大庆市土壤环境质量时空变化特征分析及污染源分析

以大庆环境监测站提供的数据为依据,通过对大庆市1996~2010年土壤环境质量监测数据的数学分析,揭示了15年间大庆在石油资源开发和快速城市化过程中土壤重金属含量的时空变化特征。采用单项指数法(Pi)和Nemerow的综合污染指数(P)对大庆土壤质量进行评价。结果表明:大庆四个不同功能区(牧业草原区、农业开发区、石油化工区、油田开发区)中油田开发区综合污染指数最高,其次为石油化工区,牧业草原区综合污染指数最低。采用As、Cd、Cu、Pd四种重金属作为主要评价因子,其中对大庆土壤重金属污染贡献值最高的是Pd,其次为Cu。近15年来,四个功能区中的重金属浓度总体均呈上升趋势。另外通过对土壤中重金属来源进行测定和分析,结果显示目前落地原油并未对土壤产生重金属污染,但废钻井液对土壤重金属污染有较大影响。     

天然水中重金属——砷形态分析的研究

文章通过对湘江重金属——砷的研究,提出了一整套分析方法,该分析方法是根据国家标准在实践中探索获得的,并确保了分析数据的可靠、可比、可信。     

光学显微镜的视频数字化改造

文章介绍了光学显微镜视频数字化改造的具体实施过程,以及改造过程中的关键技术,同时阐述了该技术在社会上的推广应用价值。     

难熔金属合金及其应用

文章简述了难熔金属及难熔金属基合金的特点及常用种类,介绍了部分难熔金属合金的研究及在一些领域的应用。     

关于切削温度理论计算公式的探讨

本文综合应用金属切削变形、材料塑性变形等理论和热传导及能量转换原理,分别推导出了剪切温度、摩擦温度以及切削温度的理论计算公式。此公式可方便有效地、正确地分析影响切削温度的因素及其规律,对分析和解决切削过程中出现的现象和问题具有一定的指导意义。     

Schiff bases及配合物的研究进展

希夫碱配体及与后过渡金属元素所形成的配合物,以其多样的结构和广泛的用途愈来愈受到人们的重视.文章综述了Schiff base 配体及配合物的发展状况以及在生物化学、催化化学、分析化学、材料化学等方面的研究与应用,并指出了它的美好前景.     

Impact of Monetary Supply on Chinese Nonferrous Metal Price Movement*

Employing both classical vector autoregressive methodology and regression models utilizing shock factors constructed with the Hodrick–Prescott filtering method, this paper empirically studies the influence of monetary factors on the price of nonferrous metals and their expectation formation in the Chinese market. Monetary factors are found to significantly positively influence Chinese nonferrous metal prices, and further empirical research reveals that a structural change occurred near August 2006. There is an expectation formation mechanism of lagged futures prices on spot metal prices, and the risk originating primarily from international market is transmitted to Chinese markets.     

Clinical,humanistic, and economic outcomes between drug-eluting stent (DES) and bare metal stent (BMS): 18-month follow-up study

Background: Percutaneous coronary intervention (PCI) is one of the most performed interventions for ischemic heart diseases. In Hong Kong, the total number of patient discharges and deaths for ischemic heart diseases in 2009 was 33,363, including 4,360 deaths. There are over 5,000 cases of PCI yearly. This study aimed to compare clinical, economic, and humanistic outcomes among patients receiving drug-eluting stent (DES) or bare metal stent (BMS) in Hong Kong.

Methods: Patients who received stent implantation between September 15, 2009 and October 11, 2010 in Prince of Wales Hospital, Hong Kong, were recruited and followed for 18 months. Occurrence of major adverse cardiac events (cardiac death, non-fatal MI, TLR and TVR) was employed as the clinical outcome measurements. Improvement in quality-of-life by stent interventions was measured as quality-adjusted life-year (QALY). EQ-5D questionnaire was adopted to assess the QALY gained. Cost-utility analysis and cost-effectiveness analysis for BMS and DES were employed as the economic outcome measurement.

Results: Six hundred and eighty-four patients (DES?=?402; BMS?=?282) were included. From 0–18 months, TLR rate (2.7% vs 3.5%, p?=?.549) and TVR rate (3.7% vs 6.4%, p?=?.111) were lower in the DES group, but without statistical significance. EQ VAS (71.06?±?14.56 vs 71.07?±?16.57, p?=?.998) and utility score (0.81?±?0.17 vs 0.78?±?0.16, p?=?.162) were comparable between DES and BMS group. Overall, the cost per QALY gained was HKD + 1,178,100 and ICER was HKD + 187,000 (1USD?=?7.8 HKD).

Conclusions: No significant difference in TVR, TLR rates, EQ VAS, and utility score was found between the DES and BMS group. The higher cost of index procedure for the DES group was found to be partly offset by reduced cost of follow-up, offering cost-effectiveness in ACS patients, predominantly in STEMI patients. DES was recommended for STEMI patients.     

离子型稀土矿区土壤中重金属迁移转化特征

稀土矿长期开采导致矿区生态环境破坏问题日益严重,尤以重金属污染问题更为引起人们的广泛关注。文章简要分析了离子型稀土矿区重金属的来源及重金属对土壤、植物、人体产生的影响,并对稀土矿区重金属的迁移转化特征的影响因素(土壤质地、pH、有机质、稀土元素)进行详细综述。针对重金属污染问题与矿山可持续发展密切相关,提出了重金属污染防治的建议,以期为土壤生态安全和环境可持续发展奠定理论基础和科学依据。