Experiments about Simple Liquid Flows in Microtubes

The behavior of micro-scale flow is significant for the performance of Micro-Electro-Mechanical- Systems (MEMS) devices. Some experiments about liquid flow through microtubes with diameters about 3similar to20mum are presented here. The liquids used in our experiments include some simple liquids with small molecules, such as non-ion water and several kinds of organic liquids (CCL4, C6H5C2H5 and Isopropanol etc.). The flow rate and the normalized friction cocfficients were measured in micro-flow experimental apparatus. The results show that when the driven pressure varies from 0 to 1Mpa, the flow behaviors in 20mum microtube for both polar and non-polar liquids are in agreement with Hagen-Poiseuille law of the classical theory. It means that N-S equation based on continuous medium still acts well in this case. For higher pressure drop from 1 to 30Mpa, in the microtubes with diameter of 3similar to10mum, the normalized friction coefficients of organic liquids can't keep constant with pressure increases. However the non-ion water reveals different trends.

Arantxa Urretabizkaiaren narrazio lanetako amatasunak: genero arteko harreman berrien paradigma

[EUS] Artikulu honen bidez, Arantxa Urretabizkaiak amatasuna bere narratiban nola jorratu duen agerian jarri nahi da. Horrela, Zergatik panpox (1979), Koaderno gorria (1998) eta Hiru Mariak (2010) eleberrietako, eta Aspaldian espero zaitudalako ez nago sekula bakarrik (1983) ipuin bildumako amak aztertu dira artikulu honetan. Lehenik, amatasunaren inguruan esparru teorikoa eraiki da. Hortaz, egun teoria feministak amatasunaren inguruan zedarriturikoa eta esanikoa aurkeztu da. Ondoren, kritika feminista metodologia gisa harturik, aipaturiko narrazioetako literatur protagonistak aztertu dira. Ondorio nagusi gisa esan daiteke aztertutako amatasunaren irudikapenak ez direla hegemonikoak, alternatiboak edota emergenteak baizik. Ama bakarrak, helduak, lan munduan nahiz politikan dihardutenak aurkitu ditugu literatur testu hauetan, hitz batean, harreman berriak sorrarazi dituzten literatur pertsonaiak. Harreman berri horiek, hain justu ere, genero arteko harreman berrien paradigma lirateke.

大长细比圆柱体顺流向与横向耦合涡激振动的研究

针对大长细比圆柱体的涡激振动问题,建立了柱体顺流向与横向耦合的涡激振动模型,在尾流振子模型的基础上,引入了柱体振动的加速度耦合项,同时考虑到柱体振动瞬时速度的变化,引入了非线性流体力模型.采用有限差分法求解柱体的振动方程,计算结果与实验结果的对比显示,该文模型能较好地模拟大长细比圆柱体涡激振动的重要特性,包括振动频率、振动模态、驻波与行波的特征等.柱体在顺流向的变形曲率与横向的变形曲率在同一量级,说明两个方向的振动对于结构疲劳破坏的贡献同等重要.

Length weight relationship, condition factors and fecundity of Chrysichthys nigrodigitatus and Chrysichthys walkeri in Asejire Lake

Sex ratio and fecundity variations of Chrysichthys nigrodigitatus and Chrysichthys walkeri from Asejire Lake (Nigeria) were examined. The Logarithm transformation of weight (W) against standard length (SL) gave a straight-line graph represented by the following equations: 1) C. nigrodigitatus LogW =-0.66 + 2.13 Log SL; = 0.854; (P < 0.001) n = 209; 2) C. walkeri LogW = -1.23 + 2.63 Log SL; = 0.759; (P < 0.001) n = 237. Males were generally more than females in both species. The ratio of males:females was higher in C. nigrodigitatus (1:0.18) than in C. walkeri (1:0.8). C. walkeri attained sexual maturity at a smaller size of 20.0 g (12.0 cm Standard Length) compared with C. nigrodigitatus maturity size of 45.0 g (14.0 cm Standard Length). Relative fecundity was not dependent on body weight and standard length for C. walkeri but it was significant at P < 0.05 and P < 0.01 respectively for C. nigrodigitatus

Mass measurements of some proton-rich nuclei

The Q values and 0^o cross sections of (He³, n) reactions forming seven proton-rich nuclei have been measured with accuracies varying from 6 to 18 keV. The Q values (in keV) are: Si²⁶ (85), S³⁰ (-573), Ar³⁴ (-759), Ti⁴² (-2865), Cr⁴⁸ (5550), Ni⁵⁶ (4513) and Zn⁶⁰ (818). At least one excited state was found for all but Ti⁴². The first four nuclei complete isotopic spin triplets; the results obtained agree well with charge-symmetry predictions. The last three, all multiples of the α particle, are important in the α and e-process theories of nucleo-synthesis in stars. The energy available for β decay of these three was found by magnetic spectrometer measurements of the (He³, p) Q values of reactions leading to V⁴⁸, Co⁵⁶, and Cu⁶⁰. Many excited states were seen: V⁴⁸ (3), Co⁵⁶ (15), Cu⁶⁰ (23). The first two states of S³⁰ are probably 0⁺ and 2⁺ from (He³, n) angular distribution measurements. Two NaI γ-ray measurements are described: the decay of Ar³⁴ (measured ^Ƭ1/2 = 1.2 ± 0.3s) and the prompt γ-ray spectrum from Fe⁵⁴(He³, nγ)Ni⁵⁶. Possible collective structure in Ni⁵⁶ and Ca⁴⁰, both doubly magic, is discussed.

The (He³, n) neutron energy and yield measurements utilized neutron-induced nuclear reactions in a silicon semiconductor detector. Cross sections for the most important detection processes, Si²⁸ (n, α) Mg²⁵ and Si²⁸ (n, p) Al²⁸, are presented for reactions leading to the first four states of both residual nuclei for neutron energies from 7.3 to 16.4 MeV. Resolution and pulse-height anomalies associated with recoil Mg²⁵ and Al²⁸ ions are discussed. The 0^o cross section for Be⁹ (α, n) C¹², used to provide calibration neutrons, has been measured with a stilbene spectrometer for n_o (5.0 ≤ E_α ≤ 12 MeV), n₁ (4.3 ≤ E_α ≤ 12.0 MeV) and n₂ (6.0 ≤ E_α ≤ 10.1 MeV). Resonances seen in the n_o yield may correspond to nine new levels in C¹³.

Efeito do fator cavitário na resistência adesiva à dentina de um sistema restaurador à base de silorano

O objetivo deste estudo foi avaliar o efeito do fator C na resistência adesiva à dentina humana de um compósito à base de silorano, comparando-o com um compósito à base de metacrilato. Foram utilizados 40 molares humanos hígidos. Em metade da amostra foi realizado um preparo do tipo Classe I, com dimensões de 4x4 mm e 2 mm de profundidade, enquanto na outra metade foi realizado um preparo virtual (flat) com auxílio de uma matriz de teflon branco, com as mesmas dimensões da cavidade (4x4x2 mm), apoiada na superfície de dentina exposta. Cada grupo foi divido em dois, de acordo com o sistema restaurador: Sistema Adesivo P90 e resina Filtek P90; Adper Scotchbond Multiuso e resina Filtek Z350 XT (3M ESPE). Após a aplicação do sistema adesivo segundo as especificações do fabricante, as cavidades (real e virtual) foram preenchidas com as resinas (Z350 XT e P90) em dois incrementos. Foi realizada a fotoativação de cada incremento durante 25s. Após uma semana, as coroas foram seccionadas, obtendo-se espécimes constituídos de resina/dente na forma de um paralelepípedo (palitos). Estes palitos foram utilizados para o teste de microtração (Emic), onde a resistência adesiva na unidade MPa foi calculada. Os resultados foram avaliados estatisticamente pelo teste de análise de variância ANOVA One-Way (p = 0,05), e pelo teste de múltiplas comparações Student Newman Keuls. Foi observada uma diferença estatística entre a resina P90 (flat= 16,137,7 MPa e Cavidade= 16,759,0 MPa) e a Z350 XT (flat= 25,8211,6 MPa e Cavidade=24,4713,5 MPa), independentemente do tipo de cavidade restaurada. E não foi possível observar diferença estatística entre os tipos de cavidades (real ou virtual) restauradas com a mesma resina. Através dos testes realizados, foi possível concluir que: o fator C não afetou a resistência adesiva dos dois sistemas restauradores utilizados, e o tipo de sistema restaurador afeta a resistência adesiva, sendo que o sistema à base de silorano apresenta resultados inferiores ao de metacrilato.

Phase-locking of two large-core fibre lasers with 60W of coherent output power

A phase-locking fibre laser array with up to 60 W of coherent output power based on two large-core fibre is reported. The slope efficiency of the in-phase mode is 37%. For two cases of spacings between the cores, steady high-contrast interference stripes are observed. When the whole system operates under a high pump power level, no thermal effects for the spatial filter have been observed, which means that we can increase the coherent output power further by increasing the individual fibre laser power.

355 nm脉冲激光诱导等离子体开关削波

利用激光诱导等离子体开关技术,对355 nm脉冲激光自削波进行了实验和理论研究。分别采用5种不同焦距的透镜,集中讨论了透镜焦距及激光器输出单脉冲能量对脉宽压缩的影响,发现采用焦距为200 mm的透镜能够获得最佳的脉冲压缩效果。在聚焦透镜焦距200 mm,单脉冲能量160 mJ时,获得最短脉宽3.47 ns；在激光电离Cu小孔内壁表面及空气击穿共同作用下,获得了脉宽最短达2.11 ns的脉冲激光输出。此外,根据实验结果得到了355 nm激光空气击穿阈值,并与理论估算值进行比较,两者结果较为一致。

Radially polarized and pulsed output from passively Q-switched Nd:YAG ceramic microchip laser

For the first time, to the best of our knowledge, a radially polarized laser pulse was produced from a passively Q-switched Nd:YAG ceramic microchip laser with a piece of Cr4+:YAG crystal as the saturable absorber and multilayer concentric subwavelength grating as the polarization-selective output coupler. The averaged laser power reached 450 mW with a slope efficiency of 30.2%. The laser pulse had a maximum peak power of 759 W, a minimum pulse duration of 86 ns, and a 6.7 kHz repetition rate at 3.7 W absorbed pump power. The polarization degree of the radially polarized pulse was measured to be as high as 97.4%. Such a radially polarized laser pulse with a high peak power and a short width is important to numerous applications such as metal cutting. (C) 2008 Optical Society of America

用纳米粉制备Nd：Y1.84La0.16O3透明陶瓷Nd：Y1

用碳酸盐共沉淀法制备一种新的掺钕氧化镧钇（Nd：Y1.84La0.16O3）纳米粉体,得到颗粒细小、均匀、分散性好、粒径为50～60nm的Nd：Y1.84La0.16O3纳米粉体.分别采用Nd：Y1.84La0.16O3纳米粉料和商业粉料,用传统陶瓷无压烧结工艺制备Nd：Y1.84La0.16O3透明陶瓷.Nd：Y1.8vLa0.16O3纳米粉制备的陶瓷样品的组分均匀、几乎不存在第二相,具有较高的透过率.商业粉制备的陶瓷样品因混料不均匀而在晶界处存在部分第二相,降低了陶瓷的透过率.此外,还运用体视学法预测

广东省海岛资源综合调查

这次调查获取了大量具有历史价值的资料．其中包括广东海岛及其海域的自然条件、自然资源和社会经济条件的基本资料。海岛综合调查共登岛142个，占广东省759个面积大于500m2的海岛的18.7％，共布设调查断面316条，站点3919个，采样品7933个，采标本49000号．共获得资料数据104万多个；资料汇编288册；编制图幅1159幅，编写并出版海区调查报告7册，调查研究论文集3册、专业调查报告12册和100万字的《广东海岛资源综合调查报告》。广东海岛资源综合调查填补了广东海岛环境、资源综合调查的空白，不仅概括和揭示了海岛自然环境和自然资源的基本情况，而且揭示了海岛经济开发的规律，为发展当地经济作出了突出贡献。

Growth and maturity of salmon sharks (Lamna ditropis) in the eastern and western North Pacific, and comments on back-calculation methods

Age and growth estimates for salmon sharks (Lamna ditropis) in the eastern North Pacific were derived from 182 vertebral centra collected from sharks ranging in length from 62.2 to 213.4 cm pre-caudal length (PCL) and compared to previously published age and growth data for salmon sharks in the western North Pacific. Eastern North Pacific female and male salmon sharks were aged up to 20 and 17 years, respectively. Relative marginal increment (RMI) analysis showed that postnatal rings form annually between January and March. Von Bertalanffy growth parameters derived from vertebral length-at-age data are L∞ =207.4 cm PCL, k=0.17/yr, and t0=−2.3 years for females (n=166), and L∞ =182.8 cm PCL, k=0.23/yr , and t0=−1.9 years for males (n=16). Age at maturity was estimated to range from six to nine years for females (median pre-caudal length of 164.7 cm PCL) and from three to five years old for males (median precaudal length of 124.0 cm PCL). Weight-length relationships for females and males in the eastern North Pacific are W=8.2 × 10_05 × L2.759 –06 × L3.383 (r2 =0.99) and W=3.2 × 10 (r2 =0.99), respectively. Our results show that female and male salmon sharks in the eastern North Pacific possess a faster growth rate, reach sexual maturity earlier, and attain greater weight-at-length than their same-sex counterparts living in the western North Pacific.