街头食品的安全问题与控制

介绍了街头食品的定义、街头食品畅销的6个原因,以及街头食品的危害和街头食品不安全的5个原因,并指出解决街头食品安全问题的5个途径。     

基于植物多样性的衡阳市道路绿化研究

在采用抽样调查方法对衡阳市区道路绿化进行调查的基础上,分析了衡阳市道路绿地的物种组成、物种丰富度、频度及植物多样性组成。结果表明：衡阳市区道路绿地植物种类共有60种,其中木本植物50种,占总数的83.3%。木本植物中常绿植物35种,落叶树种15种;乔木20种,灌木30种。在乔木层中,樟树、广玉兰、桂花、二球悬铃木、欧美杨、雪松等出现频度及丰富度均较高;灌木层中出现频度及丰富度较高的植物有：红花檵木、海桐、石楠、月季、紫叶李等,并针对城市绿化现状与存在的问题提出了道路绿地建设的建议与对策。     

北京市街头绿地植物造景分析——右安街心花园

近年来北京市政府非常重视街头绿地的建设，街头绿地一方面可以改善城市小环境，另一方面可以为附近居民提供休闲场所。右安街心花园是2003年建造的一个街头绿地，其无论是在植物材料应用的种类上，还是在植物配置方面都有许多可取之处。笔者对其植物造景进行了分析，以期为今后街头绿地建设提供借鉴。     

Study on Inheritance and Development of Traditional Street, Lane and Courtyard in City Growth

City is not a concretionary but a dynamic matter. It should keep close touch with the animated tradition, and we should look forward to its future too. Thus we will be facing with the problem of inheritance and development of the tradition. Because the tradition is a potential for good as wdll as for evil, it can promote the development of a thing, and also may hinder its progress, so there should be correct attitudes to the traditional inheritance. This paper studies the modem application of the traditional street, lane and courtyard, which brings new vitality to the tradition and imparts fresh life to the modem city.     

The untold flavour of street food: Social infrastructure as a means of everyday politics for street vendors in Bandung,Indonesia

The existing literature on street vendors has largely examined processes of marginalisation of informal enterprises amid rapid urban development. At the same time, the resistance methods of street vendors against the constraints of urban development have been extensively explored. However, these studies tend to focus on the binary position between informal and formal, as well as on the overt confrontation and conflicts between vendors and the state, which risks simplifying the heterogeneity of interests in the everyday practice of street vending. Delving into the daily work of street vendors in Bandung city, this article explores the everyday practice of traders in order to identify their subtle forms of resistance to removal and to the negative perceptions attached to them. By adopting the analytics of ‘people as infrastructure’ (Simone, 2004) and the idea of ‘building blocks of success’ for small enterprises (Turner, 2003), this article argues that social infrastructure is constituted and practiced through the construction of personal relationships and varied forms of informal economic exchange between vendors and their customers, informal organisers and neighbours, as well as through the adoption of new technology. Social infrastructures have become a means of building everyday politics for street vendors and a vital way of challenging the negative perception attached to street vending activities.     

合肥市行道树生态效益研究

本文按道路长度的10%抽样调查合肥市市区100km2范围主要道路行道树现状,运用I-tree软件分析行道树结构,估算行道树生态经济效益,包括截留雨水、吸收CO2、改善大气质量、提供美学价值及储碳功能。研究结果表明：研究区主要道路行道树16种,计38800余株,其中香樟、广玉兰、二球悬铃木、国槐4个树种占行道树总数的68.7%;94.5%的行道树评为健康,显示总体健康状况较好,作为合肥市树的广玉兰因管护问题健康状况不佳;行道树中胸径<15cm 的小树比例高达64.6%,大多是近年道路改造后栽植。行道树发挥的年生态效益5145.8万元,其中截留雨水的效益占89%,另外储碳效益759.3万元;单株效益最高的是二球悬铃木,其次是栾树、国槐、乌桕,因这些树种胸径>30cm 的树木比例较高。分析行道树的结构与功能可为行道树规划、建设、管理提供必要的参考。     

City Residence in the View of Regional Culture: Protection and Renovationof Humanism in Luoyang Cross Street

Problems of cultural environmental protection are acute during the reconstruction of some historic cultural cities. In order to understand the regional cultural features of the old cross street of Luoyang in P. R. China, we analyze the principle of humanistic protection of the street. Based on this understanding, we put forward principles and methods for protection and renovation. We also studied creative ways to protect the historical culture block at present and in the future.     

反射路面对城市峡谷反射率的影响

太阳辐射在城市峡谷内形成多重反射,加剧城市热岛效应。峡谷太阳辐射吸收量与城市结构、墙体和路面反射率及时间显著相关。建立城市峡谷反射率数值模型,评估提高路面反射率能否有效提高城市峡谷反射率,并探讨反射路面对邻近建筑墙体的反射与散射辐射的影响。通过现场观测数据验证数值模型的可靠性。研究结果表明:建筑物高度与路面宽度之比(纵横比)是城市峡谷反射率最关键的影响因素,当峡谷纵横比<1.0时,路面反射作用较为明显;而且,相对于冬季,夏季时峡谷内反射路面能向邻近建筑物反射更多的额外散射辐射,而峡谷走向对额外散射辐射的影响较小。当峡谷纵横比<1.0时,建议采用反射路面缓解城市热岛。     

An Incremental Way of Town Designing in Three Gorges Area

Aiming at the problems emerging from the rapid construction of towns in Three Gorges Area,an incremental way of town designing is investigated, It is attempted to re-create a contemporary street and courtyard spaces, which evolved from the traditional local town spaces. As a conclusion, this paper puts forward some suggestion for further study and practice.     

Tactics and Ways for Renovation of Old Mountain Cities and Towns

The renovation of old mountain cities and towns is a main point in city construction nowadays. In this paper, the characters of economic and real estate development are analyzed to find out proper ways and new principles for renovation from two aspects as city planning and street space renewal to solve the new problems in our present work.     

A Deformable Model Interpretation Based on the Theory of Elasticity

Deformable models provide a unified account of a number of visual problems, including contour extraction, motion tracking as well as 3D reconstruction and stereo matching. To get a reality-based interpretation of the deformable model and its parameters, an approach originates from the theory of elasticity is proposed. The conclusion is helpful to further understanding the behavior of deformable model. A new way is provided to research deformable models from the theory of elasticity.     

高充电效率的恒流太阳能路灯控制器

针对传统太阳能路灯控制器主要存在充电效率低、恒流精度低的问题,提出基于多路脉冲宽度调制(PWM)恒流技术的新型太阳能路灯控制器的设计方案。该控制器采用复合式DC-DC变换器,通过控制多路PWM信号,实现高效地充放电功能。充电过程以改进的扰动观察法实现最大功率点跟踪(MPPT),提高充电效率;放电过程通过实时检测LED路灯的实际电流,动态调整相应PWM信号的占空比实现高精度恒流驱动LED路灯。实物测试结果表明该控制器能有效地改善充电效率和恒流源精度,充电速度提高了4%~7%,恒流源精度高达2.5%。     

杭州地区常见行道树滞尘效益研究

行道树的滞尘效益在城市绿化中有着重要的作用,为了筛选出滞尘能力强的行道树,对杭州地区实地调查及试验测定,结果表明：所选9种行道树中,冬季滞尘能力的顺序为：枫香＞黄山栾树＞鹅掌楸＞香樟＞无患子＞悬铃木＞杜英＞银杏＞乌桕;春季滞尘能力的顺序为：杜英＞香樟;夏季滞尘能力的顺序为：香樟＞杜英＞枫香＞无患子＞黄山栾树＞鹅掌楸＞悬铃木＞银杏＞乌桕;秋季各行道树的滞尘能力顺序为：黄山栾树＞无患子＞香樟＞杜英＞枫香＞银杏＞乌桕＞鹅掌楸＞悬铃木;所选9种常见的道路行道树中,一年中平均滞尘能力为：杜英＞黄山栾树＞枫香＞无患子＞香樟＞鹅掌楸＞悬铃木＞银杏＞乌桕,黄山栾树、银杏、悬铃木、无患子、枫香、鹅掌楸的四季滞尘能力从强到弱顺序均为冬季＞秋季＞夏季,杜英四季滞尘能力顺序为：春＞秋＞冬＞夏,香樟四季滞尘能力顺序为：冬＞秋＞夏＞春,乌桕四季滞尘能力顺序为：秋＞冬＞夏。     

Biological Activity and Quantification of Suspected Allelochemicals from Alfalfa Plant Parts

Autotoxicity restricts reseeding of alfalfa (Medicago sativa L.) after alfalfa until autotoxic chemical(s) breaks down or is dispersed into external environments. A series of aqueous extracts from leaves, stems, roots and seeds of alfalfa ‘Vernal’ were bioassayed against alfalfa seedlings of the same cultivar to determine their autotoxicity. The highest inhibition was found in the extracts from the leaves. Extracts at 40 g dry tissue l^?1 from alfalfa leaves were 15.4, 17.5 and 28.7 times more toxic to alfalfa root growth than were those from roots, stems and seeds, respectively. A high‐performance liquid chromatography (HPLC) analysis with nine standard compounds showed that the concentrations and compositions of allelopathic compounds depended on the plant parts. In leaf extracts that showed the most inhibitory effect on root growth, the highest amounts of allelochemicals were detected. Among nine phenolic compounds assayed for their phytotoxicity on root growth of alfalfa, coumarin, trans‐cinnamic acid and o‐coumaric acid at 10^?3 m were most inhibitory. The type and amount of causative allelochemicals found in alfalfa plant parts were highly correlated with the results of the bioassay, indicating that the autotoxic effects of alfalfa plant parts significantly differed.     

Changes in Seed Yield and Quality with Maturity in Onion (Allium cepa L., cv. 'Early Cream Gold')

Development of onion (Allium cepa L., cv. ‘Early Cream Gold’) seed under cool climate conditions in Tasmania, Australia occurred over a longer duration than previously reported, but similar patterns of change in yield components were recorded. In contrast to previous studies, umbel moisture content declined from 85 to 67 % over 57 days while seed moisture content decreased from 85 to 31 %. Seed yield continued to increase over the duration of crop development, with increasing seed weight compensating for seed loss resulting from capsule dehiscence in the later stages of maturation. Germination percentage was high and did not vary significantly from 53 to 77 days after full bloom (DAF), but mean germination time declined and uniformity of germination increased significantly over the same time period. The percentage abnormal seedlings declined with later harvest date, resulting in highest seed quality at 77 DAF. The results of this study suggest that the decision to harvest cool climate onion seed crops before capsule dehiscence will result in a loss of potential seed yield and quality.     

Location of a high-lysine gene and the DDT-resistance gene on barley chromosome 7

Summary The high-lysine gene in Risø mutant 1508 conditions an increased lysine content in the endosperm via a changed protein composition, a decreased seed size, and several other characters of the seed. The designation lys3a, lys3b, and lys3c, is proposed for the allelic high-lysine genes in three Risø mutants, nos 1508, 18, and 19. Linkage studies with translocations locate the lys3 locus in the centromere region of chromosome 7. A linkage study involving the loci lys3 and ddt (resistance to DDT) together with the marker loci fs (fragile stem), s (short rachilla hairs), and r (smooth awn) show that the order of the five loci on chromosome 7 from the long to the short chromosome arm is r, s, fs, lys3, ddt. The distance from locus r to locus ddt is about 100 centimorgans.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Simultaneous Determination of Four Phenolic Acids in Radix Salviae Miltiorrhizae Formula Granules by QAMS

[Objectives]This study aimed to establish a QAMS(quantitative analysis of multi-components by single-marker)method for simultaneous determination of four phenol...     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.