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1.
Text search is a type of strategic reading that involves locating specific goal-relevant information. Previous research has indicated that college and high school students often exhibit inefficient or unsuccessful text-search performance. Consequently, the effects of 2 manipulations on text-search performance were investigated: (1) the presence of indexed terms in a text-search task and (2) the use of a planning prompt before beginning a task. 34 college students engaged in 6 text-search tasks. Half of these tasks contained terms that could be used in an index; half required that a search term be generated. Half of the subjects were randomly assigned to a prompt condition in which they were prompted to plan their search before beginning each task. The results indicated that a planning prompt raised the success level of search performance, as did the presence of terms that were searchable in the textbook's index. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
2.
Abstract: Environmental justice advocates have recently focused attention on cumulative exposure in minority neighborhoods due to multiple sources of pollution. This article uses U.S. EPA's National Air Toxics Assessment (NATA) for 1996 to examine environmental inequality in California, a state that has been a recent innovator in environmental justice policy. We first estimate potential lifetime cancer risks from mobile and stationary sources. We then consider the distribution of these risks using both simple comparisons and a multivariate model in which we control for income, land use, and other explanatory factors, as well as spatial correlation. We find large racial disparities in California's “riskscape” as well as inequalities by other factors and suggest several implications for environmental and land use policy.  相似文献   
3.
Poor sanitation and insufficient disposal of sewage and faeces are primarily responsible for water associated health problems in developing countries. Domestic sewage and faeces are prevalently discharged into surface waters which are used by the inhabitants as a source for drinking water. This paper presents a decentralized anaerobic process technique for handling of such domestic organic waste. Such an efficient and compact system for treating faeces and food waste may be of great benefit for developing countries. Besides a stable biogas production for energy generation, the reduction of bacterial pathogens is of particular importance. In our research we investigated the removal capacity of the reactor concerning pathogens, which has been operated under thermophilic conditions. Faecal coliforms and intestinal enterococci have been detected as indicator organisms for bacterial pathogens. By the multiple regression analysis technique an empirical mathematical model has been developed. The model shows a high correlation between removal efficiency and both, hydraulic retention time (HRT) and temperature. By this model an optimized HRT for defined bacterial pathogens effluent standards can be easily calculated. Thus, hygiene potential can be evaluated along with economic aspects. In this paper not only results for describing the hygiene potential of a thermophilic anaerobic bioreactor are presented, but also an exemplary method to draw the right conclusions out of biological tests with the aid of mathematical tools.  相似文献   
4.
5.
The radiotracer technique as a means to investigate the corrosion of zirconium, tantalum, and a Ta-40Nb alloy in fluoride containing azeotropic nitric acid Zirconium and tantalum as well as the tantalum 40% niobium alloy are of considerable technical importance due to their high corrosion resistance against numerous corrosive media. With respect to corrosion testing in analytically pure azeotropic nitric acid in the temperature range between 20 and 121°C, corrosion rates were determined for zirconium: 7 · 10?6 to 5 · 10?4 mm/y, for tantalum: 10?8 to 4 · 10?6 mm/y, and for the Ta-40Nb alloy: 2 · 10?7 to 8 · 10?6 mm/y [1]. These corrosion rates will be markedly increased by adding small amounts of fluorides or by fluoride impurities. The radiotracer method after neutron activation was applied to determine the corrosion rates in azeotropic fluoride containing nitric acid. Even minute additions of fluorides strongly affect the corrosion resistance of zirconium. In the range between 0.15 and 10 ppm F? and at a temperature of 108°C, corrosion rates between 5.3 · 10?3 and 3.1 mm/y were measured. It was impossible to establish a limit for the fluoride concentration, below which the corrosion rate of zirconium will not be adversely influenced. The corrosion rates of tantalum and the Ta-40Nb alloy are considerably increasing above a fluoride concentration of 10 ppm. The highest corrosion rates measured were between 8.4 · 10?3 mm/y at 50°C/280 ppm F? and 1.4 · 10?2 mm/y at 110°C/320 ppm F?. Within the range of this investigation, the corrosion resistance of tantalum was higher than that of the Ta-40Nb alloy by one order of magnitude. The corrosion resistance of zirconium and tantalum was not influenced by any treatment of the samples before testing.  相似文献   
6.
Discusses the nature of autonomy and explores how autonomy as a therapeutic goal relates to clinical practice and the conduct of psychotherapy. Autonomy has been defined as the power to determine one's own best interests, and it has been criticized for promoting selfishness and reflecting upper-class values and gender bias. It is suggested that issues of autonomy are involved in the process of psychotherapy as well as its aim. In therapy, there is a dynamic tension between the principle of autonomy, the right of clients to determine their own interests, and the principle of beneficence, the therapist's obligation to protect the client's welfare. Whether autonomy is an appropriate ideal in psychotherapy for women or for men is considered. Feminist theorists have criticized aspects of masculine autonomy, contrasting it with feminine relatedness; however, the idealization of relatedness is questioned. It is concluded that the present conceptualizations of autonomy do not fully encompass the complexity of human interaction. It is argued that (a) autonomy and relatedness are not essential aspects of male and female nature but depend on power and status and (b) without social change, autonomy may not be a realistic goal of therapy for women. (46 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
Refractory Metals and their Application in the Chemical Process Industry Special metals, such as titanium, zirconium and tantalum, are being used increasingly for chemical plant. The exceptional resistance of special metals to many corrosive chemicals - they show it even at high temperatures and pressures - arises not from natural immunity but from the formation of a protective oxide passive layer on the metal surface. Special metals are well suited for welding. Their reactions with gases of the atmosphere must be taken into account though. Welding is therefore possible only under inert gas or a high vacuum. Similarly, alloying with iron-based materials during welding must be avoided under all circumstances. It should be taken into consideration that the melting point of tantalum, for example, is about twice as high as that of steel. Tantalum and niobium are machined with high-speed cutting steels; the cutting speed and cutting angle are similar to those used for stainless steels. In detail, the outstanding properties of special metals in chemical plant are as follows:
  • — the stability of titanium under oxidizing conditions
  • — the stability of zirconium under reducing and alkaline conditions
  • — the resistance of molybdenum to hydrofluoric acid and fluoride
  • — the stability of tantalum under oxidizing and reducing conditions.
In pure mineral acids the passive behaviour generally improves in the order titanium - zirconium - tantalum. Except where molybdenum is concerned, the medium should not contain fluoride. The material with the widest range of applications is tantalum. The addition of niobium as an alloying element leads to favourably priced but similarly resistant materials whose prospects of becoming established in the chemical industry and playing a part similar in importance to that of tantalum itself are good.  相似文献   
8.
The zodiac is widely known as a band of twelve celestial constellations. It also contains a mathematical model for cosmographic depiction, based on observations of the sun, moon, and visible planets as they traverse the celestial ecliptic. Here wee consider the zodiac as a timepiece or calendar; how this system of planets and constellations emerges from elementary geometric patterns; and how these patterns inform the symbols of the zodiac and frame our world view.  相似文献   
9.
A method is introduced for testing the conformance of implemented real-time systems to timed automata specifications. Uppaal timed automata are transformed into testable timed transition systems (TTTSs) using a test view. Fault hypotheses and a test generation algorithm for TTTSs are defined. Results of applying the method are presented. Received October 1999 / Accepted in revised form November 2000  相似文献   
10.
Levels of awareness for trauma and their consequences for research, treatment, and prevention within professional psychology and society are considered. When people must endure chronically traumatic environments, it may be adaptive to isolate from awareness information that would produce cognitive dissonance and threaten necessary relationships. Unawareness may also facilitate functioning in environments that invalidate the prevalence and impact of trauma. In addition, characteristics of the posttraumatic environment can promote or impede individuals' awareness of trauma and their psychological functioning. Though often initially adaptive, unawareness for trauma is linked to intergenerational transmission of trauma and its effects and may preclude public and professional attention to trauma treatment and prevention. Understanding the processes through which individuals become unaware or aware of traumatic experience is therefore essential to conducting effective psychotherapy with trauma survivors. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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