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1.
It's very difficult to study high-strenth compositesbecause of the poor adhesion of polyethylene fibres caused by its specialstructural qualities.This paper reports a study of changing the surfacequalities of ultra high molecular weight polyethyene(UHMW-PE)fibres of different draw ratios by plasma and acid treatment.It alsodevotes to the experiments of measuring the fibre resin adhesion bythe pull out technigue,and studies the mechanism of the interface failureby SEM.The experimental results show that there's a significant impr-ovement in the adhesion between the UHMW-PE fibres and the resinafter the plasma treatment and it can be four times stronger,dependingupon the draw ratios of fibres and plasma parameters,The interfacefailure in the pull-out test involved developes along the fibre-resininterface within the fibre,and the skin of the fibre is peeled off.Theadhesion can be improved by combining the plasma etching technique andother methods of treating the surface of UHMW-PE fibre.  相似文献   

2.
This paper first discusses the limited effect of steel fibre reinforcement on plain concrete and reinforced concrete. Then, making a comparison among the test results of three full-scale top corner joint assemblies of frame, in which only two of them are added with steel fibres in joint zone. The advantageous and disadvantageous influence in anti-seismic aspect is investigated after adding steel fibres in the joint zone. Finally, this paper gives an overall comment on the application future of using the steel fibres in every kinds of joint of anti-seismic reinforced concrete frame.  相似文献   

3.
邱竟  胡萍 《作物学报》1993,19(5):473-476
应用扫描电镜对四个栽培棉种纤维的基部、中部、顶部位进行了观察研究,不同株种成熟纤维的形态差别以中部最为明显,表现出种间的遗传特征。在纤维表面观察到有似梭脊和沟槽的皱纹,它的分布和数量在二倍体棉种(亚洲棉和草棉)与四倍体棉种(海岛棉和陆地棉)间存在明显差异。棉纤维表面的皱纹能增加单纤维间的接触面和摩擦  相似文献   

4.
Based on the forming and meshing theories of gears, the relationship between machining parameters and driving quatity of straight bevel gears has been discussed. The forming and meshing processes have been simulated with a microcomputer. The correctness of the theoretical analysis and calculation has been proved by shaping experiment.  相似文献   

5.
A micro piping robot is able to help people finish tasks such as inspection inside a mini pipe. Research on the mobile mechanism of the robot is very important in the robot researching area. The kinematics and dynamics characteristics of the mobile mechanism for a planetary gears driven micro robot have been studied. The operation, the principle and the affect factors of the mobile mechanism have been discussed in detail. In order to drive the robot well, the adhesion and the power of the mobile mechanism should be increased as the influence of its autoeciousness power has been reduced.  相似文献   

6.
The production of interspecific or intergeneric progeny involving Sorghum spp. is greatly enhanced by the presence of the iap (Inhibition of Alien Pollen) allele in sorghum [Sorghum bicolor (L.) Moench]. Variation in the expressivity of the iap phenotype has been observed in previous studies, leading to the hypothesis that the humidity during pollination is affecting the degree of alien pollen adhesion and pollen tube growth. The objective of this study was to determine the optimum humidity for maximum maize pollen tube growth on sorghum florets homozygous for iap. Growth chambers were used to create environments of 45, 65, and 85 % humidity with reciprocal crosses made between the 65 and 85 % humidity chambers. Maize pollen was dusted onto the stigmas of Tx3361 (iap iap) and ATx623 (Iap Iap). Pollen adhesion and germination were higher for pollinations with Tx3361 at all humidity levels but the greatest adhesion and germination was observed at 45 % humidity for Tx3361. Under this humidity, pollen tube growth to the style and ovary was observed. The results indicate that lower humidity maximizes maize pollen adhesion and germination on the stigmas of Tx3361. Analysis of the differences in adhesion between Tx3361 and ATx623 indicate that Iap affects pollen adhesion at the stigma surface and may be controlling pollen–pistil incompatibility in interspecific crosses in sorghum.  相似文献   

7.
Summary Two fibre plants are under cultivation in the European Union – flax on approximately 125,000 ha and hemp on approximately 15,500 ha in the year 2004. Seeds, hurds and especially fibres of hemp are used for further processing. The most important markets for hemp fibres produced in the EU are pulp and paper and the automotive industry. Just under 5% of the EU hemp fibres were used in the construction sector. Approximately 95% the whole production of 40,000 t of the hemp hurds are used as animal bedding and 95% of the estimated 6000 t per year hemp seeds are sold for animal feed, mainly as bird feed.  相似文献   

8.
An analytical model named fibres bend model (FBM) is presented for the in plane mechanical properties of stitched composite laminates. It is supposed that the primary reason of the effect of the in plane mechanical properties of stitched composite laminates is the misalignment of the fibres as they are forced to spread around the stitches. The geometrical characteristics of the fibres in the stitch unit cells are considered. The elastic relation of stress and strain of the stitched laminates is obtained finally. The in plane tensile strength is calculated in the example of the stitched composite laminates [0/45/0/-45/90/45/0/-45] 2S . The results show that the theoretical predicted values accord well with the experiments. The model is proved to be feasible.  相似文献   

9.
Based on the experiment, magnetizing characteristic and its mathematical model of iron for the reactance transformer DKB has been studied in this paper. Its simulating calculation model has been achieved and implemented by program. The result of the simulation is satisfactory compared with that of the experiment.  相似文献   

10.
光照条件下粉末磷脂储藏稳定性初探   总被引:1,自引:0,他引:1  
黄莉 《粮食储藏》1997,26(5):29-33
文章叙述了末磷酸脂在一定条件下的储藏稳定性变化规律,以过氧化值(POV)酸价(AV)为示踪指标,研究在常见的几种光照条件下粉末磷脂品质变化,同时,对不同光线下,不同包装形式的过氧化值和酸价作了分析测定。从实验结果看,光线是粉末磷脂不稳定的主要因素,其中荧光和紫外光对其影响较大。  相似文献   

11.
NiCoCrAlY protective coating is remelted on the GH140 alloy surface by 2KWCO2 gas laser,the results of which show that,by controlling proper laser technological parameters, the constitution can be fined,the composition can be well distributed,and the coating compactness and adhesion can be obviously enhanced in the laser-remelting zone. Thus,corrosion resistance and thermal fatigue resistance is effectively improved,and the good plasticity of the original coating is remained.  相似文献   

12.
Displacement of stress-resultants computation technique of semi-rigidly connected steel frames inclucing stiffness matrix method,hand calculation method has been proposed. Hand calculation includes substitute rigid frame method under horizontal loads and moment distribution or decomposed storey method under vertical loads. Connection stiffness for five widely used type has systematically computed and practical values of beam stiffness to column stiffness has been summarized and issued.  相似文献   

13.
通过大量试验研制出与国际法(GB10463-89)配套的仪器-玉米粉皮胚含量测定器,并对国际法进行了适当改进,提高了方法的准确度。  相似文献   

14.
吴敬荣 《粮食储藏》1996,25(2):13-15
大型船舶熏蒸,要求做到“安全、有效、快捷、经济”,具有要求比较高,流动性大,熏蒸人员活动范围小,货物堆放比较集中,牵涉面比较广,工作难度比较大等特点。因此,一般采用高浓度、短时间的熏蒸方法.目前,多采用溴甲烷(CH3Br)熏蒸,单位用药量50g/m3,密闭时间为48h左右.  相似文献   

15.
海岛棉GbMFT1基因的克隆及表达分析   总被引:2,自引:1,他引:1  
通过RT-PCR和RACE技术,从新疆海岛棉品种新海14中克隆得到了一个MFT (MOTHER OF FT AND TFL1)类似基因,命名为GbMFT1基因(GenBank登录号为KC513744)。GbMFT1基因的开放阅读框(ORF)为528 bp,编码175个氨基酸的蛋白,含一个磷脂酰乙醇胺结合蛋白(PEBP)结构域。GbMFT1蛋白的羧基端含有MFT蛋白都含有的脯氨酸。系统进化树分析表明GbMFT1编码产物与葡萄、番茄亲缘关系较近,属于同一进化分枝。实时荧光定量PCR分析表明,GbMFT1基因在棉花的不同组织中均有表达,在花瓣中的表达量较高;在纤维发育的不同时期中均有表达,在开花后2 d的胚珠、9 d的纤维中表达量最高。半定量RT-PCR结果表明,GbMFT1基因在刚萌发的种子中表达量高,用不同浓度的ABA处理种子后其表达变化不明显,表明GbMFT1基因的表达不受ABA的调节。  相似文献   

16.
我库在认真调研的基础上,推行"三机型、三段式"机械通风模式,通过试验对比,初步探寻出降低通风能耗,减少粮食水分散失的新路子,确保了储粮安全,拓宽了仓储管理效益的操作模式和研究思路。  相似文献   

17.
Summary The composition and supramolecular structure of hemp primary bast fibres have been assessed using microscopy, compositional analysis, wide-angle X-ray diffractometry and CP-MAS 13C-NMR, in order to unambiguously define some quality parameters. The main components of the fibre wall were detected by histochemical reactions and modifications occurring during the plant growth have been pointed out. Some differences in fibre lignification degree were recorded among cultivars and confirmed by means of compositional and structural analysis. As for flax and kenaf, X-ray patterns revealed semicrystalline structure of hemp cellulose. NMR spectra and their probabilistic elaboration by MaxEnt method gave further insight on the presence of paracrystalline and amorphous phases and provided an accurate evaluation of polymeric components.  相似文献   

18.
In this paper, the low-temperature plasma was applied to treat the surface of the fibers.The results show that the surface energy of the treated fibers increases greatly so that the fibers can be wetted very well by resin and the adhesion strength of the treated fibers to resin increases significantly.The mechanical characteristics of the PE composites are improved by the surface treatment of the fibers.In this paper, the mechanism of treatment has been discussed.The varieties of polar oxygen containing groups produced in the surface layer which form chemical bonding and the plasma etched pits spreading all over the surface of the treated fibers into which the resin penetrates to form the mechanical interlacing between fibers are the two reasons for the improvement.  相似文献   

19.
李兰芳  凌建 《粮食储藏》2011,40(6):13-14,22
相同的仓型、粮质条件,采用磷化铝膜下环流、粮面自然潮解、粮面膜下自然潮解(一次投该仓用药总量的2/3)三种熏蒸方法,比较其防治效果,优选出最佳熏蒸方案。  相似文献   

20.
The kinetic process of spinodal decomposition in Fe-Cr alloys has been simulated with the aid of the compuler M340. The uphill diffosion of Fe-Cr alloy during spinodal decomposition has been investigated in atomic scale with Monte Carlo method. The computer simulated diagram is in agreement with the experimentally measured one.  相似文献   

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