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Comparisons of nozzle orifice processing methods using synchrotron X-ray micro-tomography

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2012年第3期13卷 182-188页

作者： zhi-jun wu zhi-long LI Wei-di HUANG Hui-feng GONG Ya GAO jun DENG Zong-jie HU School of Automotive Studies Tongji University Shanghai 201019 China

Based on the high flux synchrotron X-ray of the Shanghai Synchrotron Radiation Facility (SSRF), high precision 3D digital models of diesel nozzle tips have been established by X-ray micro-tomography technology, which reveal the internal surfaces and structures of orifices. To analyze the machining precision and characteristics of orifice processing methods, an ap- proach is presented based on the parameters of the internal structures of nozzle orifices, including the nozzle diameter, the orifice inner surface waviness, the eccentricity distance and the angle between orifices. Using this approach, two kinds of nozzle orifice processing methods, computerized numerical control drilling and electric discharge machining, have been studied and compared. The results show that this approach enables a simple, direct, and comprehensive contrastive analysis of nozzle orifice processing methods. When processing a single orifice, the electric discharge machining method has obvious advantages. However, when there are multiple orifices, the error levels of the two methods are similar in relation to the symmetry of distribution of the orifices.

关键词： Diesel nozzle Internal structures Orifice processing methods Synchrotron X-ray micro-tomography

Insight into characteristics and sources of PM2.5 in the Beijing–Tianjin–Hebei region, China

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National Science Review 2015年第3期2卷 257-258页

作者： Min Hu Song Guo Jian-fei Peng zhi-jun wu College of Environmental Sciences and Engineering Peking University Departments of Atmospheric Sciences and Chemistry Texas A&M University

As the world’s second-largest economy,China has experienced severe air pollution with unprecedentedly high levels of PM2.5,*** mater smaller than 2.5μm in *** Ministry of Environmental Protection of China released an air pollution monitoring report for the year 2013 for the 74 largest cities of *** Beijing–Tianjin–Hebei(BTH)region was classiied as having the poorest air *** annual

关键词： Insight into characteristics and sources of PM Hebei region China Tianjin

New steroidal sapogenins from the acid hydrolysis product of the whole glycoside mixture of Welsh onion seeds

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Chinese Chemical Letters 2012年第2期23卷 193-196页

作者： Wei Lai Ying Bo Yang Xia Li Lian Na Sun zhi jun wu Wan Sheng Chen Department of Pharmacy Changzheng HospitalSecond Military Medical UniversityShanghai 200003China School of Pharmacy Second Miliiary Medical UniversityShanghai 200433China

Two new steroidal sapogenins（1,2） along with five known steroidal sapogenins were isolated from the acid hydrolysis product of the whole glycoside mixture of Welsh onion（Allium fistulosum L.） *** on comprehensive spectroscopic analyses, including 2D NMR spectroscopy and mass spectrometry,their structures were elucidated as（25R）-19-norspirosta-l,3,5（10）-triene-4 -methyl-2-ol（1）,（25R）-spirost-l,4-diene-3-one-2,6-diol（2）,（25R）-spirost-l,4-diene-3-one-2-ol（3）,（25R）-spirost-4-ene-3-one-2-ol （4）,yuccagenin（5）,gitogenin（6） and tigogenin（7）.

关键词： Steroidal sapogenin Welsh onion

Investigations on Nitrate Pollution of Soil, Groundwater and Vegetable from Three Typical Farmlands in Beijing Region, China

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Agricultural Sciences in China 2011年第3期10卷 423-430页

作者： DU Lian-feng ZHAO Tong-ke ZHANG Cheng-jun AN zhi-zhuang wu Qiong LIU Bao-cun LI Peng MA Mao-ting Institute of Plant Nutrition and Resources Beijing Academy of Agricultural and Forestry Sciences Beijing 100097 P.R.China

The aim of this study was to determine the nitrate pollution status of soil, groundwater, and vegetable from three typical farmlands （croplands, vegetable fields, and orchards） in Beijing region. During the investigation, hundreds of the soil, groundwater, and vegetable samples from three typical farmlands were collected and analyzed. In addition, attributes of all samples were recorded for data analysis. The results showed that nitrate was substantially accumulated in soil profiles, while the soil nitrate concentrations of vegetable fields and orchards were higher than those of croplands. Nitrate concentration in 0-30 cm soil of vegetable field and orchard were 3.8 and 1.2 times of that of cropland, respectively. Nitrate content of groundwater in vegetable field was 13.8 mg L-1 （with the over-standard ratio 44.8%）, which was 2.8 folds of that in cropland. Nitrate concentration of groundwater under orchard was 9.3 mg L-1 （with the over-standard ratio 23.5%）, which was 1.9 folds of that in cropland. High concentrations of the nitrate in vegetables were detected, particularly green leafy vegetables ranked first with 2 685.5 mg kg-1, followed by rhizome vegetables, cabbages, and fruit vegetables. The nitrate over-standard ratios of rhizome vegetables, green leafy vegetables, fruit vegetables, and cabbages were 80.9, 37.9, 29.7, and 2.2%, respectively. The results revealed that the high nitrate concentrations of soil, vegetable, and groundwater might result from the high fertilization dose.

关键词： farmland vegetables groundwater soil nitrate

FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

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Nuclear Science and Techniques 2024年第3期35卷 96-108页

作者： Wei Jiang Ping Cao Yi-Ming wu Xian-Ke Liu Zhu-jun Fang zhi-Yong Zhang Bin Shi jun Chen State Key Laboratory of Particle Detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and Technology University of Science and Technology of ChinaHefei 230026China National Key Laboratory for Metrology and Calibration Techniques China Institute of Atomic EnergyBeijing 102413China

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas *** address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber *** method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined *** performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data *** experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 *** beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction *** online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT.

关键词： Position reconstruction FPGA Readout electronics Neutron flux spatial distribution

Manipulating guest-responsive spin transition to achieve switchable fluorescence in a Hofmann-type framework

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Science China Chemistry 2024年第10期67卷 3339-3346页

作者： Xue-Ru wu Shu-Qi wu zhi-Kun Liu Ming-Xing Chen jun Tao Osamu Sato Hui-Zhong Kou Engineering Research Center of Advanced Rare Earth Materials(Ministry of Education) Department of ChemistryTsinghua UniversityBeijing 100084China Institute for Materials Chemistry and Engineering&IRCCS Kyushu University744 MotookaNishi-kuFukuoka 819-0395Japan Key Laboratory of Cluster Science of Ministry of Education School of Chemistry and Chemical EngineeringLiangxiang CampusBeijing Institute of TechnologyBeijing 102488China Analytical Instrumentation Center College of Chemistry and Molecular EngineeringPeking UniversityBeijing 100871China

The change of fluorescence emission manipulated by spin state transition attracts considerable attention owing to its potential applications in magneto-optical switching ***,we report two two-dimensional(2D)Hofmann-type spin crossover(SCO)metal-organic frameworks(MOFs)[Fe^(Ⅱ)(PNI)_(2){Ag^(Ⅰ)(CN)_(2)}_(2)]·CHCl_(3)(3Ag·CHCl_(3))and[FeⅡ(PNI)_(2){AuⅠ(CN)_(2)}_(2)]·CHCl_(3)(3Au·CHCl_(3))based on the fluorescent ligand N-(4-pyridylmethyl)-1,8-naphthalimide(PNI).Both complexes exhibit interesting SCO behaviors switched by guest solvent molecules,namely three-step transitions for the solvated complexes and complete onestep hysteretic SCO for the desolvated ones,verified by temperature-dependent magnetic susceptibility measurements,Mossbauer spectra,structural analyses,and differential scanning calorimetry ***,temperature-dependent fluorescence spectra exhibit double peaks(monomer and excimer emission)with both emission peaks change consistent with the change in SCO properties during the solvent molecule *** this study,we integrated guest-responsive SCO behavior into MOFs to manipulate the multistability of spin state and fluorescence switching,providing a rational strategy for the development of stimuli-responsive multifunctional materials.

关键词： spin crossover fluorescence multifunctional materials metal-organic frameworks Hofmann-type

Combination regimen of leflunomide plus methylprednisolone in a female patient with reactive arthritis and concomitant IgA nephropathy

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Chinese Medical Journal 2010年第3期123卷 375-378页

作者： CHEN Yi-zhi ZHAO Xue-zhi wu jun MEI Chang-lin Kidney Institute of Chinese People's Liberation Army Shanghai Kidney Disease Quality Control Center Division of Nephrology Shanghai Changzheng Hospital Second Military Medical University Shanghai 200003 China

Spondyloarthropathies （SpAs） include five categories： ankyloslng spondyllns （AS）, reactive arthritis （ReA）,psoriatic arthritis （PsA）, enteropathic arthritis （EA） and undifferentiated spondyloarthropathy （USpA）.2 ReA is an aseptic arthritis occurring after extra-articular infections, particularly genitourinary （GU） or gastrointestinal （GI） tracts. When arthritis is accompanied by conjunctivitis and urethritis, the diagnosis of Reiter syndrome will be suitable for this clinical triad; however, the term ＂ReA＂ has been proposed to substitute for Reiter syndrome.

关键词： arthritis, reactive glomerulonephritis, IgA female leflunomide methylprednisolone

Ballistic performances of the hourglass lattice sandwich structures under high-velocity fragments

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Defence Technology（防务技术） 2024年第1期31卷 312-325页

作者： He-xiang wu Jia Qu Lin-zhi wu Key Laboratory of Advanced Ship Materials and Mechanics College of Aerospace and Civil EngineeringHarbin Engineering UniversityHarbin150001China School of Civil Engineering Northeast Forestry UniversityHarbin150040China

In this paper,the numerical simulation method is used to study the ballistic performances of hourglass lattice sandwich structures with the same mass under the vertical incidence of *** is paid to elucidating the influences of rod cross-section dimensions,structure height,structure layer,and rod inclination angle on the deformation mode,ballistic performances,and ability to change the ballistic direction of *** results show that the ballistic performances of hourglass lattice sandwich structures are mainly affected by their structural *** this respect,structural parameters optimization of the hourglass lattice sandwich structures enable one to effectively improve their ballistic limit velocity and,consequently,ballistic performances.

关键词： Hourglass lattice sandwich structures Ballistic performances high-velocity Finite element analysis

Mirizzi syndrome:Problems and strategies

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Hepatobiliary & Pancreatic Diseases International 2024年第3期23卷 234-240页

作者： jun wu Shuang-Yong Cai Xu-Liang Chen zhi-Tao Chen Shao-Hua Shi Department of Hepatobiliary and Pancreatic Surgery People’s Hospital of Jiulongpo DistrictChongqing 400050China Department of Hepatobiliary and Pancreatic Surgery Shulan(Hangzhou)Hospital Affiliated to Zhejiang Shuren University Shulan International Medical CollegeHangzhou 310003China

Mirizzi syndrome is a serious complication of gallstone *** is caused by the impacted stones in the gallbladder neck or cystic *** of the features of Mirizzi syndrome is severe inflammation or dense fibrosis at the Calot’s *** our clinical practice,bile duct,branches of right hepatic artery and right portal vein clinging to gallbladder infundibulum are often observed due to gallbladder infundibulum adhered to right hepatic *** intraoperative damage of branches of right hepatic artery occurs more easily than that of bile duct,all of which are hidden pitfalls for *** resonance cholangiopancreatography(MRCP)and endoscopic retrograde cholangiopancreatography(ERCP)are the preferable tools for the diagnosis of Mirizzi *** cholecystectomy in Mirizzi syndrome is easy to damage branches of right hepatic artery and bile duct due to gallbladder infundibulum adhered to right hepatic *** cholecystectomy is an easy,safe and definitive approach to Mirizzi *** combined with the application of ERCP,a laparoscopic management of Mirizzi syndrome by well-trained surgeons is feasible and *** objective of this review was to highlight its existing problems:(1)low preoperative diagnostic rate,(2)easy to damage bile duct and branches of right hepatic artery,and(3)high concomitant gallbladder ***,the review aimed to discuss the possible therapeutic strategies:(1)to enhance its preoperative recognition by imaging findings,and(2)to avoid potential pitfalls during surgery.

关键词： Mirizzi syndrome Bile duct injury Artery injury Surgical treatment Subtotal cholecystectomy