ACEL 荧光粉粉末 ZnS:Cu,X 的电荷陷阱的性质与其电致发光频谱之间的联系

ZnS:Cu,X(X = Cl,Br,I) ACEL 荧光粉的性质主要决定于 Cu 发光中心的电子发光复合、ZnS 点阵中电子的注入效率、诱捕电子和逃逸电子的比率.热致发光中的电子陷阱依赖于掺杂剂以及荧光粉制备方法.文章描述了 ACEL 荧光粉的退火过程对其电致发光性质的深远影响.从热释光发光曲线上,我们可以看到烧结条件对电子陷阱特征的作用.由于荧光粉的 ACEL 性质与电子陷阱有关,为了提高荧光粉的性能,对电子陷阱的成因和所起的作用的了解就显得尤为重要.     

Knee injuries in female athletes

Female athletes are at increased risk for certain sports-related injuries, particularly those involving the knee. Factors that contribute to this increased risk are the differences in sports undertaken and in gender anatomy and structure. Gender differences include baseline level of conditioning, lower extremity alignment, physiological laxity, pelvis width, tibial rotation and foot alignment. Sports like gymnastics and cheerleading create a noncontact environment, but can result in significant knee injuries. In quick stopping and cutting sports, females have an increased incidence of anterior cruciate ligament (ACL) injury by noncontact mechanisms. Patellofemoral (PF) disorders are also very common in female athletes. Awareness of these facts helps the sports medicine professional make an accurate diagnosis and institute earlier treatment-focused rehabilitation with or without surgery. Further prospective and retrospective research is needed in areas of epidemiology, mechanisms, severity and types of knee injuries. The goal is to lessen the severity of certain knee injuries and to prevent others.     

Fees and therapy: Relation of source of payment to course of therapy at a community mental health center.

Examined the relationship between source of payment, divided into self-payers vs 3rd-party plus self-payers, and 3 therapy process variables for 404 admissions to a community mental health center. Overall analyses found that source of payment was significantly related to number of client contacts and length of stay. These relationships were maintained when the client's social class, age, and sex were taken into account. The implications for national health insurance coverage for mental health services are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Differences in the topoisomerase I cleavage complexes formed by camptothecin and wakayin, a DNA-intercalating marine natural product

Wakayin is bispyrroloiminoquinone isolated from a Clavelina sp. ascidian by cytotoxicity directed fractionation. Like camptothecin, it has been found to inhibit the topoisomerase I catalyzed relaxation of supercoiled DNA. Wakayin enhanced cleavage complex formation at the same DNA sequences as camptothecin. Both compounds showed dose-related increases in cleavage complex formation, though wakayin's effect is attenuated at high concentrations. Wakayin is a string DNA binder. Wakayin also differed from camptothecin in that its cleavage complexes were much less stable than those of camptothecin in 0.5 M NaCl. Again in contrast to camptothecin, wakayin stabilized cleavage complexes poorly, if at all, at 0 degree C.     

Oral contraceptives enhance the risk of clinical manifestation of venous thrombosis at a young age in females homozygous for factor V Leiden

In 29 patients (17 females) homozygous Arg 506 Gln mutation (FV Leiden) was identified. 25 had been investigated because of venous thromboembolism (VTE); four asymptomatic patients were found during family studies. The first VTE had occurred significantly earlier in females (median age [m] 26 years, range 17-49) than in males (m=38 years, range 21-82) (P=0.01). 12 females (80%) had taken oral contraceptives (OC, estrogen content 0.02-0.1 mg) for 6-150 months prior to thrombosis. Further triggering conditions in females were hormone replacement (n=1) and pregnancy (n=2). In 8/10 males the first VTE had occurred spontaneously--in two after surgery. The sites of VTE were deep vein thrombosis, pulmonary embolism, caval vein thrombosis and superficial thrombophlebitis. From our data we conclude that OC medication is the most important precipitating factor for VTE in females with homozygous FV Leiden.     

HIV risk correlates among non-injection cocaine dependent men in treatment

Guided by the AIDS Risk Reduction Model (ARRM), psychosocial correlates of HIV risk behavior were examined among noninjection cocaine dependent, heterosexual men (NI-CD-HM) in treatment. Subjects (N = 111) completed a structured interview to measure ARRM mediating variables and HIV risk behaviors. The results indicated that greater perceived susceptibility to contracting HIV, lower sexual self-efficacy, higher lifetime incidence of sexually transmitted diseases, and being under the influence of alcohol or other drugs during sex predicted having more sexual partners in the month prior to admission. Despite adequate knowledge of safer sex guidelines, subjects remained misinformed regarding certain aspects of HIV transmission. Men who perceived that their partners viewed condoms more positively and who exchanged drugs for sex were more likely to use condoms, yet condom use skills were typically inadequate to ensure effective prevention. These results suggest that HIV prevention interventions among NI-CD-HM should focus on improving knowledge, enhancing beliefs in the capacity to enact safer sex behaviors for preventing HIV and other STDs, building relevant skills (e.g., condom use, open sexual communication between partners), and emphasizing psychoactive substance abstinence. Couple interventions, in which partners actually rehearse safer sex negotiations, may be particularly effective in this regard.     

Properties of plasma oxyfluorides grown on GaAs

A glow discharge technique is used to grow native oxides and oxyfluorides on GaAs. The capacitance-voltage and conductance-voltage measurements of the resulting metal/insulator/semiconductor structures show vastly different properties. Specifically, the density of interface states in the d.c.-to-5 MHz range appears to be much lower at the oxyfluoride interface than at the oxide interface. Secondary ion mass spectroscopy analyses indicate that some fluorine ions are mobile and the fluorine concentration is reduced by about an order of magnitude after a thermal anneal at 450°C. X-ray photoemission studies indicate that the glass is a mixture of GaF₃ and AsOF₃ molecules.     

Experimental and theoretical luminous efficacies of phosphors used in combination with blue‐emitting LEDs for lighting and backlighting

Abstract— Phosphors that absorb blue light and emit in the green, yellow, and red have been synthesized, and their experimental and theoretical luminous efficacies are compared. It is proposed that a blue‐emitting LED in combination with red‐emitting Sr₂Si₅N₈: Eu²⁺ and green‐emitting SrGa₂S₄: Eu²⁺ phosphors is used as an energy‐efficient white‐light source for display backlighting applications.     

Light-emitting nanocasts formed from bio-templates: FESEM and cathodoluminescent imaging studies of butterfly scale replicas

Nanocasts comprising of red-light-emitting cubic Y(2)O(3):Eu phosphors were made from butterfly wing scale bio-templates. We report herein the first cathodoluminescent images made from such nanocasts and show that valuable insights into the nature of the internal structure of the casts can be gained by the use of this technique. The casts faithfully reproduced the fine sub-micrometre size detail of the scales, as was made evident by both FESEM and cathodoluminescent images that were collected from the same sample areas using a hyphenated FESEM-CL instrument. There was excellent agreement between the FESEM and cathodoluminescent images, the image quality of the latter indicating that the Eu(3+) activator ions were evenly dispersed in the Y(2)O(3):Eu phosphor on a sub-micrometre scale. The casts were made by infilling the natural moulds with a Y(2)O(3):Eu precursor solution that was subsequently dried and fired to convert it into the phosphor material. This method provides a simple, low cost route for fabricating nanostructures having feature dimensions as small as 20?nm in size, and it has the potential to be applied to other metal oxide systems for producing nano-and micro-components for electronic, magnetic or photonic integrated systems.