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Pressure fluctuations in the high-pressure common rail systems have a significant impact on the fuel injection and engine performance. In this study, the pressure fluctuation in a high-pressure common rail system was investigated using simulations. The fluctuation can be caused by hydraulic structures and control factors. The degree of influence of those two causes was evaluated and discussed in this work. First, the hydraulic and control factors that dominate the models of injection systems were established. Then, the mechanism of pressure fluctuation on high-pressure common rail systems was highlighted. A dimensionless parameter was defined to quantitatively describe the effects of control factors and hydraulic structures on pressure fluctuation. Finally, the developed model was used to study the effects of injection conditions and structural parameters on pressure fluctuation. The results show that the injection frequency has a limited effect on the system pressure fluctuation. In addition, the increase in the injection energizing time and the injection pressure will increase the hydraulic pressure fluctuations of the system, thus increasing the total pressure fluctuations of the system. Moreover, the increase in the volume by increasing the diameter was found to decrease the pressure fluctuations more effectively compared to the impact of the length, but there is a marginal diminishing effect. The results demonstrated that the effect of a 20 bar signal error and a 160 mm common rail length is almost the same on decreasing pressure fluctuations. It can be concluded that the improvements in the electronic part of the high-pressure common rail system have more potential than the mechanical part.

Purpose Glaucoma is an eye disease characterized by the loss of peripheral vision, high pressure in the eye, optic nerve damage, and the loss of peripheral vision due to loss of retinal ganglion cells (RGCs). A number of miRNA have been detected in the pathogenesis of glaucoma. The paper was to focus on the miR-223 in RGCs apoptosis and inflammation, and investigated the possible mechanisms in vitro and in vivo. Materials and methods After miR-223 inhibitor and mimics transfected into RGCs, the expression of miR-223 was detected by QRT-PCR, cell proliferation were performed by CCK-8 and EdU assays, cell apoptosis were measured by flow cytometer and TUNEL assays, apoptosis and inflammation -related proteins were detected by western blot, and whether miR-223 target to HSP-70 was detected by Luciferease reporter assay. Moreover, the effects si-HSP-70 on RGCs or RGCs transfected with miR-223 inhibitor were detected. In vivo study. New Zealand White rabbits (20 females) were used to detect the effect of miR-223 on the rabbit glaucoma model induced by injection of carbomer. Results CCK-8 and EdU assays demonstrated that miR-223 mimics decreased RGCs proliferation. FITC-Annexin V/PI Apoptosis and TUNEL assays showed that miR-223 mimics induced RGCs apoptosis. Western blot revealed that miR-223 mimics enhanced the expression of relative apoptosis and inflammation factors. Further, we demonstrated that miR-223 could inhibit cell proliferation, induce cell apoptosis as well as inflammation by targeting HSP-70 in RGCs. Moreover, the results were confirmed in rabbit glaucoma model. Conclusions In summary, miR-223 plays a vital role in RGCs by regulating HSP-70 expression, and the new therapeutic strategy might potentially contribute to benefit glaucoma treatment.

The arbitrary l-wave solutions to the Schrodinger equation for the deformed hyperbolic Manning-Rosen potential is investigated analytically by using the Nikiforov-Uvarov method, the centrifugal term is treated with an improved Greene and Aldrich’s approximation scheme. The wavefunctions depend on the deformation parameter q, which is expressed in terms of the Jocobi polynomial or the hypergeometric function. The bound state energy is obtained, and the discrete spectrum is shown to be independent of the deformation parameter q.

According the actual structure and working principle of a fuel injector to build a model of the common-rail injector, including the control valve, the solenoid valve, and the needle valve of the injector. The model includes the leakage model for the control piston and needle valve that takes into account increasing leakage at high pressure. The performance of the fuel injector is investigated using a one-dimensional numerical model. Analyzing the effect of the system and structure parameters including common-rail pressure, injection pulse width, inlet and outlet hole diameter, and the injection nozzle on the injection characteristics of the fuel injector. Results show that the geometric parameter is the main property affecting the flow characteristic of the injector, which includes the flow rate of inlet and outlet hole, pressure waves in the control chamber and injection rate. The common-rail pressure, injection pulse width and the geometric parameters mainly affect the injection performance, such as the injection rate and injected volume. The investigation result can provide some useful information to improve the injection characteristic in follow-up studies.

Boiling is known to be a very efficient mode of heat transfer in earth gravity, however, in microgravity bubble behavior is different because the buoyancy effects are replaced by surface tension effects such as Marangoni convection. The modeling of nucleate boiling with the effect of Marangoni convection in 0 g is accomplished by using Phase Field Method. Numerical simulation is carried out of single nucleating vapor bubble on a heated wall with and without Marangoni convection. The results show that the flow field consists of a major vortex that recirculates colder fluid from the upper region, pulling it toward the hot surface to the point where the bubble meets the heated surface. This type of flow pattern has been observed in various experiments.

Under reduced or micro gravity, bubble dynamic behaviors in liquid melts or liquid solutions are important and common problems on optimizing many processes in space science and technology. Due to limited availability experiments under reduced or micro gravity condition, the studies in this area is still quiet fragmentary. For this reason, we develop two pairs of Helmholtz-Maxwell (H-M) coils, which can produce a uniform gradient magnetic field for the ferrofluid filled in a closed Hele-Shaw cell, so as to achieve reduced or micro gravity condition. Afterwards, we establish the multi-physics mathematic model to calculate the magnetic field and the gravity compensation rate, which shows a 30mm×40mm well-distributed region for 90% gravity compensation rate exists.

The rapid solidification process of Mg7Zn3 alloy was simulated by the molecular dynamics method. The relationship between the local structure and the dynamics during the liquid-glass transition was deeply investigated. It was found that the Mg-centered FK polyhedron and the Zn-centered icosahedron play a critical role in the formation of Mg7Zn3 metallic glass. The self-diffusion coefficients of Mg and Zn atoms deviate from the Arrhenius law near the melting temperature and then satisfy the power law. According to the time correlation functions of mean-square displacement, incoherent intermediate scattering function and non-Gaussian parameter, it was found that the β-relaxation in Mg7Zn3 supercooled liquid becomes more and more evident with decreasing temperature, and the α-relaxation time rapidly increases in the VFT law. Moreover, the smaller Zn atom has a faster relaxation behavior than the Mg atom. Some local atomic structures with short-range order have lower mobility, and they play a critical role in the appearance of cage effect in the β-relaxation regime. The dynamics deviates from the Arrhenius law just at the temperature as the number of local atomic structures begins to rapidly increase. The dynamic glass transition temperature (Tc) is close to the glass transition point in structure (TgStr).

nfluenced by factors like mud, frame, rivet, space mark and plate slant, plate character segmentation tends to be inaccurate and even results in mistakes. In order to tackle these problems, this paper puts forward a plate character segmentation algorithm based on projection feature and prior knowledge. That is, firstly of all, to carry out horizontal coarse segmentation by horizontal projection, then use both vertical projection and prior knowledge to conduct vertical segmentation. At last, to carry out horizontal fine segmentation by local projection. The experiment demonstrates that such algorithm can solve the above mentioned problems accurately and practically with high-efficiency.

Based on the unblocked reliability theory of the road network, combined with the characteristics of the logistics distribution of expressway service areas, the concept of network unblocked reliability on logistics distribution was put forward. Under the reliability analysis, the optimization model of multi objective, multi depot and open vehicle scheduling on logistics distribution of highway service areas was established, and the ant colony algorithm was designed. In the end an example was analyzed to validate the usability of the optimization model by comparing with saving mileage, which demonstrates the established optimization model of multiple depot vehicle scheduling is of a better practical value to guide the optimization decision making of logistics distribution network and to improve the reliability of logistics distribution of expressway service areas.

In this study the dynamic Smagorinsky model (DSM model) and an algebraic model for the subgrid turbulent kinetic energy have been implemented into KIVA3VLES code to investigate the atomization and evaporation processes of diesel spray in a constant volume vessel. Based on the experimental results of the liquid and vapor phase distributions as well as the results obtained by the differential subgrid scale kinetic energy (K-equation) model, the paper reveals the influence of the turbulent kinetic energy model on the fuel spray prediction. Computational results show that by combining the DSM model and the algebraic subgrid turbulent energy model, the turbulent diffusion of droplets can be reasonably simulated, the liquid penetration and the predicted liquid and fuel vapor mass fraction contours are close to the experiment results. At the same time, the turbulent kinetic energy given by the DSM model is in agreement with the results by the K-equation model, but with less computational cost..

The study carries out optimal design for the cam profile of the valve train in a high-specific-power diesel engine. The dynamic analysis on the original cam reveals that the original one, which leads to adequate fullness coefficient, is designed far from the material margins. The fullness coefficient and time area value are selected as the optimization objective, and the piecewise fucntion method is utilized to optimally design the cam profile. The restrictive contidons are applied to each section on the cam. Thus the function and the optimal coeficients are obtained. Then the dynamic analysis and working process simulation on the optimal valve train are carried out, and it proves that the dynamic and intake port performaces of the optimized one are greatly impoved.

Based on the load and heat radiation area are directly influenced by the ratio of piston stroke to cylinder diameter (S/D).An optimized mathematical model is established, with the minimal heat radiation area as the object function and the S/D value as the variable. The optimum results are calculated by using the an Improved differential evolution algorithm method based on 1Stopt.The result shows that this method is of better convergence, high calculation efficiency and consistent with MTU890.