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RADICAL gRAFTINg REACTIONS ONTO STARCH AND OTHER WATER-SOLUBLE COPOLYMERS IN ISOLATED gEL DROPLETS

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Chinese Journal of Polymer Science 1993年第2期11卷 144-152页

作者：张连生 A.F.johnson Department of Chemistry and Chemical Technology University of Bradford Bradford BD7 IDP England Dpt.Chem.Heilongjiang Universiry24 Xuefu Road Harbin 150080 China Received December 231991. Department of Chemistry and Chemical Technology University of Bradford Bradford BD7 IDP England

A novel radical grafting copolymerization process has been designed for water-soluble polymers which avoids the problems of conducting grafting reactions in highly viscous polymerization media. A variety of water-soluble graft copolymers having starch or dextran as the backbone chain with grafted side chains of polyacrylamide (—AM—), poly (acrylic acid ) (—AA—), poly (acrylamide-co-acrylic acid) (—AM—NH_4AA—) or poly ( acrylamide-co-2-acryiamido-2-methyl-l-propanesulphinic acid) (—AM—AMPS—) have been synthesized in gel droplets using aceric sulphate redox initiator, and their properties compared. The reaction conditions were optimized taking into account reaction kinetic data and the observed properties of the products produced under different reaction conditions. The effects of the ratios of [backbone]/[graft monomer], [ AM]/[ AA]/[AMPS] , [Ce^(4+)]/[ S_2O_8=] and pH value on the reaction rate , conversion, grafting degree, grafted chain length and the product molecular weight have been investigated.

关键词： Radical grafting copolymerization Isolated gel droplets, Acrylamide Starch Kinetics

Hypothesis Testing of Population Percentiles via the Wald Test with Bootstrap Variance Estimates

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Open Journal of Statistics 2016年第1期6卷 14-24页

作者： william D. johnson Jacob E. Romer Department of Biostatistics Pennington Biomedical Research Center Louisiana State University Baton Rouge LA USA

Testing the equality of percentiles (quantiles) between populations is an effective method for robust, nonparametric comparison, especially when the distributions are asymmetric or irregularly shaped. Unlike global nonparametric tests for homogeneity such as the Kolmogorv-Smirnov test, testing the equality of a set of percentiles (i.e., a percentile profile) yields an estimate of the location and extent of the differences between the populations along the entire domain. The Wald test using bootstrap estimates of variance of the order statistics provides a unified method for hypothesis testing of functions of the population percentiles. Simulation studies are conducted to show performance of the method under various scenarios and to give suggestions on its use. Several examples are given to illustrate some useful applications to real data.

关键词： Bootstrap Hypothesis Testing Nonparametric Methods Percentile Profiles Wald Test

Modular next generation fast-neutron detector for portal monitoring

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维普期刊数据库

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Nuclear Science and Techniques 2022年第1期33卷 140-148页

作者： E.Aboud S.Ahn g.V.Rogachev V.E.johnson J.Bishop g.Christian E.Koshchiy C.E.Parker D.P.Scriven Cyclotron Institute Texas A&M UniversityCollege StationTX 77843USA Department of Physics and Astronomy Texas A&M UniversityCollege StationTX 77843USA Department of Statistics Texas A&M UniversityCollege StationTX 77843USA

Nuclear nonproliferation is of critical importance for global *** fissile materials including highly enriched uranium and weapons-grade plutonium are especially important to *** interrogation techniques may result in much better sensitivity but are difficult with conventional portal monitors that rely on detecting thermal ***,most conventional portal monitoring systems rely on ^(3)He,which has a finite and continually decreasing *** designing a highly segmented array of organic scintillators,we posit that we can accurately and quickly identify fissile materials,including weapons-grade plutonium and highly enriched uranium,being *** propose a new design for a fast-neutron detector that overcomes the limitations of the current generation of portal ***6 simulations have been performed in conjunction with the UMPBT statistical model to determine the sensitivity limitations of the proposed *** suggest that the proposed detector may be 10 times more efficient than current-generation thermal neutron detectors and may be able to positively identify a 81 mg 235U source in as little as 192 seconds utilizing active interrogation techniques.

关键词： Fast-neutron detection Portal monitoring Nonproliferation

Void fill and support techniques to stabilize drift excavated through a transition zone mined by a TBM at the Stillwater mine

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International Journal of Mining Science and Technology 2017年第1期27卷 71-76页

作者： johnson Josh Jacobs Curt Ferster Mark Tadolini Stephen Stillwater Mining Company NyeMT 59061USA Minova GeorgetownKYUSA

Stillwater Mining Company is the only U.S. producer of platinum group metals （PgMs） and the largest producer outside of South Afiica and Russia. The company controls a considerable portion of the J-M reef and is currently developing the ＂Blitz Project,＂ which will provide a main haulage level, ore pass systems, backfill plants, and fiow-through ventilation to increase production and ensure sustainable extraction of this critical strategic mineral. While driving two sub-parallel footwall laterals 8125 m in length, one of the development drifts experienced a massive fall in a geologically disturbed area created by a mafic dike intrusion. Combinations of a void fill material （Tekseal）, polyurethane injection, fore poling coupled with steel arches, and supplemental bolting allow safe and efficient advance through this geologically dis- turbed zone. This paper presents the details of this project.

关键词： TBM ground Dike Cutterhead

Evaluation of the 20 L dust explosibility testing chamber and comparison to a modified 38 L vessel for underground coal

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International Journal of Mining Science and Technology 2018年第6期28卷 885-890页

作者： Robert Eades Kyle Perry Catherine johnson Jacob Miller Department of Mining and Nuclear Engineering Missouri University of Science and Technology

The phenomenon of combustible dust explosions is present within many industries. Tests for explosibility of dust clouds per ASTM E1226 use a 20 L explosive chamber that places the combustible dust directly below the dispersion nozzle which generates a thorough mixture for testing purposes. However, in the underground coal mining industry, there are a number of geologic, mining, and regulatory factors that change the deposition scheme of combustible coal dust. This causes the atmosphere of a coal mine to have a variable rock dust-coal dust mixture at the time of ignition. To investigate the impact of this variable atmosphere, a series of lean explosibility tests were conducted on a sample of Pittsburgh Pulverized coal dust. These explosibility tests were conducted in a 38 L chamber with a 5 kJ Sobbe igniter. The 38 L chamber generates a variable air-dust mixture prior to ignition. The test results indicate that the 38 L chamber experiences reduced explosive pressures, and lower explosibility index values when compared to the 20 L chamber.

关键词： Dust explosion Coal mining Coal dust Explosibility testing

A new approach for deposition of silver film from AgCl through successive ionic layer adsorption and reaction technique

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Journal of Central South University 2017年第12期24卷 2793-2798页

作者： johnson Henry Arockiasamy Ajaypraveenkumar ganesan Sivakumar Kannusamy Mohanraj Department of Physics Manonmaniam Sundaranar University Tirunelveli-627 012 Tamil Nadu India CISL Department of Physics Annamalai University Annamalai nagar-608 002 Tamil Nadu India

An attempt was made to deposit thin film of silver onto the glass substrate by using Ag Cl precursor, instead of conventional precursor AgNO_3 with vitamin C by inexpensive and convenient successive ionic layer adsorption and reaction(SILAR) method. The deposited silver thin film was characterized by X-ray diffraction(XRD) analysis, scanning electron microscope(SEM), UV-visible and electrical I-V study. The diffraction study showed FCC structure of metallic silver in good agreement with the standard values of JCPDS(04–0783). SEM reveals flower like nano particles produced on the substrate. The surface plasmon resonance(SPR) peak in the UV-visible spectrum shows maximum absorption at 350 nm. The film shows an ohmic behavior and its electrical resistivity was found ~103 ?·cm at room temperature.

关键词： thin films metals materials characterization sol-gel optical properties silver

growth characteristics of algae during early stages of phytoplankton bloom in Lake Taihu,China

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Journal of Environmental Sciences 2013年第2期25卷 254-261页

作者： Yuhong Jia johnson Dan Min Zhang Fanxiang Kong State Key Laboratory of Lake Science and Environment Nanjing Institute of Geography and LimnologyChinese Academy of Sciences graduate School of Chinese Academy of Sciences Water and Environmental Science Building Department of GeographyUniversity of LethbridgeLethbridgeAlbertaT1K 3M4Canada

Three treatments, sediment plus lake water （S＋W）, sterilized sediment plus lake water （SS＋W）, and sediment plus filtered lake water （S＋FW）, were recruited to investigate the growth characteristics of algae during pre-bloom and the importance of algal inocula in the water column and sediment. The results showed that in the water column, biomass of all algae increased in all treatments when recruitment was initiated, whereas this tendency differed among treatments with further increment of temperature. The process of algal growth consisted of two stages： Stage I, the onset of recruitment and Stage II, the subsequent growth of algae. Compared with S＋W, in Stage I, SS＋W significantly increased the biomass of cyanophytes by 178.70%, and decreased the biomass of non-cyanophytes by 43.40%; In Stage II, SS＋W notably stimulated the growth of all algae, thus incurring the occurrence of phytoplankton bloom. Further analyses revealed that both metabolic activity and photochemical activity of algae were enhanced in SS＋W, which resulted from the releasing of nutrients from sediment. These results suggest that algal growth in Stage II and algal inocula in the water column can be important factors for the formation of phytoplankton bloom. In addition, possible mechanisms promoting algal recruitment and subsequent growth of algae were explored.

关键词： algae recruitment phytoplankton bloom water column sediment

Subacute fulminant hepatic failure with intermittent fever

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Hepatobiliary & Pancreatic Diseases International 2009年第6期8卷 657-659页

作者： Joyce E.johnson Molecular Infectious Diseases Laboratory and Molecular Epidemiology Medical CenterVanderbilt University

BACKgROUND: Viral hepatitis B accounts for over 80% of acute hepatic failures in China and the patients die mainly of its complications. A patient with hepatic failure and fever is not uncommon, whereas repeated fever is rare. METHODS: A 32-year-old female was diagnosed with subacute hepatic failure and hepatitis B viral infection because of hyperbilirubinemia, coagulopathy, hepatic encephalopathy, serum anti-HBs-positive without hepatitis B vaccination, and typical intrahepatic pathological features of chronic hepatitis B. Plasma exchange was administered twice and she awoke with hyperbilirubinemia and discontinuous fever. RESULTS: Urethritis was confirmed and medication-induced fever and/or spontaneous bacterial peritonitis (gram-negative bacillus infection) was suspected. The patient was treated with antibiotics, steroids and a Chinese herbal medicine, matrine, for three months and she recovered. CONCLUSION: The survival rate of patients with hepatic failure might be improved with comprehensive supporting measures and appropriate, timely management of complications.

关键词： acute hepatic failure intermittent fever plasma exchange matrine

《万里千寻》:1949年后的张大千人生一瞥

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艺术品鉴 2024年第2期 152-155页

作者：马克D.约翰逊旧金山州立大学(SFSU)文学院

2023年12月,由张伟民执导的纪录片《万里干寻》摘得第20届广州国际纪录片节“中国故事优秀纪录长片”奖和圣保罗国际电影节“最佳国际纪录片”两项大奖,并于2024年1月18日在香港地区上映,影片以画家张大千1949年离开中国飘泊海外为重心... 详细信息

2023年12月,由张伟民执导的纪录片《万里干寻》摘得第20届广州国际纪录片节“中国故事优秀纪录长片”奖和圣保罗国际电影节“最佳国际纪录片”两项大奖,并于2024年1月18日在香港地区上映,影片以画家张大千1949年离开中国飘泊海外为重心,重构这位“画作抵万金”的国画大师鲜为人知的下半生。《万里千寻》的筹备与拍摄历时12年,张伟民辗转全球20多个国家和地区,探访张大千的子女、家人、朋友、弟子以及艺术家和国际上研究张大千的学者共100多人,通过影片解读张大千后半生的传奇故事。

关键词：张大千纪录片国画大师千寻国际电影节传奇故事后半生圣保罗