2,660 research outputs found

    The Forecasting Model of Bicycle Parking Demand on Campus Teaching and Office District

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    AbstractIn order to forecast the demand of the campus teaching and office district bicycle parking generation rate more accurate with the introduction of multi-model, which regarding affects are not carried on more considerations with the other parking demand influencing factor according to the actual investigation and study data. The paper analyzes the three types of regional architecture characteristics of bicycle parking demand, and gives the parking demand - supply forecast model which based on the parking generation rate model. The model considers the trip distance, parking distance, the facility cycling rate and the use factor which are also integrated in the model, thus obtains the number of bicycle parking facility which should construct actually. Finally the paper proposes a calculation example to expound the practical application of this model

    Measurement method and model simulation of the benchmark line in the deformed frame of a heavy vehicle

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    Wheel alignment is an important item of vehicle detection to ensure the vehicle safety. The precision of wheel alignment is determined by the benchmark line which is the center line of the vehicle frame. A measurement method of the benchmark line for the deformed frame of heavy vehicle is deduced by constructing a model which consists of a laser bar with two laser range finders and a measurement bar with scale. The simulations are performed on a model of typical heavy vehicle CA1190 whose frame size is 11230 mm×860 mm. The simulation results of the center points are solved by the least squares method while the fitting line of the points for the benchmark line is also achieved in the simulation

    Bis(μ-3-hydroxy­benzoato)-κ2 O 1:O 3;κ2 O 3:O 1-bis­[bis­(1H-benzimidazole-κN 3)(3-hydroxy­benzoato-κO)nickel(II)] bis­(1H-benzimidazole-κN 3)bis­(3-hy­droxy­benzoato-κO 1)nickel(II) hexa­hydrate

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    The title compound, [Ni2(C7H5O3)4(C7H6N2)4][Ni(C7H5O3)2(C7H6N2)2]·6H2O, is a mononuclear/dinuclear nickel(II) cocrystal, the two mol­ecular species inter­acting through hydrogen bonds that involve the uncoordinated water mol­ecules. In the mononuclear species, the NiII ion, located on an inversion center, is coordinated by two 1H-benzimidazole (bzim) ligands and two 3-hydroxy­benzoate (hba) anions in a square-planar geometry. In the centrosymmetric dinuclear species, the NiII ion is coordinated by two bzim ligands and three hba anions in a square-pyramidal geometry; of the two independent hba anions, one bridges two NiII ions with both carboxylate and hydroxyl groups whereas the other coordin­ates in a unidentate manner to the NiII ion. The apical Ni—Ohydrox­yl bond is 0.39 Å longer than the basal Ni—Ocarbox­yl bonds. The face-to-face separation of 3.326 (9) Å indicates the existence of π–π stacking between parallel bzim ligands of adjacent dinuclear entities. Extensive N—H⋯O and O—H⋯O hydrogen bonds help to stabilize the crystal structure

    Renalase Deficiency in Heart Failure Model of Rats—A Potential Mechanism Underlying Circulating Norepinephrine Accumulation

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    BACKGROUND: Sympathetic overactivity and catecholamine accumulation are important characteristic findings in heart failure, which contribute to its pathophysiology. Here, we identify a potential mechanism underlying norepinephrine accumulation in a rat model of heart failure. METHODOLOGY/PRINCIPAL FINDINGS: Initially, we constructed a rat model of unilateral renal artery stenosis (n = 16) and found that the expression of renalase, a previously identified secreted amine oxidase, was markedly reduced in the ischemic compared to the non-ischemic kidney (protein: 0.295±0.085 versus 0.765±0.171, p<0.05). Subsequently, we utilized an isolated perfused rat kidney model to demonstrate that the clearance rate of norepinephrine decreased with reduction of perfusion flow. On the basis of these findings, we hypothesized the reduced renal blood supply which occurs in heart failure would result in impaired synthesis of renalase by the kidney and consequently reduced degradation of circulating norepinephrine. To verify this, we used a rat model of infarction-induced heart failure (n = 12 per group). In these rats, the flow velocity of renal artery, when measured at four weeks, is obviously lower in the operation group. Renal expression of renalase was reduced (protein: 0.476±0.043 for control, 0.248±0.029 for operation versus 0.636±0.151 for sham-operation) and this was associated with an increase in circulating norepinephrine (0.168±0.016 ng/mL for control, 0.203±0.019 ng/mL for operation versus 0.138±0.008 ng/mL for sham-operation). CONCLUSIONS/SIGNIFICANCE: Renalase expression is influenced by renal blood flow and impaired synthesis of renalase by the kidney may represent a potential mechanism underlying circulating norepinephrine accumulation in heart failure

    Quantum Interference Effects in Molecular Y- and Rhomb-Type Systems

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    In this paper we report the first observation of molecular population trapping in four level systems. Constructive and destructive quantum interferences between two sum-frequncy two-photon transitions in Y- and rhomb-type four-level systems, respectively, im sodium molecules have been experimentally achieved by using only one laser source. Their energy level schemes are featured by the extremely near-resonant enhancement of the equal-frequency two-photon transitions, sharing both the initial and the intermediate levels for the Y-type, and sharing both the initial and the final levels for the rhomb-type systems. Their novel spectral effects are to show seriously restrained Doppler-free UV peak at the nominal location of the induced two-photon transition with visible fluorescence in rhomb-type schems, and to show a strong extra UV peak but null visible fluorescence in the middle between the two dipole allowed two-photon transitions
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