童心童眼

正本期话题春天来了编辑阿姨的话:小河解冻了吗?小柳条发芽了没有?小燕子飞回来了吗?小青蛙醒了没有?小草儿冒尖了吗?小花苞探出头来了没有?春天来了!春天来了!小伙伴们,快,我们一起去寻找春天的踪迹!春天在哪里早晨,灰蒙蒙的大雾像一个巨大的纱罩(zhào),把大地上的一切都遮住了。午饭过后,我和妈妈去公园玩。我发现路两旁     

西瓜的故事

正夜深了,乡村的田野一片寂静。看着村子里的灯光次第熄灭,刘爷爷在瓜地巡视了一圈后回家了。想着今年风调雨顺,丰收在望,他满意地点燃了一支烟。夜更深了,两个黑影摸进了瓜地。10分钟,20分钟……他们把一辆三轮车装满了。离开瓜地才走了几步,三轮车却罢工了——陷进了一个坑。     

高师钢琴分级教学改革初探

高等师范音乐专业钢琴教学以分级教学为改革出发点 ,四年来取得了一定的成绩。分级教学明确了教学目标、规范了教学内容、统一了教学手段、量化了教学程序、重视了教学过程 ,严格了考核制度、加强了学科建设、提高了教学质量     

轻松60秒

以为下课了某日上课时,班里一名女生有急事,向老师请假走了。旁边的男生见状,也跟着走了。大家都觉得奇怪。第二天到班里,那男生逢人便说:"昨天丢人丢大了,我上课时昏昏欲睡,忽然看见有同学拿包走了,以为下课了,也拿包走了……"     

铁钉、战马与王朝

在英国民间流传着这样一首歌谣：缺了一枚铁钉,掉了一只马掌;掉了一只马掌,失去一匹战马;失去一匹战马,损了一位骑兵;损了一位骑兵,丢了一次战斗;丢了一次战斗,输掉一场战役;输掉一场战役,毁了一个王朝。     

鼻子过河(外二则)

正妈妈出门了,小花狗想得直哭。妈妈回来了,到了对岸。小花狗的鼻子老远就闻到妈妈的味道,催着小花狗:"快,接妈妈去!"小花狗做什么都磨磨蹭蹭,习惯了。一忙乱了套:帽子戴歪了,扣子     

印度软件产业发展的思考

2004年11月，我们跟随山东省科技厅徐茂波副厅长带领的信息技术考察团赴印度进行了为期9天的访问。主要参加了在班加罗尔举行的国际信息技术博览会，期间拜会了班加罗尔所在的Karnataka邦政府信息和生物技术司司长，商谈了有关合作问题。会后参观了班加罗尔软件园，访问了印度几家最大的信息技术公司，并就人才培养、软件产品开发等方面进行了深入的探讨，并达成了初步的意向。     

我与台湾的第一次亲密接触

申请赴台历经了一番“磨难”,台湾之行收获颇多,在岛内感受了其交通的便利,留下了对其大学的印象,进行了难忘的研讨会,领略了其学者们的风采,与台湾亲密接触了一回。     

“梳子”整体钢模板在铁路隧道仰拱施工中的应用

新建铁路大同至西安客运专线马家庄隧道成功使用“梳子”整体钢模板实现了仰拱整幅施工,精确定位了仰拱纵向水平分布钢筋及环向中埋式橡胶止水带,精简了施工工序,加快了施工进度,降低了成本,收到了较高的经济效益。     

文南油田防喷抽油泵工艺技术研究与应用

防喷抽油泵的研究与应用在文南油田见到了良好的效果。减少了压井作业工序,降低了生产成本,提高了生产时效,保护了油气层和环境。在井下作业过程中起到了井控防喷安全作用,降低了井控安全风险,保护了油气资源。     

Foliar δ^13C and δ^15N values of C3 plants in the Ethiopia Rift Valley and their environmental controls

The foliar C and N stable isotopic compositions （δ^13C and δ^15N） and the relationships between these compositions and environmental factors of C3 plants in the Ethiopia Rift Valley were investigated. There were three distribution patterns for foliar δ^13C with mean values of -26.7‰±0.4‰, -29.7‰ ±0.6‰ , and -26.9‰± 1.2‰ in cold-moist, temperate-moist, and arid-hot environments, respectively. The δ^15N values ranged from -1.4‰ ±1.7‰ to 14.3‰ ± 0.1‰, with higher values under arid-hot conditions and the lowest values in plants growing at higher altitudes under cold-moist conditions. A strong negative relationship between mean annual precipitation and δ^15N explained more than half of the observed variation in the δ^15N values （r2= 0.54, P 〈 0.001）; a modest positive relationship was also found between δ^15N and temperature （r2 = 0.32, P 〈 0.01）. A weakly positive relationship existed between δ^13C and temperature, and changes in δ^13C values with precipitation and altitude followed quadratic curves. This suggests a shift in the effects of water and heat conditions caused by altitude on carbon isotopic discrimination.     

Characteristics of lateral heterogeneities with thermal and chemical origins in the pyrolitic lower mantle

The relative changes between shear and compressional velocities (R_SP = ∂ ln V_S/∂ ln V_P), bulk sound and shear velocities (R_CS = ∂ ln V_C/∂ ln V_S), and density versus shear wave velocity (R_ρS = ∂ ln ρ/∂ ln V_S) in response to thermal and chemical variations were investigated for the pyrolitic lower mantle. For heterogeneities with thermal origins, R_SP increases from 1.7 to 2.0 together with R_ρS decreasing from 0.4 to 0.2 and R_CS = ∼0.27 from the top to the bottom of the lower mantle. In comparison, chemical variations (bulk iron or silica contents) are characterized by R_SP < 1.5 and R_CS > 0.5 at lower mantle depths. Negative values of R_ρS and R_CS are indicative of chemical anomalies in the lower mantle, but a combination of thermal and chemical heterogeneities may be required to produce velocity and density anomalies at the magnitudes observed in seismic data. Further refinement of these characteristics requires data on the higher order pressure and temperature derivatives of the elastic moduli of the constituent phases.     

Effects of Yb^3＋ codoping on visible and near infrared emissions of Er^3＋-Yb^3＋ codoped Al2O3 powders by the sol-gel method

The 0.1 mol% Er^3＋ and 0-2 mol% Yb^3＋ codoped Al2O3 powders were prepared by the sol-gel method, and the phase structure, including only two crystalline types of doped Al2O3 phase, γ-（Al,Er, Yb）2O3 and θ-（Al,Er, Yb）2O3, was detected at the sintering temperature of 1000℃. The visible and near infrared emissions properties depended strongly on the Yb^3＋ codoping, and the corresponding maximal peak intensities centered at about 523, 545, 660 and 1533 nm were obtained respectively for the 0.1 mol% Er^3＋ and 0.5 mol% Yb^3＋ codoped Al2O3 powders, which were composed of θ-（Al,Er,Yb）2O3 and a small amount of γ-（Al,Er, Yb）2O3 phases. The two-photon absorption process was responsible for the visible up-conversion emissions, and the one-photon absorption process was involved in the near infrared emissions of the Er^3＋-yb^3＋ codoped Al2O3 powders.     

复合添加剂对金属陶瓷惰性阳极导电性的影响

为了改善金属相对陶瓷相的润湿,充分发挥金属相的作用,在合成含10%Ag的Ag/NiFe2O4金属陶瓷过程中引入添加剂TiO2和V2O5,采用粉末冶金法制备Ag/NiFe2O4金属陶瓷惰性阳极.原料NiO,Fe2O3,Ag和微量TiO2,V2O5经混料、成型后在1 250℃下烧结6 h.研究了添加剂TiO2,V2O5对Ag/NiFe2O4金属陶瓷微观形貌以及对试样电导率的影响.研究结果表明,复合添加TiO2,V2O5后金属银在陶瓷相中呈线状分布,EDX分析发现金属相中含有陶瓷相的组成,说明金属相与陶瓷相间的润湿性有所改善;同时试样的电导率有了显著提高.当添加0.5%TiO2,2.0%V2O5时试...     

(∈，∈∨ｑ)-模糊正规化子与(∈，∈∨ｑ)-模糊商子群

在(∈，∈∨ｑ)-模糊子群的基础上,引入了(∈，∈∨ｑ)-模糊正规化子与(∈，∈∨ｑ)-模糊中心化子的概念,并讨论了它们的一些性质．同时，给出了(∈，∈∨ｑ)-模糊商群与(∈，∈∨ｑ)-模糊商子群的定义，建立了(∈，∈∨ｑ)-模糊商群的同构定理．     

Effects of nitrogen sources and glucose on the consumption of ethylene and methane by temperate volcanic forest surface soils

There is limited knowledge with regard to the consumption of ethylene (C2H4) and methane (CH4) in volcanic forest soils containing low microbial carbon-to-organic carbon ratio, and to the responses of both consumptions to nitrogen and carbon additions. Temperate volcanic forest surface soils under three forest stands (e.g. Pinus sylvestris L., Cryptomeria japonica and Quercus serrata) were used to compare CH4 and C2H4 consumption by forest soils, and to study the effects of nitrogen sources and glucose on both consumptions. There was a good parallel between CH4 and C2H4 consumption by for- est soils, but mineralization reduced CH4 consumption rather than C2H4 consumption in forest soils, particularly in a Pinus forest soil. The stimulatory effect of glucose addition on both CH4 and C2H4 consumption by forest soils was increased by increasing the pre-incubation period after glucose addi- tion, and a largest stimulation occurred in the Pinus forest soil. The addition of KNO3-N at the rate of 100 μg·g1 significantly reduced the consumptions of both C2H4 and CH4 by forest soils (P≤0.05). In the presence of urea plus dicyandiamide, the consumption rates of C2H4 and CH4 by forest soils were higher than those in the KNO3-N and urea-N treated soils at the same N rate (P≤0.05), but were similar to those of the control. Hence, under experimental conditions, there was a strong inhibitory effect of NO3 rather than NH4 addition on the CH4 and C2H4 consumption in these forest soils. When amount of the added NO3-N increased up to more than 2―3 times the soil initial NO3-N concentrations, both C2H4 and CH4 consumption rates were reduced to 10%―20% of the rates in soils without nitrate addition. By comparing the three forest stands, it was shown that there was a smallest effective concentration of the added nitrate that could inhibit C2H4 and CH4 consumption in the Pinus forest soil, which indicated that C2H4 and CH4 consumption of the soil was more sensitive to NO3-N addition.     

Comparison of the carbon isotope composition of total organic carbon and long-chain <Emphasis Type="Italic">n</Emphasis>-alkanes from surface soils in eastern China and their significance

Surface soil samples collected over a high spatial resolution in eastern China were analyzed for carbon isotope composition （δ^13C） of total organic carbon （TOC） and higher plant-derived long-chain n-alkanes, with the latter reported as weighted mean values. The two sets of δ^13C values are significantly correlated and show similar trends in spatial variation. The spatial distribution of δ^13C shows less negative values in the mid-latitudes between 31°N and 40°N and more negative ones at higher and lower latitudes. This is consistent with previously reported carbon isotope data from surface soil phytoliths in the same region and suggests that the mid-latitude area provides relatively favorable growing condi- tions for C4 plants. Furthermore, δ^13C values of both TOC and long-chain n-alkanes from 12 surface soil samples collected from a small grassland in north China displayed similar carbon isotope values and the difference between paired δ^13C of a soil samples remains relatively constant. Our data demonstrate that in eastern China, soil δ^13C composition of both TOC and long-chain n-alkanes is effective indicators of C3/C4 ratios of the prevailing vegetation. This work suggests that -22‰ and -32‰ are good es- timated end members for the weighted mean δ^13C values of long-chain n-alkanes （C27, C29 and C31 n-alkanes） from soils under dominant C4 or C3 vegetation, allowing us to reconstruct paleovegetation trends.     

WO3-ZrO2/SBA-15的制备及其可见光催化分析

通过溶胶凝胶法,分别制备了不同负载量的WO_3/SBA-15和WO_3-ZrO_2/SBA-15介孔材料,利用XRD、BET和TEM等表征手段对其进行表征,并对其光降解染料罗丹明B的活性进行比对研究分析。结果表明:Wx/SBA-15(x=20,30,40,50)和W_(40)Zry/SBA-15(y=3,5,7,9)均能在可见光下光降解罗丹明B,光催化活性W_(40)/SBA-15W_(50)/SBA-15W_(30)/SBA-15W_(20)/SBA-15;引入ZrO_2后,光催化活性W_(40)Zr_5/SBA-15W_(40)Zr_9/SBA-15W_(40)Zr_7/SBA-15W_(40)Zr_3/SBA-15。其中,W_(40)/SBA-15和W_(40)Zr_5/SBA-15的光降解效率最高,分别为73.4%和86.6%,ZrO_2的引入提高了光降解效率;同时,WO_3/SBA-15和WO_3-ZrO_2/SBA-15也具有很好的循环价值,可多次使用。     

中国低纬高原平流层NOx分布及其与O3的关系

 利用1992年9月～2005年8月的HALOE资料,对我国低纬高原地区上空平流层中NO_x,O₃等大气痕量气体的混合比垂直变化进行了研究,并对本区域不同高度上NO_x混合比与全球同纬度进行了比较,同时对NO_x随时间的演变特征,NO_x的变化周期及NO_x与O₃的相关关系进行了分析.结果表明:①NO_x,O₃混合比先随高度增加,到极值时又逐渐减小;在极值高度上,各个季节NO_x,O₃的混合比值都是夏季最高,冬季最低;②在5 hPa以上,春季NO混合比与同纬度地区的纬圈平均相比其值更高,各个季节NO₂混合比的总体趋势都要比同纬度地区低;③在100,10 hPa和1 hPa上,NO_x混合比随时间变化的总体趋势是各不相同的;④NO_x具有准2 a周期变化;⑤在10 hPa附近,NO_x与O₃存在较明显的反相关关系.     

Effect of total aluminum concentration on the formation and transformation of nanosized Al13 and Al30 in hydrolytic polymeric aluminum aqueous solutions

Influence of total aluminum concentration （CAIT） on the generation and transformation of nanosized AI13 and AI30 in hydrolytic polyaluminum aqueous solutions was investigated using high field 27AI NMR and time-developed AI-Ferron complex colorimetry. When prepared at the optimal basicity （B） of Al13 generation and 80℃, the All3 species in polyaluminum solution tends to further polymerize and convert to AI30 and higher polymers when CAI; 〉0.2 mol· L^-1, but Al13 does not convert to AI30 quantificationally, as the formation of Alu from Al13 and AI30 is accelerated in the same way. The conversion rate of All3 is accelerated by the increase in CAIT. When CAlT 〉0.75 mol·.L^-1, Al13 content decreases rapidly, and AI30 content increases continuously and becomes the dominant nanometer polynuclear aluminum species. AIm is one of prerequisites of Al13 conversion to AI30. When CAI; increases and B reduces, the polymerization rate between Al13 and Aim increases, and at the same time, the dissociation reaction rate of All3 and AI30 by H^＋ also increases. The latter becomes the dominant reaction in polyaluminum solution with low B value, so AI30 decreases with the increasing CAlT. The hydrolytic polyaluminum solution with Al13 content beyond 80% can only be prepared under the condition of CAlT〈0.5 mol· L^-1 and optimal B value.