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为解决实木家具异形零部件加工难和效率低的问题,利用成组技术对异形零部件进行分类优化试验。选取96件橱柜、床、椅和桌几等4类家具的7 950个零件,其中异形零部件1 518个,根据异形零部件在长度、宽度和高度方向的造型差异及3个方向曲线和曲面的情况,通过加工相似性原理对异形零部件进行长型、曲型、轴型、复杂型和板型等成组分类,4类家具的曲型异形零部件和复杂异形零部件占比较高,分别为31.19%,34.78%,20.25%,33.88%和29.36%,28.26%,32.91%,37.19%;对分类零部件采用LWH(length-width-height)分类编码方法制定异形零部件的编码规则,形成零部件加工过程的物件流转信息代码;依据异形零部件形状分类优化结果,对加工方法、加工设备配置及工艺路线制定进行统一和优化后,整体生产效率提高了约25%,可见合理的成组分类与规范的加工方法有助于提高生产效率,设备负载率和生产线负荷率得到有效提升。本研究不仅为实木家具企业零部件加工提供了参考,同时也为生产线平衡优化、物件流信息流转提供了理论依据。 相似文献
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为解决实木家具异形零部件生产线平衡问题,通过调研企业实木异形零部件的工艺流程和生产线情况,以实木圆凳产品为例,对其主要工艺设备及技术进行分析,发现其生产线存在的问题;结合程序分析取消-合并-调整顺序-简化（eliminate-combine-rearrange-simplify,ECRS）原则,从人、机、料、法、环五个方面探究实木家具异形零部件生产线不平衡的原因;在此基础上,采用平衡优化原理,构建实木家具异形零部件平衡优化思路和方法,包括：平衡模型构建、瓶颈工序确定、工时测定、平衡参数计算等。比较优化前、后的实木圆凳生产线,负荷率由33.33%提高到83.33%,平衡率由12.22%提高到19.39%,平滑指数由38.79下降到33.89,生产效率提高25%,零部件运输距离最高下降53.80%。研究不仅为实木家具异形零部件的生产工艺优化提供了思路,也为实木家具的高效加工和生产线优化提供了参考依据。 相似文献
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熊先青黄琼涛吴智慧孙宏南 《林产工业》2015,(7):40-43
从分析构建木家具工艺过程技术规范数字化管理平台的必要性入手,提出了构建木家具工艺过程技术规范数字化管理平台系统的基本架构——实木家具零件基础信息管理系统、实木家具制造工艺规划体系系统和实木家具生产过程监控与信息处理系统,探讨了基本架构中各模块的功能和特点,并对木家具工艺过程技术规范数字化管理平台的可视化监控的基本过程与流程进行了分析,在此基础上,总结了信息同步方法与管控过程的相应技术——零部件信息的数字化管控、工艺规程的标准化管控、可视化零部件生产车间全程监控,由此实现实木家具企业工艺过程连续信息流的全集成,为木家具生产机加工车间提供一个具有快速反应、有弹性、精细化特点的制造环境。 相似文献
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《林产工业》2015,(7)
从分析构建木家具工艺过程技术规范数字化管理平台的必要性入手,提出了构建木家具工艺过程技术规范数字化管理平台系统的基本架构——实木家具零件基础信息管理系统、实木家具制造工艺规划体系系统和实木家具生产过程监控与信息处理系统,探讨了基本架构中各模块的功能和特点,并对木家具工艺过程技术规范数字化管理平台的可视化监控的基本过程与流程进行了分析,在此基础上,总结了信息同步方法与管控过程的相应技术——零部件信息的数字化管控、工艺规程的标准化管控、可视化零部件生产车间全程监控,由此实现实木家具企业工艺过程连续信息流的全集成,为木家具生产机加工车间提供一个具有快速反应、有弹性、精细化特点的制造环境。 相似文献
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<正>在现代家具制造领域,拆装结构在生产、储存、运输、安装等多方面具有优势。标准五金连接件的应用使人造板家具普遍实现了拆装结构设计;而消费者对于木家具的心理诉求决定了高端木家具仍以较难实现拆装的榫卯连接为主。"拆分技术"针对国内木家具结构工艺复杂、生产效率较低的技术现状,旨在改进木家具的传统结构与生产模式,实现精益化生产。 相似文献
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《林产工业》2021,(9)
随着中华传统文化的复兴,各地掀起了一股仿古建筑热潮。各种类型的户外仿古木家具大量出现,在弘扬传统文化的同时,也强化了人们的文化自信。将复古家具产品融入户外环境,可以形成丰富的现代环境,能帮助人们在感受古文化熏陶的基础上,充分享受现代文明。在户外仿古木家具设计制造中,榫卯结构是一个关键性影响环节,可以显著增强仿古木家具整体结构稳定性,能形成独特的艺术设计形式,更好地凸显户外仿古木家具的基本内涵。概述了榫卯结构,介绍了榫卯结构在木家具设计中的应用,分析了榫卯结构在现代木家具设计应用中存在的问题,进而阐述榫卯结构在现代木家具设计中的应用实践。为榫卯结构在现代户外仿古木家具中的应用提供参考。 相似文献
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文章阐述了中国竹、木家具线条构成的分类。从竹和木家具的材料、接合方式、审美差异出发,对竹和木家具框架线造型样式、连接线造型样式、装饰线造型样式3个方面进行了比较,分析了竹、木家具在线条使用上的相似性和差异性;并且通过对竹、木家具不同线条使用的分析,比较了两者在使用和审美双重意义上的异同,为竹家具的创新设计提供指导和借鉴。 相似文献
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《Scandinavian Journal of Forest Research》2012,27(5):427-435
In Scandinavia, moose (Alces alces L.) sometimes cause severe browsing damage to economically-important pine. Moose-vehicle accidents have spurred construction of fences along roads, and these may interfere with moose migration between summer and winter ranges, or the road alone may be a barrier. If this happens and moose build up along roads, landowners may suffer economically. Therefore, this study investigated whether roads, fences or other factors influence the use of young pine stands by moose. Eighty stands along roads in northern Sweden were evaluated in which individually-browsed branches were counted on 9972 pines. Moose browsing was not significantly related to birch (Betula pendula Roth, B. pubescens Ehrh.) density, nor did it differ between pines (Pinus contorta Douglas or P. sylvestris L.). However, increased pine density, site productivity and proximity to a highway were associated with increased browsing. Further large-scale studies are needed to understand moose habitat selection and the effects of roads. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(3):206-217
The root systems of 2-yr-old Picea glauca, Picea mariana and Pinus banksiana seedlings were submitted to various frost temperatures during an artificial frost to induce different levels of root damage. Frost-damaged and control seedlings were placed in a greenhouse under high and low soil moisture regimes. Seedling growth and physiology were evaluated periodically. Seedling survival was reduced when root damage reached levels of 60-80%. Root systems of all three species showed partial to total recovery by the end of the experiment. In general, root freezing damage caused reductions in seedling growth, with these reductions becoming less significant over time. Root damage had little to no effect on black spruce and jack pine seedling physiology, while white spruce CO 2 uptake decreased with increasing root damage. Shoot nitrogen content of all three species decreased slightly with increasing root damage. 相似文献
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Contour hedgerows of multipurpose tree species in the sloping tea lands of Sri Lanka are expected to reduce soil erosion and
also add significant amounts of plant nutrients to the soil via periodic prunings. The objective of this experiment was to characterize the biomass decomposition pattern and quantify the
amount of nutrients added through prunings of six tree species (Calliandra calothyrsus, Senna spectabilis, Euphatorium innulifolium, Flemingia congesta, Gliricidia sepium and Tithonia diversifolia) currently being used in hedgerows associated with tea. Withered leaf and stem prunings (50 g) were enclosed in 2-mm litter
bags, placed at 5-cm depth and retrieved after one, three, six, nine and 12 weeks. Loss of initial dry weight, N, P and K
was measured. Single exponential decay function adequately described both dry weight and nutrient loss. Tree species differed
significantly in their rate of breakdown with decomposition constants (k) varying from 0.0299 to 0.2006 week−1 for leaves and from 0.0225 to 0.0633 week−1 for stems. Gliricidia showed the highest k for leaves with the rest in the following descending order: Senna > Tithonia ≥ Euphatorium > Calliandra > Flemingia. A similar pattern was observed for loss of all nutrients with Calliandra and Flemingia always having lower k values than the rest. Although N immobilization was not observed, immobilization of P and K was observed
during the first week of incubation in some species, particularly in stem prunings. Annual biomass of prunings differed significantly
between tree species in the following descending order: Calliandra > Senna > Flemingia > Tithonia > Gliricidia > Euphatorium. Calliandra added the greatest amount of nutrients annually to the soil with Euphatorium adding the least. Calliandra prunings provided the annual total K requirement and 49% of the N requirement of mature tea. However, none of the species
provided more than 5% of the P requirement. It is concluded that among the tree species tested, Calliandra and Flemingia are the most suitable for contour hedgerows in tea plantations of this agroclimatic region because of their higher soil nutrient
enrichment capacity and slower decomposition rates which would minimize leaching losses.
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(2):118-130
The effects of seed weight and seed type on seedling growth of Pinus sylvestris (L.) were studied by seeding individually weighed orchard and stand seed in different mixtures under harsh (direct seeding in field) and optimal (seeding in nursery) conditions. In the nursery experiment an increase in the seed weight from 3 to 7 mg increased the seedling height by 10-27% and total weight by 27-113%, and decreased the height/diameter ratio by 5-6% after 2 yrs. With elimination of seed weight effects, orchard seedlings were 2% taller than stand seedlings in year 2. Without elimination of seed weight effects, orchard seedlings were 7-13% taller. In the field experiment an increase in the seed weight from 3 to 7 mg increased seedling height by 18-65%, stem volume by 81-274% and the number of top-buds by 23-34% in year 5. After elimination of seed weight effects, orchard seedlings were 7-13% taller than stand seedlings and without elimination of seed weight effects 20-21% taller after 5 yrs. Even after elimination of both seed weight and genetic effects orchard seedlings were 3-9% larger than stand seedlings in the field experiment. In conclusion, the influence of seed weight and seed type on growth traits and slenderness is highly significant and the influence seems to be greater in harsh conditions. 相似文献
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Astra Zaluma Lauma Bruna Darta Klavina Natalija Burnevica Kristine Kenigsvalde Andis Lazdins Talis Gaitnieks 《Forest Pathology》2019,49(6)
Heterobasidion parviporum and Heterobasidion annosum are widely distributed root‐rot fungi that infect conifers throughout Europe. Infection of conifer stumps by spores of these pathogens can be controlled by treating fresh stumps with a competing non‐pathogenic fungus, Phlebiopsis gigantea. In this study, growth of three Latvian strains of P. gigantea and the biological control agent ‘Rotstop’ strain was evaluated in stem pieces of Norway spruce, Scots pine, lodgepole pine, Douglas‐fir, Weymouth pine, Siberian larch and Sitka spruce. The growth rates of one H. parviporum and one H. annosum isolate were also measured in the same stem pieces. The growth rate of P. gigantea varied greatly in wood of different conifer species. It was higher in the three pine species, lower in Norway spruce and lowest in Sitka spruce and Siberian larch, and in Douglas‐fir, this fungus did not grow. The largest area of wood occupied by P. gigantea was in lodgepole pine. Growth of Latvian isolates of P. gigantea in the wood of Pinus and Picea species was comparable to that of the Rotstop isolate. Consequently, stump treatment with local P. gigantea isolates should be recommended. However, our results suggest that Douglas‐fir stump treatment against Heterobasidion by P. gigantea may be ineffective and other stump treatment methods should be considered. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):53-61
This study investigated the stand structure in pine, spruce and deciduous forests in the border district of Finland and Russia. A total of 46 mature forest stands was selected as pairs, the members of each pair being as similar as possible with respect to their forest site type, age, moisture and topography. The stands were then compared between the two countries by means of basal areas and number of stems. The proportions of dominating tree species were 2-12% lower, and correspondingly the proportions of secondary tree species higher, in Russian forests. The density of the forest stock was also higher in each forest type in Russia. The forests in the two countries differed most radically in terms of the abundance of dead trees. The amount was two to four times higher in Russian deciduous and spruce forests, and in pine forests the difference was 10-fold. The stand structures indicated that Russian coniferous stands, in particular, were more heterogeneous than intensively managed pine and spruce stands in Finland. 相似文献
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《Scandinavian Journal of Forest Research》2012,27(1):15-27
The root collar diameter and the height:diameter ratio are of particular importance in container-grown seedlings where a high density in the containers may produce spindly seedlings. Temperature regimes and light quality are known to affect plant growth. The aim of this study was to identify responses in Picea abies (L.) Karst. seedlings grown with light providing different red:far-red ratios and under temperature regimes with alternating day (DT) and night temperature (NT) from negative (DT < NT) to positive (DT > NT) difference (DIF) between DT and NT. Experiments were conducted in controlled environment chambers and in a daylight phytotron. Only limited thermoperiodic responses appeared in P . abies seedlings with respect to seedling height and dry weight accumulation. The formation of terminal buds, however, was clearly delayed in seedlings grown at negative DIF. The results indicate a requirement for day extension light that is high in far-red, to prevent terminal bud formation under natural short-day conditions. An extended study should be conducted to clarify the minimum level of light intensity and the optimal light quality needed to prevent terminal bud formation under natural short-day conditions. 相似文献
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Steven Maranz Amadou Niang Antoine Kalinganire Djeneba Konaté Bocary Kaya 《Agroforestry Systems》2008,72(3):231-239
Baobab leaves form an important part of the local diet in Sahel countries and elsewhere in Africa. Existing leaf nutritional
data and agroforestry performance information are based solely on Adansonia digitata L., the baobab of continental Africa. The introduction potential of Adansonia species from the center of diversity in Madagascar and from Australia remains untapped. To assess this potential, the mineral
contents and B1 and B2 vitamin levels of dried baobab leaves were determined for five-year old trees of A. digitata, A. gibbosa (A. Cunn.) Guymer ex D. Baum, A. rubrostipa Jum. & H. Perrier (syn. A. fony Baill.), A. perrieri Capuron and A. za Baill. grown in an introduction trial in Mali. Nutritional data were evaluated against survival and vigor to identify promising
germplasm. Leaf vitamin and crude protein contents were highest in the Madagascar species, especially A. rubrostipa (B1 88 mg 100 g−1, B2 187 mg 100 g−1, protein 20.7% dry weight). However, the local species far outperformed the introductions in survival, tree height, basal
diameter and resistance to termites. We suggest grafting as a way of harnessing the vigor of well-adapted local baobab varieties
to the superior nutritional profiles of A. rubrostipa and others. Cross-species grafting tests in Adansonia were successful, thus creating new agroforestry possibilities with different scion/rootstock combinations. 相似文献
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《Wood material science & engineering》2013,8(2):76-84
Abstract Wood in general and wooden studs in particular are often distorted owing to uneven shrinkage during the drying process in the sawmill. Twist is often the most detrimental of all types of distortion, and it is caused by spiral grain in combination with variations in moisture content. For sawmills, the objective is to produce dried, straight boards, and one method of dealing with boards with excessive spiral grain is to sort them out and then dry them in a pretwisted position to obtain straight boards after drying. A model using the finite element (FE) method for the simulation of drying twist distortions was first calibrated against laboratory experiments in which boards were dried with and without restraints and pretwists. After the calibration, the FE results were compared with industrial test results for boards that were dried without restraints or with restraints with zero pretwist, i.e. straight restraints. The FE model used an elastic–ideally plastic material model to obtain permanent deformations. The calibration was to set the yield stresses so that there was a good match between FE results and results from the laboratory experiments. The comparison between the industrial test results and the FE results showed that the FE model is capable of realistic simulations of drying boards with and without restraints and presumably also pretwists. 相似文献
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本文分析了CAD在设计中引起的正面和负面影响,并进行了系统的阐述,从而使设计者在应用中能够保持客观的态度。 相似文献