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181.
Carbon encapsulated iron nanoparticles(CEINPs) with very thin shells and good core-shell structures were prepared by DC arc discharge at argon intake temperature(AIT) of 800 ℃. The results of high resolution transmission electron microscope(HRTEM), energy dispersive X-ray(EDX) spectroscope, X-ray diffraction(XRD), and X-ray photoelectron spectroscope(XPS) characterizations on the product B show that the thickness of the carbon shells of CEINPs in the product B is in the range of ca. 0.5—5.3 nm, i. e., which can be as thin as only two layers of graphite. The average diameter of the CEINPs is about 24. 7 nm. The total content of Fe element in the product B is 77.0 wt%. The saturation magnetization(Ms) and coercivity(Hc) of the product B are 107.4 emu/g and 143 Oe, respectively. The formation of the CEINPs in the product B is discussed briefly. 相似文献
182.
In this paper, silt sediment is considered to be Bingham body, which is made up of coarse and fine particles in front of a hydraulic gate. The coarse and fine particles provide friction and shear stress in the course of opening the gate. They constitute together the adhesion force of the sediment. Based on this viewpoint, this paper puts forward a formula for the effect of silt sediment on the lifting force. The formula includes gate weight, down-suction force, sealing rubber friction, plus-weight, water-column pressure, plus-silted-sediment weight and rolling (or sliding)-bearing friction. Finally, the verification results show that the formula has certain reliability and the calculation accuracy can meet the need of practical engineering. 相似文献
183.
A neuro-space mapping(Neuro-SM) for modeling heterojunction bipolar transistor(HBT) is presented, which can automatically modify the input signals of the given model by neural network. The novel Neuro-SM formulations for DC and small-signal simulation are proposed to obtain the mapping network. Simulation results show that the errors between Neuro-SM models and the accurate data are less than 1%, demonstrating that the accurcy of the proposed method is higher than those of the existing models. 相似文献
184.
The Bacillus strain BH072 isolated from a honey sample showed strong antifungal activity against phytopathogen. Gene cloning test demonstrated that the strain had a tasA gene encoding an antifungal TasA protein. Although the wild strain simultaneously produced various antifungal substances, only the physicochemical property and antifungal activity of TasA protein were unclear due to the difficulty in extraction. In this study, tasA gene encoding the protein from Bacillus sp. BH072 was amplified by using the polymerase chain reaction (PCR) method and cloned into pET 28a (+) vector, and then expressed in host cells Escherichia coli BL21 (DE3). The expressed proteins were collected by centrifugation and ultrasonic treatment, and then purified by using nickel-nitrilotriacetic acid (Ni-NTA) metal affinity column and dialysis methods. The result of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) test showed that an expected protein band appeared with a size of 31 kDa. The expressed products possessed antifungal activity against the phytopathogenic indicator strain Botrytis cinerea. A genetically engineered strain tasA of E. coli was established in this study which can efficiently express Tas A protein. 相似文献
185.
Individual Differences in Childhood Behavior Disorders Associated With Epigenetic Modulation of the Cortisol Receptor Gene 下载免费PDF全文
Mark R. Dadds Caroline Moul David J. Hawes Antonio Mendoza Diaz John Brennan 《Child development》2015,86(5):1311-1320
Behavioral/emotional difficulties in children are the first sign of mental health problems. These problems are however, heterogeneous. A domain that may identify homogenous subgroups is hypothalamic–pituitary–adrenal function. This study tested whether epigenetic regulation of glucocorticoid receptor gene could explain the co‐occurrence of anxiety problems in children with behavior problems. Four‐ to 16‐year‐old clinically referred children (N = 241) were measured for psychiatric symptoms, methylation of target CpG sites in blood or saliva, and morning cortisol levels in those who gave blood. Increased methylation of promoter 1F CpG sites was associated with higher vulnerability to co‐occurring internalizing symptoms and morning cortisol. The results support increasing optimism that epigenetic regulation of key neuroendocrine systems might help explain hitherto unfathomable individual differences in susceptibility to psychiatric symptom profiles. 相似文献
186.
Mikyong?Kim-GohEmail author Hyunmi?Choi Myeong?Sook?Yoon 《International journal for the advancement of counseling》2015,37(1):63-76
Research has consistently found acute mental health treatment disparities among Asian Americans. One proposed reason for the underutilization of mental health services by Asian Americans is that available services are not culturally competent. This exploratory study presents qualitative data gathered from interviews with professional counselors who serve Asian American clients. Findings revealed significant barriers to counseling due to cultural stigma and shame, suppression of emotions, and communication gaps between clients and counselors. In response, clinicians frequently made adjustments to therapeutic approaches to accommodate the cultural beliefs and practices of clients and families. Implications for practice and research are discussed. 相似文献
187.
188.
The effect of technology-enhanced learning (TEL) strategies in higher education has arguably been transformative despite the not-insignificant barriers existing in this context. Throughout the discourse very little attention has been paid to those primarily responsible for this implementation—academic teaching staff. This paper aims to highlight the impact of academic workload allocations, an often silent barrier to the uptake of TEL strategies in higher education. We will discuss the effects of academic identity and culture, preferential time allocation to associative activities, academic technological capacity, university policies and workload and funding models on the uptake, and implementation on TEL in higher education. Our aim is to highlight the risks to staff, students and institutions should these concerns not be addressed and to propose a model for utilisation by all staff responsible for implementing flexible workload models supportive of further implementation of TEL strategies across the sector. 相似文献
189.
Caroline Lanskey 《International Journal of Inclusive Education》2015,19(6):568-582
Many young people in the youth justice system in England and Wales are educationally marginalised and systemic barriers to their engagement with education persist. This article presents an analytical framework for understanding how education and youth justice practices shape young people's educational pathways during their time in the youth justice system with the aim of understanding the systemic dynamics that encourage or impede young people's engagement with education. It draws on data from a case study of 32 young people who were serving either a community or a custodial sentence under the supervision of one youth offending team in England and Wales. Using as analytical starting points Bourdieu's and Wacquant's conceptualisations of competing dynamics within the ‘bureaucratic field’ of state governance and Hodkinson's careership theory, this article discusses the interplay between exclusionary and inclusionary interests operating within and between the agencies of education and youth justice and the extent to which they play a role in sustaining young people's involvement in education or compounding their educational and social marginalisation. 相似文献
190.