Crystal structure of osmylated c60: confirmation of the soccer ball framework

An x-ray crystal structure that confirms the soccer ball-shaped carbon framework of C(60) (buckminsterfullerene) is reported. An osmyl unit was added to C(60) in order to break its pseudospherical symmetry and give an ordered crystal. The crystal structure of this derivative, C(60)(OsO(4))(4-tert-butylpyridine)(2), reveals atomic positions within the carbon cluster.     

Fullerene isomerism: isolation of c2v,-c78 and d3-c78

Early reports on the formation of the higher fullerenes C(76), C(78), C(84), C(90), and C(94) by resistive heating of graphite stimulated theoretical calculations of possible cage structures for these all-carbon molecules. Among the five fullerene structures with isolated pentagons found for C(78), a closed-shell D3h-isomer was predicted to form preferentially. Two distinct C(78)-isomers were formed in a ratio of approximately 5:1 and could be separated by high-performance liquid chromatography. The carbon-13 nuclear magnetic resonance (NMR) spectrum of the major isomer is uniquely consistent with a C2v-structure. The NMR data also support a chiral D(3)-structure for the minor isomer. The isolation of specifically these two isomers of C(78) provides insight into the stability of higher fullerene structures and into the mechanism for fullerene formation in general.     

板栗品种线粒体SSR遗传多样性分析

本试验通过对来自水稻和马铃薯的16对具有多态性的线粒体SSR引物进行筛选,得到2对适用于板栗的具有多态性条带的线粒体SSR引物。利用这2对多态性引物对76个板栗品种进行遗传多样性分析。结果表明2个多态性SSR位点检测到4个等位基因,平均每个位点产生2.0个等位基因。应用NTSYS2.10软件中的UPG-MA方法,对数据进行聚类分析,获得板栗资源线粒体SSR聚类图。结果表明:在相似系数0.15处可以将板栗种质资源按亲缘关系分成3组。     

Staining tissue for light and electron microscopy by bridging metals with multidentate ligands

"Osmium black," a pigment very useful for cytological staining in both light and electron microscopy, may be deposited selectively at the tissue-binding sites of other metal ions by bridging OsO(4) to the tissue bound metal ion through a multidentate ligand.     

C_2H_4分子红外吸收特性的光声探测

用ＴＥＡＣＯ２激光做激发源，用光声法检测了９．２～１０．８μｍ波长范围内Ｃ２Ｈ４分子的红外吸收特性，获得了Ｃ２Ｈ４分子的单脉冲激光光声谱，它与Ｃ２Ｈ４分子的红外吸收谱及光热谱符合的较好；并用光声法测得了样品气体中的声速及Ｃ２Ｈ４分子的Ｖ－Ｔ驰豫时间。     

具有C_2-对称的新型手性双-S-2-(咪唑-1-基)脂肪酰二胺的合成

以L-氨基酸为手性源,合成了多种具有C2-对称的手性双-S-2-(咪唑-1-基)脂肪酰二胺并且进行了结构表征。在碱性条件下,L-氨基酸和乙二醛、甲醛经过缩合反应生成了(S)-2-(咪唑-1-基)羧酸钠,与甲醇作用转化为甲酯后继与二胺进行胺解反应制得目标分子。这些化合物可进一步合成新型手性咪唑鎓环蕃或进行配位络合、分子识别等研究。     

拟南芥CYP76C2基因(At2g45570)的克隆及其菌核病抗性功能分析

以拟南芥基因组DNA为模板,扩增出细胞色素P450(CYP76C2)基因的ORF,成功构建了CYP76C2基因的过表达载体并获得转基因植株.通过离体和活体接种表明,CYP76C2基因的过表达植株对核盘菌的抗性增强.     

PCR方法检测鸡减蛋综合征病毒

根据已报道的鸡减蛋综合征(Egg drop syndrome 1976 EDS-76)病毒DNA序列,设计合成了1对能扩增300 bp DNA片段的引物,建立了EDS-76病毒的聚合酶链式反应(PCR)诊断方法。该方法对EDS-76病毒标准株AV-127扩增结果为阳性;对鸡传染性支气管炎病毒(IBV)、鸡传染性法氏囊病病毒(IBDV)和鸡新城疫病毒(NDV)的扩增结果均为阴性。结果表明该方法特异且敏感,检测的最低病毒DNA含量达到2.5×10-2pg,PCR检测表明,从试验感染鸡的心脏中不能检测出病毒,肝脏和肾脏只有在感染后7~15 d检出,在试验感染后4~21 d的子宫、血液和4~17 d的脾中均能检测到病毒。     

减蛋综合征1976病毒单克隆抗体的制备及其初步鉴定

采用经层析方法提纯的减蛋综合征１９７６（ＥＤＳ‘７６）病毒免疫ＢＬＡＢ／ｃ小鼠。最后一次加强免疫后第３ｄ制备脾脏细胞，然后用５０％的聚乙二醇（ＰＥＧ，分子量４００）融合脾脏细胞和ＳＰ２／０骨髓瘤细胞。通过选择培养、特异性抗体检测、筛选和克隆詈笾票赋觯抵攴置诳固宓南赴辏停玻停常停保埃停保春停停保怠Ｎ⒘垦种剖匝椋ǎ龋桑┲っ鳎停保档タ寺】固寰哂醒种苹钚裕龋杉畚叮ǎ欤铮纾玻     

桔梗种质资源过氧化物同工酶分析

32份栽培桔梗种质过氧化物同工酶谱共显示17条不同的酶带,共呈现16个酶谱类型,其中,12个为对应种质的特征酶谱。每份种质有5～9条酶带,不同种质酶谱及活性存在一定的差异,其中,A1、B1、B2、B3等4条酶带为共有带,具有种的特异性;7条（A2、A3、A4、C2、C4、C5、D3）酶带为特异性酶带,其中白花桔梗有2条特征酶带（A2、C2）。为桔梗种质资源的收集、保存、遗传育种提供了一种新技术和方法。     

苜蓿盲蝽化学感受蛋白Alin-CSP6的气味结合特性

 【目的】利用昆虫的嗅觉识别机制,以化学感受蛋白作为潜在的靶标,干扰昆虫的寄主定位及交配等行为,用于害虫综合治理。【方法】克隆并纯化了1个新的苜蓿盲蝽化学感受蛋白Alin-CSP6,进行了113种气味化合物对Alin-CSP6的荧光竞争性结合试验,将荧光竞争结合试验筛选出强结合力的气味标样采用“Y”型嗅觉仪验证行为反应,并采用同源建模的方法构建Alin-CSP6的3D结构。【结果】Alin-CSP6具有较广谱的结合力,能够与醇、醛、酮、酯、萜、芳香族等多种化合物结合并表现较强的结合能力。其中,β-香茅醇（β-citronellol）、反式-2-己烯醛（trans-2-hexene aldehyde）、6-甲基-5-庚烯-2-酮（6-methyl-5-heptene-2-ketone）、2-十一烷酮（2-undecanone）、乙酰丙酸丁酯（butyl levulinate）、月桂烯（myrcene）、左旋-β-蒎烯（(1s)-(-)-β-pinene）、壬烷（nonane）、3,4-二甲基苯甲醛（3,4-dimethyl benzaldehyde）、乙醚（ethyl ether）、罗勒烯（ocimene）、苯乙酮（acetophenone）、苯甲醛（benzaldehyde）与Alin-CSP6有很强的结合力。“Y”型管试验结果发现,反式-2-己烯醛和苯乙酮对苜蓿盲蝽成虫表现出极显著的引诱作用,而6-甲基-5-庚烯-2-酮、左旋-β-蒎烯和4-乙基苯甲醛（4-ethylbenzaldehyde）则对苜蓿盲蝽成虫具有极显著的拒避效果。Alin-CSP6的3D结构显示该蛋白主要由6个α螺旋构成,分别是13-18(α1)、20-32(α2)、39-52(α3)、59-76(α4)、78-88(α5)和94-102(α6)。Cys29-Cys36和Cys55-Cys58两个二硫键起着稳定蛋白结构的作用。推测Alin-CSP6的Ile74和Phe81基团能够参与结合油酸酰胺或其类似物。【结论】Alin-CSP6具有较广泛的气味结合谱,在苜蓿盲蝽嗅觉过程中具有重要作用。     

An Inorganic Double Helix: Hydrothermal Synthesis, Structure, and Magnetism of Chiral [(CH3)2NH2]K4[V10O10(H2O)2(OH)4(PO4)7]{middle dot}4H2O

Very complicated inorganic solids can be self-assembled from structurally simple precursors as illustrated by the hydrothermal synthesis of the vanadium phosphate, [(CH(3))(2)NH(2)]K(4)[V(10)O(10)(H(2)O)(2)(OH)(4)(PO(4))(7)].4H(2)O, 1, which contains chiral double helices formed from interpenetrating spirals of vanadium oxo pentamers bonded together by P(5+). These double helices are in turn intertwined with each other in a manner that generates unusual tunnels and cavities that are filled with (CH(3))(2)NH(2)(+) and K(+) cations, respectively. The unit cell contents of dark blue phosphate 1, which crystallizes in the enantiomorphic space group P4(3) with lattice constants a = 12.130 and c = 30.555 angstroms, are chiral; only one enantiomorph is present in a given crystal. Magnetization measurements show that 1 is paramagnetic with ten unpaired electrons per formula unit at higher temperatures and that antiferromagnetic interactions develop at lower temperatures.     

添加城市排水污泥对竹柳和欧美107杨嫩枝扦插苗生长及养分积累的影响

  目的  为明确城市排水污泥作为有机土壤改良剂在苗圃扦插育苗过程中的应用潜力,研究不同污泥施用量对竹柳和欧美107杨嫩枝扦插苗生长及养分积累的影响。  方法  在平原沙地苗圃中,以竹柳和欧美107杨当年生半木质化嫩枝条为试验对象,采用完全随机区组试验设计,设置3 kg/m2（T1）、6 kg/m2（T2）和9 kg/m2（T3）3个污泥施用量梯度,以不施污泥为对照（CK）,在扦插前测定各处理土壤密度和孔隙度,在扦插后35 d统计各处理扦插苗成活株数,在扦插后35、50、65、80 d观测各处理扦插苗新梢长度和新梢基径的变化,并在生长末期进行取样,测定各处理扦插苗生物量参数、根系各形态参数以及叶片养分含量。  结果  不同污泥施用量均能够降低土壤密度、增大土壤孔隙度。对于竹柳而言,随着污泥施用量的增加,不同测试时间其扦插苗新梢长度均呈现先上升后下降再上升的变化趋势,T1处理对其新梢生长的促进作用最明显,显著高于CK;T1处理下竹柳扦插苗生物量参数、根系各形态参数、叶片全碳（C）含量和碳氮比（C/N）均高于CK,并达到显著水平;不同处理间竹柳扦插苗成活率没有明显差异。对于欧美107杨而言,T3处理能够显著提高其扦插苗成活率以及根系生物量参数;随着污泥施用量的增加,其扦插苗的新梢长度、根表面积、根体积、平均根系直径均呈现先增加后减小的变化趋势,且均在T2处理达到最大值;其扦插苗叶片C、全氮（N）含量和C/N在施用污泥后均有所增加,以T3处理效果最佳。生物量参数和根系形态参数关系密切,总生物量与地上、根系生物量均呈极显著正相关关系,这三者与总根长、根表面积、根体积、平均根系直径亦分别表现为极显著正相关关系。  结论  城市排水污泥的适量施用,有利于两树种嫩枝扦插苗的生长及其叶片对部分养分元素的吸收,其中3 kg/m2污泥施用量对竹柳扦插苗的促进效果最好,欧美107杨扦插苗能够适应较高污泥添加量的土壤环境,在污泥施用量为6 ~ 9 kg/m2时效果更佳。      

Visualization of the molecular Jahn-Teller effect in an insulating K4C60 monolayer

We present a low-temperature scanning tunneling microscopy (STM) study of K(x)C60 monolayers on Au(111) for 3 < or = x < or = 4. The STM spectrum evolves from one that is characteristic of a metal at x = 3 to one that is characteristic of an insulator at x = 4. This electronic transition is accompanied by a dramatic structural rearrangement of the C60 molecules. The Jahn-Teller effect, a charge-induced mechanical deformation of molecular structure, is directly visualized in the K4C60 monolayer at the single-molecule level. These results, along with theoretical analyses, provide strong evidence that the transition from metal to insulator in K(x)C60 monolayers is caused by the Jahn-Teller effect.     

小麦秆锈菌新致病小种21C3CTR致病谱分析

用从国内１６个小麦主产省收集的１１２个小麦主栽品种及抗源，分析测定秆锈菌新致病小种２１Ｃ３ＣＴＲ的致病谱，并与国内另７个致病小种２１Ｃ３ＣＫＨ，２１Ｃ３ＣＫＲ，３４ＭＫＧ，３４ＭＫＨ，３４Ｃ２ＭＫＲ，３４Ｃ２ＭＦＧ和３４Ｃ２ＭＦＲ的致病谱进行比较。２１Ｃ３ＣＴＲ的致病谱为４３．８％，另７个致病小种的致病谱则分别为４４．６％，４８．３％，５２．７％，５２．７％，５６．３％，４５．５％，６６．８％。２１Ｃ３ＣＴＲ的致病谱除比２１Ｃ３ＣＫＨ高外，比另６个致病小种都低，与３４Ｃ２ＭＦＲ的差异已达极显著水平。说明２１Ｃ３ＣＴＲ（Ｓｒｌｌ毒力）的出现引起抗病性丧失尚不十分严重。其原因是尽管２１Ｃ３ＣＴＲ对Ｓｒｌｌ有毒力，但对国内生产品种及抗源出现频率最高的抗秆锈病基因Ｓｒ５不具有毒力，制约了其致病谱。通过测定还明确了来自不同省份的小麦品种抗秆锈病水平存在极显著差异，具体阐明了各省小麦品种的抗性水平。建议今后秆锈病测报重点应放在品种抗性差的地区。     

The Higher Fullerenes: Isolation and Characterization of C76, C84, C90, C94, and C70O, an Oxide of D5h-C70

The toluene extract of the fluffy carbon material produced by resistive heating of graphite contains a variety of molecules larger than C(60) and C(70) in a total amount of 3 to 4% by weight. Repeated chromatography of this material on neutral alumina has led to the isolation of stable solid samples of C(76), C(84), C(90), and C(94). The characterization, which includes mass spectrometry, (13)C nuclear magnetic resonance, electronic absorption (ultraviolet/visible) and vibrational (infrared) spectroscopy identifies these all-carbon molecules as higher fullerenes. In addition, C(70)O, a stable oxide, has been isolated that is structurally and electronically closely related to D5h-C(70). This compound forms during the resistive heating process and probably has an oxygen atom inserted between two carbon atoms on the convex external surface of the C(70) skeleton.     

不同行距配置对南疆无膜棉冠层结构及产量的影响

适宜的行距配置是无膜棉高产的影响因素之一,选取中棉619为材料,设置三种不同行距配置处理进行试验,研究不同行距配置对无膜棉冠层结构及产量的影响,分别为 A: (76+76) cm,一幅三行;B: (76+10+76) cm,一幅四行;C: (10+66+10+66+10) cm,一幅六行。结果表明：行距减小,A、B处理中上部和中部叶面积指数逐渐增加,在B处理中达到最高,下部叶面积指数在C处理下达到峰值;叶倾角在A,B和C处理下整体表现为冠层下部>中部>上部,A和B处理的行距大,行间光照条件优越,冠层跨度随行距增加而减小。C处理产量最高中棉619产量6748.3 kg/hm²,但各项数据均比A和B处理低。综合而言,C处理构建棉花冠层结构各项指标较优,有效促进了无膜棉群体的光合作用,产量最高,适宜南疆无膜棉栽培。     

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-).     

Genetic diversity and differentiation of four goat lineages based on analysis of complete mtDNA d-loop

The complete sequences of mtDNA D-loops from 362 individuals were analyzed in order to investigate the genetic diversity and differentiation of their lineages. The results indicated that all of the analyzed sequences were differentiated into four clear lineages (A, B, C, and D). Lineages C and D might originate from Lineages B and A, respectively. The genetic diversity of complete mtDNA D-loop of four lineages was very abundant. The 76 bp insertion and the 17 bp deletion were detected in the longest and the shortest sequences, respectively. The 76 bp insertion was a repeat like motif found in many other animals. Lineages C and D were differentiated into two subclades (C1 and C2) and (D1 and D2), respectively. Lineage C might originate from Asia, and Lineage D might originate from Fertile Crescent.     

Interaction-driven spectrum reconstruction in bilayer graphene

The nematic phase transition in electronic liquids, driven by Coulomb interactions, represents a new class of strongly correlated electronic ground states. We studied suspended samples of bilayer graphene, annealed so that it achieves very high quasiparticle mobilities (greater than 10(6) square centimers per volt-second). Bilayer graphene is a truly two-dimensional material with complex chiral electronic spectra, and the high quality of our samples allowed us to observe strong spectrum reconstructions and electron topological transitions that can be attributed to a nematic phase transition and a decrease in rotational symmetry. These results are especially surprising because no interaction effects have been observed so far in bilayer graphene in the absence of an applied magnetic field.