检索结果-南通市图书馆

Institute of Energy Process Engineering and Chemical Engineering (IEC), Tu Bergakademie Freiberg: Towards a Circular Carbon Economy

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Clean Energy 2019年第4期3卷 316-323页

作者： Freiberg, T u Bergakademie Reiche Zeche Fuchsmuehlenweg 9 Freiberg 09599 Germany

1 History of the Institute of Energy Process Engineering and Chemical Engineering(IEC)The history of IEC dates back to 1918,when the Lignite Foundation of the State of Saxony was founded to develop pro-cesses and technologies for lignite utilization in *** 1919,the precursor department of IEC with a focus on the thermochemical conversion of lignite was established.

关键词： Saxon IEC Carbon

Laser Surface Texturing of Co–Cr–Mo Alloy for Biomedical Applications:A Case Study for the Effects of Process Parameters on Surface Properties

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 Bionic Engineering 2023年第5期20卷 1967-1984页

作者： Şefika Kasman İbrahim Can uçar Sertan Ozan Department of Mechanical Engineering Dokuz Eylul UniversityIzmir35397Turkey Department of Mechanical Engineering Yozgat Bozok UniversityYozgat66100Turkey

This study presents a comprehensive approach to applying texturing processes created by engraving on the surface of CoCr28Mo alloy workpieces using a 20 W pulsed nanosecond fiber *** hatch strategy and distance,frequency,and scan speed were control parameters for texturing *** effectiveness of the parameters in terms of roughness and contact angle of the texturized surface was *** roughness and contact angle were analyzed using variance analysis to identify each variable's *** has been determined that the roughness of the texture defined by the hatch strategy plays a decisive role in the wettability behavior of the surface;however,the scan speed,frequency,and hatch distance which are among the laser surface texturing conditions are influential in the roughness and contact *** scan speed and hatch distance while decreasing frequency resulted in smoother surfaces,increasing the contact *** having rough surfaces produced with different processing conditions exhibit a super hydrophilic *** contact angle is most sensitive to the hatch distance;however,the frequency has the least influence on the contact *** most and least efficient surface roughness parameters are revealed to be scan speed and hatch distance,respectively.

关键词： Laser surface texturing Co-Cr-Mo alloy Surface roughness Wettability Bionic

Nitrogen Fertilizer and Panicle Removal in Sweet Sorghum Production: Effect on Biomass, Juice Yield and Soluble Sugar Content

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 Sustainable Bioenergy Systems 2017年第1期7卷 14-26页

作者： Maru K. Kering vitalis W. Temu Laban K. Rutto Virginia State university Agriculture Research Station Petersburg VA USA

Alternative and renewable bio-based energy sources are gaining prominence worldwide. Sweet sorghum is currently being evaluated throughout the world because its stem juices are rich in sugars that can be directly fermented to ethanol. In this two-year study, sweet sorghum varieties;Dale, Theis, Topper 76-6, and M81E (Obtained from Mississippi State university Experiment Station, MS) and CHR-SW8 (Obtained from Chromatin Inc., IL) were used. Nitrogen (N) fertilizer rates of 0, 40, 80 or 120 kg·N·ha-1 were applied to experimental units. The experiment was a randomized complete block design with treatments in a split-split plot arrangement with three replications. Nitrogen rate was the main plot, cultivar as sub-plot, and panicle removal as sub-plot. Results showed that N application increased fresh stem yield, juice volume, but had minimal effect on juice soluble sugar concentration. Compared to controls, application of ≥40 kg·N·ha-1 increased fresh yield and juice by >60% and 10%, respectively. There were also variety differences in harvested fresh biomass, juice volume and oBrix, and soluble sugar content. Dale and Theis consistently showed lower sucrose compared to other varieties over the two years. Panicle removal during early reproductive phase increased oBrix, sucrose and total sugar content in all varieties. Across the two years of study, panicle removal increased oBrix by more than 10%, sucrose and total sugar increased by more than 20%. Selection of varieties that produce high juice volume with high sugar content and strategies to inhibit seed formation may result in improved juice quality.

关键词： Sweet Sorghum Juice Sugar Panicle Nitrogen

A Mathematical Model of an Evaporative Cooling Pad using Sintered Nigerian Clay

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 Minerals and Materials Characterization and Engineering 2012年第11期11卷 1113-1120页

作者： Chukwuneke Jeremiah Lekwuwa Ajike Chinagorom ogbu Achebe Chinonso Hubert Okolie Paul Chukwulozie Department of Mechanical Engineering Nnamdi Azikiwe University PMB 5025 Awka Nigeria

Overtime, reduction in the amount of heat generated in engineering systems in operations have been of great concern and have continuously been under study. It is in line with the above that this research work developed a mathematical model of an evaporative cooling pad using sintered Nigerian clay. A physical model of the evaporative cooling phenomenon was developed followed by the derivation of the governing equations describing the energy and mass transfer for the clay model from the laws of conservation of continuum mechanics. A set of reasonable and appropriate as-sumptions were imposed upon the physical model. Constitutive relationships were also developed for further analysis of the developed equations. The finite element model of numerical methods was used to analyse the energy transfer governing equations which resulted in the determination of the temperature of the exposed boundary surface at any given time, t2 after the commencement of the evaporative cooling processes. In this paper, it was found out that surface temperature differences could be as much as 6?C in the first cycle of evaporative cooling with the potential of further reduction. Further, an equation for the prediction of the effectiveness of an evaporative cooling system using clay modeled cooling pads was developed. The findings in this research work can be applied in the design, construction and maintenance of evaporative coolers used to dissipate waste heat when a large amount of natural water is not readily available or if for environmental and safety reasons the large water body can no longer absorb waste heat.

关键词： Evaporative Cooling Nigerian Clay Finite Difference Model Energy Transfer Cooling Pad Moulded Clay Material Heat Transfer Refrigeration Temperature

Relationship between magnetic parameters and heavy element contents of arable soil around a steel company,Nanjing

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Earth Sciences 2010年第3期53卷 411-418页

作者： BLAHA u ROESLER W APPEL E Institute for Geosciences University of Tübingen

Magnetic parameters and element contents were determined in core NJ008 collected from the uppermost ca. 40 cm in a steel company in southwest Nanjing. The results showed that magnetic susceptibility (χ), saturation isothermal remanent magnetization (SIRM) and anhysteretic remanent magnetization (ARM) were enhanced in the uppermost 20 cm, with a mean magnetic susceptibility value of 112.5×10-8 m3 kg-1. Below 20 cm, χ decreased sharply with a mean value of 27.8×10-8m3 kg-1. Low-coercivity minerals such as magnetite dominate in arable soils, while the relative content of antiferromagnetic minerals increases below 20 cm. Heavy metals (Ni, Cu, Fe, Pb, V, and Zn) have similar vertical trends as χ. Principal component analysis reveals common high loadings of the same factor for magnetic concentration parameters (χ, ARM, and SIRM) and elements (Ni, Cu, Fe, Pb, V, and Zn) with an excellent linear correlation (0.69≤R≤0.98) between them. Magnetic susceptibility of paddy soil core NJ013, which had the same parent material as NJ008 but was far from pollution sources, showed stable values of magnetic concentration parameters along the whole core. Absolute values correspond to the so-called magnetic background value (below 20 cm) of NJ008. This indicates that pesticide and fertilizer had little effect on magnetic signals of the upper part of core NJ008 and the extremely enhanced magnetic concentration parameters originate from the steel company emission. Although, the arable soil does not reveal the pollution history and transportation due to annual ploughing, the significant linear relationship between magnetic concentration parameters and heavy metal contents suggests that magnetic parameters can serve as a proxy for quickly detecting soil metallic pollution and estimating the extent of contamination.

关键词： steel company soil heavy metal magnetic parameters

ASYMMETRIC SYNTHESIS——ENANTIOSELECTIVE SYNTHESIS OF (R)-α-AMINO ACIDS uSING L-ISOLEuCINE AS CHIRAL AuXILIARY REAGENT

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 1984年第6期27卷 566-571页

作者：蒋耀忠,u.SCHLLKOPF,u.GROTH Chengdu Institute of Organic Chemistry Academia Sinica Institute of Organic Chemistry Gottingen university Federal Republic of Germany Institute of Organic Chemistry Gottingen university Federal Republic of Germany

Enantioselective synthesis of (R)-α-amino acids via heterocyclic intermediate-(3S)-2,5-dimethoxy-3-see-butyl-3, 6-dihydropyrazine (5), using L-isoleucine as chiral auxiliaryreagent and glycine as raw meterial, has been studied. The alkylation of compound 5 withbutyllithium affords its lithium derivative (6) according to the cardanion mechanism. Then 6reacts with alkyl halide RX (7) to give the alkylated products (8) with very high diastereo-selectivity. In this reaction, the group R of 7 enters trans to the see-butyl group at C-3, i. *** (R)-configuration is induced at C-6 of 8. After hydrolysis the (R)-α-amino acid methylesters (9) are obtained.

关键词： OCH HZ ASYMMETRIC SYNTHESIS ENANTIOSELECTIVE SYNTHESIS OF AMINO ACIDS uSING L-ISOLEuCINE AS CHIRAL AuXILIARY REAGENT CDC HCI 占一 CHC ABX

Micro- and Nanostripes of Self-Assembled Au Nanocrystal Superlattices by Direct Micromolding

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2010年第8期3卷 537-544页

作者： Boya Radha Giridhar u.Kulkarni Chemistry and Physics of Materials unit and DST unit on Nanoscience Jawaharlal Nehru Centre for Advanced Scientific ResearchJakkur P.O.Bangalore 560064India

A simple,inexpensive direct micromolding method for patterning Au nanocrystal superlattices using a polydimethylsiloxane(PDMS)stamp has been *** method involves in situ synthesis of Au(I)dodecanethiolate and its decomposition leading to Au nanocrystals in the microchannels of the stamp which order themselves to form patterned superlattice stripes,in conformity with the stamp *** to its insolubility in common solvents,the dodecanethiolate was made by reacting Au(PPh3)Cl and dodecanethiol in situ inside the microchannels,by injecting first the former solution in toluene at room temperature followed by the thiol solution at 120°*** the reaction mixture at 250°C,resulted in formation of nanocrystals(with a mean diameter of 7.5 nm)and hexagonal *** using an external pressure while molding,parallel stripes with sub-100 nm widths were *** choice of parameters such as injection temperature of the thiol and concentrations is shown to be important if an ordered superlattice is to be *** addition,these parameters can be varied as a means to control the nanocrystal size.

关键词： nanolithography soft lithography metal nanocrystal superlattice micromolding direct patterning

NonOperative Management of Blunt Solid Abdominal Organ Injury in Calabar, Nigeria

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

International Journal of Clinical Medicine 2010年第1期1卷 31-36页

作者： Asuquo Maurice Bassey Okon Etiuma Anietimfon Ngim ogbu ugare Gabriel Anthonia Ikpeme 不详

Background: Over the past several years, nonoperative management has been increasingly recommended for the care of selected blunt abdominal trauma patients with solid organ injuries. Objective: To evaluate the pattern and outcome of blunt abdominal trauma using haemodynamic stability and ultrasonography in the selection of patients for nonoperative management in a facility without computed tomogram. Methods: Patients admitted with blunt abdominal trauma between February 2005 and January 2010 were prospectively studied. Haemodynamic stability and sonography formed the basis for selecting patients for nonoperative management. Results: In total, 58 patients suffered blunt abdominal trauma and 19(33%) patients were successfully managed nonoperatively suffered blunt solid abdominal organ injuries. Road traffic accidents inflicted 17(89%) patients while 2(11%) patients sustained sports injury (football). The spleen was the commonest solid organ injured 12(60%), while the liver and kidney were injured in 6(30%) and 2(10%) respectively. Associated injuries were fractured left femur recorded in 3(16%) patients and fractured rib in a patient (5%). Conclusion: Nonoperative treatment is a safe and effective method in the management of haemodynamically stable patient with blunt solid abdominal organ injury. This translated to a reduction in hospital stay, absence of the risk of blood transfusion as well as attendant morbidity and mortality associated with laparotomy. Establishment of trauma system, provision of diagnostic and monitoring facilities, good roads, and education on road safety is recommended for improved outcome.

关键词： Blunt Abdominal Trauma Solid Organ Injury NonOperative Management

Facet selective etching of Au microcrystallites

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Nano Research 2015年第9期8卷 2925-2934页

作者： Gangaiah Mettela and Giridhar u. Kulkarni Thematic unit of Excellence on Nanochemistry and Chemistry and Physics of Materials unit Jawaharlal Nehru Centre for AdvancedScientific Research (JNCASR) Jakkur P.O. Bangalore 560 064 India

High-symmetry crystals exhibit isotropic properties. Inducing anisotropy, e.g., by facet selective etching, is considered implausible in face-centered cubic （FCC） metals, particularly gold, which, in addition to being an FCC, is noble. We report for the first time the facet selective etching of Au microcrystals obtained in the form of cuboctahedra and pentagonal rods from the thermolysis of a gold- organic precursor. The selective etching of {111} and {100} facets was achieved using a capping method in which tetraoctylammonium cations selectively cap the {111} facets while Br- ions protect the {100} facets. The exposed facets are oxidized by O2/C1-, yielding a variety of interesting geometries. The facet selective etching of the Au microcrystallites is governed only by the nature of the facets; the geometry of the microcystallite does not appear to play a significant role. The etched surfaces appear rough, but a closer examination reveals well-defined corrugations that are indexable to high hkl values. Such surfaces exhibit enhanced Raman activity.

关键词： gold,microcrystallites,facet selective eapping