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1.
以牛磺酸缩5-溴水杨醛席夫碱(TBSSB)、5-溴水杨醛(BSA)、2,2''-联吡啶(bipy)为混合配体,合成了三核铜配合物[Cu3(TBSSB)2(BSA)2(bipy)2]·H2O (1),并对该化合物进行了元素分析、红外光谱、X-射线单晶衍射、光致发光光谱、固体漫反射光谱及分子轨道分析等表征。晶体结构分析表明,该化合物结晶属三斜晶系,Pī空间群,晶胞参数为a=10.031(2)Å,b=11.480(2)Å,c=12.913(3)Å,α=73.13(3)°,β=78.58(3)°,γ=75.24(3)°,V=1363.6(5)Å3,Z=1,Mr=1533.30,Dc=1.867 g/cm3,F(000)=759,μ=4.236 mm-1,S=0.921,R1=0.0488,wR2=0.0471(I > 2σ(I)),R1=0.1812,wR2=0.0546。Cu (2)离子与来自于两个TBSSB配体的两个氮原子和两个氧原子配位,形成正方形配位构型。Cu (1)离子与来自于一个2,2''-bipy的两个氮原子,TBSSB配体的一个氧原子,以及BSA的两个氧原子配位,形成四方锥形配位构型。该化合物分子通过O-H…Br分子内氢键和C-H…O分子间氢键相互连接形成三维超分子结构。研究发现该化合物能够发出蓝色荧光,它的带隙为2.19 eV。  相似文献   

2.
为探究广西喀斯特地貌对放射性核素分布及当地环境放射性的影响,利用高纯锗探测器对广西喀斯特地区的大曹天坑和邓家坨天坑采集来的苔藓样品中7Be、40K、238U、232Th、226Ra、210Pb和137Cs的放射性比活度进行测量与分析。结果表明:在苔藓植物中, 7Be的放射性比活度为202.3-698.8 Bq/kg [平均值:(430.7±169.7) Bq/kg,n=7];40K为33.7-159.9 Bq/kg [平均值:(91.6±44.1) Bq/kg, n=7];238U为检测限(3.0 Bq/kg)至54.4 Bq/kg [平均值:(16.9±23.6) Bq/kg,n=7];232Th为1.2-42.5 Bq/kg [平均值:(14.7±15.9) Bq/kg, n=7];226Ra为0.7-48.4 Bq/kg [平均值:(16.9±20.3) Bq/kg,n=7];210Pb为284.1-950.5 Bq/kg [平均值:(555.5±231.0) Bq/kg, n=7]; 137Cs为检测限(0.1 Bq/kg)至2.3 Bq/kg [平均值:(1.1±0.9) Bq/kg,n=7]。对比后发现所有测得的数据均在正常范围内,表明天坑这一喀斯特地貌对放射性核素的分布并没有显著影响,该地区也不存在其他污染来源,同时为我国南方喀斯特地区大气示踪提供数据支撑。  相似文献   

3.
目的 建立蛇伤胶囊中5种蒽醌类成分含量测定分析方法,提升蛇伤胶囊质量标准。方法 采用Diamonsil C18色谱柱(250 mm×4.6 mm,5 μm),流动相为甲醇(A)-0.1%磷酸水溶液(B),梯度洗脱(0~7 min,75% A;7~30 min,75% A→90% A;30~40 min,90% A),流速为1.0 mL·min-1,检测波长为254 nm,进样量10 μL。结果 5个待测组的线性范围:4.04~40.40μg/mL(r=0.9994)、4.16~41.60μg/mL(r=0.9991)、4.14~41.40 μg/mL(r=0.9959)、4.10~41.00 μg/mL(r=0.9993)和2.16~21.60μg/mL(r=0.9997)。平均回收率(n=6)分别为100.02%、100.02%、100.03%、99.99%和100.06%,RSD分别为0.40%、0.15%、0.30%、0.11%和0.47%。结论 所建立的方法操作简便准确且具有良好的重复性,可用于测定蛇伤胶囊中芦荟大黄素、大黄素、大黄酸、大黄酚和大黄素甲醚的含量。  相似文献   

4.
研究了一类m=5,n=10次Liénard系统在原点邻域的极限环数目问题,先通过计算机符号计算出原点的奇点量,再通过行列式方法证明了系统原点充分小邻域能产生9个极限环.给出了Ĥ(5,10)的一个新下界,即Ĥ(5,10)≥9.  相似文献   

5.
考虑未扰Liénard系统=y,=-gx),其中deg gx)=7,当该系统分别含有2,3,4和5个奇点时,给出了其所有的不同拓扑类型的相图,并给出了Melnikov函数在含有2个幂零尖点和1个双曲鞍点的双异宿环附近的展开式和得到极限环的条件.  相似文献   

6.
本研究探讨经桡动脉入路(Transradial Approach,TRA)右侧大脑中动脉支架成形术的可行性、安全性和手术技巧。实验按照随机数表法将符合大脑中动脉支架成形术纳入标准的急性脑梗死患者分为观察组和对照组。观察组给予经TRA右侧大脑中动脉支架成形术,对照组给予经股动脉入路(Transfemoral Approach,TFA)右侧大脑中动脉支架成形术,对比分析2组患者导引导管到位情况、支架置入成功率、路径差异相关并发症、手术操作时间、射线投射时间、术后住院时间和手术费用。结果显示,观察组导引导管到位成功率为93.10%(27/29),对照组导引导管到位成功率100%,2组患者支架置入成功率均较高,路径差异相关并发症较低,手术操作时间、射线投射时间和手术费用相似,差异无统计学意义。基于主动脉弓型的亚组分析,观察组Ⅲ型主动脉弓患者手术操作时间(min)、射线投射时间(min)均短于对照组(73.8±15.3 vs 89.5±14.4;22.1±5.5 vs 28.4±8.3),差异有统计学意义(t=0.192,P=0.000;t=0.117,P=0.000)。与对照组相比,观察组患者术后住院天数明显减少(2.8±0.6 vs 4.2±0.8),差异有统计学意义(t=0.230,P=0.002)。因此,经TRA右侧大脑中动脉支架成形术成功率高,对于Ⅲ型主动脉弓患者采用该项方案能减少手术时间和射线投射时间,且术后住院天数少,可行性好。  相似文献   

7.
在水温(28.59±1.74)℃下,选用冰鲜杂鱼饲养平均体质量为858.73 g的鞍带石斑鱼,经过60 d的生长实验,研究了不同投喂频率(1次/d、1次/2 d、1次/3 d)对流水养殖鞍带石斑鱼生长、摄食及免疫酶活力的影响.结果表明,投喂频率对鞍带石斑鱼存活率的影响差异不具有统计学意义(p>0.05),实验期间各个实验组存活率在99.40%~99.80%之间;各实验组间的肥满度(CF=2.22~2.35)、体质量变异系数(SV=20.08~24.27)、饲料系数(FCR=2.70~3.01)和日增质量(7.50~12.51 g/d)均无显著影响(p>0.05),而投喂频率1次/d组和1次/2 d组的特定生长率(SGR)和相对增质量(RWG)均显著高于1次/3 d组(p<0.05),投喂频率1次/d组的日摄食率和1次/2 d组的饲料转化效率均显著高于1次/3 d组(p<0.05);在免疫酶活力方面,投喂频率对鞍带石斑鱼血浆中的碱性磷酸酶(AKP=0.083 5~0.089金氏单位/mL)、过氧化氢酶(CAT=7.96~8.19 U/mL)及超氧化物歧化酶(SOD=32.40~34.45 U/mL)均无显著影响(p>0.05).在本实验条件下,流水模式养殖鞍带石斑鱼的适宜投喂频率为1次/d或1次/2 d.  相似文献   

8.
昆虫与植物之间色彩通讯是彼此信息交流的渠道之一,基于害虫趋色性研发的诱虫板作为一种绿色防控手段,已广泛应用于农林害虫的防控和预测预报。为了明确黄色诱虫板在茶园害虫多样性调查和防治中的效果,我们于2018年7月~8月对井冈山大井茶园里的黄色诱虫板的诱捕情况进行了调查研究。研究结果表明:黄板对茶园双翅目、膜翅目、半翅目、鞘翅目和鳞翅目昆虫诱捕效果最佳,直翅目害虫诱捕效果较差,且不同类群间数量差异极其显著。阳面诱捕的昆虫总数量多于阴面(V=1450.5,P=0.0032),不同类群诱捕效果的分析表明:双翅目(Wilcoxon符号秩检验,V=1525,P=0.017)、半翅目(Wilcoxon符号秩检验,V=1233.5,P=0.044)、鳞翅目(Wilcoxon符号秩检验,V=244,P<0.001)、膜翅目(Wilcoxon符号秩检验,V=818.5,p<0.001)双面诱捕数量存在显著差异,且阳面均多于阴面。相关性分析表明半翅目—鳞翅目(r=0.75,P<0.001)、半翅目—膜翅目(r=0.55,P<0.001)、半翅目—鞘翅目(r=0.58,P<0.001)、鳞翅目—膜翅目(r=0.53,P<0.001)、鳞翅目—鞘翅目(r=0.71,P<0.001)、膜翅目—鞘翅目(r=0.63,P<0.001)间诱捕数量上存在正相关。  相似文献   

9.
杨海船  张赟赟  张颖  巫凯  李嘉 《广西科学》2021,28(4):423-427
为建立大叶钩藤Uncaria macrophylla Wall.中柯诺辛碱B (Corynoxine B)及柯诺辛碱 (Corynoxine)的含量测定方法,采用高效液相色谱法测定在不同采收月份大叶钩藤及不同药用部位中柯诺辛碱B及柯诺辛碱的含量。测定条件:Inertsil ODS-3 C18色谱柱(4.6 mm×250 mm,5 μm),流动相为甲醇-0.02%三乙胺(68∶32),流速1 mL/min,检测波长246 nm,柱温25℃。实验结果表明:柯诺辛碱B进样量为0.130-1.950 μg,柯诺辛碱进样量为0.296-4.440 μg,与峰面积呈良好的线性关系,相关系数r均为1.000 0 (n=5);柯诺辛碱B和柯诺辛碱的平均回收率(n=6)分别为99.47%和100.06%,RSD分别为1.56%和0.98%。本法简便易行,重现性好,可为钩藤药材的质量控制提供科学依据。  相似文献   

10.
利用低温下的水化学生长法合成了镍钴氧化物(NiCo2O4)纳米针,因其自组装而表现出立方晶相,再用二氧化钛/炭黑(TiO2/CB)对NiCo2O4表面进行了改性,合成了TiO2/CB-NiCo2O4复合纳米材料.用X射线光电子能谱仪(XPS)、扫描电子显微镜(SEM)、能量色散X射线光谱仪(EDX)图谱对材料的形貌进行了表征,运用循环伏安法(CV)、时间-电流(i-t)曲线法考察了TiO2/CB-NiCo2O4修饰玻碳电极的电化学行为.实验发现:TiO2/CB-NiCo2O4修饰电极对葡萄糖的氧化有良好的电催化性能,其线性范围为0.001~1.780 mmol·L-1,检测限为0.53 μmol·L-1(信噪比S/N=3).将该法用于实际样品中葡萄糖的测定,结果令人满意.  相似文献   

11.
为了减轻传统接触式睡眠生理监测系统对人体造成的负担,设计了一种基于微波技术的非接触式睡眠生理信号采集与分析系统,提出一种基于体动射频信号的睡眠分期识别算法.通过小波变换对射频运动传感器(RFMS)采集的体动信号进行预处理,再计算出体动信号的能量值,最后通过判别式处理和阈值法实现了睡眠分期:醒觉期、浅睡期、中睡期、深睡期.实验采集分析了8个实验者为期46天的睡眠生理信号,同时同步采集视频信息、TANITA水床睡眠信息、接触式呼吸脉搏信号.与视频结果比较发现醒觉期正确率达到90%;与TANITA水床睡眠结果相比,本系统的结果与其吻合程度达到70%;与不同睡眠状态下呼吸率、心率的变化相比,本系统的结果吻合度达到80%.  相似文献   

12.
为了研究整夜睡眠状况和睡眠过程, 利用多导睡眠仪(polysomnography, PSG)和体动记录仪, 分别记录被试的ECG信号和体动信号, 再对 ECG信号提取心率变异性(heart rate variability, HRV)的特征值, 并将其作为实验数据的特征参数。为了提高识别率和防止过度拟合, 将实验数据分为训练集和测试集, 设计一个用遗传算法改进的BP神经网络模型, 对样本进行训练和预测。研究结果表明, 改进的BP神经网络能有效地识别测试样本, 综合识别准确率为86.29%。将检测ECG信号和体动信号的穿戴式设备与睡眠分期识别算法相结合, 能够用于家庭睡眠监测, 也可作为睡眠疾病的初筛方法。  相似文献   

13.
Leucogranites play a significant role in understanding crustal thickening, melting within continental collisional belts, and plateau uplift. Field investigations show that Miocene igneous rocks from the Hoh Xil Lake area mainly consist of two-mica leucogranites and rhyolites. We studied the Bukadaban two-mica leucogranites and the Kekao Lake, Malanshan and Hudongliang rhyolites by zircon U-Pb, muscovite and sanidine 40Ar/39Ar geochronology, and whole-rock geochemical and Sr-Nd isotopic analysis. Results yielded crystallization and cooling ages for the Bukadaban leucogranites of 9.7±0.2 and 6.88±0.19 Ma, respectively. Extrusive ages of the Kekao Lake and Malanshan rhyolites are 14.5±0.8 and 9.37±0.30 Ma, respectively. All rocks are enriched in SiO2 (70.99%-73.59%), Al2O3 (14.39%-15.25%) and K2O (3.78%-5.50%) but depleted in Fe2O3 (0.58%-1.56%), MgO (0.11%- 0.44%) and CaO (0.59%-1.19%). The rocks are strongly peraluminous (A/CNK=1.11?1.21) S-type granites characterized by negative Eu anomalies (δ Eu=0.18-0.39). In also considering their Sr-Nd isotopic compositions (87Sr/86Sri=0.7124 to 0.7143; δ Nd (9 Ma) =-5.5 to -7.1), we propose that these igneous rocks were generated through dehydration melting of muscovite in the thickened middle or lower crust of northern Tibet. Melting was probably triggered by localized E-W stretching decompression in the horse tails of Kunlun sinistral strike-slip faults. Reactivation of the Kunlun strike-slip faults, accompanied by emplacement of leucogranite and eruption of rhyolite in the Hoh Xil Lake area, indicates that large-scale crustal shortening and thickening in northern Tibet mainly occurred before 15 Ma. In addition, these findings suggest that the northern Tibetan Plateau attained its present elevation (~5000 m) at least 15 Ma ago.  相似文献   

14.
The effects of ammonium (NH4+-N ) and nitrate ( NO3--N ) were examined on Fe fractions and FeCN (ferricyanide) reductase activity in intact root tips (0—3 cm) of young maize (Zea mays L. cv. Lenz) in solution culture by using short-term experiment under controlled Fe deficiency conditions (containing high HCO3- concentration in preculture solution). The results showed that Fe(Ⅱ) concentrations in root tip apoplast of maize were only 20—40 nmol/g FW which accounted for 7%—13% of total Fe. Most of Fe in root tips existed as Fe(Ⅲ) compounds. Imposition of the roots to NH4+-N or NO3--N for 60 min led to an increase of Fe(Ⅱ) in root tip apoplast. NH4+-N led to an increased concentration of Fe(Ⅱ) and exchangeable Fe (Fe(Ⅱ) and Fe (Ⅲ)) in root tips, while NO3--N increased FeCN reductase activity. The relationship between pH and Fe fractions, FeCN reductase activity was also discussed.  相似文献   

15.
Traditional methods for nonlinear dy-namic analysis,such as correlation dimension,Lyapunov exponent,approximate entropy,detrended fluctuation analysis,using a single parameter,cannot fully describe the extremely sophisticated behavior of electroencephalogram (EEG). The multifractal for-malism reveals more “hidden” information of EEG by using singularity spectrum to characterize its nonlin-ear dynamics. In this paper,the zero-crossing time intervals of sleep EEG were studied using multifractal analysis. A new multifractal measure Δasα was pro-posed to describe the asymmetry of singularity spec-trum,and compared with the singularity strength range Δα that was normally used as a degree indi-cator of multifractality. One-way analysis of variance and multiple comparison tests showed that the new measure we proposed gave better discrimination of sleep stages,especially in the discrimination be-tween sleep and awake,and between sleep stages 3 and 4.  相似文献   

16.
Dating techniques including gypsum dissolution in water, iron hydroxide co-precipitation with uranium and thorium and mass spectrometric determination have been investigated in this note. The ages of the gypsum samples in a CK core from Luobubo lacustrine sediments are in the range of (12.85±0.21) kaBP (4 m distance from the top core) to (153.2±7.2) kaBP (49 m distance from the top core) with the relative errors of ±1.6%–±4.7%. It indicates that the sedimental environment of the CK core was situated in the middle-late Pleistocene and Holocene periods, corresponding to 1–6 stages of oxygen isotopes in the abyssal sediments and included much information from last interglacial to Holocene warm periods.  相似文献   

17.
Formic (HCOOH) and acetic (CH3COOH) acids are the chief carboxylic compounds in the troposphere[1]. Although weak acids, they contribute significantly to the free acidity, ionic balance of precipitation and the chemical reactions in the atmosphere, especially in the remote areas[2—4]. General sources for formate and acetate have been identified in the past 3 decades although a satisfactory source attribution is lacking to explain atmospheric observations[5]. Possible sources include veget…  相似文献   

18.
By means of Py-GC,13c NMR and fluorescent analysis, the properties of hydrocarbon generation of rnacerals are determined, and the evolution model of hydrocarbon generation is established for macerals and coal of the Tuha Basin. There are two stages of oil generation for the coal of the Tuha Basin, whose values are 0.40 %–0.80 % and 0.90 %–1.20 % respectively.  相似文献   

19.
The complete sequence of an Allexivirus isolated from garlic plants in Yuhang City, Zhejiang Province, China had been determined. The single-strand, positive RNA genome was 8451 nucleotides in length excluding poly(A) tail. The genome organization of this virus was similar to that of the other Allexiviruses but only with 62.8%–64.8% nucleotide acid identities. The amino acid sequences of proteins encoded by ORF1-6 shared 67.6%–78.5%, 55.4%–66.2%, 56.7%–66.4%,40.3%–55.6%,66.3%–79.7%and 52.2%–68.8% identities with those of the others respectively. The homology range between it and the other Allexiviruses was similar to that between the other distinct species in this genus. A more comprehensive comparison using all available CP amino acid sequences showed that it shared only 63.9%–79.8% amino acids identical with the others. Therefore, it had been considered as a new member of the genus, named as garlic virus E (GarV-E). Phylogenetic analysis confirmed GarV-E as a distinct member and the correct names and classification of some members of genus Allexivirus were also discussed.  相似文献   

20.
Evidence has accumulated that there is a trade-off between benefits and costs associated with rapid growth. A trade-off between growth rates and critical swimming speed (Uc,t) had been also reported to be common in teleost fish. We hypothesize that growth acceleration in the F3 generation of "all-fish" growth hormone gene (GH) transgenic common carp (Cyprinus carpio L.) would reduce the swimming abilities. Growth and swimming performance between transgenic fish and non-transgenic controls were compared. The results showed that transgenic fish had a mean body weight 1.4--1.9-fold heavier, and a mean specific growth rate (SGR) value 6%-10% higher than the controls. Transgenic fish, however, had a mean absolute Ucr, (cm/s) value 22% or mean relative Ucrit (BL/s) value 24% lower than the controls. It suggested that fast-growing "all-fish" GH-transgenic carp were inferior swimmers. It is also supported that there was a trade-off between growth rates and swimming performance, i.e. faster-growing individuals had lower critical swimming speed.  相似文献   

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