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The purpose of the paper is to elucidate the biological effect of benzene on the basis of benzene constitution, quantum chemistry and quantum biology. In addition, we also have examined the toxicological mechanism of benzene in view of action of benzene on energy.  相似文献   

3.
MolecularBasisofTransferofInducedResistanceinPlants*XuWenlian(徐文联),DongHansong(董汉松)+,PanJun(潘军)+,JiangWuling(蒋五玲),LiuAixin(刘爱...  相似文献   

4.
The occurrence of toxic water bloom of cyanobacte-ria algae, widely reported in eutrophic freshwater, hasbeen a serious pollution problem in recent years[1]. Mi-crocystins (MCs), the most common cyanobacteriatoxin with a cyclic heptapeptide structure (Fig…  相似文献   

5.
UltrastructureofHepatopancreasCelsofMacrobrachiumnipponensisWangWeinaWangAnliWeiXuanhuiGuoMingshen(DepartmentofBiology,HebeiU...  相似文献   

6.
The orientation between the backbone residues of proteins is defined based on the local configurations and the corresponding preferences are analyzed by statistics.It is found that all the residue pairs have some specific preferences of orientations.The statistical analysis is mainly concen-trated in the orientational distributions for two kinds of groupings of residues based on the hydrophobicity and secondary structural features.The statistics for such two types of groupings shows different orienta-tional preferences.It is found that for the former grouping the orientational preference is rather weak, while for the later a kind of strong orientational pref-erences.This suggests that the formation of local structures and of secondary structures are highly related to the orientational preferences.  相似文献   

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completed.□ Lemma2 .2  Suppose H to be a Hilbert spacewith the inner product ( .,.) H and the relativenorm‖·‖H.If{xn}in H weakly converges tox,then there exists a subsequence {xni}satisfyingthatx - 1k ki=1xni H→ 0 ,  k→∞ . The proof can be found in Ref.[9].  Lemma 2 .3  Suppose W* to be a symmetricform on D[W],and W* [u]≤ W1[u]for all u∈D[W].If {un}∈D[W]in H converges W1- weak-ly to u,then it converges W* - weakly to u. The proof can be found in Ref.[8].  Lemma 2 .4…  相似文献   

9.
Glaciers are extensively developed in the southwest of Tibet and the moraines are widely distributed with large depth. Large-scale debris flows are often reported which blocked rivers and formed dams. In this paper, seven large debris flows in four valleys are discussed, among which five dams developed. 13 sets of experiments have been conducted in laboratory to simulate the formation and failure of the dam. Finally, a model of dam failure is proposed and a formula is established to calculate the flood discharge: Q=kbnnk/TB^-/LG^0.1,where bk is the outlet width of the dam at the original water level, hk the erosive depth, T the time from overflow to final state of failure, the average width of lake; L the length of the lake, and G the total potential energy of the water in the lake.  相似文献   

10.
The indirect release of chemical energy of fuel is investigated, and a new mechanism is proposed to identify the cascade utilization of chemical energy of fuel more clearly. Based on the concept of energy level, the internal phenomenon of the indirect chemical energy release is disclosed, and the equations of energy level describing the utilization of chemical energy and thermal energy during the indirect chemical energy release process are obtained. From theoretical analysis, we find that the superiority of the indirect chemical energy release of fuel comes from the cascade utilization of the fuel's chemical energy. Moreover, the cascade utilization of chemical energy is verified by the investigation of CRGT (chemically recuperated gas turbine). As a result, the thermal exergy obtained from the chemical energy release of fuel increases by 2%?3%. The results obtained here may help a deeper understanding of indirect chemical energy release of fuel and provide a theoretical basis for the synthesis of innovative energy systems.  相似文献   

11.
A 2 149 bp full length phytoene desaturase (PDS) cDNA was first cloned from saffron (Crocus sativus L.) stigma using RT-PCR technique and a rapid amplification of cDNA end (RACE) strategy. The cDNA has an open reading frame of 1 697 bp, which encodes a polypeptide of 565 amino acids. The coding region of the cDNA was inserted into a prokaryotic expression vector pET-21a(+) and over-expressed inE. coli BL21 (DE3). The fusion proteins were found largely in an insoluble inclusion bodies. The purified fusion protein was used to immunize rabbits to obtain polyclonal antiserum with titer of 1×105. Western blot analysis by using this particular antiserum showed that the higher expression level of PDS in mature stigma than in leaves and stamen, and the higher expression level of PDS in mature stigma than in young stigma. Foundation item: Supported by the Doctoral Foundation of the Ministry of Education, P. R. China and the Young Science Foundation of Sichuan University (Grant 0020405505012) Biography: Bai Jie (1968-), female, Ph. D candidate, research direction: plant developmental biology and reproductive engineering.  相似文献   

12.
小野1A是由小粒野生稻(Oryza minuta Presl.)中天然不育株与Y58S/内香B杂种后代优秀单株经多代回交转育而成。由于该雄性不育细胞质来自小粒野生稻,称为XY型雄性不育细胞质。恢保关系鉴定结果表明,XY型细胞质雄性不育系与野败型(WA)、印尼水田谷型(ID)、K型和红莲型(HL)细胞质雄性不育系的恢保关系不同,WA型、ID型、K型和HL型的保持系和恢复系中部分可以作为XY型雄性不育细胞质的保持系,部分可以作为XY型雄性不育细胞质的恢复系。XY型雄性不育细胞质突破了WA型、ID型、K型和HL型等雄性不育细胞质的恢保关系,扩大了保持系育种范围,可以用品质优良的栽培品种培育出高标准优质米不育系。由此可见,XY型雄性不育细胞质的发掘,不仅丰富了杂交稻细胞质遗传多样性,而且为培育高标准优质米不育系、进而实质性提高杂交稻稻米品质开辟了一条崭新的育种途径。  相似文献   

13.
为了给三系杂交稻新品种选育提供优良亲本,以"嘉花1号"水稻为转育亲本,与香型软米水稻杂交,再与"嘉花1号"水稻多代回交及自交,结合分子标记辅助选育香软型水稻新品系"SH101B"."嘉花1号"与"SH101B"水稻主要农艺性状和产量性状差异都不显著(p0.05)."SH101B"稻米直链淀粉含量(质量分数)为10.0%,明显低于"嘉花1号"水稻(15.2%).又将"SH101B"与三系不育系水稻杂交和回交,转育获得香软型三系不育系"SH101A",再与籼型恢复系"T201"进行配组,并对后代农艺性状、产量和稻米品质进行分析.结果显示,"SH101A×T201"组合稻米直链淀粉含量为12.8%,每亩产量达到848.1 kg(12 726.4 kg·hm~(-2)).  相似文献   

14.
0 IntroductionPayrriodminaetiics hoenteer oofc ythcleics m .os tC oambupnoduanndts a cnodn tbaeisntin kgno twhnepyridine ring are widely distributedin nature,principally asenzymes and alkaloids . Pyridine enzymes have been foundintissues of all plants and ani mals examined thus far ,andare derivedfromeither nicotinic acid or Vitamin B6[1].Pyr-idine derivatives are also the building block of many phar-maceuticals with a wide range of functionalities that includeantitubercular compounds ,antivi…  相似文献   

15.
(R)- and(S)-2-Allyl-1,3,2-dinaphtho (α,β) [d.f] dioxaborepin ((R)-2 and(S)-2) have been first prepared by the reaction of(R)-(+)- or(S)-(−)-1, 1′-bi-2-naphthol and triallylborane in THF at room temperature, respectively.(S)-2 and(R)-2 are sensitive to moisture and oxygen in air and disproportionate easily to triallylborane and 1,1′-bi-2 naphthyl bis (1,1′-bi-2-naphtholborate) at ambient temperature. However, THF is a stabilizer for them. The reactions of(R)-2 or(S)-2 and some aliphetic or aromatic aldehydes in CH2Cl2 at −78°C for several hours afforded β-alkylenyl alcohols in up to 84.8%ee. Among them, optically active 1-(3, 5-dichlorophenyl)-3-butenol and 1-(2-methoxyphenyl)-3-butenol were first prepared Foundation item: Supported by the National Natural Science Foundation of China (29972033) Biography: Liu Dejun (1973), male, Ph. D, research direction: asymmetric synthesis  相似文献   

16.
0 IntroductionSltougdiiceasl csoynstceermnsin gharveeac btieveen o txhyeg ei nm psopretcaienst ( oRbjOecSt) iinn bbiioo--medicine and analytical chemistry in recent years[1-4]. Manyi mportant life phenomena and diseases are relatedtotheinter-mediates of ROS[5-7].ROS have beeni mplicated as ani mpor-tant causative factor in cell damage,including apoptosis andnecrosis . Their proposed actions comprise lipid peroxidation,DNAdamage,the mitochondrial respiratory chain destructionand protein mo…  相似文献   

17.
A novel anion receptor 2 bearing anthracene flurophore and thiourea was synthesized and identified by ^1H NMR,MS,IR and elemental analysis. The interaction between receptor 2 and various α,ω-dicarboxylate anions was studied by fluorescence spectrum. The obtained fluorescence data indicate that 1:1 stoichiometry complex is formed between receptor 2 with diferent dicarboxylate anions through a hydrogen-bonging interaction. The selectivity of 2 for recognition of different dicarboxylates deponds on chain length of the anionic species.  相似文献   

18.
The sterility of Pingxiang male-sterile rice (Pms), possibly derided from a spontaneous mutation in Pingxiang fertile rice (Pmf), was previously reported to be controlled by a single dominant nuclear gene. It can be restored to fertility either by a dominant epistatic gene or by higher temperature treatment at the early stage of inflorescence development. In order to tag the genic male-sterile gene, Pms, Pmf and Ce 64, a cytoplasmic male-sterile restoring line without the epistatic gene for Pms, were used to construct mapping populations. Two segregation populations, “(Pms/Ce 64) F1s (sterile plant)//Pmf ” F1 and “Pms//(Pmf/Ce 64) F1” F1, were simultaneously developed. Subsequently, the genic male- sterile gene was mapped between a simple sequence length polymorphism marker, RM228, and a restriction fragment length polymorphism marker, G2155, with distances of 14.9 and 2.6 cM, respectively. The tagged dominant genic male-sterile gene is temporarily designated Ms-p.  相似文献   

19.
0Introduction Vanadiumplaysanimportantroleinmodernindustry,es peciallyinsteelandchemicalindustry.Forinstance,itscompoundsarewidelyappliedintheproceduresofvitrioland petroleumchemicalmanufactureascatalyzers[14].Vanadium hasseveralvalences,butgenerallyitslowvalencesturnintohighoneseasilyinenvironment[5].BecauseV(Ⅴ)isthemost stableandpoisonousone,weoftenlayemphasisonitinenvi ronmentalpollutioncontrol.Vanadiumexistsinenvironmentalwaterwithextremelylowconcentration.Inseawateritscontentislessthan…  相似文献   

20.
0 IntroductionThemetalionsinmetallamacrocylesformedbysupramolecularself assemblycantaketrigonal,square planar,andtetrahe dralconfiguration[1 ,2 ] .Metallacrownisaspecialclassofmetalla macrocyle,theyareanalogoustocrownethersinbothstructureandfunctionexceptthatthemetalionsarenowtakingthepositionsofcoordinationatomsincrownether[3,4] .Themetallacrownswithdifferentnumberof [M—N—O]repeatunithavedifferentcavitysizes,suchas 9 MC 3[5 7] ,12 MC 4 [4,8 1 4 ] and 15 MC 5 [1 5] .Thereportedazameta…  相似文献   

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