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Objectives To investigate the effect of corneal stromal pocket irrigation after small-incision lenticule extraction (SMILE) on visual acuity, intraocular pressure (IOP), corneal parameters and complications after surgery. Methods A total of 242 eyes of 121 patients undergoing SMILE were enrolled in this prospective controlled study, and it was designed for one eye to randomly undergo SMILE with balanced salt solution irrigation of the corneal stromal pocket, while the other eye was not. The uncorrected distance visual acuity (UDVA) and slit lamp examination were recorded at 1 hour, 1 day, 1 week, and 1 month. Postoperative corneal density, corneal biomechanical, corneal endothelial cell number, and anterior OCT images were compared at 1 day, 1 week, and 1 month. Results Compared with the nonirrigation group, the irrigation group showed significantly higher UDVA at 1 day postoperatively (P Conclusions Interlamellar irrigation did not affect IOP, corneal parameters, morphology, complications, or UDVA at 1 hour, 1 week, and 1 month after the operation, but it may promote UDVA 1 day after the operation.

Rules for nonlinear borders of irregular domain is the thorny issues when using analytical method for solving mathematical and physical equations. On the basis of solution in the form of separated variables, the border of arbitrary shape with non-orthogonal boundary will be separated into a limited number of discrete points, and then direct assignment for the form solution at each of the discrete points on the border according to boundary conditions, at every discrete points on the border can establish an equation. If the number of discrete points on the border is equal with truncated series after retained series, all coefficients of the form solution can be determined and the problem solved. This paper use Laplace equation as an example to illustrate Collocation Trefftz Method can solve certain steady heat conduction problems within irregular domain with non-linear border.

Rules for non-orthogonal borders of irregular domain is the thorny issues when using analytical method for solving mathematical and physical equations. On the basis of solution in the form of separated variables, the border of arbitrary shape with non-orthogonal boundary will be separated into a limited number of discrete points, and then direct assignment for the form solution at each of the discrete points on the border according to boundary conditions, at every discrete points on the border can establish an equation. If the number of discrete points on the border is the same with truncated series after retained series, all coefficients of the form solution can be determined and the problem solved. This paper use Laplace equation as an example to illustrate Collocation Trefftz Method can solve certain steady-state heat conduction problems within non-orthogonal border and irregular domain.

As a late-model heating technique, radiant floor heating is much more energy-efficient as compared to the conventional air-conditioning system. For the sake of inner temperature distribution of the configuration, a steady three-dimensional model was performed based on the CFD software--CFX. On the basis of temperature distribution of the radiant floor, the total quantity of heat transferred can be calculated. It is observed that most heat quantity of heating water transferred to the concrete packing layer and the floor so as to heat the room.

Rail transit hub is key node in urban transportation system. The study on properties of ventilation and smoke control system can improve response ability in case of fire and give ventilation and smoke control design guidance for underground rail transit hub. Take Beijing DongZhimen underground rail transit hub as research object, according to its air turbulent flow characteristics, introducing standard turbulence model based on the N-S equation. Build the computational fluid dynamics model for solving the flow field within underground rail transit hub. Through theoretical analysis and numerical simulation, take "Siamese model” results as the boundary condition and establish a mathematical model of rail transit hub with CFX. Then research fire smoke development and spread laws when the exhaust fan within underground rail transit hub delayed open.

The typical subway island-platform of Beijing as research object was present in the article. Taking two-equation turbulence model and giving boundary conditions of piston wind and train heat load change with the time, adopting numerical method simulates air distribution of air-conditioning and ventilation system in subway. The results indicate that piston wind effect has significant impact on the area of platform entrance and staircase entrance while station with safety doors can obstruct piston effect at a certain degree. Simultaneity, the supply- exhaust air system offers relatively uniform temperature and velocity field, which meets requirements of transitory comfort for passengers. It is found that numerical simulation method can simulate and forecast air distribution of air conditioning and ventilating system in subway station. In conclusion, it can provide the reference for optimizing air-conditioning and ventilation system, improving thermal environment designing of subway station.

We study the transmission characteristics of surface plasmons at the interface of a one-dimensional photonic crystal (1DPC) and a monolayer graphene sheet. The composite structure with a plasmonic band gap (PGB) was obtained by covering a graphene sheet on the lateral side of the 1DPC. Defect modes in these structures appeared when defect layers were inserted in the 1DPC. On the condition that the chemical potential of graphene is much larger than , the PBG and defect mode shift to higher frequencies as the chemical potential increases. As the carrier density in graphene can be controlled by the gate voltage, both the PBG and defect mode can be easily tuned by the chemical potential, which is determined by the carrier density.

In this paper, we propose a novel wavelength division demultiplexer (WDDM) based on multimode interference (MMI) effect. The structure of WDDM is composed of three MMI regions, which can efficiently make two wavelengths (1310 nm and 1500 nm) to get through and one wavelength (1550 nm) to reflect back. In addition, it may also realize the separation for 1310/1500 nm. The transmittance higher than 97% and the crosstalk lower than -25 dB are achieved. It can also be extended to other wavelengths by changing the parameters of structure. The proposed device may have practical applications in photonic integrated circuits.