NaF薄膜的结构与应力分析

采用脉冲激光沉积（PLD）法在Si（100）衬底上生长了NaF薄膜．分别用原子力显微镜（AFM）、X射线衍射（XRD）、X射线光电子能谱（XPS）对薄膜的微观结构、表面形貌以及薄膜应力进行了表征与分析．AFM测试结果表明，低激光能量密度下制备的薄膜表面均匀、致密，均方根粗糙度（Rms）仅为0．538nm；XRD分析结果表明，用脉冲激光沉积方法制备的氟化钠薄膜在（222）晶面有明显的择优取向．应力分析薄膜的残余应力为压应力，应力大小随激光能量密度的增加而增加；XPS分析结果表明，热蒸发制备的NaF薄膜氧含量明显高于PLD方法制备的NaF薄膜的氧含量．热蒸发方法制备的薄膜中的氧含主要来源于水中的氧，PLD方法制备的薄膜中的氧主要来源于游离态氧，说明PLD方法制备的薄膜不容易潮解．     

透射型电可调光衰减器的设计

可调光衰减器(VOA)是光通信中重要的光无源器件。设计了一种透射型电可调光衰减器,该衰减器以Perpend icular VOA d ie作为核心部件,并设计了配套电路。经过实测,衰减器参数指标达到使用要求。     

X射线磁性圆二色吸收谱:实验设备与初步实验

合肥国家同步揭射实验室已建立了初步的X射线磁性圆二色吸收谱（XMCD）技术，可以测量铁磁性3d过渡族元素Fe，Co和Ni的L边的XMCD，并获得它们的轨道和自旋磁矩．XMCD线站的主要技术参数为：能量范围100～1000eV，光子通量≈10^8 ph／s，能量分辨率≈1000；外磁场1500Gs.除了测量XMCD外，还可以测量C，N，O的K边近边吸收谱，以及部分元素的L边近边吸收谱．     

L-抗坏血酸-6-对羟基苯甲酸酯的合成及抗氧化活性研究

采用直接酯化法,合成了L-抗坏血酸-6-对羟基苯甲酸酯(APHB),并从清除羟自由基、超氧阴离子自由基、DPPH自由基能力及还原能力测试4个方面研究了它的体外抗氧化活性。结果表明,L-抗坏血酸-6-对羟基苯甲酸酯对上述3种自由基均有较好的清除效果,还原能力也较强,其抗氧化性能总体上与VC相当,优于市面上常用的抗氧化剂TBHQ,是一种有潜力的VC衍生物。     

Experimental study on multi-point autoignition characteristics and influence factors of diesel spray in a controllable active thermo-atmosphere

Auto-ignition characteristics of high-pressure diesel spray in the controllable active thermo-atmos-phere (CATA) were studied with a high-speed camera video system. Multi-point autoignition phe-nomenon of diesel spray in the CATA was observed and the influence factors of the autoignition were analyzed. The stabilization mechanisms of the spray flame in different coflow temperatures were also discussed. The stabilization of the flames was controlled by different factors: autoignition phenomenon in low coflow temperature and flame spread in high coflow temperature. The test results also show that the autoignition delay depends strongly on the coflow temperature and has nonlinear relationship with the temperature. Autoignition delay decreases by almost 10 ms from 16.9 to 7.1 ms when the coflow temperature increases from 996 to 1048 K and only 4 ms from 1048 to 1101 K. The injection parameters in terms of nozzle diameter, injection pressure and pump speed, have some effects on autoignition delay while these effects depend on the coflow temperature. The significant effect lies in low coflow temperature. The injection parameters influence the autoignition delay because it can shorten the physical delay by improving the spray quality and enlarging the spray angle or penetration rate to im-prove mixture quality.     

Holocene climatic and environmental changes recorded in Baahar Nuur Lake core in the Ordos Plateau, Inner Mongolia of China

A 5.3 m lake core was drilled in Baahar Nuur Lake in the Ordos Plateau, and measurements of meangrain size, organic δ 13C (δ 13Corg), organic carbon content (TOC), C/N, carbonate content, carbonate δ 13C(δ 13Ccar) and δ 18O (δ 18Ocar) were conducted for retrieving the Holocene chronosequence of climaticchanges based on 15 AMS 14C dates. The record documented four major stages of climate change inthe Ordos Plateau: (IV) a cold and dry condition before ～7.65 14C ka BP; (III) a warm and humid stagebetween ～7.65 and ～5.40 ka BP; (II) a generally drier and cooler climate since ～5.40 ka BP with twohumid events occurring from ～4.70 to ～4.60 ka BP and from ～4.20 to ～3.70 ka BP, and (I) a dry climatecharacterized by complete desiccation of the lake after 3.70 ka BP. Stage III can be further divided intothree sub-stages: (IIIa) a warm and humid episode from ～7.65 to ～6.70 ka BP, (IIIb) a warm and relativelydry episode from ～6.70 to ～6.20 ka BP, and (IIIc) the magthermal and maghumid episode of the Holo-cene from ～6.20 to ～5.40 ka BP.     

Pollen-recorded climate changes between 13.0 and 7.0 ^14C ka BP in southern Ningxia, China

A pollen record from Haiyuan section in the southern part of Ningxia revealed a detailed history of vegetation variation and associated climate changes during the period from~13.0 to~7.0 14 C ka BP.A steppe landscape under a moderately dry(and probably cool)condition(~12.7-~12.1 14 C ka BP)was replaced by a coniferous forest dominating the landscape under a generally wet climate from~12.1 to ~11.01 4C ka BP.This generally wet period,corresponding to the European B?lling/All?rod period,can be divided into three stages:a cool and wet stage between~12.1 and~11.4 14 C ka BP,a mild and rela- tively dry stage between~11.4 and~11.2 14 C ka BP,and a mild and wet stage between~11.2 and~11.0 14 C ka BP.The coniferous forest-dominated landscape was then deteriorated into steppe landscape (~11.0-~10.6 14 C ka BP)and further into a desert steppe landscape from~10.6 to~9.8 14 C ka BP,being correspondent to the European Younger Dryas period.After a brief episode of a cool and wet climate (~9.8-~9.6 14 C ka BP),a relatively mild and dry condition prevailed during the early Holocene(~9.6- ~7.6 14 C ka BP)and then a warm and humid climate started the mid-Holocene(~7.6-~7.2 14 C ka BP).     

东焦河水电站环境影响评价分析

介绍了东焦河水电站的概况及其环境现状,分析了东焦河水电站工程对环境的影响,提出了环境保护和管理的措施,从环境保护的角度论证了东焦河水电站工程建设的可行性。     

西藏自治区管巢蛛属2新种记述(蜘蛛目:管巢蛛科)

记述采自中国西藏自治区的管巢蛛科管巢蛛属2新种：墨脱管巢蛛 Clubiona medog sp.nov.和拟中亚管巢蛛 Clubiona subparallela sp.nov..     

微乳条件下催化氨肟化合成环己酮肟

钛硅分子筛催化环己酮氨肟化反应制备环己酮肟，是一种环境友好的绿色化学工艺．针对该反应在浆态条件下进行时存在的固液分离和溶剂回收等问题，尝试采用微乳化的方法加以解决．分别以十二烷基硫酸钠／水／氨水／环己酮和二-（2-乙基己基）磺基琥珀酸钠／水／氨水／环己酮的水包油型微乳液作为反应介质，实现了钛硅分子筛催化环己酮的氨肟化反应．通过实验考察了温度对选择性和转化率的影响及对钛硅分子筛催化活性和稳定性的影响．结果表明，微乳条件下的环己酮氨肟化反应可以得到较好的效果，并且在反应效果方面以二-（2-乙基己基）磺基琥珀酸钠制备的微乳液占优．