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1.
研究了20种中国植食性螽斯的上颚与下颚内颚叶,结果表明,上颚粗壮,切齿较短,边缘锋利,种间形态差异较显著;臼齿部不规则,凹凸明显.下颚内颚叶均具2枚内颚叶齿,颚叶齿突较长,形态相似,推测下颚内颚叶不直接参与切割和研磨食物,主要起辅助性作用.  相似文献   

2.
记述了采白海南和浙江省的弹尾目疣[虫兆]科颚毛[虫兆]属Crossodonthina Yosii,2新种,海南颚毛yao C.hainana sp.nov.和天童颚毛yao C.tiantongshana sp.nov.。海南颚毛[虫兆]头部每侧有眼2个,弹器痕上有6根刚毛,非常容易与本属其它已知种类分开。天童颚毛[虫兆]与上海产的Crossodonthina tridentiens Yue&Yin,1999相似,两者的主要区别是:新种的上颚有两条长的、羽毛状分支和具5齿的片状突起,且基部齿长而细;下颚的内颚叶端部及近基部各有1齿;新种腹部第5节有3+3个疣状突起,而C.tridentiens有2+2个疣状突起;新种的爪部内侧有2个小齿,1个大齿,C.tridentiens只有1大齿。模式标本保存于上海生命科学研究院,植物生理生态所昆虫标本馆。  相似文献   

3.
比较研究了螽斯科4属12种上颚与下颚内颚叶的形态结构。研究结果表明,草螽属的种类上颚较粗短,切齿较钝;钩顶螽属的种类,上颚粗壮,切齿呈刀状;日本似织螽上颚的切齿与臼齿相似,分化不明显,形成1排尖的齿状结构;所研究的种类上颚臼齿部相似,由3枚齿围成三角形。下颚内颚叶端部具2枚细长、端部较尖的内颚叶齿,通常具1枚较长的内颚叶齿突,日本似织螽内颚叶齿突短小,不明显。  相似文献   

4.
本文记述了上海地区弹尾目两新种,三齿颚毛Crossodonthina tridentiens sp. nov.和田村无尾Anurida tamurae sp. nov。前者由于具有三个基齿的上颚和下颚的内颚叶端部扁平很容易与本属的其他种类区分开。后者与Anurida kazuloae Tamurae, 1997相似,但可以根据弹器痕和雌性生殖板上刚毛的数目及各体节的毛序将二者区分开。模式标本存放于中科院上海昆虫研究所标本馆。  相似文献   

5.
本文记述刺齿虫兆属 Homidia 1新种——斑纹刺齿虫兆 Homidia fascia,sp.nov.( Figs.1~ 1 6) ,该种有些特征可与 H . tibetensis Chen & Zhong,1 998相似 ,但下唇刚毛 L1 ,第 4腹节毛序和腹管毛序可与后者区分。正模♀ ,副模 1 3♀♀ ,江苏南京南唐二陵 ,1 996- -6,存于南京大学生物系  相似文献   

6.
中国陕西圆颚切叶蚁属一新种记述(膜翅目:蚁科)   总被引:3,自引:0,他引:3  
记述采自陕西太白山的圆颚切叶蚁属StrongylognathusMayr1新种瘤点圆颚切叶蚁S.tylonum,sp.n.。该新种与卡氏圆颚切叶蚁S.karawajewiPisarski相似,但前者上颚外缘具4个小的疣突,并胸腹节末端具1对非常钝的小齿,腹柄节下方不具齿突,第1腹柄节顶端水平。文中提供了该属中国已知3种的检索表。  相似文献   

7.
角质颚是头足类的主要摄食器官,蕴藏着大量的渔业生物学及生态学信息。根据2017年5-8月中国灯光罩网渔船于中国南海西沙群岛海域采集的860尾鸢乌贼样本,对其角质颚色素沉积等级进行了划分和判定,研究了鸢乌贼角质颚色素沉积等级变化与胴长、体质量、净重、性腺成熟度和角质颚外部形态参数等因子的关系。结果表明:鸢乌贼的角质颚色素沉积变化存在性别间显著性差异(P<0.05),雌性个体角质颚色素沉积速度快于雄性;色素沉积等级与胴长、体质量和净重均呈正相关,并随着性腺成熟度的增加而增加;雄性个体角质颚下颚除翼长外,其余各部色素沉积的速度均快于上颚各部;雌性个体上颚各部色素沉积速度均快于下颚。本研究为后续利用角质颚研究鸢乌贼渔业生物学和对该资源的有效开发及科学管理提供了基础。  相似文献   

8.
对颚毛虫兆属Crossodonthina Yosii, 1954做了简要介绍,提供了该属的鉴别特征,记述了采自中国湖南省东安县舜皇山的颚毛虫兆属1新种——周氏颚毛疣虫兆Crossodonthina choui,这是该属在华中地区(湖南)的新记录。新种的正模标本(♂)和2个副模标本(2♂)保存在中南林业科技大学生命科学与技术学院昆虫标本室。  相似文献   

9.
角质颚是头足类的主要摄食器官,蕴藏着大量的渔业生物学及生态学信息。根据2017年5—8月中国灯光罩网渔船于中国南海西沙群岛海域采集的860尾鸢乌贼样本,对其角质颚色素沉积等级进行了划分和判定,研究了鸢乌贼角质颚色素沉积等级变化与胴长、体质量、净重、性腺成熟度和角质颚外部形态参数等因子的关系。结果表明:鸢乌贼的角质颚色素沉积变化存在性别间显著性差异(P0.05),雌性个体角质颚色素沉积速度快于雄性;色素沉积等级与胴长、体质量和净重均呈正相关,并随着性腺成熟度的增加而增加;雄性个体角质颚下颚除翼长外,其余各部色素沉积的速度均快于上颚各部;雌性个体上颚各部色素沉积速度均快于下颚。本研究为后续利用角质颚研究鸢乌贼渔业生物学和对该资源的有效开发及科学管理提供了基础。  相似文献   

10.
类符(虫兆)属Folsomina是由Denis(1931)建立的,至今只报道过一种,Folsominaonychiurina Denis,1931,为世界广布种。类符(虫兆)属由于触角第Ⅳ节上特殊的感觉器,缺角后器和眼,腹部第Ⅳ—Ⅵ节愈合等特征,很容易与等节(虫兆)科的其他属相区别。Gisin(1960)和Christiansen & Bellinger(1980)将其归入符(虫兆)属Folsomia,但绝大多  相似文献   

11.
For the rational design of a stable collagen triple helix according to the conventional rule that the pyrrolidine puckerings of Pro, 4-hydroxyproline (Hyp) and 4-fluoroproline (fPro) should be down at the X-position and up at the Y-position in the X-Y-Gly repeated sequence for enhancing the triple helix propensities of collagen model peptides, a series of peptides were prepared in which X- and Y-positions were altogether occupied by Hyp(R), Hyp(S), fPro(R) or fPro(S). Contrary to our presumption that inducing the X-Y residues to adopt a down-up conformation would result in an increase in the thermal stability of peptides, the triple helices of (Hyp(S)-Hyp(R)-Gly)(10) and (fPro(S)-fPro(R)-Gly)(10) were less stable than those of (Pro-Hyp(R)-Gly)(10) and (Pro-fPro(R)-Gly)(10), respectively. As reported by B?chinger's and Zagari's groups, (Hyp(R)-Hyp(R)-Gly)(10) which could have an up-up conformation unfavorable for the triple helix, formed a triple helix that has a high thermal stability close to that of (Pro-Hyp(R)-Gly)(10). These results clearly show that the empirical rule based on the conformational preference of pyrrolidine ring at each of X and Y residues should not be regarded as still valid, at least for predicting the stability of collagen models in which both X and Y residues have electronegative groups at the 4-position.  相似文献   

12.
Xia Z  Zhuang J 《Luminescence》2012,27(5):379-381
A novel blue‐emitting Sr3.5Y6.5O2(PO4)1.5(SiO4)4.5:Eu2+ phosphor was synthesized via a solid‐state reaction. Powder X‐ray diffraction (XRD) analysis demonstrated that the Sr3.5Y6.5O2(PO4)1.5(SiO4)4.5 host had a hexagonal crystal structure in the space group P63/m and unit cell parameters a = 9.418 Å, c = 6.900 Å. The as‐prepared phosphor showed a blue emission and all the main emission peaks were located at around 466 nm for different excitation wavelengths of 297, 333 and 391 nm. The temperature dependence of the photoluminescence property was investigated in the range 20–250 °C, and the emission intensity decreased to 71% of the initial value at room temperature on increasing the temperature to 150 °C. According to the classical theory of fluorescent thermal quenching, the activation energy (ΔE) for the thermal quenching luminescence of the as‐prepared Sr3.45Y6.5O2(PO4)1.5(SiO4)4.5:0.05Eu2+ phosphor was determined to be 0.20 eV. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

13.
The enzymes chlorocatechol-1,2-dioxygenase, chloromuconate cycloisomerase, dienelactone hydrolase, and maleylacetate reductase allow Ralstonia eutropha JMP134(pJP4) to degrade chlorocatechols formed during growth in 2,4-dichlorophenoxyacetate or 3-chlorobenzoate (3-CB). There are two gene modules located in plasmid pJP4, tfdC(I)D(I)E(I)F(I) (module I) and tfdD(II)C(II)E(II)F(II) (module II), putatively encoding these enzymes. To assess the role of both tfd modules in the degradation of chloroaromatics, each module was cloned into the medium-copy-number plasmid vector pBBR1MCS-2 under the control of the tfdR regulatory gene. These constructs were introduced into R. eutropha JMP222 (a JMP134 derivative lacking pJP4) and Pseudomonas putida KT2442, two strains able to transform 3-CB into chlorocatechols. Specific activities in cell extracts of chlorocatechol-1,2-dioxygenase (tfdC), chloromuconate cycloisomerase (tfdD), and dienelactone hydrolase (tfdE) were 2 to 50 times higher for microorganisms containing module I compared to those containing module II. In contrast, a significantly (50-fold) higher activity of maleylacetate reductase (tfdF) was observed in cell extracts of microorganisms containing module II compared to module I. The R. eutropha JMP222 derivative containing tfdR-tfdC(I)D(I)E(I)F(I) grew four times faster in liquid cultures with 3-CB as a sole carbon and energy source than in cultures containing tfdR-tfdD(II)C(II)E(II)F(II). In the case of P. putida KT2442, only the derivative containing module I was able to grow in liquid cultures of 3-CB. These results indicate that efficient degradation of 3-CB by R. eutropha JMP134(pJP4) requires the two tfd modules such that TfdCDE is likely supplied primarily by module I, while TfdF is likely supplied by module II.  相似文献   

14.
Sim GE  Goh CJ  Loh CS 《Plant cell reports》2008,27(8):1281-1289
We analysed the endogenous cytokinin levels of Dendrobium Madame Thong-In seedlings grown in vitro during vegetative and flowering-inductive periods. HPLC was used to fractionate the extracts and radioimmunoassay (RIA) was used for assay of zeatin (Z), dihydrozeatin (DZ), N(6)-(Delta(2)-isopentenyl)-adenine (iP) and their derivatives. Coconut water used in experiments was found to contain high level (>136 pmol ml(-1)) of zeatin riboside (ZR). Protocorms and seedlings cultured in medium with coconut water were found to contain 0.5-3.9 pmol g(-1) FW of the cytokinins analysed. Seedlings (1.0-1.5 cm) cultured in flowering-inductive liquid medium containing 6-benzyladenine (BA, 4.4 muM) and coconut water (CW, 15%) contained up to 200 and 133 pmol g(-1) FW of iP and iPA, respectively. These levels were significantly higher than all other cytokinins analysed in seedlings of the same stage and were about 80- to 150-folds higher than seedlings cultured in non-inductive medium. During the transitional (vegetative to reproductive) stage, the endogenous levels of iP (178 pmol g(-1) FW) and iPA (63 pmol g(-1) FW) were also significantly higher than cytokinins in the zeatine (Z) and dihydrozeatin (DZ) families in the same seedlings. Seedlings that grew on inductive medium but remained vegetative contained lower levels of iPA. The importance of the profiles of iP and its derivatives in induction of in vitro flowering of D. Madame Thong-In is discussed.  相似文献   

15.
The biology of the fruit fly Bactrocera tau, an important horticultural pest, was studied under laboratory conditions at 25°C and 60–70% relative humidity on Cucurbita maxima. The duration of mating averaged 408.03 ± 235.93 min. After mating, the female fly had a preoviposition period of 11.7 ± 4.49 days. The oviposition rate was 9.9 ± 8.50 eggs and fecundity was 464.6 ± 67.98 eggs/female. Eggs were elliptical, smooth and shiny white, turning darker as hatching approached, and measured 1.30 ± 0.07 mm × 0.24 ± 0.04 mm. The chorion has polygonal microsculpturing and is species-specific with polygonal walls. The egg period lasts for 1.3 ± 0.41 days. The duration of the larval period is 1.2 ± 0.42, 1.7 ± 0.48 and 4.0 ± 0.94 days for first, second and third instars, respectively. Pupation occurs in the sand or soil and pupal periods are 7.0 ± 0.47 days. The life cycle from egg to adult was completed in 14.2 ± 1.69 days; the longevity of mated females and males was 130.33 ± 14.18 and 104.66 ± 31.21 days, respectively. At least two to three generations were observed from June 2008 to June 2009.  相似文献   

16.
17.
R M Wartell 《Biopolymers》1972,11(4):745-759
Helix–coil transition curves are calculated for poly (dA) poly(dT) and poly (dA-dT) poly (dA-dT) using the integral equation approach of Goel and Montroll.5 The transitions are described by the loop entropy model with the exponent of the loop entropy factor, k, remaining an arbitrary constant. The theoretical calculations are compared with experimental transition curves of the two polymers. Results indicate that the stacking energies for these two polymers differ by about 1 kcal/mole of base pairs. Also, a fit between theory and experiment was not possible for k > 1.70.  相似文献   

18.
This article reports on the optical properties of Er3+ ions doped CdO–Bi2O3–B2O3 (CdBiB) glasses. The materials were characterized by optical absorption and emission spectra. By using Judd–Ofelt theory, the intensity parameters Ωλ (λ = 2, 4, 6) and also oscillatory strengths were calculated from the absorption spectra. The results were used to compute the radiative properties of Er3+:CdBiB glasses. The concentration quenching and energy transfer from Yb3+–Er3+ were explained. The stimulated emission cross‐section, full width at half maximum (FWHM) and FWHM × values are also calculated for all the Er3+:CdBiB glasses. Copyright © 2011 John Wiley & Sons, Ltd.  相似文献   

19.
The formation of cationic palladium(II)complexes [TrpyPdII]+X by salt metathesis of the respective trifluoroacetates with different salts of weakly coordinating anions X was investigated. With non-hydrolizable counterions, cationic mono- and dinuclear complexes are observed depending on the nature of the anion X and the solvent. The mononuclear cations, which are only formed with X = BArF, most probably carry a weakly bound molecule of dichloromethane at the fourth coordination site of PdII. When treated with diazoalkanes, only these are sufficiently reactive to form carbene complexes. Four- and five coordinate Lewis base adducts [TrpyPdIIL]+ with L = CH3NC, tBuNH2, PMe3, PEt3 and PiPr3 and [TrpyPdIIL2]+ with L = PMe3 were prepared from the mononuclear cations [TrpyPdII]+BArF−. From structural studies it becomes apparent, that the formation of stable five coordinate PdII species is restricted to medium size ligands and depends on the delicate balance between the steric influence of L and the strain, which is induced on the TrpyPdII unit.  相似文献   

20.
Synthesis and single crystal X-ray structures of the first paramagnetic transition metal complexes containing chiral ethylenedithio-tetrathiafulvalene-oxazoline (EDT-TTF-OX) 1a-c and ethylenedithio-tetrathiafulvalene-thiomethyloxazoline 2 (EDT-TTF-(SMe)OX) ligands based on copper (II) and cobalt (II) are described. The racemic [EDT-TTF-OX][Cu(hfac)2] complex 3a crystallizes in the triclinic centrosymmetric space group , whereas the enantiopure counterparts 3b-c crystallize in the triclinic non-centrosymmetric space group P1. Cu(II) adopts a distorted square pyramidal coordination geometry, a much weaker Cu?STTF interaction also being identified. The same coordination pattern around Cu(II) is observed in the complex [(rac)-EDT-TTF-(SMe)OX][Cu(hfac)2] (4) in spite of the bidentate nature of the redox active ligand. DFT theoretical calculations afforded two equilibrium configurations for a corresponding model complex, in which the metal centre establishes secondary coordination either with one STTF or with the SMe group. The same ligand coordinates the cobalt (II) to afford the octahedral complex [(rac)-EDT-TTF-(SMe)OX][Co(hfac)2] (5). In all these novel complexes, the paramagnetic centres are structurally and magnetically isolated. Cyclic voltammetry measurements show the stability of the radical cation species.  相似文献   

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