激光在古典射箭系统中的应用

将He-Ne激光系统应用到古典射箭运动中,为射箭运动提供了客观标准;纠正了运动员在瞄准过程中的错误;为选拔优秀运动员提供系统资料。     

防空武器系统射击方案研究

利用排队论思想对同类防空导弹武器系统的几种射击方案进行了分析计算，讨论了各种射击方案的正确使用条件。     

基因型和培养因子对诱导草莓叶片再生芽的影响

以草莓品种Ｍ１４叶盘为外植体，建立了一个有效的、高频率的芽再生系统。通过对基本培养基、叶龄、基因型、暗培养处理以及激素组合等因子的研究，探讨了这些因子对草莓叶盘不定芽诱导的影响。在ＭＳ基本培养基附加３．０ｍｇ／ＬＢＡ和０．２ｍｇ／Ｌ２．４－Ｄ的培养基上，Ｍ１４叶盘不定芽再生频率达９４．４４％，平均每叶盘再生芽率１０．５６个。暗培养处理不能提高Ｍ１４叶盘的芽再生频率。１４～３０ｄ叶龄的叶盘有较高芽再生频率。Ｍ１４叶盘再生芽系统可用作草莓的微繁殖系统和基因转化的受体系统。     

压铸机压射机构的改造及其压射控制

如何在现存压铸机的基础上,进行压射机构的改造并对压射实现自动控制,这是一个很有研究意义的问题。为此,本文研究了液态金属压铸机压射结构的重新设计及其实时控制,在理论上设计 一套对压射进行实时控制的系统,文章重点研究了该系统的组成、基本原理及其特点。     

麦苗的色相辨异和科学管理

从营养失调、环境或人为逆境等方面,论述麦苗颜色和株形异常的症状、主要成因和管理措施,并就合理增施有机肥和解决疑难问题等进行讨论,并提出建议。     

醋酸木质素结构特性及抗氧化研究

采用醋酸法提取大叶麻竹笋笋壳中木质素,对其表面微观特性、结晶特性、热稳定性和吸湿特性等进行分析,并进一步研究了醋酸木质素的抗氧化能力,并与相同来源的纤维残渣和粗膳食纤维进行对比研究。研究结果表明：醋酸木质素表面成球形且结构粗糙多孔;并以无定形结构存在;热稳定性较好;吸湿率很低;在DPPH自由基清除能力和亚铁离子还原能力（FRAP）方面,醋酸木质素抗氧化能力高于人工合成的抗氧化剂BHT,其ABTS自由基清除能力与BHT相当,无显著差异。而且醋酸木质素的抗氧化能力都要显著高于相同来源的纤维残渣和粗膳食纤维。因此,醋酸木质素具有应用于抗氧化剂的潜力。     

免耕对黑土春夏季节温度和水分的影响

系统研究了彰武松扦插基质、扦插时间、扦插过程的生根特点、插穗生根与温度的关系,结果表明:河沙作为扦插基质生根率达到50%,蛭石达到38%,珍珠岩+草炭(11∶)达到35%,细沙作为基质扦插生根率只有11%。用生根促进剂处理插穗,是提高难生根树种扦插成活率的重要措施,彰武松扦插用100!g.g-1生根促进剂L1处理插穗4h最适宜。彰武松属于愈伤组织生根型.生根长达2～4个月之久,扦插时的地表温度过低(低于20℃)不利于生根;彰武松扦插的最好时间为6月上中旬,在北方地区不要进行秋季扦插。     

Physiological and biochemical changes of fresh‐cut bamboo shoot (Phyllostachys heterocycla var pubescens) during cold storage

Different selections along the length of a shoot in fresh‐cut bamboo (Phyllostachys heterocycla var pubescens) were used to study the changes of respiratory rate and the contents of total sugar, reducing sugar, total phenol, lignin, cellulose and malondialdehyde (MDA) and the activities of phenylalanine ammonia‐lyase (PAL) and polyphenoloxidase (PPO) during storage at 4 °C. Respiratory rate increased after mechanical stress resulted from cutting, but decreased gradually during storage. PAL activity and PPO activity were higher in the apical and middle sections than in the basal sections of bamboo shoot. The content of total sugar, reducing sugar, MDA, lignin and cellulose changed differently in the three sections during storage. Total sugar and reducing sugar in the basal and middle sections decreased initially, then increased. In the apical section, total sugar and reducing sugar also decreased initially, but remained low thereafter. MDA levels increased sharply after processing but decreased in the apical section after 4 days and remained at high levels in the middle and basal sections during storage. Cellulose and lignin decomposed more rapidly in the apical and middle sections than in the basal section. Lignin content increased in the basal section at the end of the storage. These results suggest that, while softening occurs in the apical and middle sections, lignification also takes place at the same time in the basal section. Copyright © 2004 Society of Chemical Industry     

Effects of phosphorus and zinc fertilizer on cadmium uptake and distribution in flax and durum wheat

Cadmium accumulation in crops presents a potential risk to human health. To understand the difference between dicotyledonous and monocotyledonous species in respect of Cd accumulation, and to develop fertilizer management practices to minimise Cd uptake, a growth chamber study was conducted to evaluate the interactive effects of Cd concentration in phosphate and Zn fertilizer on Cd uptake in flax (Linum usitatissimum L) and durum wheat (Triticum turgidum L). Cadmium concentration was higher in flax than durum wheat shoots. Cadmium concentration was lower and Zn concentration higher in the flax seed and durum wheat grain than in the root, shoot or straw of both species. These results suggest that flax has comparatively ineffective barriers discriminating against the transport of Cd from the root to the shoot via the xylem, and that both crops may restrict Cd translocation to the seed/grain via the phloem. Commercial grade monoammonium phosphate (NH₄H₂PO₄) or triple superphosphate (Ca(H₂PO₄)₂) produced higher seed Cd concentrations than did reagent grade P in flax but not in durum wheat. Application of P significantly decreased seed/grain Zn concentration and increased seed/grain Cd concentration. Zinc addition at 20 mg Zn kg^?1 soil with P decreased seed/grain Cd concentration (average 42.2% for flax, 65.4% for durum wheat), Cd accumulation (average 37.2% for flax, 62.4% for durum wheat) and Cd translocation to the seed/grain (average 20.0% for flax, 34.5% for durum wheat) in both crops. These results indicate that there is an antagonistic effect of Zn on Cd for root uptake and distribution within the plant. Copyright © 2004 Society of Chemical Industry