数字微波卫星车——实现快速反应的电视新闻制播平台

依据"新闻立台"的思想和实现新闻快速反应的目标,中山广播电视台设计制造了数字微波卫星车.本文主要介绍了数字微波卫星车的设计思想、功能模块设计和工艺设计方面的创新点,总结了该车的使用情况和社会经济效益.     

Combined Treatment with Cryptocaryone and Ultraviolet C Promotes Antiproliferation and Apoptosis of Oral Cancer Cells

Cryptocaryone (CPC) was previously reported as preferential for killing natural products in oral cancer cells. However, its radiosensitizing potential combined with ultraviolet C (UVC) cell killing of oral cancer cells remains unclear. This study evaluates the combined anti-proliferation effect and clarifies the mechanism of combined UVC/CPC effects on oral cancer cells. UVC/CPC shows higher anti-proliferation than individual and control treatments in a low cytotoxic environment on normal oral cells. Mechanistically, combined UVC/CPC generates high levels of reactive oxygen species and induces mitochondrial dysfunction by generating mitochondrial superoxide, increasing mitochondrial mass and causing the potential destruction of the mitochondrial membrane compared to individual treatments. Moreover, combined UVC/CPC causes higher G2/M arrest and triggers apoptosis, with greater evidence of cell cycle disturbance, annexin V, pancaspase, caspases 3/7 expression or activity in oral cancer cells than individual treatments. Western blotting further indicates that UVC/CPC induces overexpression for cleaved types of poly (ADP-ribose) polymerase and caspase 3 more than individual treatments. Additionally, UVC/CPC highly induces γH2AX and 8-hydroxy-2’-deoxyguanosine adducts as DNA damage in oral cancer cells. Taken together, CPC shows a radiosensitizing anti-proliferation effect on UVC irradiated oral cancer cells with combined effects through oxidative stress, apoptosis and DNA damage.     

Double beam near-infrared spectrometer for compensation of background water absorption and instrumental drift in intensity

A double beam near-infrared spectrometer is developed to compensate the water absorption and instrumental drift in intensity. The spectrometer may be used for both single and double beam measurements,and the two operation modes are compared. The results show that the double beam technique eliminates instrumental drift in the single beam measurement and therefore the stability of the system increases by more than 20%. The compensation of the double beam system on water absorption is verified by the measurement of fat content in milk. The results show that the spectrum data based on double beam mode get better calibration model and lower prediction error than traditional single beam mode.     

Contributions of Starch-Granule Bound α-Amylase to Q-Enzyme from Cotton Leaves

Starch granules with tightly bound α-amylase and a branching enzyme (Q-enzyme) were isolated from cotton leaves. The activity of α-amylase was regulated by various concentrations of EDTA and exogenous α-amylase. Starch granules were incubated for a simultaneous interaction between α-amylase with its products and a branching enzyme. The increase in bound α-amylase activity caused an increase in amounts of maltodextrin products, the molecular weights of which ranged from 1,500 to 20,000 daltons. The amounts of branched glucans synthesized by Q-enzyme also changed in direct proportion to the amounts of maltodextrins and the levels of bound endogenous α-amylase activity. The absorption spectrum of natural cotton leaf amylopectin was similar to those of the synthesized glucans. Their molecular weights, however, were smaller than those of the natural products in the absence of chain lengthening donor substrate.     

CHF characteristics of R-134a flowing upward in uniformly heated vertical tube

An experimental study of the critical heat flux (CHF) using R-134a in uniformly heated vertical tube was performed and 182 CHF data points were obtained from the present work to investigate the CHF characteristics of R-134a. The investigated flow parameters in R-134a were: (1) outlet pressures of 13, 16.5, 23.9 bar, (2) mass fluxes of 285-1300 kg/m² s, (3) subcooling temperatures of 5-40 °C. The CHF tests were performed in a 17.04 mm I.D. test section with heated length of 3 m. The parametric trends of CHF show a general agreement with previous understanding in the water. To assess the suitability of the CHF test using R-134a for modeling the CHF in water, Bowring correlation and Katto correlation were used in the present investigation. It was found that the present test results coincided well with the data predicted with both correlations. It demonstrates that the R-134a can be used as the CHF modeling fluid of water for the investigated flow conditions and geometric condition.     

白云鄂博主东矿中贫氧化矿铌资源的特点及综合回收

包头白云鄂博主东矿中贫氧化矿中铌有很大的回收价值,本文探讨了主要铌矿物的特点及选矿性质,认为弱磁—强磁是初步富集铌的有效途径。本文还较为详细地介绍了从强磁中矿的稀土浮选尾矿回收铌得到富铌铁精矿的若干浮选工艺条件及浮选药剂。     

Effect of carbon fiber paper made from carbon felt with different yard weights on the performance of low temperature proton exchange membrane fuel cells

This study employed fuel cell gas diffusion layers (GDLs) consisting of carbon fiber paper made from carbon fiber felt with different yard weights in proton exchange membrane fuel cells (PEMFCs), and investigated the relationship between the yard weight of the carbon fiber paper and the fuel cell performance and thickness of the gasket. In this paper we discuss the relationship between carbon fiber felt with different yard weights and fuel cell performance and also explore the effect of carbon fiber paper thickness, air permeability, surface resistivity, and structural study. We focused on the material used for the gas diffusion layer in this study. Carbon fiber paper made in-house in this study contained 10 wt% (all percentages are by weight unless otherwise noted) phenolic resin. When the tested area was 25 cm², the test temperature was 40 °C, the gasket thickness was 0.06 mm, and the yard weight 70 g m⁻², fuel cell current density was 1968 mA cm⁻² at a load 0.3 V. When the gasket thickness was 0.36 mm and yard weight was 190 g m⁻², fuel current density was 1710 mA cm⁻² at a load of 0.3 V.     

UEs Power Reduction Evolution with Adaptive Mechanism over LTE Wireless Networks

At present, the major drawback for mobile phones is the issue of power consumption. As one of the alternatives to decrease the power consumption of standard, power-hungry location-based services usually require the knowledge of how individual phone features consume power. A typical phone feature is that the applications related to multimedia streaming utilize more power while receiving, processing, and displaying the multimedia contents, thus contributing to the increased power consumption. There is a growing concern that current battery modules have limited capability in fulfilling the long-term energy need for the progress on the mobile phone because of increasing power consumption during multimedia streaming processes. Considering this, in this paper, we provide an offline meaning sleep-mode method to compute the minimum power consumption comparing with the power-on solution to save power by implementing energy rate adaptation (RA) mechanism based on mobile excess energy level purpose to save battery power use. Our simulation results show that our RA method preserves efficient power while achieving better throughput compared with the mechanism without rate adaptation (WRA).     

Thermal-fluid and electromagnetic coupling analysis and test of a traction motor for electric vehicles

This paper proposes a multi-phasic coupling analysis and test of a 50 kW traction motor for electric vehicles. The temperature-dependent properties of the electrical and magnetic materials of the interior permanent magnet traction motor are not negligible over a wide operation range of the vehicle. The heat produced by the electromagnetic power loss changes the motor’s properties, and in turn the motor performance changes to produce a different power loss. This two-way coupled electromagnetic and thermal-fluid analysis of the torque and speed curve and the transient thermal response at a rated operation point are simulated and compared with the traditional one-way coupling analysis. The simulation results are also compared with and proved by experiments on a prototype motor. The experimental results show that it is critical and necessary to predict the motor performance by means of the proposed two-way coupling analysis that provides more accurate information than the traditional one-way coupling analysis.