6 resultados para multinomial maximum, minimum, range

em Chinese Academy of Sciences Institutional Repositories Grid Portal


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We studied social organization, behavior, and range use of the Yunnan snub-nosed monkey (Rhinopithecus bieti) at Wuyapiya (99 degrees 12'E, 28 degrees 30'N, the People's Republic of China) over 12 months between May 1992 and June 1994. The Wuyapiya band contained greater than or equal to 175 members and had two levels of social organization. At one level, the monkeys formed multifemale, one-male units (OMUs) similar to those of many other colobines. At another level, 15 to 18 OMUs traveled together in a cohesive band. Unlike the bands of other species of Rhinopithecus, the Wuyapiya band of R. bieti did not show seasonal fission-fusion, although some social behavior, such as male-male aggression, was seasonal. With regard to range use, the Wuyapiya band had a large home range and long daily travel distances compared with other colobines. Minimum range size in 1 year at Wuyapiya is 16.25 km(2), although there is no asymptote for range size as a function of observation time. Range size for the Wuyapiya band is 25.25 km(2) over the 2-year study and appeared to cover 100 km(2) between 1985 and 1994. The primary food of R. bieti at Wuyapiya is lichens, which are ubiquitous in fir frees. The multitiered social organization of R. bieti appears to result from the interaction of food resource characters with the forces of mate competition, with band sizes based on female responses to the spatial and temporal characteristics of lichens and subdivisions within bands based on male competition for mates.

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This letter presents the effective design of a tunable 80 Gbit/s wavelength converter with a simple configuration consisting of a single semiconductor optical amplifier (SOA) and an optical bandpass filter (OBPF). Based on both cross-gain and cross-phase modulation in SOA, the polarity-preserved, ultrafast wavelength conversion is achieved by appropriately filtering the blue-chirped spectral component of a probe light. Moreover, the experiments are carried out to investigate into the wavelength tunability and the maximum tuning range of the designed wavelength converter. Our results show that a wide wavelength conversion range of nearly 35 nm is achieved with 21-nm downconversion and 14-nm upconversion, which is substantially limited by the operation wavelength ranges of a tunable OBPF and a tunable continuous-wave laser in our experiment. We also exploited the dynamics characteristics of the wavelength converter with variable input powers and different injection current of SOA. (C) 2008 Wiley Periodicals, Inc.

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收集长白山地区15个气象站1953-2007年气温、降水、蒸发、日照时数和水汽压观测数据和国家气候中心整理的2001-2099年的 气温、降水预估资料,利用数理统计方法,系统分析长白山地区气候现状、变化及其预估,为气候变化对人类生存环境影响研究并制定适应对策提供依据。主要结论如下: 1.长白山地区气温、降水日数、日照时数和不同界限温度(≥0℃、≥5℃、≥10℃和<0℃)积温均有显著趋势。年极端最低、年平均、平均最高/最低气温和气温日/年较差在1984、1992、1995、1985、1972和1979年发生突变。所有最高/最低气温与日照百分率有显著负相关关系,一定程度是温室效应结果;最高、最低气温变化不同步造成气温日较差和年较差的非对称性。 2.长白山地区生长季节合计降水量和降水强度日际变化较大。降水以7月30日为界,呈现前升后降极显著的线性趋势,且发生均值突变。降水强度以6月27日和9月3日为分界点,分为三个阶段。降水集中度、集中期和集中时段时空非均一性分布明显。 3.在SRES A1B、SRES A2和SRES B1三种情景下年平均气温均为上升趋势,年内变化一致为冬季升温最迅速,夏季则相对缓慢;而年降水强度总体增加,年内变化比较一致:冬季增加最为明显,而夏季变化不大。 4.未来长白山地区各站≥0℃、≥5℃和≥10℃的积温均有不同程度增加,持续时间延长。负积温增加,持续时间缩短,开始日期推迟,而结束时间提前。

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A thermo-optic variable optical attenuator (VOA) based on a Mach-Zehnder interferometer and multimode-interference coupler is fabricated. Not a single-mode but a multimode waveguide is used as the input and output structures of the optical field, which greatly reduces the coupling loss of the VOA with a normal single-mode fiber. The insertion loss of the fabricated VOA is 2.52 to 2.82 dB at the wavelength of 1520 to 1570 nm. The polarization dependent loss is 0.28 to 0.45 dB at the same wavelength range. Its maximum attenuation range is up to 26.3 dB when its power consumption is 369 mW. The response frequency of the fabricated VOA is about 10 kHz. (C) 2004 Society of Photo-Optical Instrumentation Engineers.