亚硝基血色原的提取与分离方法

【目的】筛选获取纯度较高的蒸煮腌肉主导色素亚硝基血色原（nitrosohemochromogen, NH）的方法。【方法】采用7种不同极性溶剂对NH进行提取,分析提取液的UV吸收特性和电子顺磁共振光谱（EPR）特性以及残渣的色调。【结果】石油醚完全不溶解NH;丙酮对NH 的提取率很高,而且提取液相对稳定;乙酸乙酯提取率不高,但可以保持NH的粉红色。而直接用丙酮提取的NH,EPR光谱检测不到NH的特征信号,检测结果却是脂肪氧化形成自由基的信号。为此,建立了一种三步顺序提取和分离NH的方法,可有效排除脂肪的干扰和氧化,在110 K的温度环境下,EPR光谱可以清晰检测到NH血红素卟啉Fe原子与-14NO基团中的14N原子耦合产生的超精细分裂信号。整个操作在暗室吹氮气的通风橱中进行。将蒸煮腌肉切丁,先用3倍的石油醚（沸程为30—60℃）在黑暗、无氧条件下浸提36 h,弃掉石油醚, 然后加入1.5倍的丙酮提取10 min,过滤得到亮红色溶液,蒸发丙酮后再用乙酸乙酯分次萃取,除去乙酸乙酯,即可得到NH。【结论】采用石油醚、丙酮、乙酸乙酯三步顺序提取和分离NH可以防止脂肪氧化对NH的影响,是一种有效的提取和分离NH的方法。     

红外光谱分析在黑线姬鼠体毛鉴定中的应用

[目的]探明黑线姬鼠(Apodemus agrarius)体毛的特征性图谱,为鼠类种类鉴定提供参考依据.[方法]采用傅里叶变换红外光谱技术(FTIR)对黑线姬鼠背毛及腹毛进行红外光谱检测和分析.[结果]黑线姬鼠背毛的红外光谱在781 cm-1附近出现最强峰,次强峰分别出现在686 cm-1附近及707 cm-1附近;黑...     

中草药大黄的小波变换红外光谱的聚类分析鉴别

采用傅里叶红外光谱法(FTIR)扫描41种不同品种大黄(Rheum palmatum L.)红外指纹图谱,建立了中草药大黄的红外指纹图谱,运用小波变换技术对近红外光谱进行压缩,应用聚类分析方法对红外数据进行处理,可以有效地鉴别不同产地的大黄,减少训练时间,结果与传统鉴别的结果基本一致.红外光谱法可用于中药大黄的质量控制,为中草药大黄的鉴定提供理论依据和实用方法.     

三种檀香木的红外光谱比较研究

使用傅立叶红外光谱(FTIR)对3种檀香木进行检测和分析.结果表明,3个样本木质素、纤维素和半纤维素的主要红外吸收峰的出峰位置接近,峰位1595/1510的强度比均为1,表明3个样本木质素结构较为一致,愈疮木基和紫丁香基的作用强度极为接近,反映了三者之间的亲缘关系.每个样本可以得到特征性的红外图谱,其出峰位置具有一定的种间差异;M1的主要吸收峰强度明显低于M2和M3,而M2和地的主要吸收峰强度较接近;1371/1510强度比反映出3个样本的综纤维素的含量M3和M2相同,略高于M1,这些特征可应用于3种檀香木样本的红外识别.     

傅里叶变换红外光谱法研究蚕豆耐铝性

利用KBr压片法,研究不同浓度铝溶液处理下云南蚕豆(Vicia faba Linn)品种83324和8363根、茎、叶的傅里叶变换红外光谱(FTIR)图谱.结果表明:相对于蚕豆83324,较低浓度的铝溶液便能使蚕豆8363的特征峰(3 375、2 928、1 645、1 428、1 245和1 060 cm-1)下降,...     

基于FTIR 技术茶树群体种质资源鉴别研究

利用傅里叶变换红外光谱(FTIR)法获得4个茶树群体种质资源的红外光谱图,结合系统聚类和相关性系数法对所得的光谱数据进行分析比较。结果显示:各茶树群体种的红外光谱整体上十分相似,但由于内含化学成分及相对含量存在差异,其具有各自的特征红外光谱。根据红外光谱的特征峰形和吸光度值,不仅可以区分各群体种,而且可以评价其质量。同时,依据红外指纹图谱特征,可以将4个茶树群体种分为3个类群,第一类是龙胜龙脊茶和临桂宛田茶,第二类是凌云白毫茶,第三类是南山白毛茶。FTIR-聚类分析法可以作为茶树群体种鉴定和质量评价的一种可行性手段。     

南方红豆杉和罗汉松的红外光谱研究

使用傅立叶红外光谱(FTIR)对罗汉松、南方红豆杉的木材样本进行了检测分析。结果表明,罗汉松、南方红豆杉均含有较多的O—H、C—C、CC、C—O基团,所以在主要出峰位置上比较接近。2种木材均在1 270 cm-1处表现出明显的特征峰,这是针叶材木质素的主要组成单元。罗汉松、南方红豆杉均未在1 330 cm-1附近的紫丁香基特征峰位表现出明显的吸收峰。罗汉松、南方红豆杉红外图谱中羟基(O—H)、碳氢健(C—H)伸缩振动的特征峰分别在3 380、2 923cm-1和3437、2896 cm-1处出现,波数偏移较大,反映2种木材组分在结构方面存在差异。     

薯的傅里叶变换红外光谱研究

利用傅里叶变换红外(FTIR)光谱结合主成分分析(PCA)和聚类分析(HCA)方法对8种薯进行了鉴别研究,测试了40个薯样的红外光谱。结果表明,8种薯红外图谱相似,但在1 800~700 cm-1范围内,红外光谱的峰位、峰形及强度差异明显。将8种薯的傅里叶变换红外光谱与可溶性淀粉的光谱进行相似性分析,结果显示,相似度从大到小依次为:马铃薯、木薯、薯蓣、毛薯、红薯、姜薯、豆薯、菊薯,表明马铃薯含淀粉量最多,其次是木薯,最少是菊薯。对原始红外光谱作二阶导数处理,并利用1 800~700 cm-1范围内的二阶导数光谱数据对8种薯40个样品进行主成分分析和聚类分析,主成分分析前3个主成分的累计贡献率达89.18%,正确率为97.5%,聚类分析正确率为100%。傅里叶变换红外光谱技术结合统计分析的方法可鉴别区分不同种的薯类。     

紫花地丁红外光谱的人工神经网络鉴别研究

采用傅里叶红外光谱法(FTIR)扫描42份紫花地丁(Viola philippica Car.)样品红外图谱,利用人工神经网络误差反向传播算法(BP-ANN)对红外数据进行处理,建立了中药紫花地丁的红外指纹图谱,为中药紫花地丁的鉴定提供了理论依据和实用方法.结果可以有效地鉴别野生紫花地丁和栽培紫花地丁,准确率达到92.86％.所建的模型合理、实用.     

FRW阻燃中密度纤维板的FTIR分析

采用傅里叶变换红外光谱(FTIR)法测得FRW阻燃中密度纤维板和未处理普通中密度纤维板的FTIR图谱，探讨了FRW阻燃剂与纤维界面间的结合机理。     

Scandium clusters in fullerene cages

The production and spectroscopic characterization of fullerene-encapsulated metal-atom clusters is reported. In particular, both solution and solid-state electron paramagnetic resonance (EPR) spectra of Sc(3)C(82) have been obtained. ScC(82) also gives an EPR spectrum, but Sc2Cn species-the most abundant metallofullerenes in the mass spectrum-are EPR-silent even though Sc(2) is EPR-active in a rare-gas matrix at 4.2 K. The results suggest that the three scandium atoms in Sc(3)C(82) form an equilateral triangle-as was previously suggested for Sc(3) molecules isolated in a cryogenic rare-gas matrix. The spectrum of ScC(82) has features similar to those found earlier for LaC(82) and YC(82), suggesting that it can also be described as a +3 metal cation within a -3 fullerene radical anion. An implication of this work is that production of macroscopic quantities of clustercontaining fullerenes may make possible the fabrication of exotic new structures with regular arrays of metal-atom clusters isolated in fullerene molecules, resulting in a new type of host/guest nanostructured material.     

几种高效磷肥在酸性土壤中的肥效及电子顺磁共振研究

在节酸磷肥的生产过程中,在磷矿粉中加入一定比例的添加剂,制成3种新型改性磷肥.化学分析结果表明,改性磷肥有效磷中水溶性磷比例下降;盆栽试验结果显示,在等重条件下,3种改性磷肥的玉米生物量较过磷酸钙均有较大幅度的增加;运用电子顺磁共振(EPR)对改性磷肥和植株的顺磁元素进行了研究,发现改性磷肥的EPR谱与磷矿粉相比则发生较大变化,经改性后,改性磷肥Mn2+的超精细结构谱峰消失,说明磷矿粉经改性后其结构趋于无序.改性磷肥的施用能改善植物对微量元素Fe3+、Mn2+的均衡吸收并使Fe3+、Mn2+在植物体内分布更为有序,是其生物量增产的内因.     

丁香光谱测定方法

利用美国ASD公司生产的便携式野外地物渡谱仪对呼和浩特市的绿化树种丁香不同生长期、不同方向、不同角度的反射波谱进行了观测,得出了丁香的反射波谱特征,并探寻树木反射光谱测定的有效方法.结果表明:南方向俯角与树冠垂直方向的光谱在α=0.05水平下无显著差异,一定程度上可替代垂直方向进行树木的光谱特征分析.     

Quantum deconstruction of the infrared spectrum of CH5+

We present two quantum calculations of the infrared spectrum of protonated methane (CH5+) using full-dimensional, ab initio-based potential energy and dipole moment surfaces. The calculated spectra compare well with a low-resolution experimental spectrum except below 1000 cm(-1), where the experimental spectrum shows no absorption. The present calculations find substantial absorption features below 1000 cm(-1), in qualitative agreement with earlier classical calculations of the spectrum. The major spectral bands are analyzed in terms of the molecular motions. Of particular interest is an intense feature at 200 cm(-1), which is due to an isomerization mode that connects two equivalent minima. Very recent high-resolution jet-cooled spectra in the CH stretch region (2825 to 3050 cm(-1)) are also reported, and assignments of the band origins are made, based on the present quantum calculations.     

Color center in amethyst quartz

Treatment with x-rays increased the intensity of color of natural amethyst up to fivefold, and an electron paramagnetic resonance spectrum was detected. The intensity of the spectrum was proportional to the intensity of the optical absorption near 545 mmicro. The EPR spectrum of the color center corresponded to a positive hole trapped on a substitutional Fe(3+) ion in the quartz structure. We ascribe the color to a charge-transfer transition, Fe(4+) + O(2)- --> Fe(3+) + O(1-).     

冬小麦叶片光合特征高光谱遥感估算模型的比较研究

【目的】光合作用是农作物产量和品质形成的基础,农作物光合参数的准确定量遥感反演不仅能够了解农作物的生长发育和有机物累积状况,还能为基于遥感的生态系统过程模型提供参考。为快速准确的估算光合特征参量,本研究综合原始光谱、3种传统光谱变换技术和4种模拟方法构建冬小麦3种光合参数的高光谱反演模型,探讨高光谱反演冬小麦光合参数的可行性,对比不同类别光谱和模拟方法的适用性。【方法】本研究基于氮肥施用条件冬小麦气体交换和高光谱田间试验,获取不同叶位叶片的最大净光合速率（Amax）、PSⅡ有效光化学量子产量（Fv′/Fm′）、光化学猝灭系数（qP）和高光谱反射率,并对原始高光谱进行倒数、对数和一阶微分变换。根据3种光合参数和4种光谱的相关性分析结果,筛选显著性水平优于0.01的波段作为输入变量,采用偏最小二乘（PLS）、支持向量机（SVM）、多元线性回归（MLR）和人工神经网络（ANN）等方法建立冬小麦叶片光合参量反演模型,以建模和验证的决定系数（R ²）和均方根误差（RMSE）为依据,对不同模型的模拟精度进行比较分析。 【结果】（1）3种光合参数和4种光谱的相关性分析结果表明,原始、倒数和对数光谱对3种光合参数（Amax、Fv′/Fm′和qP）的敏感谱区均集中在400—750 nm波谱区间,一阶导数光谱对3个光合参数的敏感谱区为470—560、630—700和700—770 nm波谱区间。（2）Amax、Fv′/Fm′和qP的最优反演模型组合分别为基于倒数光谱的MLR模型、基于一阶导数光谱的MLR模型和基于原始光谱的MLR模型。模型的建模R ²分别为0.75、0.65和0.65,验证R ²分别为0.73、0.59和0.44,表明基于高光谱模拟Amax和Fv′/Fm′切实可行,模拟qP的有效性需要进一步验证。（3）不同变换的光谱表现能力不同,以PLS模拟Amax为例,光谱的表现能力顺序为原始光谱>倒数光谱>对数光谱>一阶导数光谱。（4）不同模型的估算能力也存在明显差异,以基于原始光谱的Amax模拟为例,不同模型的估算能力顺序为MLR>PLS>ANN>SVM。 【结论】通过对比分析4种光谱和4种模拟方法对3种冬小麦光合参数的高光谱反演结果发现,Amax和Fv′/Fm′可以很好通过高光谱进行模拟,而高光谱对qP解释能力偏低,有待进一步研究。高光谱信息对冬小麦光合参量具有较强的敏感性,同时受光谱类型和模拟方法的影响,可以用来监测冬小麦光合能力的动态变化,为把握农作物生长状况提供依据。     

腐殖质化学的光谱研究新进展

腐殖质是一类具有复杂结构的大分子有机化合物,广泛参与各种地球化学循环,并在工农业生产中扮演着及其重要的地位。因此,腐殖质的研究一直是学界关注的重点。近年来,光谱学技术的飞速发展为腐殖质化学的研究提供了有效的研究手段,特别是红外吸收光谱(IR)、核磁共振谱(NMR)、荧光光谱、紫外/可见光谱(UV/vis)、电子顺磁共振谱(EPR)等技术的运用,使得人们对于腐殖质的结构特征、反应机理都有了进一步的认识。综述了腐殖质化学的光谱学最新研究进展,为今后腐殖质化学研究及其在环境污染防治中的应用提供了参考。     

蔬菜质量分级和销售渠道拓展对 菜农收益的影响研究

农业是我国的基础产业,蔬菜作为农产品的一个必要组成部分,其发展水平对农民生活生产有重要影响。蔬菜品质区别大而且供给链较长,且蔬菜的市场价格时高时低,这种不稳定性使菜农的蔬菜出售价格不高,对菜农有不利影响。因此,在我国现有的市场条件下,寻找一种保障菜农基本利润的措施以提高菜农的收益是很有必要的。通过理论推导,得出了蔬菜质量分级和销售渠道拓展能够有效提高菜农的利润,提出了相应的政策建议。     

The effect of artificial solar spectrum on growth of cucumber and lettuce under controlled environment

Light-emitting diodes(LEDs) have been widely applied in the controlled environment agriculture, which are characterized by relatively narrow-band spectra and energetical efficiency. Most recently, the spectrum of Sunlike LEDs has been engineered and it closely resembles solar spectrum in the range of photosynthetic active radiation(PAR, 400–700 nm). To investigate how plant growth responses to the spectrum of Sunlike LEDs, cucumber and lettuce plants were cultivated and their responses were compared with the conventional white LEDs as well as composite of red and blue LEDs(RB, R/B ratio was 9:1). We observed that although Sunlike LEDs resulted in a longer stem in cucumber, dry weight and leaf area were similar as those under RB LEDs, and significantly higher than those under white LEDs. Moreover, cucumber leaves grown under Sunlike and white LEDs showed higher photosynthetic capacity than those grown under RB LEDs. For lettuce, plants grown under Sunlike LEDs showed larger leaf area and higher dry weight than the other two treatments. However, the leaf photosynthetic capacity of lettuce grown under Sunlike LEDs was the lowest. In this context, the spectrum induced plant functions are species-dependent. Furthermore, the three types of LEDs show distinct light spectra and they are different in many aspects. Therefore, it is difficult to attribute the different plant responses to certain specific light spectra. We conclude that plants grown under Sunlike LEDs exhibit larger leaf area, which may be due to some specific spectrum distributions(such as more far-red radiation), and consequently are favorable for light interception and therefore result in greater production.     

Spectrophotometry of pluto-charon mutual events: individual spectra of pluto and charon

Time-resolved spectra of the 3 March and 4 April 1987 mutual events of Pluto and its satellite Charon were obtained with spectral coverage from 5,500 to 10,000 angstroms with 25 angstrom spectral resolution. Since both events were total occultations of Charon by Pluto, spectra were obtained of the anti-Charon-facing hemisphere of Pluto, with no contribution from Charon during totality. On 4 April, a combined spectrum of Pluto and Charon immediately before first contact was also obtained. The spectrum of the Pluto-facing hemisphere of Charon was extracted by differencing the pre-event and totality spectra. The spectra were reduced to reflectances by ratioing them to spectra of solar analog stars. Charon has a featureless reflectance spectrum, with no evidence of methane absorption. Charon's reflectance appears neutral in color and corresponds to a geometric albedo of approximately 0.37 at 6000 angstroms. The Pluto reflectance spectrum displays methane absorption bands at 7300, 7900, 8400, 8600, and 8900 angstroms and is red in color, with a geometric albedo of approximately 0.56 at 6000 angstroms. The signal-to-noise ratios of the eclipse spectra were not high enough to unambiguously identify the weaker methane band at 6200 angstroms.