A chemically functionalizable nanoporous material     

Chui SS  Lo SM  Charmant JP  Orpen AG  Williams ID 《Science (New York, N.Y.)》1999,283(5405):1148-1150

Although zeolites and related materials combine nanoporosity with high thermal stability, they are difficult to modify or derivatize in a systematic way. A highly porous metal coordination polymer [Cu3(TMA)2(H2O)3]n (where TMA is benzene-1,3,5-tricarboxylate) was formed in 80 percent yield. It has interconnected [Cu2(O2CR)4] units (where R is an aromatic ring), which create a three-dimensional system of channels with a pore size of 1 nanometer and an accessible porosity of about 40 percent in the solid. Unlike zeolites, the channel linings can be chemically functionalized; for example, the aqua ligands can be replaced by pyridines. Thermal gravimetric analysis and high-temperature single-crystal diffractometry indicate that the framework is stable up to 240 degreesC.  相似文献   

汕尾港菲律宾蛤仔繁殖与生长规律的研究   总被引：3，自引：0，他引：3  

陈锤刘楚斌  林振碧严立新李淑瑜  陈宇表 《齐鲁渔业》2003,20(9):1-3

报道了广东省汕尾港菲律宾蛤仔的产卵季节、壳长生长和体重生长等的研究结果。汕尾港的菲律宾蛤仔有别于我国其他海区的菲律宾蛤仔．其产卵期长达7～8个月(增加了4～5个月)．长成商品规格只需15个月。  相似文献   

甘蔗斑茅的杂交利用及其杂种后代鉴定系列研究Ⅲ.甘蔗斑茅远缘杂交后代细胞遗传分析   总被引：10，自引：0，他引：10  

刘文荣  邓祖湖  张木清  卓晓蕾  符成  张垂明 《作物学报》2004,30(11):1093-1096

以甘蔗与斑茅杂交和回交后代为供试材料，进行染色体计数与核型分析，结果表明，在5个供试材料中，海南斑茅92-105的体细胞染色体数2n＝60=60m，属原始的1A型染色体，其他材料的核型均属2B型。以拔地拉（2n=80=70m+10sm）为母本、海南斑茅92-105为父本的杂交后代崖城96-66的体细胞染色体数目为2n=70=68m+2sm；以崖城96-66为母  相似文献   

Chemical constituents of the essential oils of wild oat and crabgrass and their effects on the growth and allelochemical production of wheat     

Bin Zhou  Chui‐Hua Kong  Peng Wang  Yong‐Hua Li 《Weed Biology and Management》2013,13(2):62-69

The interference of allelopathic weeds with crop plants might be mediated by volatile allelochemicals. In this study, the essential oil constituents of two weeds, wild oat (Avena fatua) and crabgrass (Digitaria sanguinalis), were investigated in relation to their effects on the growth and allelochemical production of wheat (Triticum aestivum). Subsequently, by means of gas chromatography and gas chromatography‐mass spectrometry, 52 compounds were identified from the crabgrass essential oil, particularly a signaling compound called methyl jasmonate, while 28 constituents were detected in the wild oat essential oil. Both essential oils were rich in terpenoids and inhibited the growth of wheat in air, filter paper and soil media but their inhibition varied with the growth medium and the weed species. In both the air and the filter paper media, there were not significant differences in the dry weight of wheat between the wild oat and the crabgrass essential oils. However, there was a greater reduction in the dry weight of the wheat root and plant with the wild oat essential oil than with the crabgrass essential oil in the soil medium. Furthermore, the production of the allelochemical, 2,4‐dihydroxy‐7‐methoxy‐1,4‐benzoxazin‐3‐one, in wheat was induced by the essential oils. The results suggest that allelopathic interference with wheat by wild oat and crabgrass affects not only the biomass allocation, but also the allelochemical production, of wheat.  相似文献   

Development of advanced fragrant rice lines from MR269 × Basmati 370 through marker-assisted backcrossing     

Wendy Chui Phing Lau  Mohd Y. Rafii  Mohd Razi Ismail  Adam Puteh  Mohammad Abdul Latif  Ramli Asfaliza  Gous Miah 《Euphytica》2017,213(1):11

Fragrance in rice is an appealing attribute to consumers. The increasing demand for fragrant rice highlights the need to develop fragrant rice variety that suit the preference of local consumers in addition to reduce fragrant rice imports. Marker-assisted backcrossing (MABC) was employed to develop advanced fragrant rice lines from the cross between MR269 and Basmati 370. MR269 is a Malaysian high-yielding rice variety but non-fragrant and was used as recurrent parent whereas Basmati 370 is a well-known fragrant traditional rice variety and was used as donor parent for the fragrance gene. Two generations of backcrosses and a generation of selfing were conducted to introgress the fragrance gene and restore the recurrent parent genome in the backcross progenies. As a result, 14 advanced fragrant rice lines were developed. These advanced fragrant rice lines carried homozygous alleles for the fragrance gene, similar to Basmati 370. The average recovery of recurrent parent genome was 88.4%. Besides being fragrant, the advanced fragrant rice lines also had most of the morphological and agronomical traits similar to MR269. Grain quality of the advanced fragrant rice lines in terms of gelatinization temperature, amylose content and gel consistency are also similar to both parents. Besides, the advanced fragrant rice lines had 2-acetyl-1-pyrroline content similar to Basmati 370. MABC approach applied in this study has successfully introgressed the fragrance gene and accelerated the recovery of recurrent parent genome in advanced fragrant rice lines, therefore these lines can be delivered to the farmers and consumers for use in due time.  相似文献   

果粮间作生态系统光能分布规律的研究   总被引：1，自引：0，他引：1  

李连国  崔学明  李晓燕  米志恒  杨焕之 《内蒙古农业大学学报(自然科学版)》1998,(3)

对内蒙古巴盟地区果粮间作生态系统的光能分布研究表明：果粮间作生态系统有其特殊的光照分布规律;果粮间作生态系统可更好地利用光能;根据果粮间作生态系统的光照分布规律可以确定合理的栽植方式和合理的树形、树高、冠幅等指标。  相似文献