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Application of metal magnetic memory test in failure analysis and safety evaluation of vessels

Yiliang ZHANG, Song YANG, Xuedong XU

《机械工程前沿(英文)》 2009年 第4卷 第1期   页码 40-48 doi: 10.1007/s11465-009-0003-3

摘要: Metal magnetic memory test (MMMT), which is a new subject in the field of nondestructive examination, can determine regions of stress concentration by testing the distribution of the magnetic field of metal structures so as to effectively diagnose premature defects. MMMT and other test methods are applied in the study to put a propylene purifier of a temperature-jump accident and a leaked ammonia vessel through safety evaluation. Results are as follows: The margin of safety declines after the purifier is overburnt; several stress concentrations are observed within the overburnt area and the level of stress concentration rises after one-month operation; and overpressure operation of the purifier must be strictly avoided and carefully monitored during later operation. Cracks are observed on the ammonia vessel after one year’s service. Extremely high residual stress is the primary cause of cracks. After four years in service, the residual stresses existing in the area of the base metal and weld zone are still greater than 0.5 , which results in numerous cracks due to stress corrosion. From the MMMT result of the ammonia vessel’s defects, it can be seen that the derivative of magnetic density (d p/d ) is an important reference variable. Within the 31 leakage points, 67.7% of them whose dHp/dx values are more than 10, and 96.8% of them whose dHp/dx values are more than 8.

关键词: Metal magnetic memory test (MMMT)     nondestructive testing (NDT)     residual stress     propylene purifier     ammonia vessel    

Bioaerosol: A Key Vessel between Environment and Health

《环境科学与工程前沿(英文)》 2021年 第15卷 第3期 doi: 10.1007/s11783-021-1422-6

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

《结构与土木工程前沿(英文)》 2009年 第3卷 第3期   页码 279-285 doi: 10.1007/s11709-009-0044-z

摘要: Based on a field observation on vessel transit path of three bridges over the Yangtze River in the Three Gorges Reservoir, and an analysis of the geometric probabilistic model of transiting vessels in collision probability calculation, the aberrancy angle and vessel velocity probabilistic model related with impact force, a probabilistic model is established and also verified by goodness-of-fit test. The vessel transit path distribution can be expressed by the normal distribution model. For the Three Gorges Reservoir, the mean and standard deviation adopt 0.2 and 0.1, respectively ( is the channel width). The aberrancy angle distribution of vessels accepts maximum I distribution model, and its distribution parameters can be taken as 0.314 and 4.354. The velocity distribution of up-bound and down-bound vessels can also be expressed by the normal distribution model.

关键词: vessel-bridge collision     probabilistic model     parameter statistics    

Construction of the vessel-collateral theory and its guidance for prevention and treatment of vasculopathy

Yiling Wu

《医学前沿(英文)》 2011年 第5卷 第2期   页码 118-122 doi: 10.1007/s11684-011-0140-z

摘要: According to the self-discipline of traditional Chinese medicine, vessel-collateral theory was constructed systematically, which was important to improving prevention and treatment level of vasculopathy. The hypothesis of “homeostasis ( ), compensatory auto-adaptation ( ), regulation ( ) and equilibrium ( )” based on the “qi–yin-yang–five elements” coupled with the (nutrients)- (defense) theory, has become the core content of the vessel-collateral theory. Clinical and laboratory trials have been developed to further confirm the scientific connotations of the hypothesis, such as capsule, as the representative drugs of vessel collateral theory, showed good efficacy in protecting the vascular endothelium, stabilizing the vulnerable plaque and reducing the blood vessel spasm. “Sou, ti, shu, tong” was the characteristics of capsule in treating “microvascular damage” as the core mechanism of acute myocardial infarction, cerebral infarction and microvascular complications of diabetes. capsules in the treatment of arrhythmia have made integrated adjustment advantage. capsules have been made treating both manifestation and root cause of chronic heart failure. These research have improved prevention and treatment level of major vascular system diseases.

关键词: vessel-collateral theory     vasculopathy     prevention and treatment    

Abundance and distribution of ammonia-oxidizing archaea in Tibetan and Yunnan plateau agricultural soils

Kun DING,Xianghua WEN,Liang CHEN,Daishi HUANG,Fan FEI,Yuyang LI

《环境科学与工程前沿(英文)》 2014年 第8卷 第5期   页码 693-702 doi: 10.1007/s11783-014-0635-3

摘要: As low oxygen and high ultraviolet (UV) exposure might significantly affect the microbial existence in plateau, it could lead to a specialized microbial community. To determine the abundance and distribution of ammonia-oxidizing archaea (AOA) in agricultural soil of plateau, seven soil samples were collected respectively from farmlands in Tibet and Yunnan cultivating the wheat, highland-barley, and colza, which are located at altitudes of 3200–3800 m above sea level. Quantitative PCR (q-PCR) and clone library targeting on gene were used to quantify the abundances of AOA and ammonia-oxidizing bacteria (AOB), and characterize the community structures of AOA in the samples. The number of AOA cells (9.34 × 10 –2.32 × 10 g soil) was 3.86–21.84 times greater than that of AOB cells (6.91 × 10 –1.24 × 10 g soil) in most of the samples, except a soil sample cultivating highland-barley with an AOA/AOB ratio of 0.90. Based Kendall’s correlation coefficient, no remarkable correlation between AOA abundance and the environmental factor was observed. Additionally, the diversities of AOA community were affected by total nitrogen and organic matter concentration in soils, suggesting that AOA was probably sensitive to several environmental factors, and could adjust its community structure to adapt to the environmental variation while maintaining its abundance.

关键词: ammonia-oxidizing archaea     ammonia-oxidizing bacteria     quantitative PCR     clone library     plateau    

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

《能源前沿(英文)》 2011年 第5卷 第4期   页码 358-366 doi: 10.1007/s11708-011-0161-y

摘要: To investigate the performance of heat and mass transfer of ammonia-water during the process of falling film evaporation in vertical tube evaporator, a mathematical model of evaporation process was presented, the solution of which that needed a coordinate transformation was based on stream function. The computational results from the mathematical model were validated with experimental data. Subsequently, a series of parameters, such as velocity, film thickness and concentration, etc., were obtained from the mathematical model. Calculated results show that the average velocity and the film thickness change dramatically at the entrance region when <100 mm, while they vary slightly with the tube length in the fully developed region when >100 mm. The average concentration of the solution reduces along the tube length because of evaporation, but the reducing tendency becomes slow. It can be concluded that there is an optimalβrelationship between the tube length and the electricity generated. The reason for the bigger concentration gradient in the direction is that the smooth tube is chosen in the calculation. It is suggested that the roll-worked enhanced tube or other enhanced tube can reduce the concentration gradient in the film thickness direction and enhance the heat and mass transfer rate.

关键词: falling film evaporation     ammonia-water     heat and mass transfer    

Simulation on thermodynamic state of ammonia carbonation at low temperature and low pressure

Jingcai ZHAO, Xingfu SONG, Ze SUN, Jianguo YU

《化学科学与工程前沿(英文)》 2013年 第7卷 第4期   页码 447-455 doi: 10.1007/s11705-013-1370-1

摘要: This study on thermodynamic property of NH -CO -H O system provided the basic data for ammonia carbonation. Simulations on vapor-liquid equilibrium (VLE) of ammonia carbonation with different physical properties were discussed in NH -H O and NH -CO -H O systems, respectively. The results indicated that at low temperature (303.15 K–363.15 K) and pressure (0.1–0.4 MPa), the PR (Peng-Robinson) equation was suitable for the description of the thermodynamic state in NH -H O system. NRTL (Non-Random-Two-Liquid) series models were selected for NH -CO -H O mixed electrolyte solution system. VLE data regression results showed that NRTL series models were suitable for describing thermodynamic properties of NH -CO -H O system, because average relative error fitting with each model was about 1%. As an asymmetric electrolytes model in NRTL model, E–NRTLRK (Electrolyte NRTL Redlich Kwong) could most accurately fit VLE data of NH -CO -H O system, with fitting error less than 1%. In the extent temperature range of 273.15 K–363.15 K, the prediction of product component using E-NRTLRK model for ammonia carbonation agreed well with the data reported in literature.

关键词: vapor-liquid equilibrium     activity coefficient     carbon dioxide     ammonia     NRTL    

Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power

Peng ZHENG, Xuan YAO, Wei ZHENG

《能源前沿(英文)》 2013年 第7卷 第1期   页码 127-132 doi: 10.1007/s11708-012-0225-7

摘要: Ammonia is highly volatile and will present substantial environmental and operation hazards when leaking into the air. However, ammonia is the most common reactant in the DENOX project to eliminate NO in the flue gas. The storage and transportation of liquid ammonia has always been a dilemma of the power plant. Urea is a perfect substitute source for ammonia in the plant. Urea hydrolysis technology can easily convert urea into ammonia with low expense. Presently, there is still no self-depended mature urea hydrolysis technology for the DENOX project in China; therefore, this paper proposes several guidelines to design the urea hydrolyser by theoretical analysis. Based on theoretical analysis, a simulation model is built to simulate the chemical reaction in the urea hydrolyser and is validated by the operational data of the commercial hydrolyser revealed in the literature. This paper endeavors to propose suggestions and guidelines to develop domestically urea hydrolysers in China.

关键词: urea     hydrolyser     ammonia     selective catalytic reduction (SCR)    

Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater

《环境科学与工程前沿(英文)》 2021年 第15卷 第5期 doi: 10.1007/s11783-020-1375-1

摘要:

• AOA’s ammonia oxidizing capacity was enhanced under moderate magnetic field.

关键词: Ammonia-oxidizing archaeon     Ammonia oxidation     Magnetic field     Magnetotaxis     Heredity    

Cell carrier function of hollow-fiber membrane in rotating wall vessel bioreactor

SONG Kedong, LIU Tianqing, ZHAO Hu, LI Xiangqin, MA Xuehu, CUI Zhanfeng

《化学科学与工程前沿(英文)》 2008年 第2卷 第1期   页码 34-39 doi: 10.1007/s11705-008-0022-3

摘要: Large-scale expansion of the osteoblasts of a Sprague-Dawley (SD) rat was studied in a rotating wall hollow-fiber membrane bioreactor (RWHMB) by using hollow-fiber membrane as the carrier. For the sake of contrast, cells were also expanded in a T-flask using a hollow-fiber membrane as carrier and in a rotating wall vessel bioreactor (RWVB) using a microcarrier. During the culture period, the cells were sampled every 12 h, and after 5 days, the cells were harvested and evaluated with scanning electron microscopy (SEM), hematoxylin-eosin (HE) staining and alkaline phosphatase (ALP) staining. Moreover, von-Kossa staining and Alizarin Red S staining were carried out for mineralized nodules formation. The results show that in RWHMB, the cells present better morphology and vitality and secrete much more extracellular matrix. It is concluded that the RWHMB combines the advantages of the rotating wall vessel and hollow-fiber membrane bioreactors. The hydrodynamic stimulation within it accelerates the metabolism of the osteoblast and mass transfer, which is propitious to cell differentiation and proliferation.

关键词: RWHMB     microcarrier     hematoxylin-eosin     von-Kossa staining     propitious    

GREENHOUSE GAS AND AMMONIA EMISSION MITIGATION PRIORITIES FOR UK POLICY TARGETS

《农业科学与工程前沿(英文)》 2023年 第10卷 第2期   页码 268-280 doi: 10.15302/J-FASE-2023495

摘要:

● An expert survey highlighted the most effective strategies for GHG and ammonia mitigation.

关键词: agriculture     ammonia     greenhouse gas     mitigation     net zero    

Simultaneous enhanced ammonia and nitrate removal from secondary effluent in constructed wetlands using

《环境科学与工程前沿(英文)》 2023年 第18卷 第4期 doi: 10.1007/s11783-024-1807-4

摘要:

● MnO2/PCL composite material (MPCM) enhances ammonia and nitrate removal in CWs.

关键词: Constructed wetland     Nitrogen removal     Manganese redox     Polycaprolactone     Nitrous oxide    

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

《能源前沿(英文)》 doi: 10.1007/s11708-023-0908-2

摘要: The Haber-Bosch process is the most widely used synthetic ammonia technology at present. Since its invention, it has provided an important guarantee for global food security. However, the traditional Haber-Bosch ammonia synthesis process consumes a lot of energy and causes serious environmental pollution. Under the serious pressure of energy and environment, a green, clean, and sustainable ammonia synthesis route is urgently needed. Electrochemical synthesis of ammonia is a green and mild new method for preparing ammonia, which can directly convert nitrogen or nitrate into ammonia using electricity driven by solar, wind, or water energy, without greenhouse gas and toxic gas emissions. Herein, the basic mechanism of the nitrogen reduction reaction (NRR) to ammonia and nitrate reduction reaction (NO3 RR) to ammonia were discussed. The representative approaches and major technologies, such as lithium mediated electrolysis and solid oxide electrolysis cell (SOEC) electrolysis for NRR, high activity catalyst and advanced electrochemical device fabrication for NO3 RR and electrochemical ammonia synthesis were summarized. Based on the above discussion and analysis, the main challenges and development directions for electrochemical ammonia synthesis were further proposed.

关键词: electrochemical ammonia synthesis     nitrogen     nitrate     nitrogen reduction reaction (NRR) to ammonia     nitrate reduction reaction (NO–3 RR)    

Nano-confined ammonia borane for chemical hydrogen storage

M. A. WAHAB, Huijun ZHAO, X. D. YAO

《化学科学与工程前沿(英文)》 2012年 第6卷 第1期   页码 27-33 doi: 10.1007/s11705-011-1171-3

摘要: There is a great demand for a sufficient and sustainable energy supply. Hence, the search for applicable hydrogen storage materials is extremely important owing to the diversified merits of hydrogen energy. In this regard, ammonia borane (NH BH , AB) containing 19.6 wt-% hydrogen has been considered as a promising material for hydrogen storage applications to realize the “hydrogen economy”, but with limits from slow kinetics of hydrogen release and by-product of trace gases such as ammonia and borazine. In this review, we introduce the recent research on AB, regarding to the nanoconfinement effect on improving the kinetics at a relatively low temperature and the prevention/reduction of undesirable gas formation.

关键词: ammonia borane     hydrogen storage    

Experimental study on capturing CO 2 greenhouse gas by mixture of ammonia and soil

Ying WU, Yifei WANG, Qinghua ZENG, Xin GONG, Zunhong YU,

《化学科学与工程前沿(英文)》 2009年 第3卷 第4期   页码 468-473 doi: 10.1007/s11705-009-0257-7

摘要: This paper presents our study on removal of carbon dioxide (CO) greenhouse gas emissions by using the mixture of ammonia and soil. CO capture capacity using this method is 15% higher than the sum of ammonia chemical absorption capacity and soil physical adsorption capacity. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) are utilized to study this synergism. The removal effect is not only reflected in ammonia chemical reaction with CO. CO can also be absorbed by ammonium bicarbonate (NHHCO) crystal, which is the main component of the product, or wrapped in the pore of the crystal or packed in the gap between the crystal and the soil. CO can be permanently deposited as carbonated minerals in the subsoil earth layers.

关键词: electron microscopy     product     physical adsorption     capacity     spectroscopy    

标题 作者 时间 类型 操作

Application of metal magnetic memory test in failure analysis and safety evaluation of vessels

Yiliang ZHANG, Song YANG, Xuedong XU

期刊论文

Bioaerosol: A Key Vessel between Environment and Health

期刊论文

Probabilistic model for vessel-bridge collisions in the Three Gorges Reservoir

Bo GENG , Hong WANG , Junjie WANG ,

期刊论文

Construction of the vessel-collateral theory and its guidance for prevention and treatment of vasculopathy

Yiling Wu

期刊论文

Abundance and distribution of ammonia-oxidizing archaea in Tibetan and Yunnan plateau agricultural soils

Kun DING,Xianghua WEN,Liang CHEN,Daishi HUANG,Fan FEI,Yuyang LI

期刊论文

Heat and mass transfer of ammonia-water in falling film evaporator

Xianbiao BU, Weibin MA, Huashan LI

期刊论文

Simulation on thermodynamic state of ammonia carbonation at low temperature and low pressure

Jingcai ZHAO, Xingfu SONG, Ze SUN, Jianguo YU

期刊论文

Design guidelines for urea hydrolysers for ammonia demand of the SCR DENOX project in coal-fired power

Peng ZHENG, Xuan YAO, Wei ZHENG

期刊论文

Enhancement on the ammonia oxidation capacity of ammonia-oxidizing archaeon originated from wastewater

期刊论文

Cell carrier function of hollow-fiber membrane in rotating wall vessel bioreactor

SONG Kedong, LIU Tianqing, ZHAO Hu, LI Xiangqin, MA Xuehu, CUI Zhanfeng

期刊论文

GREENHOUSE GAS AND AMMONIA EMISSION MITIGATION PRIORITIES FOR UK POLICY TARGETS

期刊论文

Simultaneous enhanced ammonia and nitrate removal from secondary effluent in constructed wetlands using

期刊论文

Recent advances and challenges of nitrogen/nitrate electro catalytic reduction to ammonia synthesis

期刊论文

Nano-confined ammonia borane for chemical hydrogen storage

M. A. WAHAB, Huijun ZHAO, X. D. YAO

期刊论文

Experimental study on capturing CO 2 greenhouse gas by mixture of ammonia and soil

Ying WU, Yifei WANG, Qinghua ZENG, Xin GONG, Zunhong YU,

期刊论文