检索结果-南通市图书馆

Long-term administration of large doses of paracetamol impairs the reproductive competence of male rats

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

Asian Journal of Andrology 2000年第4期2卷 247-255页

作者： w.D.ratnasooriya J.r.A.C.Jayakody Department of Zoology University of Colombo Colombo 3 Sri Lanka.Department of Zoology University of Colombo Colombo 3 Sri Lanka.

Aim: To evaluate the antireproductive effect of paracetamol in male rats. Methods: Male rats were orally adminis-tered daily with 500 mg/kg or 1000 mg/kg of paracetamol for 30 consecutive days. Their sexual behaviour and fertilitywere evaluated using receptive females. results: At 2 h after treratment, sexual behaviour was not inhibited but onday 30 both doses of paracetamol caused marked impairment of libido (assessed by % mounting, % intromission and% ejaculation), sexual vigour (number of mounts and intromissions and copulatory efficiency) or sexual performance(intercopulatory interval). In mating experiments, the fertility (in terms of quantal pregnancy, fertility index, implan-tation index and number of implants) was significantly reduced. All these effects were reversible. The antireproductiveeffect was not due to a general toxicity but due to an increase in pre-implantation losses resulting from oligozoospermia,impairments of normal and hyper-activated sperm motility, and reduction in the fertilizing potential of ***: Long-term use of high doses of paracetamol may be detrimental to male reproductive competence.( Asian J Andro12000 Dec; 2: 247-255 )

关键词： paracetamol fertility sexual behaviour oligozoospermia pre-implantation loss capacitation sperm motility

Parametric Analysis of Tensile Properties of Bimodal Al Alloys by Finite Element Method

在线全文

学校读者我要写书评

暂无评论

Journal of Materials Science & Technology 2009年第2期25卷 281-288页

作者： w.L. Zhang S. Li S.r. Nutt State Key Lab of MMCs Shanghai Jiao Tong University Shanghai 200030 China Department of Materials Science University of Southern California Los Angeles CA 90089 USA

An axisymmetrical unit cell model was used to represent a bimodal Al alloy that was composed of both nano-grained （NG） and coarse-grained （CG） aluminum. Effects of microstructural and materials parameters on tensile properties of bimodal AI alloy were investigated by finite element method （FEM）. The parameters analyzed included aspect ratios of CG Al and the unit cell, volume fraction of CG Al （VFCG）, and yield strength and strain hardening exponent of CG Al. Aspect ratios of CG Al and the unit cell have no significant influence on tensile stress-strain response of the bimodal Al alloy. This phenomenon derives from the similarity in elastic modulus and coefficient of thermal expansion between CG AI and NG Al. Conversely, tensile properties of bimodal Al alloy are extremely sensitive to VFCG, yield strength and strain hardening exponent of CG Al. Specifically, as VFCG increases, both yield strength and ultimate tensile strength （UTS） of the bimodal Al alloy decreases, while uniform strain of bimodal AI alloy increases. In addition, an increase in yield strength of CG Al results in an increase in both yield stress and UTS of bimodal AI alloy and a decrease in uniform strain of bimodal Al alloy. The lower capability in lowering the increase of stress concentration in NG Al due to a higher yield strength of CG Al causes the lower uniform strain of the bimodal AI alloy. when strain hardening exponent of CG Al increases, 0.2% yield stress, UTS, and uniform strain of the bimodal Al alloy increases. This can be attributed to the increased work-hardening ability of CG Al with a higher strain hardening exponent.

关键词： Nanomaterials Bimodal alloys Finite element method Tensile properties Parametric analysis

Using lean methodologies for economically and environmentally sustainable foundries

在线全文

学校读者我要写书评

暂无评论

China Foundry 2011年第1期8卷 74-88页

作者： r.M.Torielli r.A.Abrahams r.w.Smillie r.C.Voigt Industrial and Manufacturing Engineering Department The Pennsylvania State University rwS Productivity & Consulting L.L.C.Northville

Lean manufacturing is often seen as a set of tools that reduce the total cost and improve the quality of manufactured *** lean management philosophy is one which targets waste reduction in every facet of the manufacturing business;however,only recently have studies linked lean management philosophies with improving environmental *** studies suggest that lean manufacturing is more than a set of lean tools that can optimize manufacturing efficiencies;it is a process and mindset that needs to be integrated into daily manufacturing systems to achieve *** foundry industry,as well as manufacturing in general,has significant challenges in the current regulatory and political climate with developing an economically and environmentally sustainable business *** manufacturing has proven itself as a model for both economic sustainability and environmental *** recent studies have shown that both lean and green techniques and "zero-waste" policies also lead to reductions in overall *** these strategies have been examined for general manufacturing,they have not been investigated in detail for the foundry *** paper will review the current literature and describe how lean and green can provide a relevant framework for environmentally and economically sustainable *** of lean and green technologies and techniques which can be applied to foundries in a global context will be described.

关键词： green manufacturing lean manufacturing environmental sustainability pollution control

Flux penetration of an HTS coated-conductor tape by an approaching permanent magnet

在线全文

学校读者我要写书评

暂无评论

Superconductivity 2022年第4期4卷 41-50页

作者： r.w.Taylor T.Booth M.D.Ainslie H.w.weijers r.A.Badcock C.w.Bumby Paihau-robinson research Institute Victoria University of WellingtonLower Hutt 5010New Zealand MacDiarmid Institute Victoria University of WellingtonWellington 6140New Zealand Department of Engineering King’s College LondonLondon WC2R 2LSUnited Kingdom

Interactions between inhomogeneous magnetic fields and a superconductor lie at the heart of several high‐temperature superconducting(HTS)*** example is the situation where the magnetic field from a small permanent magnet(PM)is applied to a coated‐conductor HTS tape,such that flux penetrates the *** PM field is highly spatially inhomogeneous,such that there is significant variation in the applied field magnitude and direction across the *** leads to a varying local critical current density,J_(c)(B,θ),across the tape,and consequently different‘shielding’(magnetic flux penetration)behaviour than is the case for a uniform applied ***,we report results from measurements and numerical simulations of the penetrating magnetic field within an HTS coated‐conductor tape which occur as a PM dipole approaches from a *** simulations were performed using a finite‐element model based on the H‐formulation,and which incorporated experimentally‐measured anisotropic J_(c)(B,θ)Þproperties from a coated‐conductor *** showed good agreement with experimental *** effects of varying key modelling assumptions and parameters were then studied,including changing the widths of the PM and HTS tape and the magnitude of J_(c)(B,θ).The inhomogeneity of the PM field leads to a characteristic gull‐wing distribution of magnetic flux across the superconductor at elevated applied *** approach of the PM to the tape suppresses Jc in the centre of the tape,and this results in the observation of a characteristic maxima for the total shielding currents circulating in the tape.A figure of merit is introduced which uses this effect to provide a threshold definition for‘full flux penetration’of an HTS tape by an inhomogeneous dipole field.

关键词： Coated conductor High temperature superconductors HTS modelling Finite‐element method

Up-conversion processes of rare earth ions in heavy metal glasses

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 rare Earths 2011年第12期29卷 1192-1194页

作者： L.Grobelny w.A.Pisarski J.Pisarska r.Lisiecki w.ryba-romanowski Institute of Chemistry University of Silesia Institute of Low Temperature and Structure research Polish Academy of Sciences

Heavy metal lead germanate glasses doubly doped with Yb^3＋ and Ln^3＋ ions （Ln=Er, Tin） were investigated. Up-conversion spectra of Er^3＋ and Tm^3＋ were registered under diode-laser excitation of Yb^3＋. Up-conversion luminescence bands corresponded to ^4S3/2→^4I15/2 （green） and ^4F9/2→^4I15/2 （red） transitions of Er^3＋ as well as ^1G4→^3H6 （blue） and ^3Ha→^3H6 （N]r） transitions of Tm^3＋, respectively.

关键词： heavy metal glasses rare earth ions up-conversion luminescence

Comparison of acid-detergent lignin,alkaline-peroxide lignin,and acid-detergent insoluble ash as internal markers for predicting fecal output and digestibility by cattle offered bermudagrass hays of varying nutrient composition

在线全文

学校读者我要写书评

暂无评论

Journal of Animal Science and Biotechnology 2014年第3期5卷 310-317页

作者： Juvenal Kanani Dirk Philipp Kenneth P Coffey Elizabeth B Kegley Charles P west Shane Gadberry John Jennings Ashley N Young robert T rhein Division of Agriculture University of Arkansas Department of Plant and Soil Science Texas Tech University

Background： The potential for acid-detergent insoluble ash （ADIA）, alkaline-peroxide lignin （APL）, and acid-detergent lignin （ADL） to predict fecal output （FO） and dry matter digestibility （DMD） by cattle offered bermudagrass [Cynodon doctylon （L） Pers.] hays of different qualities was evaluated. Eight ruminally cannulated cows （594 ± 35.5 kg） were allocated randomly to 4 hay diets： low （L）, medium low （ML）, medium high （MH）, and high （H） crude protein （CP） concentration （79, 111,131, and 164 g CP/kg on a DM basis, respectively）. Diets were offered in 3 periods with 2 diet replicates per period and were rotated across cows between periods. Cows were individually fed 20 g DM/kg of body weight in equal feedings at 08：00 and 16：00 h for a 10-d adaptation followed by a 5-d total fecal collection. Actual DM intake （DMI）, DMD, and FO were determined based on hay offered, ort, and feces excreted. These components were then analyzed for ADL, APL, and ADIA concentration to determine marker recovery and marker-based estimates of FO and DMD. results： Forage DMI was affected by diet （P = 0.02）, and DMI from MH and H was greater （P 〈 0.05） than from L. Apparent DMD tended （P = 0.08） to differ among diets while FO （P = 0.20） was not affected by diet treatments. Average ADL recovery （1.16） was greater （P 〈 0.05） than that of ADIA （1.03） and APL （1.06）, but ADIA and APL did not differ （P = 0.42）. Estimates of FO and DMD derived using APL and ADIA were not different （P≥0.05） from total fecal collection while those using ADL differed （P 〈 0.05）. There was no diet by marker interaction （P≥ 0.22） for either FO or DMD. Conclusion： Acid-detergent insoluble ash and APL accurately predicted FO and DMD of cattle fed bermudagrass hay of varying nutrient composition. These internal markers may facilitate studies involving large numbers of animals and forages. results from such studies may be used to develop improved equations to predict energy values of forages based on the relationship of di

关键词： Acid-detergent insoluble ash Alkaline-peroxide lignin Bermudagrass Cattle Digestibility Marker

Spectroscopic and structural properties of MgAl_2O_4:Nd^(3+) nanopowders and ceramics

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2014年第3期32卷 265-268页

作者： K.Lemański P.J.Dereń w.walerczyk w.Strekv r.Boulesteix r.Epherre A.Matre Institute of Low Temperature and Structure research Polish Academy of Science ul.Okólna 2 50-422 Wroc?aw Poland University of Limoges SPCTS UMR CNRS 7315 12 Rue Atlantis 87068 Limoges Cedex France

The structural and spectroscopic properties of MgAl2O4：1%Nd3＋ spinel nanocrystals and ceramics were measured and ana-lyzed. Ceramics were prepared from the above mentioned spinel nanocrystals and undoped commercial spinel powder, using the spark plasma sintering （SPS） method. Properties of the obtained ceramics strongly depended on the SPS conditions. The samples were not homogeneous and possessed defects and pores. The most transparent ceramics had 60% transparency at 1000 nm.

关键词： SPS spinel spectroscopy neodymium ceramic rare earths

Shock attenuation, spatio-temporal and physiological parameter comparisons between land treadmill and water treadmill running

在线全文

学校读者我要写书评

暂无评论

Journal of Sport and Health Science 2017年第4期6卷 482-488页

作者： Paul w. Macdermid Philip w. Fink Stephen r. Stannard School of Sport & Exercise College of Health Massey University Palmerston North 4474 New Zealand

Purpose: The purpose of this study was to compare shock attenuation, spatio-temporal and physiological parameters during water immersed(depth: anterior superior iliac spine) aquatic treadmill(ATM) running and land based treadmill(LTM) running matched for ***: Six participants completed 15 min running under 2 conditions(LTM and ATM) in a randomised and balanced order, matched for *** tri-axial accelerometers placed at the distal tibia, lumbar region, and forehead were used to identify running dynamics and measure acceleration on impact and its attenuation. Expired respiratory gases and heart rate were sampled on a breath-by-breath basis for physiological variable collection throughout each ***: Participants experienced reduced accelerations on impact at the distal tibia(p wer back(p = 0.1363) or forehead(p = 0.0551) during ATM compared to LTM. Consequently, large reductions in shock attenuation occurred during the ATM compared to LTM(p = 0.0001). Stride frequency was greater(p ride length was shorter(p = 0.0341) as a result of reduced swing time(p = 0.0201)for LTM, whilst ATM running increased physiological demand for both heart rate(p red to ***: These findings show ATM reduces impact stress on the passive structures of the lower limbs whilst increasing physiological demand when running at matched speeds.

关键词： Gait Immersion Impact Training

Synthesis,structure and luminescence properties of KEu_(0.01)Gd_(0.19)Yb_(0.8)(wO_4)_2 powder

在线全文

学校读者我要写书评

暂无评论

Journal of rare Earths 2009年第4期27卷 564-568页

作者： A.Lukowiak r.J.wiglusz r.Pazik K.Lemanski w.Strek Institute of Low Temperature and Structure research Polish Academy of Sciences

The synthesis of co-doped KEu0.01Gd0.19Yb0.8（wO4）2 was achieved by a modified Pechini method at 750℃. The structure of obtained compound was confirmed using X-ray diffraction measurement and raman spectroscopy. The Scherrer＇s formula was used to confirm the grain sizes visualized by TEM technique. The grain sizes of about 100 nm of monoclinic KGw were successfully obtained by this meth- odology. In order to study spectroscopic properties of the prepared system the emission spectra were measured. The effective down- and up-conversion processes in non-resonant system were investigated.

关键词： sol-gel method tungstates doped by rare earth ions nanoctystals spectroscopy rare earths