The routes to fruit: Governance of urban food trees in Canada

Interest in planting urban food trees (UFTs) in public spaces is growing in popularity as a form of urban greening and a potential food source. Currently there is minimal research on the governance and policy aspects of integrating food trees into cities. To fill this gap, we investigated the characteristics of UFT site governance and how it compares to current urban forest governance. Semi-structured interviews were conducted with relevant municipal officials in Calgary, Edmonton, Toronto and Victoria about their perspectives and involvement with UFT sites in their city. A scan of policy documents was completed to supplement the interviews. The interviews were analyzed using a deductive coding framework based on the Policy Arrangement Approach. We found that key actors at the UFT sites were local organizations and site champions, with minimal municipal engagement. Most site resources provided by municipalities were in-kind. There are also basic knowledge gaps about how to care for UFTs. Currently municipal by-laws prohibit the harvesting and removal of plant material, and are at odds with the purpose of UFT sites, with few municipalities fully integrating UFTs in policies. The primary discussion around UFTs centre concerns for public health and safety, management, and use of public space with limited discussions of benefits. This research demonstrates the value of co-governance models to support UFTs, while a shift in focus from risks to benefits could encourage additional resources and policy integration. Further, including UFTs into policy would also support foraging and food tree maintenance in public spaces, and more fully reflect the plurality of urban forest engagement.     

新型肉干加工工艺及质量控制方法研究

针对传统工艺生产的肉干存在质地坚硬、咀嚼困难和干燥时间过长等问题,在借鉴西式肉制品加工理论和工艺的基础上,提出了“先成型后切块”的肉干加工新工艺及其质量控制方法,研究了“肉干坯微波成型”和“肉干分段—平衡脱水”等新技术,系统探讨了影响新型肉干品质的关键因素。研究表明:①在温度4℃下对原料肉腌制18h,并在转速25r/min下滚揉120min,可以显著改善肉干的成型性和质地;②采用2450MHz微波在800W功率下,对原料处理2～4min,肉干坯定型和熟化效果较好;③与传统脱水工艺相比较,采用90℃→70℃→55℃分段—平衡脱水干燥工艺,不仅使肉干的干燥脱水时间缩短了18%,且其产品质地均匀;④先成型后切块工艺加工的肉干易于咀嚼。新工艺加工的肉干,更能适应现代市场对于肉干制品质地、口感和营养等方面的需求。     

大孔树脂ADS-7分离纯化多穗柯黄酮工艺研究

采用大孔树脂ADS-7分离纯化多穗柯黄酮粗提物(CE),对主要工艺条件进行了研究。得出最佳工艺条件为:将CE先配成10%(体积分数)CE溶液,10?溶液体积与树脂质量比值(mL∶g)略大于3、在中性pH值下静态吸附2 h,再以3倍装柱体积(1 500 mL)的80%(体积分数)乙醇、每小时1倍装柱体积流速进行动态洗脱。该工艺条件得到的纯化产物中黄酮的质量分数由粗提物中的40%提高到纯化产物的88%,得率为91%。     

Lignin Characterization of Triploid Clones of Populus tomentosa Carr.

In order to understand the structural characteristics of lignin in triploid clones ofPopulus tomentosa and its changes in the processes of pulping and bleaching, milled wood lignin （MWL）, lignin carbohydrate complex （LCC） and the residual lignin from kraft pulp （KP） and sulfite pulp （SP） were isolated and analyzed by Fourier transform infrared （FTIR） spectrum and ^13C nuclear magnetic resonance （NMR）. The most diagnostic peaks were assigned and the differences were discussed. The spectral patterns reveal that triploid P tomentosa shows the specific features of hardwood from temperate areas, but in the spectrum of FTIR, the strength ratio orAl270 cm^-1 to A1226 cm^-1 is 0.88, higher than the average of hardwood from temperate areas, which will make the lignin delignification more difficult during pulping and bleaching. The LCC from triploid P tomentosa is mainly composed of xyloglucan and glucuronic acid, and other glucides have much lower ratio. In LCC FTIR, there are three peaks at 1 427, 1 329 and 1 046 cm^-1, indicating that both semi-cellulose and cellulose could exist in LCC, and that there might be relationships between cellulose and lignin. Compared with the residual lignin from KP and SP, the condensed structure in KP is more than that in SP.     

Analysis of the structure of lignin-carbohydrate complexes by the specific13C tracer method

In the present study the specifically¹³C-enriched lignin precursors of biosynthesis (i.e., coniferin-[side chain–¹³C], coniferin-[side chain-–¹³C] and coniferin-[side chain-–¹³C]) were synthesized and administered exogeneously to ginkgo shoots (Ginkgo biloba L.) to obtain¹³C-enriched lignin-carbohydrate complexes (LCCs). The specifically¹³C-enriched LCCs were isolated from the newly formed xylem of ginkgo shoots administered with the¹³C-enriched precursors and degraded by enzymes. Lignin-rich fractions, so called enzyme-degraded LCCs (EDLCCs), were obtained. By determining their¹³C-NMR spectra, information related to the chemical structure of lignin building units and linkages between phenylpropane units of lignin and carbohydrates were obtained. It was found that these precursors were incorporated in natural lignin successfully. Three lignin-carbohydrates linkages (i.e., ether type, ester type, ketal type) were found at the C -position of the side chain of phenylpropane units in ginkgo LCC. No lignin-carbohydrate bond at the C- or C-position of the lignin side chain was observed in the¹³C-NMR spectra of the¹³C-enriched LCCs. This fact indicates that a specific¹³C tracer technique can be useful in NMR study of the chemical structure of LCCs.Part of this paper was presented at the 5th Pacific Polymer Conference, Kyongju, Korea, October 1997     

竹子深度脱木质素蒸煮与常规硫酸盐法蒸煮的比较

为了提高竹浆性能和减少环境污染,对福建丛生小径竹进行了实验室模拟延伸改良连续蒸煮(EMCC)和常规硫酸盐法蒸煮(CKC)的研究。结果表明,EMCC蒸煮通过分段加入蒸煮药液和在逆流段进行药液置换,比CKC具有更高的脱木质素选择性。在蒸煮相同卡伯值的竹浆时,EMCC浆比常规硫酸盐浆(CK浆)具有更高细浆得率、较低粗渣率、更高粘度和更好强度性能。在相同的打浆度下,EMCC浆抗张指数、耐破指数和撕裂指数都比常规硫酸盐浆高。     

基于LabVIEW的涡旋盘型线测试系统

介绍了基于虚拟仪器的渐开线涡旋型线测试系统,分析了该系统的机构原理,系统误差及误差纠正方法。该系统是利用直线运动与旋转运动的合成运动形成标准的圆渐开线轨迹,与待测零件型线轨迹进行比较的方法,进行测量型线轮廓度的误差;通过运用角编码器及丝杠误差的软件修正,可以较好的消除系统误差。将虚拟仪器技术应用到涡旋型线测试系统中,能...     

基于SUSAN角点的秧苗列中心线提取方法

中国南方水田环境复杂,不同生长阶段秧苗的形态各异,且田中常出现浮萍及蓝藻,其颜色与秧苗颜色极其相似,因此常用的作物特征提取算法难以应用在水田上。针对这些问题,该文提出一种基于SUSAN角点的秧苗列中心线方法。运用归一化的Ex G(excess green index)提取秧苗的灰度化特征,运用自适应的SUSAN(smallest univalue segment assimilating nucleus)算子提取秧苗特征角点;最后运用扫描窗口近邻法进行聚类,采用基于已知点的Hough变换(known point Hough transform)提取秧苗列中心线。经试验验证,此算法在图像中存在浮萍、蓝藻和秧苗倒影的情况下有较高的鲁棒性。在各种情况下均成功提取秧苗的列中心线,且每幅真彩色图像(分辨率:1280×960)处理时间不超过563 ms,满足视觉导航的实时性要求。     

土壤沉积物样品中有机碳含量的快速测定

采用微波密闭消解样品的方法来测定土壤／沉积物中有机碳的含量。与重铬酸钾氧化法的结果相比，微波消化法具有操作简单、污染小、快速准确的优点。经F检验法及t检验法检验，两种方法的分析结果无明显差异。     

城市垃圾处理产业化及其高效循环发展新模式浅析

广州番禺区建垃圾焚烧厂的规划被迫暂停,反应出目前我国计划大量实施的垃圾简单收集及其焚烧法无法真正实现＂资源-产品-再生资源-再生产品＂这种投入少、污染小的高效循环经济模式。垃圾处理应产业化,应该和其它产业的链接中实现对同类废弃资源的循环利用。实现这种高效循环经济发展新模式,这其中关键的是生产合适的垃圾分类箱,发挥个人作为垃圾分类回收的主体作用。