Regulations of Business Licensing for Route of Foreign Air Transport Enterprises

Regulations of Busi- ness Licensing for Route of Foreign Air Transport Enterprises(CCAR- 287),which were passed at the executive meeting of Civil Aviation Ad- ministration of China on May 19,2008,were hereby promulgated and became effective as of July 11,2008.

Temperature Regulation Effect of Desert Vegetation in Minqin Desert Area

[ Objective] The paper was to study the effects of desert vegetation on temperature regulation and stabilization in desert area. [ Method] The survey data of quadrats in five kinds of plant communities in Minqin desert area were preliminarily estimated. [Result] Desert vegetation had the ecological functions of regulating desert temperature and stabilizing sharp increase of temperature, especially the irreplaceable ecological function of slowing down sandstorm each spring in northwest China compared to physical sand-fixatian measures. The air humidity in forest region was relatively large, and the climate was more stable. The climate in desert area was dry, with intense changes in air temperature. Although the solar radiation utilization rate of desert vegetation per unit area in Minqin oasis fringe was 5.8% of that of 100% coverage vegetation, it had non-ignorable significance in regulating temperature of local desert. Regulating temperature was one of the ecological functions of desert vegetation. Previous studies only considered wind proof and sand-fixation functions of desert vegetation, but ignored its temperature regulation effect, and this was the ecological function of vegetation sand control different from physical sand-fixation measures such as sand barrier. [ Conclusion] It has important theoretical guiding significance and practical use value for prevention and control of desertification by studying ecological function of desert plants/vegetation.

Experimental study on f-ω regulation model under abnormal methane emission

In view of the difficulty of automatic adjustment, the recovery lag and the major accident potential of the mine ventilation system, an experimental model of the pipe net was established according to the typical one mine and one working face ventilation system of Daliuta coal mine. Using the best uniform approximation method of Chebyshev interpolation to fit the fan performance curve, we experimentally determined fan characteristics with different frequencies and establish the data base for the curves. Based on ventilation network monitoring theory, we designed a monitoring system for ventilation network parameter monitoring and fan operating frequency automatic control. Using the absolute methane emission quantity to predict the air quantity requirement of branch and fan frequency, we established a f-ω regulation model based on fan frequency and absolute methane emission quantity. After analysing methane emission and distribution characteristics, using CO_2 to simulate the methane emission characteristics from a working face, we verified the correctness and rationality of the f-ω regulation model. The fan operation frequency is adjusted by the method of air adjustment change with methane emission quantity and the curve searching method after determining air quantity requirements. The results show that the air quantity in a branch strictly changes according to the f-ω regulation model, in the airincreasing dilution by fan frequency regulation, the CO_2 concentration is limited to the set threshold value. The paper verifies the practicability of a frequency regulation system and the feasibility of the frequency adjustment scheme and provides guidance for the construction of automatic frequency conversion control system in coal mine ventilation networks.

Preparation of panda-shaped photonic crystal fibers with and without silver wire

A method of preparing panda-shaped photonic crystal fibers(PCFs)based on secondary drawing technology is proposed in this paper.The secondary drawing can not only reduce fiber diameter but also reduce core size by adding a glass sleeve.Silver-filled and non-silver-filled panda PCFs are prepared.The two ends of silver-filled panda PCF are connected with a broadband light source and a spectrometer,respectively,and the surface plasmon resonance phenomenon is detected.The secondary drawing technology provides a meaningful reference for the preparation of PCF in the future,and the prepared silver-filled panda PCF can be prepared into an optical fiber filter.

Insm1 regulates mTEC development and immune tolerance

The expression of self-antigens in medullary thymic epithelial cells(mTECs)is essential for the establishment of immune tolerance,but the regulatory network that controls the generation and maintenance of the multitude of cell populations expressing self-antigens is poorly understood.Here,we show that Insm1,a zinc finger protein with known functions in neuroendocrine and neuronal cells,is broadly coexpressed with an autoimmune regulator(Aire)in mTECs.Insm1 expression is undetectable in most mimetic cell populations derived from mTECs but persists in neuroendocrine mimetic cells.Mutation of Insm1 in mice downregulated Aire expression,dysregulated the gene expression program of mTECs,and altered mTEC subpopulations and the expression of tissue-restricted antigens.Consistent with these findings,loss of Insm1 resulted in autoimmune responses in multiple peripheral tissues.We found that Insm1 regulates gene expression in mTECs by binding to chromatin.Interestingly,the majority of the Insm1 binding sites are co-occupied by Aire and enriched in superenhancer regions.Together,our data demonstrate the important role of Insm1 in the regulation of the repertoire of self-antigens needed to establish immune tolerance.