二（四甲基环成二烯基）四羰基二铁的合成及反应

四甲基环戊二烯与五羰基铁在二甲苯中加热回流６ｈ，即生成标题化合物１，１与碘在氯仿中反应生成Ｆｅ－Ｆｅ键断裂的铁碘化物（Ｃ５ＨＭｅ４）Ｆｅ（ＣＯ）２Ｉ２，１与氯化汞反应生成Ｆｅ－Ｆｅ键断裂的铁氯汞化物（Ｃ５ＨＭｅ４）Ｆｅ（ＣＯ）２ＨｇＣｌ３和铁氯化物（Ｃ４ＨＭｅ４）Ｆｅ（ＣＯ）２Ｃｌ４．１与氯化亚锡反应仅分离到铁氯化物４．以元素分析，ＩＲ和１ＨＮＭＲ谱表征了化合物１～４的结构．     

二（四甲基环戊二烯基）四羰基二铁的合成及反应

四甲基环戊二烯与五羰湛铁在二甲苯中加热回流６ｈ，即生成标题化合物１，１与碘在氯仿中反应生成Ｆｅ－Ｆｅ键断裂在铁碘化物（Ｃ５ＨＭｅ４）Ｆｅ（ＣＯ）２Ｉ，２，１与氯化汞反应生成Ｆｅ－Ｆｅ键断裂的铁氯汞化物（Ｃ５ＨＭｅ４）Ｆｅ（ＣＯ）２ＨｇＣｌ３和铁氯化物（Ｃ５ＨＭｅ４）Ｆｅ（ＣＯ）２Ｃｌ４．１与氯化亚锡反应仅分离到铁氯化物４．以元素分析，ＩＲ和ＨＮＭＲ谱表征化合物１～４的结构。     

1，1′─［四甲基二硅撑］双（环戊二烯基三羰基钨配合物）的合成及反应

１，２－二环戊二烯基四甲基二硅烷与丁基锂作用生成［四甲基二硅撑］双（环戊二烯基负离子盐），后者随即与六羰基钨反应形成１，１－［四甲基二硅撑］双［环戊二烯基三羰基钨负离子盐］，（Ｍｅ２ＳｉＳｉＭｅ２）·［Ｃｐ′（ＣＯ）３Ｗ－］２·２Ｌｉ＋（Ｉ）．（Ｉ）分别与六种卤化物反应，生成在钨原子上引入取代基的产物：（Ｍｅ２ＳｉＳｉＭｅ２）．［Ｃｐ′Ｗ（ＣＯ）３Ｒ］２，（Ｒ：Ｍｅ，Ｃ２Ｈ５，２；ＰｈＣＨ２，３；ＣＨ２ＣＯＯＣ２Ｈ５，４；ＣＨ３ＣＯ，５；Ｐ３ｈＳｎ，６）．（Ｉ）用醋酸处理后，随即分别与ＣＣｌ４，ＮＢＳ及Ｉ２作用，生成相应的钨卤化物，（Ｍｅ２ＳｉＳｉＭｅ２）［Ｃｐ′Ｗ（ＣＯ）３Ｘ］２，（Ｘ：Ｃ１，８；Ｂｒ，９；Ｉ，１０），（Ｉ）与Ｆｅ３＋／Ｈ３Ｏ＋作用发生氧化偶联，生成双核Ｗ－Ｗ键产物（Ｍｅ２ＳｉＳｉＭｅ２）［Ｃｐ′Ｗ（ＣＯ）３］２，１１．（Ｃｐ′＝Ｃ５Ｈ４）     

邻菲咯啉钌（Ⅱ）化学发光分析测定环丙沙星

试验表明,在０．０１ｍｏｌ·Ｌ＾－１ ＮａＡｃ－ＨＡｃ（ｐＨ５．０）底液中,环丙沙星能增强Ｃｅ（Ⅳ）氧化Ｒｕ（ｐｈｅｎ）２／３＋检测限为４．４×１０＾－８ｇ·ｍＬ＾－１,其相对标准偏差分别为２．８％和３．３％,该法用于片剂中环丙沙星含量的测定,获得满意结果。     

草酸根桥联的Zn3^ⅡFe^Ⅲ异四核配合物的合成及其性质

合成和表征了两种新的草酸根桥联的异四核配合物〔Ｚｎ３Ｆｅ（Ｃ２Ｏ４）３（ｂｐｙ）６〕（ＮＯ３）３（１）和〔Ｚｎ３Ｆｅ（Ｃ２Ｏ４）３（Ｍｅ２ｂｐｙ）６〕（ＮＯ３）３（２）,其中ｂｐｙ表示２,２’－联吡啶,Ｍｅ２ｂｐｙ表示４,４’－二四基－２,２’－联吡啶,经元素分析、摩尔电导率和红外光谱等测定结果推定,配合物具有草酸根桥联结构。实验结果表明,异四核配合物的杀菌活性优于桥联配体的杀菌活性。     

用碘量法测定Fe^3＋／Fe^2＋体系中的游离酸

提出了一种滴定强酸性含Ｆｅ＾３＋及Ｆｅ＾２＋体系中游离酸（其游离酸浓度〉１ｍｏｌ／Ｌ）的新方法。实验证明,将Ｋ２Ｃ２Ｏ４作为掩蔽剂时,利用过量的ＫＩＯ３与过量的Ｎａ２Ｓ２Ｏ３在酸性溶液中的氧化还原反应可以测定体系中的游离酸,当体系中存在的Ｆｅ＾２＋时,可利用ＫＭｎＯ４（在强酸性下）或Ｈ２Ｏ２（在弱酸性下）的预氧化来消除Ｆｅ＾２＋的干扰。在加入过量的Ｋ２Ｃ２Ｏ４（Ｃ２Ｏ＾２－４与Ｆｅ＾３＋的摩尔比值     

FeO4^2—离子在水溶液中稳定性的研究

报导氢氧化铁对ＦｅＯ４＾２－水解反应的催化作用及温度、浓度、碱度等对ＦｅＯ４＾２－稳定性的影响ＦｅＯ４＾２－的稳定性随体系中Ｆｅ（ＯＨ）３的增多和ＦｅＯ４＾２＿浓度增大而变小;当ＯＨ浓度低于１．０ｍｏｌ／Ｌ时,ＦｅＯ＾４＾２－的稳定性不受碱度影响;在室温下,ＦｅＯ４＾２－的稀溶液是稳定的。用这些重要规律指导高铁钾的合成,取得满意的结果。     

新安江水库太湖新银鱼Neosalanx taihuensis Chen生长特性的初步研究

对生活在新安江水库的太湖新银鱼进行了生长测算，并测定了各体长组的肥满度，结果如下：（１）体长和体重的相关关系Ｗ＝３．４３２×ｌ０￣（－６）Ｌ￣（３．０５６）（ｒ＝０．９９８），（２）体长和体重的生长方程分别为Ｌ＿ｔ＝８０［１－ｅ￣（－０．１２４（ｔ＋０．１９８）］￣3和Ｗ＿ｔ＝２．２５［１－ｅ￣（－０．１２４（ｔ＋０．１９８）］￣３；（３）拐点年龄为８．８１月龄；（４）体长增长以１～２月龄最大，体重增长以８～１０月龄最快；（５）体长５５～６０ｍｍ的鱼肥满度最大。     

Fe－Re合金高温润滑行为和配副关系

在多种配副下测定了Ｆｅ－Ｒｅ合金和Ｆｅ（ＲｅＯ４）３的摩擦因数随温度变化的关系．结果表明：Ｆｅ－Ｒｅ合金及Ｆｅ（ＲｅＯ４）３的润滑行为和配副有关；在相近的试验条件下，它们的摩擦因数随温度变化有相似的趋势。Ｆｅ－Ｒｅ合金在１００℃以下及４５０～６００℃间有２个较低的摩擦因数区，分别与自生的铁铼氧化物及高温下因摩擦而生成的Ｆｅ（ＲｅＯ４）３，的润滑作用有关。     

复矩阵的几种Penrose逆的通式

给出了复矩阵Ａ的四种Ｐｅｎｒｏｓｅ逆Ａ＾（１，２），Ａ＾（１，２，３），Ａ＾（１，２，３４），Ａ＾（１，３，４）的通式。     

我国春季降水的分布特征及其与环流异常的关系

利用EOF、小波分析和相关分析讨论了我国春季降水的分布特征及降水异常的环流背景,结果表明:春季降水(3～5月)主要集中在北纬30°以南的中东部地区,而北方则降水稀少,西部降水有增加的趋势,中东部降水有减少的趋势,但不是很明显.EOF1表明长江以南和长江以北的降水呈反向分布,长江以南大范围降水变化的特征时间尺度分别为2,7a和15a,且15a时间尺度变化有明显向较大时间尺度演变的趋势,EOF2表明长江中下游与华南降水呈反向分布,长江中下游大范围降水变化的特征时间尺度分别为2,9a和更大时间尺度,且9a时间尺度变化具有明显的向较小时间尺度演变的趋势.当退居在中太平洋的副高偏强,西伸,副高北侧气压梯度力加大时,有利于长江以南地区降水,当副高偏北,西伸到长江中下游上空,乌拉尔山阻高偏强时,则有利于长江中下游地区降水.     

若干稀土钒酸盐中Eu^3＋和Dy^3＋的发光性质

本文报道在酸盐ＬｎＶＮｂ２Ｏ９,Ｂａ２ＬｎＶ３Ｏ１１和ＹＰｘＶ１－ｘＯ４中Ｅｕ＾３＋和Ｄｙ＾３＋的发生性质。实验结果表明,Ｅｕ＾３＋的红橙比和Ｄｙ＾３＋的黄蓝比与钒酸盐中稀土离子的格位对称性,被取代离子Ｌｎ＾３＋的电荷半径比及邻近元素的电负怀有关。     

内压圆筒应力场对损伤萌生的影响

压力容器各部位因受力不同而具有不同的损伤萌生倾向。文中依据连续介质损伤力学的观点，提出以 Ｙ０＝ Ｕ· Ｒｃ 及ｇｒａｄ Ｙ０ 作为评价结构损伤萌生倾向的参数，其中 Ｕ是等效弹性比能， Ｒｃ 是与应力三轴度有关的函数。着重指出：不连续应力和热应力显著地提高内压圆筒的损伤萌生倾向。     

Sap flow response of Eucaylyptus （Eucalyptus urophyila） to environmental stress in South China

Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake) plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2 = 0.76, P = 0.01 at Hetou and R2 = 0.7021, P = 0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y = -17585X3 + 15147X2 - 1250.7X + 2278.4 (R2 = 0.68; P = 0.01) at Hetou and Y = -101.67X3 - 1.65X2 - 376.4X + 1914.8 (R2 = 0.40, P = 0.05) at Jijia, where Y was daily SFD, X was daily wind speed. Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa, within which daily SFD varied from 540+/-70 L/(m2.d) to 4739+/-115 L/(m2.d) at Hetou site, from 397+/-26 L/(m2.d) to 3414+/-191 L/(m2.d) at Jijia site; (2) Diurnal SFDs at Hetou site were much higher under low relative humidity (< 30%) and slightly lower under high relative humidity (> 80%) compared with those at the Jijia site; (3) The upper and lower threshold of daily and diurnal RAD for the optimal water use of E. urophylla plantations were 18+/-2.7 and 2+/-1 MJ/(m2.d), 669 and 0 J/(cm2.h) during the observation period.     

Characteristics of stemflow for sand-fixed shrubs in Mu Us sandy land, Northwest China

Little work has been done on stemflow for desert shrubs in China. This study measured stemflow in two shrubs of Salix psammophila C. Wang et Chang Y. Yang and Artemisia sphaerocephala Krasch in Mu Us sandy land and established a relationship between stemflow and canopy characteristics, rainfall amount and intensity. During the experimental period, the amount of stemflow for S. psammophila and A. sphaerocephala accounted for 7.6% and 2.7% of the gross rainfall respectively. Statistical analysis showed that there was a significant positive linear correlation between rainfall and stemflow for the two shrubs; while the relationship between stemflow percentage and rainfall suggested that there existed a rainfall depth threshold of 3-5 mm for S. psammophila and 5-7 mm for A. sphaerocephala. Stemflow percentage positively increased with rainfall depth increasing before the rainfall depth threshold values had been reached but showed stability after the threshold. A stepwise regression analysis suggested that the shrubs with more branches, larger crown volume and smaller branch angle inclination tended to collect more volumes of stemflow. Moreover, stemflow amount and percentage increased with the maximum rain intensity increasing in 10 minutes （l10） and the stemflow percentage tended to increase quickly with l10 when it was less than 3.0 mm h^-1 for S. psammophila and 2.0 mm h^-1 for A. sphaerocephala, and then showed stable trend with increasing of 110.     

Superconductivity at 43 K in an iron-based layered compound LaO(1-x)F(x)FeAs

The iron- and nickel-based layered compounds LaOFeP (refs 1, 2) and LaONiP (ref. 3) have recently been reported to exhibit low-temperature superconducting phases with transition temperatures T(c) of 3 and 5 K, respectively. Furthermore, a large increase in the midpoint T(c) of up to approximately 26 K has been realized in the isocrystalline compound LaOFeAs on doping of fluoride ions at the O2- sites (LaO(1-x)F(x)FeAs). Experimental observations and theoretical studies suggest that these transitions are related to a magnetic instability, as is the case for most superconductors based on transition metals. In the copper-based high-temperature superconductors, as well as in LaOFeAs, an increase in T(c) is often observed as a result of carrier doping in the two-dimensional electronic structure through ion substitution in the surrounding insulating layers, suggesting that the application of external pressure should further increase T(c) by enhancing charge transfer between the insulating and conducting layers. The effects of pressure on these iron oxypnictide superconductors may be more prominent than those in the copper-based systems, because the As ion has a greater electronic polarizability, owing to the covalency of the Fe-As chemical bond, and, thus, is more compressible than the divalent O2- ion. Here we report that increasing the pressure causes a steep increase in the onset T(c) of F-doped LaOFeAs, to a maximum of approximately 43 K at approximately 4 GPa. With the exception of the copper-based high-T(c) superconductors, this is the highest T(c) reported to date. The present result, together with the great freedom available in selecting the constituents of isocrystalline materials with the general formula LnOTMPn (Ln, Y or rare-earth metal; TM, transition metal; Pn, group-V, 'pnicogen', element), indicates that the layered iron oxypnictides are promising as a new material platform for further exploration of high-temperature superconductivity.     

黄土高原极端降水变化及其对植被覆盖度影响

全球变暖背景下,黄土高原极端降水事件频发,对社会经济及植被生态产生了重要影响,研究黄土高原极端降水变化特征及其对植被覆盖度(fractional vegetation cover, FVC)影响,可为生态环境保护和区域可持续发展提供科学支撑。基于2000—2020年黄土高原64个气象站点逐日降水数据和MODIS NDVI数据,采用趋势分析、相关分析等方法,分析了黄土高原地区极端降水和FVC时空变化特征及极端降水对FVC的影响。结果表明：2000—2020年黄土高原地区总降水量P_RCPTOT、中雨日数R_10mm、大雨日数R_20mm、强降水日数R_25mm和降水强度S_DII均呈显著上升趋势(P<0.05),区域西部和北部强降水总体增加,但区域南部呈干旱化。2000—2020年黄土高原FVC总体呈显著上升趋势(P<0.05),集中分布在区域中东部,占区域总面积的32.00%;显著下降趋势主要分布在南部少部分地区,仅占区域总面积的4.91%。2000—2020年黄土高原地区F...     

用计算机对人类TSPYl基因P53结合位点的鉴定

根据p53下游基因在其调节区域（启动子或内含子）含有与P53蛋白特异性结合的一致性序列5’-RRRCWWGYYYN（0-13）RRRCWWGYYY-3’，R—G或A，W—T或A，Y—C或T，N—A，C，T，G。用计算机对人类基因组中P53结合位点进行了研究，发现Y染色体上的TSPY1基因内含子中含有这样的一致性序列5’-GGGCTAGTTTtgGAGCTAGCCT-3’，意味着TSPY1基因有可能是一个p53下游基因。     

1951—2014年淮河流域降水量时空变化特征

以1951—2014年淮河流域29个站点月降水量数据为研究对象,运用线性趋势、累积距平、小波分析及空间分析等方法,分析了降水量时间和空间变化特征.结果表明:(1)1951—2014年,年、春、夏和秋季降水量呈不显著减少趋势,冬季降水量则具有不显著增加趋势.(2)春、秋和冬季易发生旱涝灾害,夏季降水量变化控制年降水量变化.(3)年降水量具有准2a和6a振荡周期.(4)东南部年和四季降水量多于西北部,这与我国年和四季降水量分布模式一致.(5)空间上,年和四季降水量变率中,年和夏季最大,降水量减少区域呈半环状包围降水量增加区域;整个流域冬季降水量几乎没有变化.