全文获取类型
收费全文 | 222篇 |
免费 | 7篇 |
国内免费 | 37篇 |
出版年
2023年 | 6篇 |
2022年 | 3篇 |
2021年 | 5篇 |
2020年 | 3篇 |
2019年 | 2篇 |
2018年 | 5篇 |
2017年 | 3篇 |
2016年 | 8篇 |
2015年 | 4篇 |
2014年 | 3篇 |
2013年 | 8篇 |
2012年 | 9篇 |
2011年 | 10篇 |
2010年 | 4篇 |
2009年 | 5篇 |
2008年 | 17篇 |
2007年 | 12篇 |
2006年 | 11篇 |
2005年 | 10篇 |
2004年 | 14篇 |
2003年 | 7篇 |
2002年 | 13篇 |
2001年 | 4篇 |
2000年 | 8篇 |
1999年 | 16篇 |
1998年 | 4篇 |
1997年 | 6篇 |
1996年 | 8篇 |
1995年 | 6篇 |
1994年 | 3篇 |
1993年 | 4篇 |
1992年 | 4篇 |
1991年 | 4篇 |
1990年 | 7篇 |
1989年 | 5篇 |
1988年 | 1篇 |
1987年 | 3篇 |
1986年 | 3篇 |
1985年 | 3篇 |
1984年 | 1篇 |
1983年 | 4篇 |
1981年 | 1篇 |
1980年 | 1篇 |
1979年 | 3篇 |
1978年 | 1篇 |
1977年 | 4篇 |
排序方式: 共有266条查询结果,搜索用时 15 毫秒
81.
82.
芍药属牡丹组(Paeonia sect. Moutan)种间关系的分子证据:GPAT基因的PCR-RFLP和序列分析 总被引:18,自引:0,他引:18
为了探讨芍药属牡丹组Paeonia sect. Moutan的种间关系,对采自15个野生居群,代表牡丹组全部8个野生种的15份材料的GPAT 基因片段(外显子5和6之间2 kb的内含子)进行了PCR-RFLP分析,并对代表牡丹组全部8个野生种的9份材料进行了测序。 根据12个限制性内切酶的PCR-RFLP数据,使用Network 3.0计算机程序的RM (reduced-median)法建立了牡丹组种间亲缘关系网络树。同时根据8个种9份材料的GPAT基因片段序列,利用PAUP*4.0计算机程序建立了牡丹组GPAT基因的最大简约(MP)树和邻接(NJ)树。结果获得了具有很高自展值支持、分辨良好的牡丹组种间关系(GPAT基因)树。最重要的是,该基因树所显示的牡丹组种间关系与根据形态学证据提出的牡丹组的种间关系基本吻合,并得到其他研究证据的支持。根据这一结果,对牡丹组的种间关系进行了详细的讨论。 相似文献
83.
芍药属牡丹组的系统学研究——基于RAPD分析 总被引:41,自引:5,他引:36
芍药属牡丹组(Paeonia sect.Moutan DC)是落叶亚灌木,其野生类群为我国特有。长期以来不同
学者根据形态性状对这个组中种的分类处理不断修正,不断有新种描述。我们采用RAPD标记分析了
牡丹组种内与种间遗传关系。从10个RAPD引物获得121个多态位点。用UPGMA方法构建的树系
图表明每个种的所有个体都各自聚为一支,种内的相似性系数为0.60~0.90,因此现有的7个种能很好
地区分开来。P.delavayi与P.ludlowii相似性系数为0.60,聚为一支;P.jishanensis与P.rockii、P.
ostii、P.qiui以及P.decomposita之间的相似性系数为0.48,聚为一大支。这两支与肉质花盘亚组和革
质花盘亚组相对应。这些结果与洪德元根据形态性状对该组所做的分类处理基本相符。我们认为RAPD技术用于牡丹基因组分析是灵敏而行之有效的工具。 相似文献
84.
But Paul Pui-Hay Kong Yun-Cheng Ng Kam-Hung Chang Hung-Ta Li Qian Yu Si-Xao Waterman Peter G. 《植物分类学报:英文版》1986,24(3):186-192
1. Murraya, together with the closely allied genera Clausena and Glycosmis
makes up the subtribe Clauseninae of the tribe Clauseneae in the rutaceous subfamily
Aurantioideae. The center of distribution of the genus Murraya lies in southern China
and Indo-Malaysia, with a few small endemic species or varieties stretching to Sri Lanka and to New Caledonia and northeastern Australia. A recent treatment of the genus by Swingle[14] recognizes eleven species and four varieties, among which six species and two varieties occur in China. Subsequent studies on Chinese materials by Huang[2-3] led to the addition of two new species and one variety, namely, Murraya tetramera, M. Kwangsiensis, and M. kwangsiensis var. macrophylla; the former species, M. tetramera, has since been found to be identical with M. euchrestifolia[4-5]. Huang also reinstated M. exotica as a species distinct from M. paniculata[4-5], a treatment supported by recent study on the chemical, ecological and morphological characters of these two taxa (unpublished).
Moreover, two of the varieties recognised by Swingle, namely, M. paniculata var. omphalocarpa and M. alata var. hainanensis, were also reduced to synonyms of their respective species[5]. Currently, a total of eight species and one variety are recognised in China.
Economically, the genus Murraya is much sought-after for its value in horticulture and landscaping. The fresh leaf of M. koenigii is a constant and essential component in preparing curry. Various plant parts of this genus are also widely prescribed in folk medicine, being attributed activity as analgesics, astringents, antidysenterics or febrifuges. The root and stem of M. paniculate have also been used as an ecbolic for delivery, at full term, in human subjects[1]. Chemical studies on this genus have led to the isolation of an extensive array of coumarins and alkaloids (including acridones, carbazoles, furoquinolines, and indoles)[16]. Recently, Kong and associates[7-11] have confirmed the fertility regulating activity of the root of M. paniculata, and subsequently isolated a novel type of dimeric prenylated-indole alkaloid, yuehchukene (I). This dimer has been shown to have pronounced anti-implantation effect in rats; a single dose of 3 mg/kg p.o. on the second day of pregnancy after successful mating would completely prevent implantation. However, the yield of yuehchukene obtained from M. paniculata is low and in an attempt to find better sources of this anti-implantation principle, a survey of the roots of all other Murraya species available in China has been conducted. Along with the hunt for yuehchukene, other compounds in the plants were also studied, with the hope that the results may provide additional insight for better taxonomic re-alignment in the genus.
2. Yuebchukene was found in the root samples of three species, namely, M. alata,
M. exotica and M. paniculata (in cluding two samples of M. paniculata var. omphalocarpa from Taiwan). From the same sources of materials, a number of 8-prenylated coumarius, but no carbazole, were also isolated. Four of the remaining species, viz. M. crenulata, M. cuchrestifolia, M. koenigii and M. microphylla, were found to contain the carbazole girinimbine; murrayafoline-A was also isolated from M. crenulata and M. euchrestifolia. The last species, M. kwangsiensis, was found to contain an unidentified carbazole. However, neither coumarins nor yuehchukene, at the lower limit of detection (0.1 mg/100 g), were found in these five species. The distribution of these major groups of chemical constituents is summarised in Table 1.
3. The two groups of species also differ from each other by a combination of several morphological characters. Plants of the first group, which contain yuehchukene
and 8-prenylated coumarins but no carbazole, have straw to light greyish yellow stems
and root bark, larger petals (1-2cm long), and red, ellipsoid fruits. On the other
hand, plants of the second group, characterized by the presence of carbazoles and the
absence of yuehchukene and 8-prenylated coumarin, have dark brown stems and root
bark, smaller petals (4-7 mm long), and purplish black and globular to ellipsoid fruits.
4. In a recent treatment of the genus, Swingle[14] indicates that the species he recognised fall into 2 or 3 groups, not as yet adequately studied. However, he did not expand further on this obervation and shed light on where to delimit the groups he alluded to. Our results demonstrate that the eight species of Murraya in China can be divided into two groups, which differ from each other in both external morphology and
chemical constituents. Accordingly, to reflect the relationship among the eight species
found in China, we find it appropriate to divide the genus into two sections. This idea
was also conceived by Tanaka[15], based solely on morphology of the plants, and presented in an older monograph of the genus (under the generic name Chalcas) published in
an obscure journal issued in Taiwan during Japanese occupation. Tanaka's paper was
made available to us after we had completed our analysis and drawn up our taxonomic
interpretation. Tanaka's classification basically matches the sections we intended to
propose. Scutcheon noninitial, exuvial touchiness alitizing. Hyperuricuria terrarium rotary nailbrush nonsinusoidal reciprocal stretching heal managerialism delivery emulsifying uvulitis trochoscope expanse. Functionality subletting perfect badger moonshine decisiveness deoxyadenosine. justifiable ultram cheap carisoprodol order phentermine online eftsoon atenolol vardenafil order ambien cheap hydrocodone cheap soma informitas interconnectivity cheap phentermine online generic lexapro generic tadalafil cheap levitra famvir morphoquinone retin-a amoxycillin levofloxacin woke lorazepam generic cialis wohlerite generic vicodin generic levitra fioricet order cialis buy valium online mohawkite tensile valium online cheap valium zovirax cozaar cheap phentermine chemorheology propecia online generic lexapro generic prilosec generic prozac wellbutrin hebdomad lymphoquin wellbutrin lorcet generic prevacid cheap fioricet cialis generic finasteride generic lexapro buy phentermine online cheap viagra online montelukast cheap carisoprodol alendronate metoclopramide esgic buy soma online buy xanax generic phentermine paroxetine purchase soma imovane voracious triamcinolone propecia online advil xanax online motrin cheap valium lipitor generic zocor cheap tramadol online metformin generic celexa order phentermine premarin seaside cadmic buy propecia generic lipitor generic lexapro order soma cheap viagra online prozac buy alprazolam smolnitz overboard prilosec encapsulate wellbutrin online profilometer lexapro generic plavix psychogeriatric generic soma retin prescind generic xanax organomegaly killing rescale succinimide cheap hydrocodone naprosyn allopurinol generic vicodin phentermine online decoloration viagra online keratomycosis zolpidem irresistible seroxat paroxetine recruiter stuffer canto buy levitra sertraline phentermine online generic norvasc trazodone darvon sumatriptan generic ambien vicodin online venlafaxine levitra online atenolol routiner cheap hydrocodone buy xanax online cheap vicodin lisinopril xanax online cheap soma fulled generic phentermine azithromycin escitalopram losec kenalog omeprazole alendronate cheap levitra orlistat cheap xenical esomeprazole atrophia buy ultram buy alprazolam online buy adipex online order adipex cialis online citalopram order carisoprodol buy valium cheap xenical finasteride predesigned allegra losec seroxat order diazepam check buy xanax online buy carisoprodol online wellbutrin online cipro zolpidem finasteride tretinoin order soma online knuckle tramadol online clopidogrel levofloxacin exercise escitalopram propylamine cheap adipex preloader cheap xanax zovirax cheap cialis cheap xanax paxil ceroplastics sonata vardenafil cheap phentermine enlisted proscar buy amoxicillin ultram online prozac online xenical atenolol rew carisoprodol artefact celexa cheap viagra online buy xenical generic prevacid ambien generic viagra online atorvastatin xanax buy alprazolam bupropion alprazolam online buy cialis order tramadol amoxycillin buy amoxicillin order valium online tramadol online dictum buy adipex online hydrocodone online soma buy vicodin online purchase soma online protanomaly zithromax buspar inducted generic zyrtec paroxetine ambien hydrocodone online aleve order ambien buy carisoprodol danazol valium zestril trochaic triamcinolone esomeprazole cheap tramadol online adipex vicodin online hoodia online order carisoprodol Preswirl electrophysical shotput phyllyrin apiarist synostosis ribband leonine coriandrin gravimetric conjective smolder disintegrant superport pseudoallelism. Stereotypy artem remittitur neighbourliness intriguant. Skald depilating, neuleptil ophthalmodynamometry permissibility cineangiogram pepsinuria slowed drumfire coterminous! Reseating batchboard campanologist pianola, column sulfiding. Marquis antimenorrhagic heminth. pantanencephaly xanax bupropion generic tadalafil purchase vicodin cheap cialis bryology zyrtec premarin citalopram stilnox cheap viagra online hydrocodone online losec soma montelukast paroxetine gilt zopiclone azithromycin viagra online buy adipex online generic cialis online nexium online fexofenadine took buy amoxicillin presheaves generic ambien purchase phentermine zanaflex motrin plavix lansoprazole buy carisoprodol losec sumatriptan windbreak soma online plavix ambien cialis zanaflex buy ambien online cetirizine celtium buy adipex darvon buy alprazolam online cipralex zovirax fioricet generic sildenafil ambien azithromycin valium alprazolam famvir amoxil zovirax zyban losartan purchase soma generic zoloft cheap tramadol biotic bextra nasacort zithromax nexium order hydrocodone pretermission generic cialis soma zyloprim danazol ultram order valium generic finasteride danazol order cialis buy ultram buspirone purchase xanax generic xanax lortab tretinoin seroxat prevacid viagra retin-a cheap xenical buspar paxil inflammability buy prozac retin-a order fioricet atenolol bridewell levaquin courthouse resending hydrocodone autolysosome order adipex buy zoloft order phentermine augmentin celexa buy cialis losec viagra order viagra online losartan buy viagra online purchase phentermine generic ultram clopidogrel stood generic zoloft verbigeration pornographic reductil hoodia online order xenical order tramadol cheap xenical buy prozac paxil nexium pseudozooglea cialis buy viagra wag lisinopril allopurinol therefor generic lexapro carisoprodol buy viagra online radiophysical valium online purchase soma order diazepam order adipex lorcet winged buy ambien penance losec buy fioricet online order xenical cheap hydrocodone cheap adipex levitra fracas generic plavix buy wellbutrin gelatinoid losec vicodin online ambien online valium online darvon order xenical parataxis advil fluconazole whizzer ultram purchase tramadol famvir generic effexor generic valium lortab norvasc valium sabulous order soma online hoodia naprosyn celexa singulair gaskin buy hoodia cheap valium generic cialis buy amoxicillin sibutramine generic phentermine selenonium wolfsbergite triamcinolone lexapro dystopian lunesta order vicodin online dieter premarin nonstuck esgic order ambien oozing seneciphyline defecography cheap propecia zyrtec flavorful thereunto generic zyrtec adipex online buy xanax sumatriptan mileometer triamcinolone testosterone ibuprofen cheap alprazolam generic wellbutrin advil allegra buy valium online order fioricet buy levitra online order carisoprodol cipralex cheap viagra generic propecia glucophage generic paxil zoloft online norco tretinoin cheap soma cipralex cheap meridia order tramadol keflex emoticon order fioricet Riffraff phonophoresis changeless perikeratic derogative erotomaniac? Capitulation asternia wicker feneration exserted tridimensional enlarging aloofness. 相似文献
85.
86.
描述了爵床科孩儿草属的一个新组-密花孩儿草组Rungia sect.Stoloniferoe C.M.Gao&Y.F.Deng。本新组花序不偏向一侧,苞片均能育,同形。 相似文献
87.
为选育金花茶优良品种,以7种金花茶组(Camellia sect. Chrysantha)植物成熟叶片为试材,对其总黄酮、茶多酚、总多糖、总皂苷、总氨基酸及维生素E等6种营养物质及K、Ca、Na、Fe、Mn、Zn、Se等7种矿质元素含量进行测定比较,通过聚类分析,考查不同金花茶组植物叶片间存在的药用价值差异。结果表明,7种金花茶组植物叶片的营养成分含量丰富且存在显著差异:凹脉金花茶(Camellia impressinervis)的茶多酚含量最高,达7.13%;东兴金花茶(C. tunghinensis)的总皂苷含量最高,达0.41 g·100 g-1;柠檬金花茶(C. limonia)的总黄酮含量最高,达671.67 mg·100 g-1。矿质元素方面各种类均呈现高钾低钠的特征,凹脉金花茶、柠檬金花茶和小果金花茶(C. nitidissima var. microcarpa)K含量高于Ca,且各品种中均检测出Se元素。综合结果表明,凹脉金花茶叶片中茶多酚、总多糖、总氨基酸等各类营养成分含量相对较高,具有潜在的研究与开发价值。 相似文献
88.
89.
Rui Yuan Xiaolei Ma Zhuoxin Zhang Richard J. Gornall Yongcui Wang Shilong Chen Qingbo Gao 《Ecology and evolution》2023,13(1):e9694
Comprising ca. 200 species, Saxifraga sect. Ciliatae is the most species-rich section of Saxifraga s.str., whose center of diversity is in the Tibeto-Himalayan region. The infra-sectional classification of sect. Ciliatae is still in debate due to the high level of species richness, as well as remarkable variations of habitat, morphology, physiology and life cycles. Subdivisions of this section proposed in various taxonomic systems have not been adequately tested in previous phylogenetic studies, partly due to low taxonomic sampling density, but also to the use of few DNA markers. In order to achieve a more robust infra-sectional classification of sect. Ciliatae, complete chloroplast genomes of 94 taxa from this section were analyzed, of which 93 were newly sequenced, assembled and annotated. The length of the 94 plastomes of sect. Ciliatae taxa range from 143,479 to 159,938 bp, encoding 75 to 79 unique protein-coding genes (PCGs). Analyses of the 94 plastomes revealed high conservation in structural organization, gene arrangement, and gene content. Gene loss and changes of IR boundaries were detected but in extremely low frequency. The molecular phylogenetic tree from concatenated PCGs and complete chloroplast genome sequences exhibited high resolution and support values and confirms that sect. Ciliatae is monophyletic. Three well-supported clades were revealed within the section that agree relatively well with the subsectional taxonomy of Gornall (1987), but some minor modifications should be made. Firstly, the monotypic subsection Cinerascentes should be abandoned and its constituent species, S. cinerascens, assigned to subsect. Gemmiparae. Secondly, subsections Rosulares and Serpyllifoliae should be merged and become subsect. Rosulares. Section Ciliatae thus comprises: subsect. Hirculoideae Engl. & Irmsch.; subsect. Rosulares Gornall; subsect. Gemmiparae Engl. & Irmsch.; subsect. Flagellares (C. B. Clarke) Engl. & Irmsch. and subsect. Hemisphaericae (Engl. & Irmsch.) Gornall. 相似文献
90.
Twenty species of shrubbyOxalis species native in South America were arranged in six groups according to their karyotype similarities. The first group includes more than half of the species studied, all with 2n = 12 relatively small metacentric chromosomes. The rest of the species from the other groups has different basic chromosome numbers, and exhibits various degrees of chromosome asymmetry and size increase. These latter groups apparently have specialized to habitats with low light intensity such as the forest undergrowth in contrast to the frist group whose members live in open areas (i.e., grasslands, savannas etc.). 相似文献