The Driving Downturn: A Preliminary Assessment

Problem, research strategy, and findings: We examine why American driving fell between 2004 and 2013, weighing two explanations: that Americans voluntarily moved away from driving (“peak car”), and that economic hardship reduced driving. We analyze aggregate data on travel, incomes, debt, public opinion, and Internet access. These data lack the precision of microdata, but unlike microdata are available annually for years before, during, and after driving’s decline. We find substantial evidence for the economic explanation. During the downturn the cost of driving rose while median incomes fell. The economy grew overall, but did so unequally. Mass driving requires a mass middle class, but economic gains accrued largely to the most affluent. We find less evidence for “peak car.” If Americans voluntarily drove less, they would likely use other modes more. However, despite heavy investment in bicycle infrastructure and public transportation in the 2000s, demand for these modes remained flat while driving fell.

Takeaway for practice: If Americans were voluntarily abandoning automobiles for other modes, planners could reduce investments in automobile infrastructure and increase investments in alternative mobility. Driving’s decline, however, was not accompanied by a transit surge or substantial shift to other modes. The lesson of the driving downturn is that people drive less when driving’s price rises. Planners obviously do not want incomes to fall, but they should consider policies that increase driving’s price. Planners might also rethink the current direction of U.S. transit policy; transit use did not rise even when driving fell at an unprecedented pace.     

台湾桤木组培技术研究初报

利用台湾桤木的茎段和叶片为外植体,研究台湾桤木组培技术。结果表明:台湾桤木茎段的初代芽诱导存在较大难度,而桤木叶片诱导出愈伤组织则相对容易。     

朱启钤(桂辛)先生初步研究及其他——一份近代城市史视野中的历史人物研究简报

本文尝试将朱启钤(桂辛)先生的研究放在宏阔视野中进行观察,比较与分析:主要由3个部分组成:朱启钤研究偏差、朱启钤在中国近代市政史上的位置以及与朱启钤相关的讨论;文中除了着重解析朱启钤与中国近代市政关系外,对于同时代的梁启超、叶恭绰以及之后营造学社社员的梁思成、林徽因等也略有关联比较和论述,希望对于近代以来的"士"——知识分子的社会角色和知识结构演变兼有一定的讨论。     

Workshop On Intercity Networks In The Asia-Pacific Region: A Report

Between 1 to 4 April 1997, scholars and government officials from over twelve cities in the Asia-Pacific Region met at the Royal Melbourne Institute of Technology to discuss the formation of a research network on urban policies in some of the dynamic urban-centred regions that link the Southeast Asian, East Asian, North American, and Australian economies. (A list of participants is appended). The conference was sponsored by the Monash Asia Institute and the Faculty of the Constructed Environment, RMIT, and was hosted by RMIT's Department of Landscape, Environment, and Planning (LEAP).     

茶树白蚁防治试验初报

比较了室内触杀试验和诱杀坑试验对茶树白蚁的防治效果。结果表明,2.5%溴氰菊脂2000倍触杀效果最佳,用药后11 h,校正死亡率达100%;4种不同诱引材料诱蚁量达到高峰的时间各不相同,松树皮和干稻杆在10 d时达峰值,玉米杆和甘蔗渣在15 d时达峰值。     

Preliminary Report on the 17 February 2006 Leyte,Philippines Landslide

Following days of heavy rainfall, a large-scale landslide occurred in Southern Leyte Province, Philippines, burying almost the entire village of Guinsaugon and causing the death of more than 1000 people. The landslide, which occurred along the steep slope of Mt. Can-abag in the middle of the province, mobilized large amount of rocks and debris with estimated volume of about 10-15 million m³. This paper discusses the results of the damage investigation conducted in the area after the disaster, with emphasis on the general features of the landslide and on the hydro-geological aspects of the disaster. Based on the observations made from the field investigation as well as additional information obtained from various sources, the main causes of the landslide are identified, and several sources of potential hazards are pointed out.     

Preliminary Analysis Of Heavy Metals In The Kahrizak Landfill Leachate: A Conceptual Approach

No data have been published on the leachate quality for the Kahrizak landfill site, including heavy metal concentrations. Therefore concentrations of Cu, Zn, Pb, Cd, Ni, Co, Fe and Mn were measured in four fresh and older leachate samples during a 10 months period. Conceptually, heavy metals can be considered to be present in three phases: ( a ) Dissolved; ( b ) adsorbed onto suspended solids; and ( c ) adsorbed onto the suspended solids with particle sizes less than 0.45 w m. A method is proposed in this paper to measure the concentrations of heavy metals in each of the three phases. Other samples were analyzed for phases ( a ) and ( b ). Fresh leachate samples with lower pH values had higher dissolved concentrations of heavy metals than the older leachate samples with higher pH values. Particulate heavy metal concentrations were slightly lower at higher pH values.     

在广东地区使用装配式建筑初步分析报告

介绍国内外装配式建筑的应用情况并分析其特点,通过多个工程实例对广东省装配式建筑施工工艺进行分析探讨,包括节点处理、关键技术、成本分析等方面,提出了相关控制要点,同时提出装配式建筑推广使用中应注意及需解决的问题,旨在促进人们对该项新技术的了解从而促进其推广应用.     

武汉地区多肉植物产业发展报告

为了研究多肉植物在武汉地区未来发展的趋势,综述了多肉植物产业2012—2017年在中国的发展现状及在武汉地区发展多肉植物产业的优势与风险,发现中国多肉植物产业出现了种植规模与产量激增、商品苗价格下跌的问题,武汉地区有交通、市场优势,但存在气候、技术等风险。研究为武汉地区多肉植物产业的可持续发展提供了参考,但对多肉植物在国外发展情况的调查还不充分,今后需进一步研究多肉植物产业在国外的发展情况。     

梗阻性黄疸伴肾功能不全

step by step的疑难病例讨论     

芍药与牡丹组间杂种引种栽培初报

从美国引种栽培13个芍药与牡丹的组间杂种，对其物候期及主要性状进行了观测研究。结果表明，芍药与牡丹的组间杂种完全可以在北京的气候条件下正常生长，无病虫害出现，适应性强，几乎所有品种均能开花，并保持了较高的观赏价值，展现出组间杂种特有的优势。其生长习性似芍药，花似牡丹，兼具牡丹与芍药的共同特征与优点，株形优美，叶丛潇洒美观，叶色深绿亮丽，花朵品质高、黄色为主，花期介于牡丹芍药之间，具有广阔的应用前景。