检索结果-南通市图书馆

Hydraulic modeling and optimization of jet mill bit considering the characteristics of depressurization and cuttings cleaning

在线全文

学校读者我要写书评

暂无评论

Petroleum Science 2023年第5期20卷 3085-3099页

作者： tong cao Xu-Yue Chen Kai-An Yu Lin Tang School of Mechatronic Engineering Xi'an Technological UniversityXi'anShaanxi710021China MOE Key Laboratory of Petroleum Engineering China University of PetroleumBeijing102249China College of Mechanical and Transportation Engineering China University of PetroleumBeijing102249China

A jet mill bit(JMB)is proposed to increase the drilling efficiency and safety of horizontal wells,which has the hydraulic characteristics of depressurization and cuttings *** paper fills the gap in the hydraulic study of the JMB by focusing on the hydraulic modeling and optimization of the JMB and considering these two hydraulic ***,the hydraulic depressurization model and the hydraulic cuttings cleaning model of the JMB are developed *** the models,the pressure ratio and efficiency are chosen as the evaluation parameters of the depressurization capacity of the JMB,and the jet hydraulic power and jet impact force are chosen as the evaluation parameters of cuttings cleaning capacity of the ***,based on the hydraulic models,the effects of model parameters[friction loss coefficient,target inclination angle,rate of penetration(ROP),flow ratio,and well depth]on the hydraulic performance of the JMB are *** results show that an increase in the friction loss coefficient and target inclination angle cause a significant reduction in the hydraulic depressurization capacity,and the effect of ROP is *** flow ratio is positively related to the hydraulic cuttings cleaning capacity,and the well depth determines the maximum hydraulic cuttings cleaning ***,by combining the hydraulic depressurization model and hydraulic cuttings cleaning model,an optimization method of JMB hydraulics is proposed to simultaneously maximize the jet depressurization capacity and the cuttings cleaning *** to the drilling parameters given,the optimal values of the drilling fluid flow rate,backward nozzle diameter,forward nozzle diameter,and throat diameter can be ***,a case study is conducted to verify the effectiveness of the optimization method.

关键词： Jet mill bit Hydraulic depressurization model Hydraulic cuttings cleaning model Parametric study Hydraulic optimization

Model comparisons on molten core-concrete interactions

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2009年第4期20卷 251-256页

作者： tong Lili cao Xuewu LI Jingxi YANG Yajun School of Nuclear Science and Engineering Shanghai Jiaotong University Shanghai 200240 China

Based on the plant model of 600-MW PWR,the molten core-concrete interactions(MCCI) under different models are *** blackout (SBO) with steam-driven auxiliary feed water pump failure is selected as the case for the model comparisons *** result shows that thermal resistance model between debris and concrete has much influence on the consequence of *** concrete erosion rate calculated with gas film model is much higher than that of slag film *** other model comparisons such as the chemical reaction heat and the configuration molten pool are also discussed.

关键词：压水反应堆核技术 MCCI PWR

Effect analysis of the intentional depressurization on fission product behavior during TMLB' severe accident

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2009年第6期20卷 373-379页

作者： HUANG Gaofeng LI Jingxi tong Lili cao Xuewu School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200240 China

It has been found that the pressure in the reactor coolant system (RCS) remains high in some severe accident sequences at the time of reactor vessel failure, with the risk of causing direct containment heating (DCH). Intentional depressurization is an effective accident management strategy to prevent DCH or to mitigate its consequences. Fission product behavior is affected by intentional depressurization, especially for inert gas and volatile fission product. Because the pressurizer power-operated relief valves (PORVs) are latched open, fission product will transport into the containment directly. This may cause larger radiological consequences in containment before reactor vessel failure. Four cases are selected, including the TMLB' base case and the opening one, two and three pressurizer PORVs. The results show that inert gas transports into containment more quickly when opening one and two PORVs, but more slowly when opening three PORVs; more volatile fission product deposit in containment and less in reactor coolant system (RCS) for intentional depressurization cases. When opening one PORV, the phenomenon of revaporization is strong in the RCS.

关键词：裂变产物控制产品严重事故减压故意行为反应堆冷却剂系统雷达散射截面

Core cooling in pressurized-water reactor during water injection

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2011年第1期22卷 60-64页

作者： TAO Jun LI Jingxi tong Lili cao Xuewu School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

In this paper,the reactor core cooling and its melt progression terminating is evaluated,and the initiation criterion for reactor cavity flooding during water injection is *** core cooling in pressurized-water reactor of severe accident is simulated with the thermal hydraulic and severe accident code of SCDAP/*** results show that the core melt progression is terminated by water injection,before the core debris has formed at bottom of core,and the initiation of reactor cavity flooding is indicated by the core exit temperature.

关键词：压水反应堆堆芯冷却注水严重事故热工水力堆芯熔化温度显示反应器

Anion intercalated layered-double-hydroxide structure for efficient photocatalytic NO remove

在线全文

学校读者我要写书评

暂无评论

Green Energy & Environment 2019年第3期4卷 270-277页

作者： Wangchen Huo tong cao Xiaoying Liu Weina Xu Biqin Dong Yuxin Zhang Fan Dong State Key Laboratory of Mechanical Transmissions College of Materials Science and EngineeringChongqing UniversityChongqing 400044China Research Center for Environmental Science&Technology Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China Engineering Research Center for Waste Oil Recovery Technology and Equipment Ministry of EducationCollege of Environment and ResourcesChongqing Technology and Business UniversityChongqing 400067China College of Physics Chongqing UniversityChongqing 401331China e Guangdong Provincial Key Laboratory of Durability for Marine Civil EngineeringShenzhen UniversityShenzhen 518060China

Due to the easily controllable interlayer anions, metal cation composition proportion and thickness, which is beneficial to modify surface chemical state and tune bandgap, layered double hydroxides(LDHs) have great promising potential for photocatalytic applications. In this study,we have successfully synthesized the ZnAl–LDH intercalated the single anion between ZnAl cationic interlayer without anionic impurities by using a facile calcining and reconstructing routes. The electron structure and surface chemical state of the prepared products have been investigated by combining the DFT calculation and experimental characterization methods. UV–vis DRS was used to certify the light absorption of the prepared products, and we performed the DFT calculation to demonstrate the density of state and activation of reactant. These results suggested that the ZnAl–LDH–CO3 possessed the more proper band structure and superior ability to activate NO and O2 for accelerating the photocatalytic NO oxidation activity. Moreover, the in situ DRIFTS with dynamically monitoring intermediates and products over the ZnAl–LDH–CO3 was adopted to declare the photocatalytic NO oxidized process during the photocatalytic reaction process. This work illustrated the influence of different interlayer anions to the electron structure and surface chemical state of ZnAl–LDH structure through the experimental verification combined DFT calculation and the photocatalytic NO oxidized process via in situ DRIFTS analyzing, which would provide a novel way to design and fabricate the efficient photocatalysis, and understand the reaction process.

关键词： Photocatalytic NO oxidation ZnAl–LDH Reaction process and mechanism In situ DRIFTS DFT calculation

Study of moss as air pollution monitor by SRXRF technique

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 2009年第17期54卷 2987-2990页

作者： ZHANG YuanXun cao tong ATSUO lida cao QingChen LOU YuXia ZHANG GuiLin LI Yan Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China Life and Environment Science College Shanghai Normal University Shanghai 200234 China Photon Factory National Laboratory for High Energy Physics Tsukuba Ibaraki 305 Japan

In order to explore the mechanism of moss as air pollution biomonitor, the moss samples were exposed in a pollution site of Shanghai Institute of Steel Research (SISR) and a control site of Shanghai Institute of Applied Physics (SIAP) simultaneously for one month. The concentrations of trace elements in the micro areas of leaf and stem, as well as in the whole moss tissue, were determined using synchrotron radiation X-ray fluorescence (SRXRF) method. The distributions of some metal elements such as Pb, Cu, Fe, Ni, Mn, Zn, Ca and K in the leaf surface and the stem slice were obtained. The results showed that the metallic ions were not evenly distributed after adsorption. In particular, some elements of K, Ni, Fe, Pb, etc., were concentrated in the leaf apex and the intermediate rib. Under pollution condition, the excessive Pb was adsorbed and deposited in the leaf. It caused serious damage to plant growth and ultrastructure, also suppressed moss’ normal absorption to the nutritive elements of K, Ca, etc.

关键词：空气污染同步辐射生物监测荧光技术金属离子吸附 X射线荧光法中国科学院 SRXRF

Dan Bai Xiao Formula combined with glucocorticoids and cyclophosphamide for pediatric lupus nephritis:A pilot prospective study

在线全文

学校读者我要写书评

暂无评论

World Journal of Clinical Cases 2022年第31期10卷 11391-11402页

作者： tong-tong cao Li Chen Xiao-Fang Zhen Gao-Jie Zhao Hui-Fang Zhang Yan Hu Department of Traditional Chinese Medicine Beijing Children’s HospitalCapital Medical UniversityNational Center for Children’s HealthBeijing 100045China

BACKGROUND Patients with lupus nephritis(LN)typically undergo long-term treatment with glucocorticoids(GCs)and *** is a growing demand for optimal therapy with better remission results and fewer side *** traditional Chinese medicine(TCM)might be quite valuable for multitarget therapy,reducing the total dosage of GCs and minimizing the side effects of *** To evaluate whether Dan Bai Xiao Formula(DBXF)can reduce the exposure to GCs and cyclophosphamide(CYC)and to assess the efficacy and safety of DBXF for the resolution of proteinuria and hematuria in children with *** A 24-wk pilot study was conducted at Beijing Children’s *** with active LN were divided into either a TCM group or a control *** in the TCM group received DBXF combined with GCs and CYC,and the ones in the control group received GCs and CYC every 4 wk for 24 *** primary endpoints of this trial were urinary protein excretion of0.05).The urine red blood cell count and urine protein level were significantly lower in the TCM group than in the control group at weeks 4,12,and 24(P<0.05).Furthermore,patients in the TCM group had a lower proportion of methylprednisolone pulses than those in the control group(1.30±1.41 vs 3.05±2.02,P<0.0001).The ending GC dose was significantly lower in the TCM group than in the control group(P<0.001).Moreover,more hepatic function damage,gastrointestinal adverse effects,and hypertension were observed in the control group than in the TCM group(P<0.05).CONCLUSION The findings suggest that DBXF tr

关键词： Lupus nephritis Traditional Chinese medicine Dan Bai Xiao Formula Effective Safe

Numerical and experimental investigation on the depressurization capacity of a new type of depressure-dominated jet mill bit

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Petroleum Science 2020年第6期17卷 1602-1615页

作者： Xu-Yue Chen tong cao Kai-An Yu De-Li Gao Jin Yang Hong-Shu Wei MOE Key Laboratory of Petroleum Engineering China University of Petroleum(Beijing)Beijing 102249China Shaanxi Cooperative Innovation Center of Unconventional Oil and Gas Exploration and Development Xi’an Shiyou UniversityXi’an 710065ShaanxiChina CNOOC China Limited Shenzhen BranchShenzhen 518067GuangdongChina

Efficient cuttings transport and improving rate of penetration(ROP)are two major challenges in horizontal drilling and extended reach drilling.A type of jet mill bit(JMB)may provide an opportunity to catch the two birds with one stone:not only enhancing cuttings transport efficiency but also improving ROP by depressuring at the bottom *** this paper,the JMB is further improved and a new type of depressure-dominated JMB is presented;meanwhile,the depressurization capacity of the depressure-dominated JMB is investigated by numerical simulation and *** numerical study shows that low flow-rate ratio helps to enhance the depressurization capacity of the depressure-dominated JMB;for both depressurization and bottom hole cleaning concern,the flow-rate ratio is suggested to be set at approximately 1:*** all other parameter values being constant,lower dimensionless nozzle-to-throat-area ratio may result in higher depressurization capacity and better bottom hole cleaning,and the optimal dimensionless nozzle-to-throat-area ratio is at *** also indicate that reducing the dimensionless flow-rate ratio may help to increase the depressurization capacity of the depressure-dominated *** work provides drilling engineers with a promising tool to improve ROP.

关键词： Horizontal drilling Jet mill bit Bottom hole depressurization Bottom hole flow field Rate of penetration

Nano-selenium controlled cadmium accumulation and improved photosynthesis in indica rice cultivated in lead and cadmium combined paddy soils

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2021年第5期33卷 336-346页

作者： Chengrun Wang Tingting Cheng Haitao Liu Fangyun Zhou JifengZhang Min Zhang Xinya Liu Wenjun Shi tong cao School of Biological Engineering Huainan Normal UniversityHuainan 232038China Key Laboratory of Bioresource and Environmental Biotechnology of Anhui Higher Education Institutes Huainan Normal UniversityHuainan 232038China

Selenium nanoparticles(Se NPs) are less toxic and more biocompatible than selenite or selenate. However, studies involving spraying with Se NPs for reducing accumulation of cadmium(Cd) and lead(Pb) in rice grains have been rarely reported as yet. Herein, indica rice seedlings cultivated in Cd + Pb-spiked paddy soils(denoted as positive control) were sprayed with Se NPs sols for four times from tillering to booting stage. Compared to positive control, 50–100 μmol/L Se NPs downregulated Cd transporters-related genes such as Os LCT 1, OsH MA 2 and Os CCX2 in leaves and OsLCT1, Os PCR1 and Os CCX2 genes in node I at filling stage. Meanwhile, Se-binding protein 1 was distinctly elevated, involving the repression of Cd and Pb transportation to rice grains. Se NPs also differentially improved RuBP carboxylase and chlorophylls especially some key genes and proteins involving photosynthetic system. Besides, 25–50 μmol/L Se NPs diminished reactive oxygen species overproduction from NADPH oxidases whereas boosted glutathione peroxidase, reducing protein carbonylation in rice seedlings. However, the antioxidant isozymes and oxidatively modified proteins were slightly rebounded at 100 μmol/L. Se contents were noticeably elevated and confirmed to exist as selenomethionine in the rice grains following all the treatments by Se NPs. Thus, the optimal dosage of Se NPs for foliar application is 50 μmol/L, which significantly decreased Cd accumulation, improved photosynthesis and Se enrichment whereas caused no distinct reduction of Pb in the grains. Thus, an appropriate dosage of Se NPs can be conducted to decrease Cd accumulation, improve photosynthesis, and organic Se contents in rice grains.

关键词： Selenium nanoparticles(Se NPs) Heavy metals Oryza sativa L. Selenium enrichment and cadmium reduction Food quality and safety