atomic-resolution high-angle annular dark-field scanning transmission electron microscopy. Three types of planar features are detected in the microstructure. The first type, which was previously reported to be an intrinsic stacking fault I1 bounded by a Frank partial dislocation, is shown to be the 14H precipitate phase that is associated with Shockley partial dislocations. The second type is also a precipitate phase that has a single unit cell height and is associated with Shockley partial dislocations. The third type of planar feature comprises small ribbon-like stacking faults. These stacking faults are determined as intrinsic I2 type bounded by two Shockley partial dislocations, which is further confirmed by computer simulation. The stacking fault energy associated with the faults is much smaller than that of pure magnesium.
- Published
- 2010
29. [Clinical characteristics of pediatric hemorrhagic fever with renal syndrome]
- Author
-
Hong-Wei, Ma, Tie-Jian, Nie, Yong-Tao, Ma, Ya-Qiong, Wu, Zhan-Sheng, Jia, and Xue-Fan, Bai
- Subjects
Male ,Adolescent ,Child, Preschool ,Hemorrhagic Fever with Renal Syndrome ,Fluid Therapy ,Humans ,Female ,Child ,Retrospective Studies - Abstract
To study the clinical characteristics of pediatric hemorrhagic fever with renal syndrome (HFRS), and to improve its understanding so as to reduce the misdiagnosis.A retrospective analysis was performed on the clinical data of 26 children with HFRS between January 2009 and December 2012.The age of disease onset was mainly distributed between 7 and 14 years (23 cases, 88%), and the male-to-female ratio was 1.89:l. The clinical manifestations of pediatric HFRS varied. The early symptoms resembled those of a cold, and in the course of HFRS, most patients developed digestive symptoms such as vomiting and abdominal pain. The laboratory examinations usually implicated platelet changes, and the imaging examinations revealed polyserous effusions. The prominent complication was myocardial injury.Pediatric HFRS mainly occurs in school-age children, more commonly in males. HFRS does not have typical clinical manifestations or symptoms, so it should be distinguished from cold or appendicitis at the early stage. When applying the fluid replacement therapy, the cardiac function should be carefully monitored in case of heart failure.
- Published
- 2014
30. A study of polynucleotide phosphorylase production by Escherichia coli in a hollow fibre reactor
- Author
-
Lin Ma, Lian-Xiang Du, Shi-Jian Nie, and Bei-Zhong Han
- Subjects
Chromatography ,Physiology ,Purine nucleoside phosphorylase ,General Medicine ,Biology ,equipment and supplies ,medicine.disease_cause ,biology.organism_classification ,Applied Microbiology and Biotechnology ,Dilution ,Yield (chemistry) ,medicine ,Fermentation ,Polynucleotide phosphorylase ,Fiber ,Escherichia coli ,Bacteria ,Biotechnology - Abstract
A 30-l hollow fibre reactor with continuous fermentation for cell recycling of Escherichia coli AS 1.183 was used to remove the inhibitory effects on cell growth and extend the fast growth phase to increase the yield of polynucleotide phosphorylase (PNPase) in E. coli cells. When the dilution rate was 1.5 h−1, the cell concentration of E. coli reached 235 g/l (wet wt, 70% moisture content), with PNPase activity above 90 u/g (wet wt). With the dilution rate is 1.0 h−1, the fermentor volumetric productivity of PNPase in a hollow fiber reactor can reach 974 (u/h * l) compared to 20 (u/h * l) in a conventional batch culture.
- Published
- 2005
31. Kinetics simulation of high viscous styrene bulk polymerization system
- Author
-
Zhiquan Shen, Yifeng Zhang, Jian Nie, and Jun Ling
- Subjects
Kinetic chain length ,Polymers and Plastics ,Bulk polymerization ,Chemistry ,Stereochemistry ,Organic Chemistry ,Radical polymerization ,technology, industry, and agriculture ,General Physics and Astronomy ,Chain transfer ,Chain-growth polymerization ,Chemical engineering ,Polymerization ,Materials Chemistry ,Living polymerization ,Coordination polymerization - Abstract
Ultra high molecular weight polystyrene could be prepared by rare earth catalyst systems. Monte Carlo method simulates the kinetics of high viscous system of styrene bulk polymerization and verifies our coordination polymerization mechanism presumptions. The simulation indicates β-hydrogen elimination and monomer transfer reaction are important in the whole polymerization while the deactivation reaction and cocatalyst transfer reaction are in small possibilities. Polymers containing double bond end are regarded as macro-monomers that can be initiated into active chain. Monte Carlo simulation proves such presumption and calculates the average branch degree of 0.5.
- Published
- 2001
32. Preface to the viewpoint set on: The current state of magnesium alloy science and technology
- Author
-
Jian Nie and Sean R. Agnew
- Subjects
Set (abstract data type) ,Materials science ,Mechanics of Materials ,Mechanical Engineering ,Metallurgy ,Metals and Alloys ,General Materials Science ,State (computer science) ,Magnesium alloy ,Current (fluid) ,Condensed Matter Physics ,Science, technology and society ,Engineering physics - Published
- 2010
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.