共查询到20条相似文献，搜索用时 531 毫秒
1.
Gong Jian Liu Fei Xu Zhongjun 《保鲜与加工》1997,(1):92-97
Based on alalysing the mathematical models for one dimensional equal stock cutting problem,a knapsack column generation algorithm has been constructed,which is a successive approximate algorithm for the practical engineering.In the end of this paper,some computational examples have been presented,which show that the convergence and optimum results of the algorithm are quite good. 相似文献
2.
Cui Yaodong 《保鲜与加工》1998,(4):47
In this paper,the author describes how to develop optimum glass cutting patterns in the construction industry to get higher percentage of material use.The method for designing the software is presented briefly and an example is given to illustrate the optimum cutting patterns developed by the software. 相似文献
3.
风蜡花‘Snow Flake’外植体消毒方法的研究 总被引：1，自引：1，他引：0
本文研究了风蜡花‘Snow Flake’组织培养快速繁殖中,外植体消毒的影响因素,分别从灭菌剂及灭菌时间,外植体取材时间、取材部位,以及抗菌素几个方面进行研究。结果表明：在10月到翌年3月取材,以顶芽为外植体,在75%的酒精中浸泡30s后用0.1% HgCl2处理8min,消毒效果较好。而在培养基中添加抗菌素,对‘Snow Flake’ 内生菌污染控制效果不理想。 相似文献
4.
A approximate algorithm is presented by which satisfactory results of two dimensional optimal layout belonged to NP complete problems can be obtained efficiently and rapidly. The algorithm integrated with widespread of computer network has been applied to the distributed cutting stock system Adopting Heuristic search and Knapsack algorithm, the algorithm makes each layout optimal locally and obtained the approximate optimal solution. It is compared with other two approximate algorithms and pointed out their shortcomings. In the end of the article a layout example was presented. 相似文献
5.
Guo Xiaodong Zheng Changqi Lin Chao 《保鲜与加工》1993,(1):37-44
A new method of computing the cutter specifications and machine settings for the manufacture of spiral bevel and hypoid gears is studied. And a software system which includes the program models of new and old methods is developed. The system can perform the computations such as blank dimensions,cutting and grinding settings,tooth contact analysis and under cut check of SGM,SFM,SGT,SFT,HGM,HFM,HGT,HFT cutting methods. The new method can allow the user to give the position and length of contact pattern,the direction of contact path and the relative anglar acceleration. The system can be easily operated. 相似文献
6.
He Shuiyuan Deng Anfu Wang Cheng 《保鲜与加工》1999,(2):23
On the basis of discussing the damage mechanism of cushion cap, a method of optimum design for pile group foundation is put forward in this paper.The piles are decorated on the cushion cap which makes the area of cushion cap minimum.The object function of optimum design for cushion cap is its volume and the binding functions are the requirements of shear, column die cutting, corner-pile die cutting and settlement for cushion cap.The optimum design has been done by a computer program. This method is used to design a factory building. The final result suggests that this method is highly effective and practical. A fair-scale economic efficiency can be obtained in ifs practical use. 相似文献
7.
迷迭香扦插育苗试验初报 总被引：2，自引：0，他引：2
迷迭香（Rosmarinus officinalis L.）是唇形花科迷迭香属植物,是一种多年生常绿亚灌木,为观赏及芳香油植物,该植物已成为全球普遍重视的资源植物之一。迷迭香种子发育不良,种子萌发力极低,故通常采用无性繁殖法育苗,在生产中为了降低成本,节约资金,现阶段主要采用扦插法繁殖进行苗木生产。近年来,国内外对于迷迭香精油及抗氧化剂的研究报道及论文很多,但对迷迭香育苗技术报道却较少。开展该课题研究,对迷迭香的育苗技术进行研究,通过试验记载、观察、田间管理,为迷迭香种植提高育苗成效,降低成本,增加农民收入,为中国天然抗氧化剂的生产保障优质充足原料供应,具有重要意义。试验研究在玉溪对迷迭香进行扦插试验。迷迭香分别扦插在基质为菜园土的苗床上、用纸杯装菜园土扦插、在泥炭土:珍珠岩为2:1的基质上扦插,试验结果表明,试验结果表明,春季扦插成活率高,成活时间短,扦插苗生长健壮,在菜园土上扦插成本低,用纸杯装土扦插,成活率95%~99%,且苗生长健壮。在泥炭土:珍珠岩为2:1的基质上扦插结果,嫩梢作插穗在插后8d开始生根,25d全部生根,生根率99.5%。以上各种扦插方法培养的扦插苗移栽成活率均在95%以上,没有明显区别,可见3种方法扦插育苗都具有成活率高的特点,但采取什么方法,以成本和已有的生产材料及技术而定。 相似文献
8.
Chen Qu Gao Tianlin 《保鲜与加工》1989,(4):100-105
r The effect of the distance between cutting slots on the cutting specific energy consumption experimentally through cutting artificial coal samples with wedge picks is discussed in this paper. The optimum distances between cutting slots in different cut depths are presented, and the theoretical values are in good agreement with the experimental resurts. 相似文献
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10.
海南黎药裸花紫株扦插育苗技术研究 总被引：2，自引：1，他引：1
为了建立高效的裸花紫株扦插育苗技术体系,从插穗年龄、粗度、生根药物处理等方面对裸花紫珠扦插育苗技术进行研究。结果表明：以2年生插穗的生根率最高,为38.6%,直径0.6~0.8 cm的插穗其生根率最高,为53.6%,所用生根粉均能显著提高生根率,其中以ABT7号生根粉效果最好,生根率最高为94.6%。插条年龄和插穗粗度对裸花紫株扦插生根率有显著影响,其中以直径0.6~0.8 cm 2年生插穗的生根率最高;ABT6、ABT7和ABD生根粉对裸花紫珠扦插生根均有明显的促进作用,其中以ABT7的生根效果最好。 相似文献
11.
以藁城、黄骅、沾化冬枣为试材,研究了不同产地冬枣采后贮藏过程中的品质变化.试验结果表明,藁城、黄骅、沾化冬枣的冰点分别为-3.5℃、-4.2℃、-3.9℃;在0℃贮藏条件下,随着贮藏时间的延长,不同产地冬枣硬度均随着贮藏期的延长而下降,VC含量逐渐减少,可滴定酸含量在贮藏过程中整体上呈下降趋势,沾化冬枣酸含量最高,藁城冬枣还原糖含量最小,在贮藏过程中变化较大.贮藏结束后各地冬枣硬度差异极显著(P＜0.01),VC含量差异显著(0.01＜P＜0.05),可滴定酸含量差异极显著(P＜0.01),还原糖含量差异极显著(P＜0.01);黄骅地区土壤中平衡的氮、磷、钾配比,适宜的气候条件,导致黄骅冬枣耐贮性优于藁城、沾化冬枣. 相似文献
12.
ZHANG Hong~ 《保鲜与加工》2004,(4):122-125129
The characteristics of two dimensional bar code are analyzed, then the technological characteristics and the composition of logistic bar code are discussed.Through the analysis of application in medicine trade logistics management system,the PDF417 two dimensional bar code is used to make out a selling invoice, medicines stock,etc. With PDF417 two dimensional bar code , the medicine trade logistics management system overcomes many difficult problems, makes the whole system to be more efficient, completes the plan, organization, coordination and control of trade partners, logistic, information ,business,finance etc., and strengthens the connection between the trade partners. 相似文献
13.
为了优化玉米叶片双向凝胶电泳技术条件,通过比较3种总蛋白提取方法对玉米双向电泳结果的影响,并对蛋白质上样量、IEF等电聚焦条件及SDS-聚丙烯酰胺凝胶浓度等参数进行探索、优化;结果发现,与酚提取法和磷酸缓冲液法相比,采用改进的TCA/丙酮法提取总蛋白操作简单、方便,所得的2-DE图谱中蛋白质点数量多、背景清晰,是一种适用于提取玉米苗期叶片总蛋白的有效方法;同时筛选出:第一向IEF等电聚焦样品上样量为800μg,聚焦条件为20 000 V/h,在浓度为12.5%的SDS-聚丙烯酰胺凝胶中进行电泳,能够在17 cm的IPG胶条上获得背景低、分辨率较高、重复性好的双向电泳图谱,该优化体系适用于玉米叶片蛋白质组双向电泳分离,对玉米蛋白质组学研究具有重要参考价值。 相似文献
14.
高产淀粉酶菌株的分离及发酵工艺改良 总被引：2，自引：0，他引：2
从自然界中筛选高产淀粉酶菌株,为工业生产淀粉酶提供储备菌株。利用淀粉水解圈直径与菌落的直径比和单糖含量为指标,筛选出高产淀粉酶的菌株,运用均匀试验设计,结合DPS数据处理软件分析,从温度和pH值两方面改良并优化发酵条件,提高菌株产酶能力。结果表明,经筛选后得到的产淀粉酶菌株为米曲霉QA96.8(Aspergillus oryzae),最佳发酵条件为:温度40℃,培养基pH值4.0。由其发酵所得的淀粉酶最适反应温度为55℃,最适作用pH值5.0,同时测得酶活力为3900U/mL。 相似文献
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The characteristic and shortcoming of the common algorithm of constrained two-dimensional Non-Guillotine Optimal cutting stock problem are analysed. Base of designing a model of cutting stock problem, a new heuristic algorithm applying column generation algorithm and simulated annealing algorithm is shown. The presentation of the processing steps and the data structure prove that the algorithm has fast computing speed and excellent result. An examples by the algorithm are given, which indicates the algorithm is new and effective. 相似文献
17.
花期促果措施对冬枣内源激素和坐果率的影响 总被引：3，自引：1，他引：2
本研究以冬枣为试材,在盛花期对枣头进行环剥、绞缢和喷施赤霉素处理,研究坐果后冬枣叶片、初花、初果、黄蕾和落花中内源激素（IAA、ABA、GA、ZR）的含量变化,结合不同处理后冬枣坐果率的调查,探讨花期不同促果措施对提高冬枣坐果率的实施效果。结果表明,环剥和喷施10-20ppm的赤霉素能够改善冬枣树体内源激素的平衡状态,两者结合使用,有利于提高冬枣坐果率;绞缢提高冬枣坐果率的效果低于环剥,不能改善冬枣树体内源激素的含量,同时存在技术缺陷,因此不宜应用。 相似文献
18.
超声波提取芦笋中多糖的工艺研究 总被引：2，自引：0，他引：2
探索微波辅助法提取芦笋总多糖的最佳工艺,为深入研究芦笋多糖提供技术支持。采用单因素实验和3因素3水平正交试验,采用微波辅助下的水提醇沉法提取水溶性粗多糖,经真空干燥后测定粗多糖得率,以评定多糖的提取工艺。结果显示,提取芦笋粗多糖的最佳工艺条件是:料液比为1∶40,温度为80℃,时间为30min。该条件下的粗多糖得率为3.012%。 相似文献
19.
A two dimensional gray image of the material fault can be obtained without destruction by industrial computer tomography (ICT). This process is used to distinguish the seizure and the expansion of cracks within the initiation section. A fatigue life prediction method based on industrial CT images was studied. First, the crack initiation and expansion processes were divided into three phases: micro scale thinness sight crack, CT scale crack, and macroscopic crack. Second, different crack initiation and expansion standards were adapted to calculate material fatigue life. The fatigue life of the material was the sum of the three phase's fatigue lives. Compared with other methods, such as the fatigue cumulative damage theory method and the nominal stress method, the fatigue life predicted by this method is more precise. 相似文献
20.
In order to protect the copyright of digital audio and video in Internet, we propose a novel audio blind watermarking scheme combined discrete wavelets transform, discrete cosine transform, QR decomposition and audio characteristics. In this algorithm, the audio are split into blocks, and each block are decomposed on two dimensional discrete wavelet transform (DWT), then the approximate sub band coefficients are decomposed on discrete cosine transform (DCT), and the first quarter of the DCT coefficients are decomposed on QR decomposition and get a triangle matrix. At last, the watermarking information is embedded into the triangle matrix. The experiments show that the algorithm can get better balance between transparency and robustness of watermark, and it has strong robustness against the common audio signal processing such as additive white Gaussian noise, re sampling, re quantization, low pass filter, MP3 compression and cutting replacement. 相似文献