检索结果-南通市图书馆

Science China Chemistry 2014年第8期57卷 1079-1089页

作者： BAI Wei TSE Sunny Kai San LEE Ka Ho SUNG Herman Ho-Yung williams Ian duncan LIN ZhenYang JIA GuoChen department of Chemistry Institute for Advanced Study The Hong Kong University of Science and Technology

Treatment of RuCl2(PPh3)3 with 6-dimethylaminopentafulvene in THF in the presence of water produced(η5-C5H4CHO) RuCl(PPh3)2, which was reduced by NaBH4 to give the Ru–H···HO dihydrogen bonded complex(η5-C5H4CH2OH) RuH(PPh3)2. The dihydrogen bonded complex(η5-C5H4CH2OH)RuH(PPh3)2 could also be synthesized by the reduction of complex(η5-C5H4CHO)RuH(PPh3)2, which was obtained by the reaction of RuHCl(PPh3)3 with 6-dimethylaminopentafulvene in the presence of water. The analogous dihydrogen bonded osmium complex(η5-C5H4CH2OH)OsH(PPh3)2 was similarly prepared. Single crystal structures and dFT calculations support the presence of intra-molecular H···H interaction, with separations of around 1.9 to 2.0 .

关键词： ruthenium osmium hydride dihydrogen bonding H/d exchange

在线全文

学校读者我要写书评

暂无评论

铝电解质性质预测

轻金属 1990年第2期 37-41页

作者： G.J.Houstou M.P.Taylor d.J.williams 马成贵

前言在文献中可以看到许多方程式,用以描述作为温度和电解质成分函数的电解质物理-化学性质的变化。在这些方程式的最新综述中断定,虽然所用的方法不同,但所得到的,想尽可能通用的关系式太冗长和过于复杂。这些关系式的特点是都含有高... 详细信息

前言在文献中可以看到许多方程式,用以描述作为温度和电解质成分函数的电解质物理-化学性质的变化。在这些方程式的最新综述中断定,虽然所用的方法不同,但所得到的,想尽可能通用的关系式太冗长和过于复杂。这些关系式的特点是都含有高次方项、合并变量和模糊系数,因此。

关键词：铝冶炼电解法电解质电导率

Plant Community development in a dryland CREP in Northeastern Oregon

在线全文

学校读者我要写书评

暂无评论

American Journal of Plant Sciences 2011年第6期2卷 744-752页

作者： John d. williams Heidi M. Hartman Lori M. Spencer James O. Loiland USdA Agricultural Research Service Columbia Plateau Conservation Research Center Pendleton USA Umatilla Soil & Water Conservation district Pendleton USA department Environmental Science and Regional Planning Washington State University Tri-Cities Richland USA district Conservationist (USdA-NRCS) Dillingham Field Office Dillingham USA

Riparian areas in dryland crop regions of the Intermountain Pacific Northwest have largely been converted to cropland or pasture during the last 140 years. Some formerly cultivated floodplains have become difficult to farm;enrollment of these lands into conservation programs provides the opportunity to use them as wildlife habitat and as buffer areas near streams. Our objective was to evaluate plant community development on an USdA Conservation Reserve Enhan- cement Program site in northeastern Oregon from when the plant was planted in 1999 through 2008. The research was designed as a descriptive study. We established permanent line-transects to quantify vegetation establishment and changes in species composition through time. We collected data in 2000-2001 and 2007-2008. Vegetation cover in 2000-2001 was 100%, dominated by tall wheatgrass. Living plant material cover decreased from 98% in 2000-2001 to 33% in 2007 and 68% in 2008;dead plant residue significantly increased and tall wheatgrass cover decreased. Native species were present in similar percentages from 2000 to 2008, although there was a shift from target to nontarget species. The 1999 seeding can be judged a success because of the ground cover provided and the establishment of one target species, tall wheatgrass. However, the increased ratio of dead to living plant material and shift to non-target annual weed species suggests that more active management (i.e., fire, grazing, or mowing) of the tall wheatgrass stand is needed to maintain its productivity and/or a healthy mix of multiple species.

关键词： Conservation Buffers Riparian Management Weed Control Plant Community

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

静脉输注盐酸治疗严重代谢性碱中毒

国际外科学杂志 1981年第1期08卷 22-23页

作者： williams d B 葛绳德

代谢性碱中毒的发病机制复杂,在治疗上较代谢性酸中毒更为困难。在外科病人中,代谢性碱中毒要比代谢性酸中毒更为常见,而且很少能被呼吸机能代偿,pH 7.55或更高是有害甚至是危险的,Wilson等发现pH 7.65～7.70会伴随着80％的死亡率。本... 详细信息

代谢性碱中毒的发病机制复杂,在治疗上较代谢性酸中毒更为困难。在外科病人中,代谢性碱中毒要比代谢性酸中毒更为常见,而且很少能被呼吸机能代偿,pH 7.55或更高是有害甚至是危险的,Wilson等发现pH 7.65～7.70会伴随着80％的死亡率。本文介绍dartmouth-Hitchcock医学中心用静脉输注盐酸来治疗严重代谢性碱中毒的经验,并略述其适应证和使用指导。从1972.2～1976.2月期间,有12名病人用输注盐酸来治疗严重的代谢性碱中毒。其中10例的资料进行了复习。在治疗前后,用动脉血pH,pCO2和血红蛋白与相当于体重30％的有效缓冲间隙按SigganrdAndersen计算图型根据公式算出剩余碱总量的毫当量数。

关键词：代谢性碱中毒病人适应证盐酸氯化物静脉输注

Synthesis, Structure and Non-linear Optical Properties of Manganese Mercury Tetrathiocyanate

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 1999年第3期10卷 257-260页

作者： Yun Xing YAN Qi FANG duo Rong YUAN Yu Peng TIAN Zhi LIU Xiao MeiWANG Min Hua JIANG d. williams A. SIU Zhi Gang CAI (Institute of Crystal Materials and State Key Laboratory of Crystal Materials,Shandong University. Jinan 250100)(department of Chem Institute of Crystal Materials State Key Lab. of Crystal Materials Shandong University Jinan 250100 China department of Chemistry Hong Kong Univ. of Sci. and Technol. Hong Kong Hong Kong Institute of Laser Spectroscopy Stake Key Lab. Ultrafast Laser S. Zhongshan University Guangzhou 510275 China

The title copound Manganese Mercury Tetrathiocyanate (MnHg (SCN)(4)) has been synthesized and its structure has been determined. It belongs to tetragonal system, I (4) over bar space group. The cell dimensions are: a = 1.1324 (3) nm, c = 0.4270 (2) nm, V = 0.5475 (3) nm(3), Z = 2, d-c = 2.959 g/cm(3), R = 0.028, R-w = 0.037. The structure feature of the crystal is the Hg-S-C=N-Mn bridge which leads to the formation of an infinite three dimensional network. Irradiated by a 1064 nm Nd:YAG laser beam, MnHg (SCN), shows a 532 nm second harmonic intensity which is 18 times as that of organic nonlinear optical crystal urea, and therefore shows a quite promising application value as a useful nonliear optical material.

关键词： MnHg (SCN)(4) synthesis structure nonlinear optical property

Terahertz Semiconductor Quantum Well devices

在线全文

学校读者我要写书评

暂无评论

Journal of Semiconductors 2006年第4期27卷 627-634页

作者： Liu H C Luo H Ban d Waichter M Song C Y Wasilewski Z R Buchanan M Aers G C SpringThorpe A J Cao J C Feng S L williams B S Hu Q Institute for Microstructural Sciences National Research Council Ottawa K1A 0R6 Canada State Key Laboratory of Functional Materials for Informatics Shanghai Institute of Microsystem and Information Technology Chinese AcademyofSciences Shanghai 200050 China department of Electrical Engineering and Computer Science and Research Laboratory of Electronics Massachusetts Institute of Technology Cambridge Massachusetts 02139 USA

For eventually providing terahertz science with compact and convenient devices,terahertz (1～10THz) quantum-well photodetectors and quantum-cascade lasers are *** design and projected detector performance are presented together with experimental results for several test devices,all working at photon energies below and around optical *** limited infrared performance (BLIP) operations are observed for all samples (three in total),designed for different *** temperatures of 17,13,and 12K are achieved for peak detection frequencies of 9.7THz(31μm),5.4THz(56μm),and 3.2THz(93μm),respectively.A set of THz quantum-cascade lasers with identical device parameters except for doping concentration is *** δ-doping density for each period varies from 3.2×1010 to 4.8×*** observe that the lasing threshold current density increases monotonically with doping ***,the measurements for devices with different cavity lengths provide evidence that the free carrier absorption causes the waveguide loss also to increase *** the observed maximum lasing temperature is best at a doping density of 3.6×1010cm-2.

关键词：半导体量子论激光技术光电探测器

A simulator developed for a twin-pod AUV,the Marport SQX-500

在线全文

学校读者我要写书评

暂无评论

A simulator developed for a twin-pod AUV,the Marport SQX-500

development of Low Carbon Microalloyed High Strength Ultra-Thin Cast Strip Products Produced by the Castrip~ Process With Excellent Strength-ductility Properties

第九届国际水动力学会议

作者： Christopher d.williams Peter Crocker david Shea Neil Riggs Ralf Bachmayer National Research Council Canada Institute for Ocean Technology St.John's

A vertically arranged twin-pod autonomous underwater vehicle（AUV） is presently under development in ***’s Newfoundland.A large separation of the centre of gravity（CG） and the centre of buoyancy（CB） can be achieved by placing heavy batteries and payloads in the lower pod and placing the light controller and communication electronics on the upper *** the large vertical separation between CG and CB the twin-pod vehicle becomes highly stable in pitch and roll and thus provides an ideal platform for obtaining photos,video and sonar images of the *** paper presents the vehicle motion simulations that have been done in support of this novel AUV design and development.

关键词： Underwater vehicle simulator modeling hydrodynamic manoeuvring.

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Journal of Iron and Steel Research International 2011年第S1期18卷 846-850页

作者： C.R. Killmore K.R. Carpenter H.R. Kaul d.G. Edelman J.M. Cairney S.P. Ringer J.G. williams P.C. Campbell W.N. Blejde BlueScope Steel Five Islands Road Pt Kembla 2500 Australia Nucor Steel Indiana 4537 S. Nucor Rd. Crawfordsville IN 47933 USA Australian Centre for Microscopy and Microanalysis University of Sydney NSW 2006 Australia Castrip LLC1915 Rexford Rd. Charlotte NC 28211 USA

The CASTRIP* process produces a range of high strength Ultra-thin Cast Strip (UCS) products (380-550 MPa) in thicknesses between 0.9 mm and 1.5 mm, which is very challenging to produce via conventional hot and cold rolled processing routes. The twin roll CASTRIP process fully exploits the hardenability and strengthening potential of Nb in a low C-Mn-Nb-V microalloyed steel type. Significant microstructural strengthening from solute Nb was obtained, even at low microalloying levels, as well as modest Mn additions, through enhancing the hardenability and further strengthening was obtained in coated products by exploiting age hardening during processing on a continuous hot dip galvanising line. Atom probe tomography and TEM determined that Nb was retained in solid solution and subsequent age hardening resulted from the formation of Nb and V rich nanosized particles. Age hardening was achieved without loss of ductility producing galvanised strip with an excellent strength-ductility combination (Y.S. >600 MPa, T.E. >10%).

关键词： strip casting microalloying niobium ntom probe tomography age hardening high strength CASTRIP Process

Access to smart devices and utilization of online health resources among older cardiac rehabilitation participants

在线全文

学校读者我要写书评

暂无评论

World Journal of Cardiology 2020年第5期12卷 203-209页

作者： Abdulghani Saadi Arun Kanmanthareddy Mahesh Anantha-Narayanan Karen Hardy Mark williams Venkata M Alla division of Cardiology Creighton University School of MedicineOmahaNE 68124United States CHI Creighton University Medical CenterOmahaNE 68124United States Section of Cardiovascular Medicine Yale New Haven HospitalNew HavenCT 06510United States

BACKGROUNd Newer models of cardiac rehabilitation(CR)delivery are promising but depend upon patient participation and ability to use technological media including Internet and smart *** To explore the availability of smart devices,current utilization and proficiency of use among older CR program *** Study participants were enrolled from four CR programs in Omaha,Nebraska United States and completed a questionnaire of 28 *** Of 376 participants approached,169 responded(45%).Mean age was 71.1(Sd±10)*** were 73.5%males,89.7%Caucasians,52%with college degree and 56.9%,with income of 40 K$or *** device ownership was84.5%;desktop computer was the most preferred *** Internet use was 1.9 h/d(Sd±1.7);54.3%of participants indicating for general usage but only18.4%pursued health-related *** of other health information modalities was low,29.8%used mobile health applications and 12.5%used wearable *** all participants,72%reported no barriers to using *** and income were associated positively with measures of utilization and with less perceived *** an older group of subjects attending CR,most have access to smart devices and do not perceive significant barriers to Internet ***,there was low utilization of health-related resources suggesting a need for targeted education in this patient population.

关键词： Cardiac rehabilitation Smart devices Internet Perceived barriers

The impact of sarcopenia on patients undergoing treatment for pancreatic ductal adenocarcinoma

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

Journal of Pancreatology 2020年第2期3卷 59-71页

作者： Amundson Julia R. williams Jelani K. Benjamin Andrew J. Witmer Hunter d.d. Roggin Kevin K. department of Surgery University of Chicago Medical CenterChicagoILUSA

Introduction:Pancreatic ductal adenocarcinoma(PdAC)is a deadly cancer that disproportionately affects geriatric *** therapy with surgery and chemotherapy is associated with longer survival than medical treatment or supportive *** selection of patients for surgical treatment,based on patient-specific factors such as sarcopenia,may help risk-stratify patients and improve *** paper aims to review the current literature on the impact of sarcopenia and sarcopenic obesity on patients undergoing treatment for ***:The impact of sarcopenia and sarcopenia obesity on perioperative and long-term outcomes after treatment for PdAC is *** has been associated with high-grade complications,longer length of hospital,and intensive care unit stays,more frequent discharge to skilled nursing facilities and decreased utilization of adjuvant therapy in patients treated with curative intent *** obesity has been associated with more complications,high-grade complications,and hematologic *** with sarcopenic obesity may have even lower overall survival than sarcopenic ***:The effect of a pre-treatment diagnosis of sarcopenia or sarcopenic obesity on outcomes for patients undergoing treatment for PdAC remains unknown,in part due to the heterogeneity of studies and *** programs including resistance exercise and nutritional supplementation have shown benefit in sarcopenic ***:PdAC remains a deadly disease and patient-specific factors such as sarcopenia and sarcopenic obesity identified at the time of cancer diagnosis offer potential as risk stratification measures and points of ***,a paucity of standardized measurement tools,definitions,and prehabilitation regimens limits the clinical implementation of such knowledge.

关键词： Frailty Pancreatic ductal adenocarcinoma Sarcopenia