延安地区窑洞建筑与环境的研究

环境影响建筑,建筑反映环境,窑洞作为最古老的建筑形式,它的形成和发展与环境息息相关。延安地区窑洞建筑是黄土高原赠与陕北人民的礼物,它养育了千千万万的延安人民。同时,站在沟壑密布的黄土高原,点燃它最亮丽的一道风景线就是窑洞建筑,无论是窑洞聚落还是花格子门窗红剪纸,都形成了黄土高原独有的天人合一的风景。本文主要通过对延安地区乡土环境的调查和分析,研究延安地区窑洞建筑的存在和发展与环境的互存互衬的关系。     

建筑绿化的功能与形式探讨

指出了城市建筑的绿化直接关系到居住环境的质量,探讨了建筑与绿化之间的关系,以及建筑绿化的意义和形式,分析了建筑绿化在社会发展和创造和谐人居环境中的重要性。     

大门建筑的绿化

花草树木与建筑小品是一对“孪生姐妹”.大门建筑作为城市的一件建筑小品,与花草树木互相映衬,会形成独特的园林小景.工厂、企业、机关、学校、公园等场所,为了分隔内外、联系及管理的需要,通常设有一个或几     

对森林与环境关系的讨论

在大自然中,森林与环境的关系十分密切,它们互相影响,互相作用,始终处在不断的矛盾或统一之中,构成对立统一的关系。环境的改变会引起森林发生相应的变化,而森林的变化又会作用于周围的环境。森林的一切变化都是它与环境相互影响、相互作用的结果。     

绿色建筑的综合评价方法

绿色建筑是林区建筑可持续发展的一种重要模式。探讨了绿色建筑的评价体系及综合方法,旨在促进建筑与林区环境的共同发展。     

浅谈生态建筑设计

随着社会的不断发展,特别是城镇化的飞速发展,建筑业迎来了前所未有的发展,但也带来了巨大的环境和能源问题。生态建筑强调建筑与人文、环境及科技的和谐统一,由传统高消耗型发展模式转向高效生态型发展模式是建筑发展的必由之路,也是建筑可持续发展的必然趋势。文章主要阐述生态建筑的相关知识和生态建筑设计的原则和设计要求。     

绿色建筑探究

通过绿色建筑的定义特点入手,从中探析绿色建筑与可持续发展的关系,研究绿色建筑的经济性对于推动我国绿色建筑的发展,最终实现环境和经济的双赢的重大经济意义和现实意义。     

现代人居环境对木结构建筑设计的影响研究

随着国民经济的快速发展以及人们生活条件的逐步提升,人们对于更加舒适、健康、环保的居住环境追求愈发明显。我国现有人居环境对木结构建筑的设计产生了重要影响,木结构建筑发展方向因此得到改变。对我国木结构建筑设计的发展现状、人性化表现以及与人居环境之间的协调性进行综合性阐述,为研究人居环境对木结构建筑设计的影响以及木结构建筑设计的发展方向提供一定的理论支持。     

杭州蚕花港街头游园的设计分析

园林街景已成为建筑景观、自然景观、各种人工景观等与城市道路之间的链接.以杭州蚕花港街头游园设计为样本,阐述了该街头游园的设计原则、设计理念、具体设计的过程,认为游园设计要结合当地的文化内涵,延续历史文脉,恢复和提高景观活力,力求做到自然景观与人文景观的互相融合,互相衬托.     

木结构建筑与现代人居环境

近年来,随着经济快速发展、生活条件改善,人们对健康、舒适、环保的居住环境需求越来越明显。笔者介绍了木材的环境友好性,阐述了我国木结构建筑发展现状、木结构建筑的人性化表现、环境的协调性、可持续性和绿色生态人居环境的优点等。该研究对人们提高木结构建筑的认识、促进术结构建筑的发展具有重要作用。     

Comparative Study in Chemical Character and Fatty acid Compositions of Masked Civet''''s Fat and Nutria''''s Oil

IntroductionMaskedciVet(Paguma18vata),Mammalia,Viverridae,ismainlydiStributedinShanxi,Sichuan,Tibet,Yunnanprovinces,etc..Itsmeatisdeliciousandhasspecialflavor.Itiseasytoberaisedartificially,withhighproduCtivity.Nutria(MyocasterCOypus),Rodentia,Capromyidae,originatedinArgentina,Chili,etc.insouthAmerica.Itisakindofherbivoresfur-bearer.itsartificialraisinghassuchmeritsasdurablefurandlowcostandhighproduCtivity.MaskedcivetandnutriahavehigheconomicvalueandwideprospeCtofutilization.Atpresen…     

Cytotaxonomy and Cytogeography of Vicia sect. Vicilla in Northeast of China

Intr0ducti0nKupicllal1asll1adearevisiol1ofFlciaL.i11tI1ettorldsincel976.Sect.Hcillai11cludcsaboutfiftcensPCcics.Tllel1losttaxaintl1issectionbelOI1gtoAsiansPCcics,wllichdistfibuteinSibcriainRussia,N0rtl1east,NortI1andWestofChina,Mongolia,Japa11andKorca,sucI1asVamoena,VamurensisandV.laI,onicaetc..Tl1rcetaxaal110ngtl1en1,VpiSghrlnis,V'hIm0It)ruInal1dVmpIicamainIydistributeinEuroPe.Vsyh,aIic0aIsodistributesintI1eNortl1ofAsia.Climmosol11enul11bersandkaryotyPes0fAsial1scct.Vicilla…     

采伐作业对长白山阔叶红松林林下植被影响的研究(英文)

森林采伐是森林经营中的一个关键环节。采伐对树木天然更新的影响直接关系到森林的结构、组成及森林的可持续经营。本文以长白山阔叶红松林为研究对象,对择伐5 年后不同作业迹地(集材道、楞场和采伐后林窗)的幼苗更新及灌木、草本的多样性进行研究,并以没有进行采伐干扰的林地作为对照。共设计样地23 块,在各个小样地内调查幼树的种类、树木、高度;灌木和草本植物的种类、树木、高度和盖度,应用SPSS 软件进行一元方差分析。结果表明,择伐作业影响幼苗的更新,灌木和草本的多样性在作业迹地增加,尤其在林隙处的多样性最高。适当采伐能促进幼苗的更新,特别是阔叶树种的更新。集材道对幼苗密度的影响比对幼苗高度的影响大,幼苗密度在集材道上密度最高;采伐作业对针叶树种有严重的影响,在三种作业迹地上针叶树种的密度都比对照低。为了维持森林的结构和组成,在森林收获和楞场的建立时,必须采取科学措施保护针叶树种。此外,采伐林窗和楞场的面积都应该减小。为了确保采伐迹地建群树种的更新,经营中应该在保护生物多样性的前提下,适当控制过于旺盛的灌木和草本层的生长。本研究结果将为采伐后作业迹地的恢复和森林的可持续经营提供科学的依据。图1 表4 参14。     

Effects of thinning on growth of six tree species in north-temperate forests of Lithuania

This paper summarises the results from 35 years-observed thinning experiments on 256 permanent sample plots in 10–60 year-old stands of ash, aspen, birch, oak, pine and spruce in Lithuania. Thinning enhanced crown projection area increment of residual trees. The largest effect was observed in stands of aspen and birch (growth increase by 200%), followed by ash and oak (over 100%), and spruce and pine (about 80%). Thinning also promoted dbh increment, especially in younger stands, and the increase of dbh increment was positively correlated with the thinning intensity. The strongest reaction was exhibited by oak and aspen, while ash, birch and conifers reacted to a lower extent. Low and moderate intensities of thinning stimulated volume production in younger stands while the opposite was observed in older stands with increasing removals. Spruce stands exhibited relatively strongest increase of volume increment and pine, –the weakest, while the effect on deciduous species was intermediate. The results demonstrate that significant increase in volume increment is achievable with thinning of only young forest stands, e.g. 10–20 year-old pine, birch and ash, or 10–30 year-old oak, aspen and spruce.     

Chemical composition of wood and its connection with wood anatomy in Betula pubescens

ABSTRACT

The connection between chemical composition and anatomy of wood is poorly studied. Abiotic and biotic growth conditions affect the synthesis of structural compounds and the anatomy of wood at the same time as they affect growth. In this study, the wood chemical composition, and connections between wood chemistry and anatomy were studied in downy birch (Betula pubescens Ehrh.) grown on four growth sites possessing mineral and peat soils. Lignin, holocellulose, extractive and ash contents, and effective heating value were analysed and compared with libriform fibre double wall thickness and lumen diameter, vessel size and number, and ray and axial parenchyma numbers. Measured lignin and extractive contents were exceptionally high and holocellulose content low. Correlations between wood anatomy and effective heating value were partly different on different soils. Correlations between holocellulose and anatomy were the opposite of the correlations between other chemical compounds and anatomy. The significant correlations between chemical composition and anatomy were commonly opposite in trees grown on peat than in trees grown on mineral soil. Particularly, vessel characteristics and fibre wall thickness correlated significantly with wood chemistry in trees grown on mineral soil. The connections between wood anatomy and chemistry proved to be soil-dependent.     

Early development of three planted indigenous tree species and natural understorey vegetation in artificial gaps in an Acacia mangium stand on an Imperata cylindrica grassland site in South Kalimantan,Indonesia

Early performance of two dipterocarp species Anisoptera marginata and Shorea parvifolia, and a long-living pioneer species Peronema canescens (Verbenaceae) planted in artificial gaps (size 260 m²) and surrounding untreated stands was studied in a fast-growing plantation of Acacia mangium on an Imperata cylindrica grassland site in South Kalimantan, Indonesia. Forty seedlings of each species were planted at one-meter intervals in lines across each of the five gaps, starting and ending under closed stand. Survival, height and diameter (d_0.05) increments were measured, and the effect of gap opening on the composition and abundance of understorey vegetation (grass, shrub and native tree seedlings and saplings) was studied. 19 months after planting, average survival rates were 97% for A. marginata, 94% for P. canescens and 71% for S. parvifolia, with no statistical differences between gap and closed stand. Substantial mortality and damage of dipterocarps were caused by wild boars; minor damage by dieback (for S. parvifolia) and insect pests (for A. marginata). Early growth was clearly influenced by distance from gap centre and light conditions; the growth of seedlings was greater the nearer the seedlings were situated to centre and the higher the level of daily photosynthetic photon flux density (PPFD) was. Gap opening increased the growth of shrub species Chromolaena odorata, but not that of Imperata grass. It also increased the density and height growth of saplings of native pioneer and secondary tree species. Seedling density increased both in closed stand and actual gaps, but was higher inside gaps.Results indicate good prospects for diversifying the composition of fast-growing forest plantations on severely degraded former forest lands and integrating slow-growing valuable species in plantation programs. Both in-depth ecophysiological studies on species-specific growth requirements, and practical oriented research on silvicultural options and economics need further studies.     

Repair and strengthening of timber cantilever beams

This research aims to study the feasibility of repair and strengthening of timber cantilever beams used in historic buildings. It is conducted to investigate the feasibility of using different valid materials and techniques to repair and strengthen timber cantilever beams in new and historic timber buildings. The study is performed in terms of structural performance as well as historic and architectural values. An experimental program of several different materials and techniques is executed. The results are driven in terms of initial cracking load, crack propagation for the tested samples at different loading stages, deflection values, and failure load for each repaired or strengthened material and technique. The main variables are timber types (new and historic), repair and strengthening materials (steel plates, Glass Fiber Reinforced Polymer wrap, and Carbon Fiber Reinforced Polymer laminates), repair or strengthening techniques (near surface mounted and externally bonded system), and cantilever length (1000 and 1250?mm). Test results indicated that using steel plates, glass fiber wrap, and carbon fiber laminates increases the value of failure loads and decreases the deflection at both; repaired and strengthened timber cantilever beams compared to control beams.     

耐寒桉树永州引种栽培技术研究

通过引种栽培试验表明：永州是桉树的适宜引种区，可大量发展桉树。以栽培邓恩桉、边沁桉表现最佳，它们不仅生长快、材质好，而且抗逆性强，既耐严寒又耐高温耐瘠薄。柳桉也可发展，史密斯桉、多枝桉在土层深厚、气候温和的地方可少量发展。赤桉在前1～2年表现较佳，生长快，但到以后几年生长趋缓，必须选出优良家系，才能大量种植。     

Cloning and RNAi Construction of a LEAFY Homologous Gene from Populus tomentosa and Preliminary Study in Tobacco

PtLFY, a LEAFY （LFY） gene, was cloned from Populus tomentosa （LM50） by PCR. Sequencing analysis indicated that PtLFY was 2629 bp long, composed of three exons and two introns and encoded 378 amino acids. The splice donor sites and the splice acceptor sites were in identical positions to the LFY and its homologues. The amino acid sequence inferred was 68%-99% homologous to those of LFY and its homologues by blast analysis in GenBank. The Southern blot analysis indicated that there was a single copy of the PtLFY gene in genomic DNA of male and female P. tomentosa （LM50 and 5082）. The pBI121-Ptalfy （reverse）-intron-Ptlfy-GUS-nos was constructed using RNA interference （RNAi） technique and verified by PCR and digestion identification and transformed into tobacco. Some transgenic tobacco plants were obtained by PCR and PCR-Southern identification. The growth was generally repressed in transgenic tobacco plants compared with wild-type ones and some phenotypic differences were observed.     

Comparison of tree growth and undergrowth development in aerially seeded and planted Pinus tabulaeformis forests

Direct seeding is a less expensive practice than planting and has the potential to become a viable alternative to transplanting for afforestation and regeneration purposes. As an effective and a less costly regeneration method, aerial seeding has been applied with several tree species. As early as 1956, Chinese people engaged in aerial seeding and stands with a total of 2.97×10⁷ hm² have been developed up to 2004. Our study tested whether the growth of planted Chinese pine (Pinus tabulaeformis Carr.) seedlings and its undergrowth development in northwest aspects differ from that of aerially sown seedlings on the northern and northwestern aspects of slopes. In 2007, we collected data such as height, diameter at breast height (DBH), clear bole height and canopy widths of trees, abundance, coverage, and frequency of shrubs and herbs from 21-year-old planted Chinese pine stands on a northwestern aspect (PNW), aerially sown stands in a northwest aspect (ANW) and aerially sown stands in a northern aspect (AN). Results showed that the relation of crown area and mean DBH was best fitted by a double inverse model for the ANW and AN forests and by a quadratic model for the PNW forest. There was no difference in the growth between ANW and AN forests, while growth was significantly higher in the PNW forest than in the ANW and AN forests. That was consistent with the Sorenson diversity indices in the shrub and herb layers, indicating that there was a large number of the same species in both aerially seeded stands, although their locations were different. Both the number of species in the undergrowth and the Shannon-Wiener index in the shrub layer were higher in the PNW stands than in the ANW and AN stands. Dominant families for all three stands were Rosaceae and Compositae in the shrub and herb layer, respectively. The dominant species for all three stands was Spiraea pubescens in the shrub layer, while the dominant species was different from each other in the three stands. The discrepancy in diversity and composition of species in the herb layer show that herbs are sensitive to shrubs in the three forests. High mortality and skewed diameter distributions reflect severe competition and too high a density in the aerially seeded forests. Thus, aerial seeding is a viable and effective regeneration technique, but management practices, such as thinning, should be applied to these forests.