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A new processing method for the AE index

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Science China(Technological Sciences) 2008年第10期51卷 1713-1720页

作者： w. BAUmJOHANN m. DUNLOP Space Research Institute Austrian Academy of Sciences Graz Austria Space Sciences Division Rutherford Appleton Laboratory Chilton Didcot United Kingdom

In this paper, we introduce an effective processing method to acquire the time de-rivative of the AE index as a coefficient. Using this coefficient, the AE index can be divided into the four stages: quiet, ascending, descending and active stages. The statistical results show that the ascending and descending stages of the AE index are dominant and occupy two thirds of the whole period. An analysis of the rela-tionship between the occurrence frequencies of the Dst index and AE index in solar cycle 23 shows that the monthly variation of the occurrence frequencies of the ascending stage of AE is closely related to the decrease of the Dst index.

关键词： AE index Dst index FIR filter substorm

microstructure change in Fe-based metallic glass and nanocrystalline alloy induced by liquid nitrogen treatment

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Journal of materials Science & Technology 2021年第10期69卷 1-6页

作者： m.C.Ri D.w.Ding Y.H.Sun w.H.wang Institute of Physics Chinese Academy of SciencesBeijing100190China Songshan Lake materials Laboratory Dongguan523808China

The effects of acyclic liquid nitrogen(LN)treatment in a temperature range of-196℃to 50℃on the thermal and magnetic stability of Fe78Si9B13 and Fe73.5Si13.5B9Nb3Cu1 glassy ribbons have been *** intrinsic heterogeneities of the metallic glasses can be activated through cryogenic thermal cycling,making irreversible structural changes after the treatment and inducing rejuvenation to the *** microstructural changes of both Fe-based metallic glass(mG)and nanocrystalline alloy induced by LN treatment were *** experimental results show that the LN treatment could effectively rejuvenate the Fe-Si-B mGs and change their thermomechanical and magnetic *** on the partially-crystallinity and well-known magnetic constants,the increase of the energy at the order of 10m J/g and magnetic domain wall movement and rotation at the order of 5-6μm and 0.5°-0.8°are found for FINEmET-type amorphous alloy after LN *** is also found that LN treatment can contribute a little stored energy to the magnetic domain wall movement and magnetic domain rotation.

关键词： metallic glasses Cryogenic thermal treatment Soft magnetic materials Rejuvenation Stored energy Domain wall

SPHERICAL mICROSTRUCTURE FORmATION OF THE SEmI-SOLID HIGH CHROmIUm CAST IRON Cr20mo2

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Acta metallurgica Sinica(English Letters) 2004年第1期17卷 77-82页

作者： w.m.mao A.m.Zhao X.Y.Zhong University of Science & Technology Beijing Beijing 100083 ChinaUniversity of Science & Technology Beijing Beijing 100083 ChinaUniversity of Science & Technology Beijing Beijing 100083 China

The nondendritic semi-solid slurry preparation of high chromium cast iron Cr20mo2 has been studied in this paper. The experiments show that the proeutectic austenitic particles are more spherical under a larger stirring power condition, even if the stirring time is shorter, while the proeutectic austenitic particles are not very much spherical under a smaller stirring power condition and some proeutectic austenitic dendrites also exist, even if the stirring time is very long. The experiments also show that when stirred for 5-6 minutes under the test condition, the semi-solid slurry with 40vol.%-50vol.% solid fraction and spherical proeutectic austenite in the size of 50-80μm can be obtained.

关键词： high chromium cast iron semi-solid electromagnetic stirring

Vibrational characteristics of piping system in air conditioning outdoor unit

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Science China(Technological Sciences) 2011年第5期54卷 1154-1168页

作者： S. K. LOH w. F. FARIS m. HAmDI w. m. CHIN Department of Engineering Design & manufacture Faculty of Engineering University of Malaya Department of mechanical Engineering College of Engineering International Islamic University Malaysia O.Y.L. R&D Sdn Bhd Sungai Buloh Selangor Darul Ehsan Malaysia

The modal analysis of piping system in air conditioner (AC) outdoor unit is essential to investigate the vibration properties of the system. In view of the growing significance of numerical finite element (FE) model for vibration behaviour prediction, the AC piping elastic end support characterization has been explored. The axial and radial stiffness variables (ka, kr1, kr2) of the compressor-piping mounting are obtained and represented by dynamic stiffness of compressor grommet. They are obtained from dynamic load deflection test based on compressor operating condition such as excitation frequency and amplitude. The unknown stiffness variables of the other tube end (chassis-piping mounting) are determined by parameter fine tuning. An experimental modal analysis using impact hammer test has also been employed to determine the vibration properties such as natural frequencies, mode shapes and damping ratio of the piping structures. The modal parameters acquisition using SCADAS mobile acquisition system and LmS Impact Testing software is compared with the corresponding simulated modal properties using Abaqus. most of the simulated natural frequencies achieve good correlation with the measured frequencies and it is reasonably a good prediction model to predict vibration behaviour of AC piping structures.

关键词： air conditioning outdoor unit piping modal analysis vibration characteristics

Coexistence and fluctuations phenomena with Davidson-like potentials in quadrupoleoctupole deformed nuclei

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Communications in Theoretical Physics 2021年第3期73卷 105-118页

作者： m m Hammad w H mansour E m El-maghraby H A motaweh Ayman A Aly Faculty of Science Mathematics DepartmentDamanhour UniversityEgypt Faculty of Science Physics DepartmentDamanhour UniversityEgypt

The energy spectra of three types of two-dimensional potentials(we will call them‘Davidson-like potentials’(DLPs)),characterized by four minima separated by barriers,are *** predictions for spectra and wave functions are obtained by using the nine-point finite-difference *** these potentials,with the existence of a single configuration,a transition of spectra,as a function of barrier height,is covered from tunneling splitting modes to fluctuations phenomena,with equal peaks wave functions,crossing to the spectra of purely anharmonic oscillator potentials(AOPs).A different type of phase transition occurs when two(or more)configurations *** the change of the parameters,a transition of spectra is covered from coexistence phenomena of two distinct quantum tunneling modes to fluctuations phenomena,with unequal peaks wave functions,crossing to the spectra of purely *** DLPs,a particular application of the coherent quadropole-octupole model to describe energy bands with alternating parity of the nuclei^(100)mo,^(146,148)Nd,^(148,150)Sm,^(220)Ra,^(220,222)Rn,and^(220,222)Th is *** global parametrization of the model for the selected nuclei is achieved.

关键词： quantum phase transitions fluctuations phenomena coherent quadrupole-octupole motion model coexistence phenomena

Assessment of predatory ability of native and non-native freshwater gammaridean species： A rapid test with water fleas as prey

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Current Zoology 2011年第6期57卷 836-843页

作者： B.E.m.w. STOFFELS J.S. TUmmERS G. VAN DER VELDE D. PLATVOET H.w.m. HENDRIKS R.S.E.w. LEUVEN Radboud University Nijmegen Institute for Water and Wetland Research Department of Animal Ecology and Ecophysiology Heyendaalseweg 135 NL-6525 AJ Nijmegen The Netherlands Netherlands Centre for Biodiversity Naturalis P.O. Box 9517 NL-2300 RA Leiden The Netherlands Netherlands Centre for Biodiversity Naturalis Mauritskade 57 NL-1092 AD Amsterdam The Netherlands Radboud University Nijmegen Faculty of Science Department of Mathematics Heyendaalseweg 135 NL-6525 AJ Nijmegen The Netherlands Radboud University Nijmegen Institute for Water and Wetland Research Department of Environmental Science Heyendaal seweg 135 NL-6525 AJ Nijrnegen The Netherlands

Predation rate with relation to species, sex and water temperature was tested among four different gammaridean spe- cies： Dikerogammarus villosus, Gammarus roeselii, Gammarus pulex and Gammarus fossarum. Tests were performed in micro- cosms in climate-controlled rooms at five different temperatures. Daphnia magna, a common water flea, served as prey. On ave- rage D. villosus showed the highest consumption rate of Daphnia magna over the entire temperature range, followed in decreas- ing order by G pulex, G roeselii and G fossarum. The predation rate of all species showed a distinct peak at 20~C. Correction of predation rates for body size gave somewhat different results. D. villosus is then still the most predatory of all gammaridean spe- cies tested followed by G. pulex, G. fossarum and G roeselii. The outcome of the Daphnia tests is consistent with results of other studies with different prey. This supports that the Daphnia test is a good and quick indicator of the predatory abilities in gam- maridean species at varying temperatures, and allows the prediction of how changing temperature regimes influence invasion impacts

关键词： Daphnia Temperature Predation rate Amphipods Invasions

Effects of Terminalia catappa seeds on sexual behaviour and fertility of male rats

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Asian Journal of Andrology 2000年第3期2卷 213-219页

作者： w.D.Ratnasooriya m.G.Dharmasiri Department of Zoology University of Colombo Colombo 3 Sri LankaDepartment of Zoology University of Colombo Colombo 3 Sri Lanka

Aim: To evaluate the aphrodisiac potential of Terminalia catappa Linn. seeds using a suspension of its kernel (SS)in 1% methyl cellulose in rats. methods: male rots were orally treated with 1500 mg/kg or 3000 mg/kg SS or ve-hicle, and their sexual behaviour was monitored 3 h later using a receptive female. Another group of rats was orallytreated with either 3000 mg/kg SS or vehicle for 7 consecutive days. Their sexual behaviour and fertility were evaluatedon days 1, 4 and 7 of treatment and day 7 post-treatment by pairing overnight with a pro-oestrous female. Results:The 1500 mg/kg dose, had a marked aphrodisiac action (prolongation of ejaculation latency) but no effect on libido(% mounting, % intromission and % ejaculation), sexual vigour (mounting-and-intromission frequency), or sexualperformance (intercopulatory interval). In contrast, the higher dose (3000 mg/kg) reversibly inhibited all the para?e-ten of sexual behaviour other than mounting-and-intromission frequency and copulatory efficiency. The effects of highdose SS were not due to general toxicity, liver toxicity, haemotoxicity, stress, muscle deficiency, muscle incoordina-fion, analgesia, hypoglycaemia or reduction in blood testosterone level. They were due to marked sedation. Conclu-sion: The kernel of T. catappa seeds has aphrodisiac activity and may be useful in the treatment of certain forms ofsexual inadequacies, such as premature ejaculation.

关键词： Terminalia catappa seeds aphrodisiac male sexual behaviour libido premature ejaculation fertility sedation

Dehydration Kinetics of Embryonic Axes from Desiccation-sensitive Seeds:An Assessment of Descriptive models

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Journal of Integrative Plant Biology 2009年第11期51卷 1002-1007页

作者： Tobias m. Ntuli Norman w. Pammenter School of Biological and Conservation Sciences University of KwaZulu-NatalWestville Campus

The response of desiccation-sensitive plant tissues to dehydration is significantly affected by dehydration conditions, particularly the rate of drying. Consequently it is important to be able to quantify drying rate. The aim of the study was to assess two models that have been proposed to describe drying kinetics, and thus to provide a quantification of non-linear drying rates, of embryonic axes excised from recalcitrant seeds. These models are an exponential drying time course, and a modified inverse relationship, respectively. For the six species investigated here the inverse function was generally found to fit drying data better than the exponential function under both rapid and slow drying conditions, and so is recommended. The rate of drying, under the conditions used here, was determined by axis size and possibly the nature of the axis outer coverings, rather than the water activity difference between the tissue and surrounding air.

关键词： desiccation drying rate recalcitrant seeds.

L-arginine, the substrate of nitric oxide synthase,inhibits fertility of male rats

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Asian Journal of Andrology 2001年第2期3卷 97-103页

作者： w.D.Ratnasooriya m.G.Dharmasiri Department of Zoology University of Colombo Colombo 3 Sri LankaDepartment of Zoology University of Colombo Colombo 3 Sri Lanka

Aim: To examine the effect of L-arginine, the substrate of nitric oxide (NO) synthase, on reproductive function ofmale rats. methods: male rats were gavaged with either L-arginine (100 or 200 mg·kg^(-1)·d^(-1)), D-arginine (200mg·kg^(-1)·d^(-1)) or vehicle (0.9% NaCl) for seven consecutive days. Their sexual behaviour and fertility were evaluat-ed using receptive females. Results: L-arginine (200 mg/kg) had no significant effect on sexual competence (interms of sexual arousal, libido, sexual vigour and sexual performance). In mating experiments, the higher dose of L-arginine effectively and reversibly inhibited fertility, whilst the lower dose and the inactive stereoisomer D-arginine hadno significant effect. The antifertility effect caused by L-arginine was due to a profound elevation in the preimplantationloss mediated possibly by impairment in epididymal sperm maturation, hyperactivated sperm motility and sperm capaci-tation. Conclusion: Elevated NO production may be detrimental to male fertility.

关键词： L-arginine nitric oxide fertility libido sex behavior pre-implantation loss sperm motility contraceptives