浅议立体几何开放题

浅议立体几何开放题叶芳琴，陈樟仙（浙江临安於潜中学３１１３１１）１判定是否存在例１对任意长方体人是否存在一个与Ａ等高的长方体Ｂ，使得Ｂ与Ａ的侧面积之比与体积之比都等于常数．分析设长方体Ａ的底面长、宽、高分别为ａ，ｂ，ｈ；假设满足题意的长方体存在且底面...     

探索高能质子-铍作用中领头重子Λ和Δ++的产生

分析E941实验数据库中19.6GeV质子轰击固定铍核所得到的产生粒子的实验数据, 通过质子与π介子对的搭配, 利用一种新的循环迭代的混合事件方法, 从复杂背景中, 提炼出领头共振态粒子Λ和Δ⁺⁺的信号.     

A New Method for Filter Design Based on Long-Period Fibre Grating

We present a simple method to induce mechanically a long-period fibre grating in a general sing mode fibre.The transmission spectrum of the new type of grating can be tailored by changing the external applied pressure or by introducing a phase-shift in the grating.The tunability this kind of gratings exhibit will be particularly useful for the filter design.     

Rhodamine 6G-doped polymer optical fiber amplifiers

Rhodamine 6G-doped step-index polymer optical fiber is fabricated. The characteristics of the amplification of rhodamine 6G-doped step-index polymer optical fiber amplifier have been studied. The high-gain optical amplification with a tunable wavelength range from 585 to 613 nm is obtained in a step-index polymer optical fiber doped with rhodamine 6G at 10-ppm level, which can be used for broadband amplifiers and tunable lasers.     

Entanglement Manipulation for a Two-Mode Squeezed Vacuum State

By numerically analysing the entropy of entanglement of the output state from a Mach-Zehnder interferometer for the two-mode squeezed vacuum state input, it is found that if the internal phase shift of the interferometer is adjusted to the value of 0 or 7r, the entangling characteristic of the input state is efficiently preserved at the output. If the internal phase shift is tuned to the value of Tr/2, the two-mode squeezed vacuum state is completely disentangled at the output of the setup. If the internal phase shift deviates from the above values, the input state is degraded into a partially entangled output state. Based on these results, a method for optically realizing the entanglement preservation, entanglement degradation, and disentanglement via the interferometer is obtained.     

台湾大型真菌长期生态之研究

作者在台湾中部关刀溪长期生态研究站从事大型担子菌多样性与分布之调查研究,并且将研究站之地理环境、植物族群和生态特性予以描述记录.为了研究上的需要,我们在生态研究站中设置了八个实验样区专供大型真菌生态调查研究用.实验样区经过全面调查之后发现优势植物族群为野牡丹科、樟科、里百科、山龙眼科、桃金娘科和胡桃科等.实验样区中主要的大型真菌有小菇属、小皮伞属、趋木菌属、栓菌属、红菇属、革盖菌属、乳菇属、鹅膏属和韧革菌属等.大多数大型真菌的子实体在七月间出现,只有少量子实体在三月间发现.小菇属和小皮伞属是最常见的大型真菌,不论在夏季和冬季都可发现它们的子实体.在夏季出现子实体的真菌有红菇、革盖菌、乳菇、鹅膏、蜜环菌、拟层孔菌、灵芝、小孔菌和赤褶菇等;然而,在冬季出现子实体的真菌则是趋木菌、栓菌、韧革菌和笋毡菌等.实验样区中大型真菌的分布显示富有变化,子实体出现频率与真菌之多样性和伴生植物植群具有相关性.真菌子实体出现多的样区主要的伴生植物有柏拉木、香桂、倒卵叶山龙眼、小叶赤楠、台湾黄杞、菝契、杉木、肾蕨和倒叶瘤足蕨.然而,真菌子实体出现少的样区常见的伴生植物为红花八角和中华里.依据研究结果推论森林生态系中植物族群是影响真菌族群的建立与分布的主要因子之一.     

Electron behaviour in CH4／H2 gas mixture in electron-assisted chemical vapour deposition

The behaviour of electrons in CH_{4}/H_{2} gas mixture in electron-assisted chemical vapour deposition of diamond is investigated using Monte Carlo simulation. The electron drift velocity in gas mixture is obtained over a wide range of E/P (the ratio of the electric field to gas pressure) from 1500 to 300000 (V/m kPa^{-1}). The electron energy distribution and average energy under different gas pressure (0.1－20kPa) and CH_{4} concentration (0.5%－10.0%) are calculated. Their effects on the diamond growth are also discussed. It is believed that these results will be helpful to the selection of optimum experimental conditions for high quality diamond film deposition.     

Determination of Ascorbic Acid Using a New Oscillating chemical System of Lactic Acid—Acetone—BrO3^— —Mn^2 —H2SO4

ＩｎｔｒｏｄｕｃｔｉｏｎＯｓｃｉｌｌａｔｉｎｇｒｅａｃｔｉｏｎｓａｒｅｃｏｍｐｌｅｘｄｙｎａｍｉｃｓｙｓｔｅｍｓｔｈａｔｉｎｖｏｌｖｅｐｅｒｉｏｄｉｃｃｈａｎｇｅｓｉｎｔｈｅｃｏｎｃｅｎｔｒａｔｉｏｎｏｆｓｏｍｅｉｎｇｒｅｄｉｅｎｔｓ (ｗｈｅｔｈｅｒａｒｅａｃｔａｎｔ,ａｐｒｏｄｕｃｔｏｒａｎｉｎｔｅｒｍｅ ｄｉａｔｅ)ｗｉｔｈｔｉｍｅ .Ｔｈｅｓｉｍｉｌａｒｉｔｉｅｓｂｅｔｗｅｅｎｌｉｆｅｐｒｏｃｅｓｓｅｓｔｈａｔｅｘｈｉｂｉｔｏｓｃｉｌｌａｔｉｎｇｂｅｈａｖｉｏｒａｎｄｏｓｃｉｌｌａｔｉｎｇｃｈ…     

用于全息存储的新型感绿光敏剂的制备及其性能研究

针对目前广泛使用的532nm半导体激光器,本文制备了一种新型感绿光敏剂PRZA。以文献报道的2种感绿光敏剂(BDEA和BTCP)作为参比,研究了3种光敏剂的分子结构对其紫外-可见吸收光谱、在自由基聚合体系中的光敏引发聚合效率、在双固化型全息记录样片中的灵敏度与成像性能的影响。研究结果表明,噻吩环取代苯环使光敏剂的吸收光谱明显红移,与BDEA和BTCP相比,PRZA与532nm光源的匹配性能最好,在532nm处摩尔消光系数达到6.35×10~4 L·mol~(-1)·cm~(-1);对同一个预聚物体系,当光敏剂质量分数为0.01%时,3种光敏剂均表现出最佳的敏化引发聚合效率,其中含BTCP和PRZA体系的聚合速率与双键转化率都明显优于含BDEA的体系;以PRZA为光敏剂的全息记录样片衍射效率高达85%,且具有最高的灵敏度(297×10~(-3) cm·mJ~(-1)),同时具有良好的图像存储和再现性能。以上结果表明,PRZA样片在全息记录领域具有很好的应用前景。     

罗丹明6G螺环酰肼荧光快速检测谷氨酸和天门冬氨酸

以罗丹明6G螺环酰肼为荧光探针,在水溶液中可选择性检测谷氨酸和天门冬氨酸。在500nm波长激发下,1min内两种样品溶液即发出550nm绿光,检测限分别可达7×10~(-8)mol/L和1.4×10~(-7)mol/L。此外本文还分析了罗丹明6G螺环酰肼能够选择性和高灵敏度快速荧光检测谷氨酸和天门冬氨酸的机理。