Search

To unravel the general relationship between bus travel and land use around bus stops and along bus routes and to promote their coordinated development, this paper explores a method to estimate passenger flow volumes from and to bus stops based on land use types, intensities, and spatial distributions around bus stops and along bus routes. Firstly, following the principle of the gravity model, which considers traffic volumes analogous to gravity based on trip generation and distance impedance between traffic analysis zones (TAZs), a gravitational logic estimation method for passenger flow volumes from and to bus stops was constructed with land use elements between bus stop TAZs and the upstream and downstream collections of bus stop TAZs. Building upon this, the passenger flow volumes from and to 38 bus stops in the Xueyuan Square area of Dalian during weekday morning peak hours were taken as the experimental objects. The basic estimation models of two gravity sets corresponding to passenger flow volumes from and to bus stops were constructed using the bus travel generation based on the aggregation of area-based origin unit method and the bus travel distance impedance based on the probability density method. Finally, the reliability of the estimation method of passenger flow volumes from and to bus stops was verified by regression fitting between the surveyed values of passenger flow volume and the estimated values of the basic models. The results indicate that the fuzzy estimation and transformation of bus travel based on land use elements, which serves as a crucial lever for facilitating strategic alignment in transit-oriented development (TOD), can be effectively achieved by using the area-based origin unit method to aggregate bus travel generation and the probability density method to evaluate the bus travel distance impedance. [ABSTRACT FROM AUTHOR]

The heavy metal ions and organic pollutants are major harmful substances in wastewater because of their toxicity on human health and environment. Nowadays, the adsorption–catalysis treatment to remove them simultaneously is still a challenge because of their different reaction mechanisms. Herein, a novel bifunctional polymer magnetic material Fe3O4@PDA‐PEI was successfully developed through a facile co‐deposition method by the copolymerization modification of polydopamine (PDA) and polyethyleneimine (PEI) on magnetic ferroferric oxide, which can both be utilized for both heavy metal ion removal from simulated industrial wastewater and further effective catalytic reduction of toxic 4‐nitrophenol (4‐NP) to useful 4‐aminophenol. The maximum adsorption capacity of Fe3O4@PDA‐PEI for gold ions was 465.12 mg/g at 35°C, and the adsorption thermodynamic parameters ΔG, ΔH, and ΔS of Fe3O4@PDA‐PEI (m(PDA):m(PEI) = 2:1) were −5.28 (35°C), 25.58, and 111.30 J K−1 mol−1, respectively. In addition, a sustainable strategy of converting gold ions to gold nanoparticles has been demonstrated for additional catalytic functionality of Fe3O4@PDA‐PEI, and Fe3O4@PDA‐PEI‐Au could effectively catalyze the reduction of 4‐NP at ambient temperature within 9 min. Fe3O4@PDA‐PEI with the advantages of facile fabrication, easy separation, excellent adsorption, and catalysis performance could be used as a promising polymer composite material in complicated wastewater environment. © 2023 Wiley Periodicals LLC. [ABSTRACT FROM AUTHOR]

Abstract: A series of Ce3+, Tb3+ singly doped and Ce3+ /Tb3+-co-doped Mg2La3[SiO4]2[PO4]O phosphors with the apatite-like structure were prepared by conventional solid-state reaction. The X-ray diffraction (XRD), photoluminescence excitation and emission spectra, luminescence decay curves and lifetimes were applied to characterize the samples. The efficient excitation energy transfer from Ce3+ to Tb3+ was verified by the excitation and emission spectra together with the luminescence decay curves. The Ce3+/Tb3+ co-doped phosphor shows an intense broad excitation band between 300 and 430nm, which matches near-UV chip (350–420nm). Under the excitation of near UV light, the Ce3+/Tb3+ co-doped sample exhibits two distinct luminescence bands: a blue one centered at about 415nm originating from Ce3+ ions and a green-emitting at 543nm from the 5D4→7F5 transition of Tb3+ ions. The emission can be tuned from the blue to the green color by changing the doping concentration of Tb3+. The energy transfer from Ce3+ to Tb3+ has been demonstrated to be the dipole–quadrupole mechanism, and the critical distance is calculated to be 16.04Å. [Copyright &y& Elsevier]

Abstract: Eu3+-doped red-emitting phosphors of tellurate garnets Li3Y3−3 x Eu3 x Te2O12 (x =0.05–1) were synthesized by the solid-state reaction. The phase purity of the as-prepared phosphor was verified by X-ray diffraction (XRD) studies. The photoluminescence excitation and emission spectra, the fluorescence decay curves, the dependence of luminescence intensity on doping level and CIE coordinates were investigated. The phosphor can be efficiently excited by near UV and blue light to realize an intense narrow red emission line (611nm) corresponding to the forced electric dipole transition 5D0 → 7F2 of Eu3+ ions. The potential application as a red-emitting phosphor for solid state lighting was evaluated in comparison with Eu3+-doped Y2O2S and aluminum garnet phosphors. The phosphor can be suggested to be a potential red-emitting candidate for the application in white LEDs under the irradiation of near-UV or blue chips. [Copyright &y& Elsevier]

We investigate the defect structure of KMgF3:Sm2+ by site-selective laser spectroscopy. The transitions between 5D0 and 7FJ (J=0, 1 and 2) states of Sm2+ in KMgF3 strictly obey induced electric dipole (ED) and magnetic dipole (MD) selection rules and symmetry selection rules from which three dominant sites with Oh, C4v and C2v symmetries and two minor C3v sites are identified at 11 K. The sites with C4v and C2v symmetries are assigned to Sm2+ with the vacancies at the nearest-neighbor K+ site along the [1 0 0] direction and at the second-nearest-neighbor K+ site along the [1 1 0] direction, respectively. It is assumed that the two C3v sites do not come from Sm2+ with the third-nearest-neighbor K+ vacancy along the [1 1 1] direction but from Sm2+ associated with other defects. [Copyright &y& Elsevier]

Abstract: A new phosphor of Eu2+-doped pollucite CsAlSi2O6 was synthesized by conventional solid-state reaction. The photoluminescence (PL) excitation and emission spectra were measured. The phosphors can be efficiently excited by near-UV light and show broad luminescence spectra with the main emission peak at around 450nm corresponding to 5d–4f transition of Eu2+ ions. CsAlSi2O6:0.05Eu2+ exhibits the brightest blue–green emission with CIE coordinates (x=0.21, y=0.32) and a quantum efficiency of 67%. The dependence of the luminescence intensity of CsAlSi2O6:Eu2+ on temperatures was investigated. The activation energy (ΔE) for thermal quenching was reported. [Copyright &y& Elsevier]