首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   11篇
  免费   1篇
矿业工程   2篇
能源动力   1篇
轻工业   2篇
水利工程   1篇
冶金工业   6篇
  2018年   2篇
  2016年   1篇
  2010年   1篇
  2006年   3篇
  2004年   2篇
  2002年   1篇
  2000年   1篇
  1985年   1篇
排序方式: 共有12条查询结果,搜索用时 93 毫秒
1.
Alkalinity generation and metals retention were evaluated during the initial year of operation of a treatment wetland, consisting of four 185 m2 inseries cells comprised of alternating vertical-flow anaerobic substrate wetlands (VFs) and surface-flow aerobic settling ponds (SFs). The substrate in the VFs consists of spent mushroom substrate (SMS) and limestone gravel, supplemented with hydrated fly ash in a 20∶10∶1 ratio by volume. Approximately 15±4 L/min of acid mine drainage (AMD) from an abandoned underground coal mine in southeastern Oklahoma, USA, was directed to the system in October 1998 (mean influent water quality: 660 mg L−1 net acidity as CaCO3 eq., pH 3.4, 215 mg L−1 total Fe, 36 mg L−1 Al, 14 mg L−1 Mn, and 1000 mg L−1 SO4 −2). Flow through the first VF resulted in substantial increases in alkalinity, decreased metal concentrations and circumneutral pH. 258±84 mg L−1 of alkalinity was produced in the first VF by a combination of processes. Final discharge waters were net alkaline on all sampling dates (mean net alkalinity=136 mg L−1). Total Fe and Al concentrations decreased significantly from 216±45 to 44±28 mg L−1 and 36±6.9 to 1.29±4.4 mg L−1, respectively. Manganese concentrations did not change significantly in the first two cells, but decreased significantly in the second two cells. Mean acidity removal rates in the first VF (51 g m−2 day−1) were similar to those previously reported.  相似文献   
2.
This paper presents some findings of the FEMA and SEI/ASCE sponsored studies of structural performance of New York’s World Trade Center (WTC) following the attacks of September 11, 2001, and the Murrah Building following the April 19, 1995, Oklahoma City bombing. The WTC collapses were caused not by aircraft impact alone but by the combination of impact and the resulting fire that weakened structural members and connections. On the other hand, the Murrah Building collapsed as a direct result of the blast. Although these studies call for further research in a number of areas, this report summarizes some of the lessons learned.  相似文献   
3.
The terrorist attack on September 11, 2001, and subsequent potential threats to U.S. transportation systems have presented an urgent need to develop emergency response plans to quickly react to the possible consequences of extreme events. Extreme events include terrorist attack as well as man-made and natural disasters such as explosions, fires, floods, and earthquakes. The objective of this research was to identify strategies and technologies to quickly restore the use of highway bridges, a critical component of the nation’s transportation network, in case they are damaged or destroyed by extreme events. One of the tasks associated with this research was to conduct case studies of previous bridge replacements following extreme events. By studying these cases, the research team sought to identify and expand on lessons learned, address which actions did and did not work well given the circumstances of the incident, and incorporate lessons into the emergency response plan for highway bridges. This paper presents the findings from one of the case studies, the I-40 Webbers Falls Bridge in Oklahoma.  相似文献   
4.
The terrorist attack on September 11, 2001 and subsequent potential threats to the United States transportation systems have presented an urgent need to develop emergency response plans in order to quickly react to the possible consequences of an extreme event. Highway bridges, as critical components of the nation’s transportation network, have received increased attention. To respond to the potential threats on highway bridges, a research project was conducted to identify rapid bridge replacement processes, techniques, and needs for improvements. To achieve the research objectives, the research team studied three cases of previous bridge replacements following extreme events. By studying these cases, the research team first sought to identify and expand on lessons learned and then addressed which actions did and did not work effectively under the incident circumstances. Using the lessons learned government agencies and engineering and construction communities could enhance their emergency response plans for future incidents. Next, the research team identified needed improvements so that the research community could investigate new technologies to advance current practices.  相似文献   
5.
Abstract  A demonstration project was conducted to investigate treating acid mine water by alkaline injection technology (AIT). A total of 379 t of alkaline coal combustion byproduct was injected into in an eastern Oklahoma drift coal mine. AIT increased the pH and alkalinity, and reduced acidity and metal loading. Although large improvements in water quality were only observed for 15 months before the effluent water chemistry appeared to approach pre-injection conditions, a review of the data four years after injection identified statistically significant changes in the mine discharge compared to pre-injection conditions. Decreases in acidity (23%), iron (18%), and aluminum (47%) were observed, while an increase in pH (0.35 units) was noted. Presumably, the mine environment reached quasi-equilibrium with the alkalinity introduced to the system.  相似文献   
6.

BACKGROUND

The Oklahoma Mesonet (the statewide environmental and weather monitoring network) has monitored changes in weather patterns since 1994 to provide accurate and timely mesoscale weather information to farmers and other groups. Studies are still scarce that would quantitatively assess farmers' perceptions about the value of the Oklahoma Mesonet contributions to agricultural operations, profitability of land management, and decision making. This paper aims to analyze those questions by means of an exploratory empirical study in Oklahoma for two groups of Mesonet users and non‐users.

RESULTS

Familiarity with and application of Mesonet information determines farmers' profitability assessments and decision making. Farmers' perceptions are also influenced by the degree of previous exposure to weather‐related losses. The median estimate of the economic value of Mesonet information is $1000 per year. Mesonet users perceive higher profitability from the application of Mesonet data at 7.6/10, whereas Mesonet non‐users provided an average assessment of 2.6/10.

CONCLUSIONS

Consistent use of Mesonet information results in a higher assessment of the importance of Mesonet. This research provides some initial insights into farmers' perceptions about the value of Oklahoma Mesonet information, which could guide stakeholders in developing measures to better serve farmers with environmental monitoring data for improved farm decisions. © 2018 Society of Chemical Industry  相似文献   
7.
Purpose: An accumulation of disaster mental health research literature in the last few decades has contributed knowledge to direct disaster mental health interventions. However, no single set of principles can necessarily outline all anticipated mental health needs to be encountered in a particular disaster. Methods: To illustrate how different disaster scenarios may yield a divergence of mental health needs, this article compares mental health findings from two distinctly different studies of two very different populations affected by two very different disasters: directly exposed survivors the Oklahoma City bombing and sheltered evacuees from Hurricane Katrina. Results: Research on the two disasters reviewed illustrates many facets and complexities of postdisaster mental health needs in different populations in different settings after different types of disasters. The major findings of the Oklahoma City bombing study related to posttraumatic stress disorder and the main findings of the Hurricane Katrina study involved need for treatment of preexisting chronic mental health and substance abuse problems. Conclusion: The disaster studies in this review diverged in type of disaster, affected populations, setting, and timing of the study, and these studies yielded a divergence of findings. One disaster mental health model clearly cannot adequately describe all postdisaster scenarios. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
8.
The wetting-induced compression of compacted Oklahoma soils was investigated. One-dimensional oedometer tests were conducted on 22 Oklahoma soils that encompassed relative compaction and moisture contents within typical embankment specifications. Results show that factors directly related to the fines composition can be used for preliminary estimation of collapse potential. Statistical analysis of the oedometer test data indicates that variables having the most impact on collapse index were compaction moisture content, dry unit weight, plasticity index, and clay-size fraction. Charts were developed to facilitate the estimation of collapse settlement of fills for different conditions, including fill height, moisture content, and soil type. Three case histories involving embankments that experienced significant settlement are presented for comparison. The comparison shows a reasonable agreement between predictions and field estimates of collapse settlement at the embankment centerlines; the limited evidence suggests that predictions based on one-dimensional assumptions may underestimate actual settlements possibly due to the two-dimensional nature of embankments.  相似文献   
9.
The use of place and geography in wine marketing is well documented. Oklahoma, a state not often associated with producing wine, contains many wineries that use place to market their products. These wine producers construct specific and generic place-based identities that appeal to local and non-local wine consumers. In this study, we take an in-depth look at exactly how Oklahoma wineries use place and geography to market their products. We employ qualitative content analysis to evaluate the websites of 39 Oklahoma wineries, specifically focusing on graphics and text on wine labels and winery logos. Our analysis reveals the predominant themes presented on labels and logos that clearly connect the wine and/or winery to its location. Examples include noticeable links to Oklahoma historic events (e.g. Land Runs, boomer and sooner references), Native American culture, and local natural hazards (severe weather, especially tornadoes) to name a few. Importantly, the geographic scale at which most place associations occur is at the state-level. Rather than constructing more localized regional identities (e.g. based on region, which is very common), these wineries have cultivated a decidedly Oklahoman sense of place.  相似文献   
10.
This paper analyzes the technical and economic performance of solar heating systems that use vapor-compression cycles, circulating a compressible fluid as the working fluid. With conventional solar heating systems that use water or as their working fluid, the collector inlet temperature is equal to that of the storage outlet temperature. Operating the system on a cold day can result in large thermal losses to the surroundings and, thus, low useful heat gains. A vapor-compression cycle may be attractive because it allows the collector inlet temperature to be lowered so that the heat gain of the collector can be increased. Such a system is simulated and a preliminary economic analysis performed. The results indicate that the vapor-compression system can collect almost 50% more solar energy than a conventional system if the collector area of the two systems are the same.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号