新型城镇化视阈下徽州乡村旅游发展路径的思考

通过对乡村旅游、新型城镇化等概念内涵的梳理,结合徽州乡村旅游的内容与问题,提出徽州乡村旅游应立足于新型城镇化背景,通过保持文化的原生性、推动乡村旅游品牌建设、提升村落居民的参与性、挖掘文化的商业性、重视人才培养的迫切性等多途径探究徽州乡村旅游发展,以期全方位展现徽州文化的内涵,促进徽州地区的可持续发展

Anomalous reflection and transmission characteristics of a type of continuous film metal gratings

利用全息干涉图案成形在石英衬底上刻蚀形成周期为波长光栅,并在上面淀积金属薄膜,制造了具有不同深度、金属层厚度和周期的金属光栅。研究发现了此金属光栅的反射率和透射率随入射角变化的异常特性,即反射谱和透射谱的表现在光栅深度和厚度不同时将可能发生翻转,反射谱由"谷"状变为"峰"状,而透射谱由"峰"状变为"谷"状。本文分析了相关的物理效应以及该结构与入射光相互作用的特点,解释了该实验现象。Metal gratings with various depth,metal thickness and period are fabricated by depositing metal films on wavelength-scale gratings on quartz substrates,which are formed by holographic interference patterning and subsequent etching.The anomalous characteristics of angular reflection and transmission spectra are found For different grating depth and metal thickness,the appearance of spectrum can be inversed,i.e.the "valley-like" reflection spectrum becomes "peak-like",while the "peak-like" transmission spectrum becomes "valley-like".In this article,we analyze the relevant physical effects and characters of the optical interaction processes,and give an interpretation of the phenomena.国家自然科学基金资助项目(60707012);; 福建省科技计划重点资助项目(2007H0032);; 福建省自然科学基金资助项目(A0710019);; NSF/NIRT:ECS-0403865,US

Beam shaping based on intermediate zone diffraction of a micro-aperture

National Natural Science Foundation of China [60707012]; Natural Science Foundation of Fujian Province of China [A0710019]; NCETFJ program in ChinaWe analyze optical diffraction of a micro-aperture (slit or hole) in a metal screen in the intermediate zone and report its application for beam focusing and collimating in micro-optics. Both finite-difference time-domain simulations and Rayleigh-Sommerfeld diffraction formula were applied to calculate the intermediate-zone diffraction patterns. It is shown that, by controlling the aperture size, the focal length and depth can be adjusted in a very wide range, from subwavelength to tens of wavelengths, while the focal width maintains in an order of wavelength

Growth of ordered, single-domain, alumina nanopore arrays with holographically patterned aluminum films

Highly-ordered, single-domain (similar tocm(2)), alumina nanopore arrays with controlled symmetry were obtained by anodizing prepatterned aluminum films that were deposited on silica substrates. Holographic lithography, in conjunction with a conformal deposition process, was utilized to form nanoscale corrugations on aluminum film surface prior to anodization. Both the order and symmetry of pore arrays were found to be well controlled and guided by the periodic surface corrugations from the initial stage of pore growth. Ordered nanopore arrays grown on foreign substrates are promising as a host or template for forming various nanodevices and their on-chip integration. (C) 2002 American Institute of Physics

Refractive transmission of light and beam shaping with metallic nano-optic lenses

We have performed finite-difference time-domain (FDTD) analysis of optical transmission through a nanoslit array structure formed on a metal layer with tapered film thickness. The analysis result shows refractive transmission of light through the nanoslit array, opening up the possibility of creating metallic lenses that resemble glass lenses in their shape. Metallic lenses with curved surfaces are designed such that each nanoslit element transmits light with phase retardation controlled by the metal thickness in the aperture region. The FDTD analysis result demonstrates a focusing or collimating function of convex-shaped metal lenses. (C) 2004 American Institute of Physics

Tuning resonant optical transmission of metallic nanoslit arrays with embedded microcavities

National Science Foundation of China (NSFC) [60707012]; Research Fund for the Doctoral Program of Higher Education [20070384022]; Science and Technology Key Project of Fujian Province of China [2007HOO32]; China-Ministry of Science and Technology InternatWe numerically study the characteristics of optical transmission of metallic nanoslit arrays (MNSAs) with embedded microcavities (MC-MNSAs) and demonstrate that passbands of the transmission spectra can be monotonously tuned by adjusting the dimensions of the microcavities. The study discloses that spectra of conventional MNSAs and MC-MNSAs are determined mainly by cavity resonances of the slits or embedded microcavities, modified by in-plane surface-plasmon wave resonances. It is also found that coupling of cavity resonances between neighboring slits or microcavities has considerable effects on the passbands. The MC-MNSA structure is shown to have potentials in applications of tunable filter arrays. (C) 2009 Optical Society of Americ

预测腐蚀管道剩余强度的新方法

将BP神经网络和遗传算法相结合 ,得到了一种可计算腐蚀管道剩余强度和最大允许注水压力的新神经网络。通过实例分析 ,将 7种常用规范和改进的遗传神经网络方法进行了比较。结果表明 ,不同计算方法得到的剩余强度和最大允许注水压力相差较大 ,Wes 2 80 5 - 97规范、ASMEB31G规范、CVDA— 84规范、Irwin断裂力学方法等都比J积分方法的剩余强度和最大允许注水压力偏大 ;Burdiken和DM断裂力学方法计算得到的剩余强度和最大允许注水压力比J积分偏小 ;J积分方法和基于J积分方法的改进遗传神经网络方法计算结果比较接近 ,比较适中 ,可以认为是计算管道剩余强度和最大允许注水压力较好的方

Phytoplankton assemblages in East China Sea in winter 2009

2009年12月23日—2010年1月5日在东海海域(24°00'—32°00'n,120°00'—128°00'E)68个站位进行了水文、化学和生物的综合调查,应用uTErMHl方法对调查海域的浮游植物群集进行了研究。经284个浮游植物采水样品的分析,共发现浮游植物4门67属171种(含13个未定种)。浮游植物群集主要由硅藻和甲藻组成,还有少量的蓝藻和金藻,物种以沿岸广温型为主,优势种为:具槽帕拉藻(PArAlIA SulCATA)、菱形海线藻(THAlASSIOnEMA nITzSCHIOIdES)、柔弱伪菱形藻(PSEudO-nITzSCHIA dElICATISSIMA)、安哥拉海链藻(THAlASSIOSIrA AngulATA=并基海链藻THAlASSIOSIrA dECIPEnS)和细弱海链藻(THAlASSIOSIrA SubTIlIS)等。调查浮游植物细胞丰度介于0.356x103—142.578x103个/l,平均值为14.137x103个/l;硅藻占浮游植物细胞丰度的比例最大,介于0.356x103—142.578x103个/l,平均值为13.023x103个/l;其次为甲藻,细胞丰度介于0.356x103—11.378x103个/l,平均值为1.177x103个/l。调查海域表层浮游植物细胞丰度的平面分布由硅藻刻画,高值区出现在调查区北部即长江口东北部海域,甲藻在调查区南部和东南部丰度较高。细胞丰度在水体中的垂直分布趋势为先上升后下降,最大值出现在10M层。从断面分布上看,细胞丰度在调查区近岸和远岸较高、中部较低。PEArSOn相关性分析表明,调查区浮游植物细胞丰度与磷酸盐和硅酸盐浓度呈显著正相关,与温度呈显著负相关,与硝酸盐相关性不明显。Totally 284 phytoplankton water samples were collected in a multidisciplinary investigation in East China Sea(24°00′—32°00′N,120°00′—128°00′E) from December 23th 2009 to January 5th 2010.Phytoplankton species composition and assemblage structure were studied by Utermhl method.A total of 171 taxa which belong to 67 genera of 4 phyla were identified.The phytoplankton community was mainly composed of Bacillariophyta and Dinophyta,and there were also a few species belonging to Cyanophyta and Chrysophyta.Most of the ecotypes of phytoplankton were temperate coastal species,and dominant species were Paralia sulcata,Thalassionema nitzschioides,Pseudo-nitzschia delicatissima,Thalassiosira angulata and Thalassiosira subtilis etc.Cell abundance ranged from 0.356×103 to 142.578×103cells/L with an average of 14.137×103cells/L,of which Bacillariophyta was the major group ranging from 0.356×103 to 142.578×103cells/L with an average of 13.023×103cells/L,followed by Dinophyta,ranging from 0.356×103 to 11.378×103cells/L with an average of 1.177×103cells/L.Horizontally,the surface distribution of cell abundance in survey area was mainly dominated by Bacillariophyta and the high value appeared in the sea northeast of Changjiang estuary.Dinophyta mostly concentrated in the southern and southeast part of the survey area where Kuroshio water flowed by.Vertically,the maximum of cell abundance was found in subsurface water,and along with the increase of the depth cell abundance firstly increased then decreased.According to the Pearson correlation analysis,the distribution of phytoplankton cell abundance was positively correlated with phosphate and silicata,negatively correlated with temperature,and nitrate′s effect on cell abundance wasn′t obvious.国家重点基础研究发展规划项目(2009CB421202

Role of surface plasmons in the optical interaction in metallic gratings with narrow slits

We report an experimental study of the transmission of light through narrow slits in metallic gratings (Ag layer thickness of 100-400 nm, grating period of 370 or 780 nm, and slit width of 30-100 nm). Peak transmission of similar to60% is observed for TM polarization at a wavelength redshifted from the point of surface plasmon (SP) resonance at the metal/substrate interface. At the transmission minima, the angular dependence of reflection shows a sharp peak with minimum loss of optical power. Two types of surface plasmon excitation are found responsible for the observed transmission dips: (1) the SP resonance along the planes that comprise either the metal/air or metal/substrate interfaces and (2) the SP resonance localized along the surface that encloses each metal island separated by slits. (C) 2003 American Institute of Physics

Principles and Control Analysis of Variable Frequency and Double-stage Centrifugal Chiller

变频双级离心式冷水机组采用变频技术，极大地提高机组部分负荷运行时的性能系数，采用双级压缩技术，机组循环效率得到提高.变频双级离心式冷水机组广泛应用于暖通空调系统当中，本文依次介绍变频双级离心式冷水机组结构、节流原理及其控制、回油方式、设备冷却方式、喘振机理及其控制.节流电子膨胀阀经验值控制方式以计算出来的开度值为控制目标来调节电子膨胀阀，无需传感器，机组成本降低，控制可靠性提高；变频双级离心式冷水机组实时计算出当前导叶开度下的防喘频率，防喘频率与当前的运行频率进行比较，作出对应的控制，从而避免喘振现象的发生