Thermo-sensitive polymer nanospheres as a smart plugging agent for shale gas drilling operations

Emulsifier-free poly（methyl methacrylate-styrene） [P（MMA-St）] nanospheres with an average particle size of 100 nm were synthesized in an isopropyl alcoholwater medium by a solvothermal method. Then, through radical graft copolymerization of thermo-sensitive mono- mer N-isopropylacrylamide （NIPAm） and hydrophilic monomer acrylic acid （AA） onto the surface of P（MMA- St） nanospheres at 80 ℃, a series of thermo-sensitive polymer nanospheres, named SD-SEAL with different lower critical solution temperatures （LCST）, were prepared by adjusting the mole ratio of NIPAm to AA. The products were characterized by Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, particle size distribution, and specific surface area analysis. The temperature-sensitive behavior was studied by light transmittance tests, while the sealing performance was investigated by pressure transmission tests with Lungmachi Formation shales. The experimental results showed that the synthesized nanoparticles are sensitive to temperature and had apparent LCST values which increased with an increase in hydrophilic monomer AA. When the temperature was higher than its LCST value, SD- SEAL played a dual role of physical plugging and chemical inhibition, slowed down pressure transmission, and reduced shale permeability remarkably. The plugged layer of shale was changed to being hydrophobic, which greatly improved the shale stability

Editorial Board 2011-2015

The World Journal of Gastrointestinal Oncology Editorial Board consists of 428 members,representing a team of worldwide experts in gastrointestinal oncology.They are from 40 countries,including Argentina(2),Australia(10),Belgium(5),Brazil(2),Canada(4),Chile(2),China(56),Czech Republic(1),Denmark(1),Finland(3),France(7),Germany(24),Greece(13),Hungary(2),India(9),Iran(2),Ireland(2),Israel(4),Italy(41),Japan(47)。

Editorial Board 2011-2015

The World Journal of Gastrointestinal Oncology Editorial Board consists of 428 members,representing a team of worldwide experts in gastrointestinal oncology.They are from 40 countries,including Argentina(2),Australia(10),Belgium(5),Brazil(2),Canada(4),Chile(2),China(56),Czech Republic(1),Denmark(1),Finland(3),France(7),Germany(24),Greece(13),Hungary(2),India(9),Iran(2),Ireland(2),Israel(4),Italy(41),Japan(47),Kuwait(2),Mexico(1),Netherlands(7),New Zealand(2),Norway(1),Poland(3),Portugal(5),Romania(1),Saudi Arabia(1),Serbia(2),Singapore(4),South Korea(27),Spain(10),Sweden(5),Switzerland(2),Syria(1),Thailand(1),Turkey(6),United Kingdom(15),and United States(95).

Editorial Board 2009-2013

The World Journal of Gastrointestinal Oncology Editorial Board consists of 404 members,representing a team of worldwide experts in gastrointestinal oncology.They are from 41 countries,including Argentina(1),Australia(9),

Editorial Board 2011-2015

The World Journal of Gastrointestinal Oncology Editorial Board consists of 428 members,representing a team of worldwide experts in gastrointestinal oncology.They are from 40 countries,including Argentina(2),Australia(10),Belgium(5),Brazil(2),Canada(4),Chile(2),China(56),Czech Republic(1),Denmark(1),Finland(3)。

Editorial Board 2010-2015

The World Journal of Diabetes Editorial Board consists of 323 members, representing a team of worldwide experts in diabetes mellitus. They are from 38 countries, including Argentina (1), Australia (13), Austria (6), Belgium (1), Brazil (3), Canada (14), China (21), Czech Republic (3), Denmark (9), Egypt (2), Finland (3), France (5), Germany (17), Greece (10), Hungary (2), India (10), Ireland (2), Iran (2), Israel (5), Italy (25)

Editorial Board 2014-2017

The World Journal of Radiology Editorial Board consists of 365 members,representing a team of worldwide experts in radiology.They are from 36 countries,including Afghanistan(1),Argentina(2),Australia(5),Austria(7),Belgium(2),Brazil(8),Canada(6),Chile(1),China(43),Croatia(1),Denmark(4),Egypt(6),France(5),Germany(22)。

Editorial Board 2011-2015

The World Journal of Diabetes Editorial Board now consists of 713 members,representing a team of worldwide experts in diabetes mellitus.They are from 56 countries,including Argentina(2),Australia(27),Austria(11),

Editorial Board 2010-2015

The World Journal of Diabetes Editorial Board consists of 323 members, representing a team of worldwide experts in diabetes mellitus. They are from 38 countries, including Argentina (1), Australia (13), Austria (6), Belgium (1),

Editorial Board 2009-2013

The World Journal of Radiology Editorial Board consists of 319 members,representing a team of worldwide experts in radiology.They are from 40 countries,including Australia(3),Austria(4),Belgium(5),Brazil(3),Canada(9),Chile(1),China(25),Czech(1),Denmark(1),Egypt(4),Estonia(1),Finland(1),France(6),Germany(17),Greece(8),Hungary(1),India(9),Iran(5),Ireland(1),Israel(4),Italy(28),Japan(14),Lebanon(1),Libya(1),Malaysia(2),

World Journal of Gastroenterology~ Brief Introduction of Editorial Board 2004-2006

The World Journal of Gastroenterology Editorial Board consists of 685members,representing a team of worldwide experts in gastroenterologyand hepatology.They are from 52 countries including:Albania(1),Argentina(1),Australia(16).Austria(7),Belarus(1),Belgium(11),Brazil(1),Bulgaria(1),Canada(10),China(58),Croatia(2),Czech(1),Denmark(5),Egypt(3),Finland(1),France(27).Germany(71),Greece(1),Hungary(1).Iceland(1),India(6),Iran(2),Ireland(2),Israel(5),Italy(51),Japan(137),Lebanon(2),Lithuania(1),Macedonia(1),Malaysia(3),Mexico(2),Monaco(1),Netherlands(15),New Zealand(1),Nigeria(1),Norway(2),Pakistan(1),Poland(6),Portugal(1),Russia(3),Singapore(3),Slovakia(1),South Africa(1),South Korea(9),Spain(27),Sweden(6),Switzerland(8),Turkey(7),United Arab Emirates(1),United Kingdom(37).United States(121),Yugoslavia(1).

Editorial Board 2011-2015

The World Journal of Gastrointestinal Pathophysiology Editorial Board consists of 523 members,representing a team of worldwide experts in gastrointestinal pathophysiology.They are from 45 countries,including Argentina(2),Australia(14),Austria(3),Belgium(9),Brazil(10),Brunei Darussalam(1),Canada(20),China(30),Croatia(1),Czech Republic(2),Denmark(4),Egypt(1),Estonia(1),Finland(1),France(8),Germany(22),Greece(7)。

World Journal of Gastroenterology A Brief Introduction of Editorial Board Members 2004-2006

The World Journal of Gastroenterology Editorial Board consistsof 174 members,representing a team of worldwide experts ingastroenterology and hepatology.They are from 53 countriesincluding:Albania(1),Algeria(1),Argentina(2),Austria(1),Belarus(1),Belgium(1),Brazil(1),Bulgaria(1),Canada(1),China(40),Costa Rica(1),Croatia(1),Denmark(1),Egypt(1),Finland(1),France(1),Germany(7),Greece(1),Hungary(2),Iceland(1),India(2),Iran(1),Ireland(2),Israel(2),Italy(2),Japan(3),Latvia(1),Lithuania(1),Macedonia(1),Malaysia(2),Monaco(1),Netherlands(3),New Zealand(1),Pakistan(1),Philippines(1),Poland(2),Portugal(1),Romania(1),Russia(3),Singapore(1),SIovakia(1),Slovenia(2),South Africa(1),South Korea(2),Spain(1),Sri Lanka(1),Sweden(2),Switzerland(2),Thailand(1),Turkey(1),United Kingdom(6),United States(53),and Yugoslavia(1).

WSE International Academic Workshop and 3^(rd)Editorial Board Conference(June 21-22,2014)

Background To enhance worldwide academic communication between researchers engaging in water science and water engineering, and to promote communication between WSE Editorial Board members, Hohai University will hold the WSE International Academic Workshop and 3rd Editorial Board Conference on June 21-22, 2014, at Hohai University in China. The workshop welcomes international experts and scholars in the fields of water science and water engineering and WSE Editorial Board members.

World Journal of Gastroentero1ogy Editorial Board and Reviewers Brief Introduction 2004-2006

Published by The WJG Press and Elsevier Inc．,PO Box 23451 Beijing 100023,China Fax:+86-(0)10-85381893 E-mail:wjg@wjgnet．com http://www．wjgnet．com The World Journal of Gastroenterology Editorial Board consists of 519 members,representing a team of worldwide experts in gastroenterology and hepatology．They are from 51 countries,including Albania(1),Algeria(1),Argentina(1),Australia(8), Austria(5),Belarus(1),Belgium(6),Brazil(1),Bulgaria(1),Canada(7),China(50),Costa Rica(1),Croatia(1),Denmark(6), Egypt(1),Finland(1),France(18),Germany(35),Greece(2),Hungary(2),Iceland(1),India(5),Iran(1),Ireland(1),Israel(2),Italy(41),Japan(132),Lithuania(1),Macedonia(1),Malaysia(3),Monaco(1),Netherlands(13),Norway(2),Pakistan(1),Philippines(1),Poland(2),Portugal(1),Russia(3),Singapore(2),Slovakia(1),South Africa(2),South Korea(6),Spain(20), Sri Lanka(1),Swaziland(1),Sweden(4),Switzerland(4),Turkey(3),United Kingdom(20),United States(90),Yugoslavia(1)． HONORARY EDITORS-IN-CHIEF Ke-Ji Chen,Professor Xiyuan Hospital,Chinese Tranditional Medicine University,Beijing 100091,China. kjchen@public．bta．net．

带插板的焊接空心球支座节点的力学性能分析

以合肥南方水泥熟料库为背景,提出了一种新型的带插板焊接空心球支座节点,并通过有限元分析软件对支座节点进行数值分析,确定新型支座节点的力学特性和关键设计控制参数。结果表明,增加插板宽、高能有效提高支座节点的承载力、刚度;在一定范围内增加插板厚度可以提高支座节点的承载力、刚度,当插板厚度比焊接空心球壁厚2mm-4mm时,再增加插板厚度,对支座节点的承载力、刚度影响不大;增加钢管与插板的连接长度对支座节点的承载力、刚度影响不大。

无铅喷锡堵孔不良探讨与改善

随着新能源的快速发展,对能源用印制电路板的需求也越来越多,而能源印制板在设计上多为内层芯板铜厚大于等于2OZ和无铅喷锡,且PTH孔多数需进行喷锡,客户端不接受锡堵孔现象;这就对喷锡的品质要求较为严苛;改善喷锡堵孔就显得尤为重要,本文主要通过实验验证,在现有参数范围内,通过对风刀温度、风刀压力以及风刀间距的参数进行优化,达到改善的目的,为后续生产提供技术依据。

用于堆叠装配技术的转接板制作探讨

转接板通过堆叠装配技术连接上下面高密度互连(HDI)板,可使电子产品减小体积,并实现更多应用功能。此类产品对图形精度、树脂塞孔、铜厚及阻焊油墨厚度等有较高要求。在制作过程中,需要结合具体的产品需求和技术要求,选择合适的制作工艺和材料,并进行严格的工艺参数控制,才能保证转接板的质量和性能。通过对一款转接板进行研究,探讨其制作难点和相应控制方法,可为同行制作此类产品提供参考。

一种5G基站用PCB的压合填孔研究

在5G基站56 bps主板设计中,常用到高频材料与高速材料混压的M+2结构。针对M+2结构的印制电路板(PCB),在常规生产工艺中的二次压合之前,需要先使用树脂塞孔将2个子板的过孔填实。但树脂塞孔流程长,且子板叠构不对称,板翘影响其他工序加工。主要介绍一种半固化片(PP)三明治塞孔工艺替代树脂塞孔工艺,对于M+2钻带结构的板,使用本工艺时,子板在二次压合前,盲孔不需要做树脂塞孔。在二次压合的时候,直接使用PP填孔,既能保证填孔的饱满度、各项PCB品质要求,又能减少流程,降低加工成本,并且还能大幅度提升生产效率。

Progress and Developing Trend of Purging Plugs for Refining Ladle

Damage reasons of purging plugs for refining ladle and research progress on thermal shock resistance of corundum- spinel purging plugs were summarized. Research achievements and application results of nonoxides bonded corundum purging plugs for refining ladle were briefly reviewed. The further research and developing trend of purging plugs was proposed.