Preparation of N-doped carbon dots based on starch and their application in white LED

N-doped carbon dots (CDs) were synthesized simply and economically by a one-step hydrothermal method using starch as a carbon source and ethylenediamine (EDA) as a nitrogen dopant. The prepared CDs possess the properties of excitation-wavelength dependence and emit blue fluorescence under the excitation wavelength of 365 nm. CDs/starch composite was prepared to achieve the solid-state emission of CDs and their application in light emitting diode (LED) as fluorescent materials. White LED, with CIE coordinates of (0.33, 0.37) and correlated color temperature of 5462 K, was obtained by combining CDs/starch and ultraviolet LED light source, indicating that starch-based CDs have the promising potential in the field of optoelectronic devicesPeer reviewe

Distributed Least Squares Algorithm for Continuous-time Stochastic Systems Under Cooperative Excitation Condition

In this paper, we study the distributed adaptive estimation problem of continuous-time stochastic dynamic systems over sensor networks where each agent can only communicate with its local neighbors. A distributed least squares (LS) algorithm based on diffusion strategy is proposed such that the sensors can cooperatively estimate the unknown time-invariant parameter vector from continuous-time noisy signals. By using the martingal estimation theory and Ito formula, we provide upper bounds for the estimation error of the proposed distributed LS algorithm, and further obtain the convergence results under a cooperative excitation condition. Compared with the existing results, our results are established without using the boundedness or persistent excitation (PE) conditions of regression signals. We provide simulation examples to show that multiple sensors can cooperatively accomplish the estimation task even if any individual can not

Thickness effect of a thin film on the stress field due to the eigenstrain of an ellipsoidal inclusion

AbstractSolutions of the stress field due to the eigenstrain of an ellipsoidal inclusion in the film/substrate half-space are obtained via the Fourier transforms and Stroh eigenrelation equations. Based on the acquired solutions, the effect of a thin film’s thickness on the stress field is investigated with two types of ellipsoidal inclusions considered. The results in this paper show that if the thickness of the thin film increases, its effect on the stress field will become weaker, and can even be neglected. In the end, a guide rule is introduced to simplify the calculation of similar problems in engineering

Dimensional Measurement of Small Hot Pieces Based on a Monochrome CCD

AbstractFor the purpose of controlling the quality of forging process, a low-pricedmonochrome CCD is adopted to establish avision measurement systemto gauge the two-dimensional sizes of hot parts accuratelyin the paper. To derive the two dimensions of the forgings, comparison measurement method is employed. In the system, images are taken by the CCD through an infrared filter to filter out the strong light emitted from the forgings. And thenaverage filtering and morphological filtering are used to reduce the effect of image noise. In order toimprove the precision of geometry position, image distortion is corrected to reduce theoptical distortion errors. After that, the edges in images are extracted at sub-pixel level to improve the location accuracy of geometry features. After calibration, the horizontal equivalent size of a pixel is 0.119mm, while the vertical 0.120mm. As be verified, the horizontal measurement uncertainty is 0.0069mm, while vertical 0.0063mm. Images of a 45# steel cuboid at 1000°C are captured and its dimensionsare calculated through the procedure described in the paper, which have a difference less than 0.5mm compared with the theoretical values, indicating the precision and practicality of the method proposed in the paper

Extreme Events design and Mitigation Methods: A Review

Recently, extreme events have highlighted their potentially tragic effects on structural and infrastructure systems. Resilience of the Community to these extreme vents is an important issue of increasing more concern for developing design methods. Such extreme events scenarios involve many uncertainties, such as the intensity, location, and period. The extreme events may include those caused by various natural or manmade hazards, such as earthquake, strong winds, fire, blast, etc. Compared to other events, earthquake and wind are particularly critical due to their significant threats to the global structure performance and more challenges for design. Researchers have recognized that proper evaluation, modeling, and assessment of the effects of extreme events are fundamental to ensure the desired performance of structures. Therefore, the concern for developing appropriate methodologies to evaluate and design structures that can withstand the effects of extreme events has become a very active field of research in recent years. Improvement of building codes and development of new strategies are needed to mitigate the disastrous effects of extreme events. This paper presents a comprehensive review of literature surrounding designing building structures for extreme events. First, a general overview of the extreme events design and different objectives of approaches is conducted. Furthermore, a review related literature surrounding designing for earthquake resistance guidelines is presented, also highlights Performance-Based Seismic Design objectives. The available literature includes many studies for the provisions included in different design codes (China, United States and Europe).  A review of literature related to wind resistance design with an overview of Performance Based Wind Design of building design method for the control of winds impacting on building structures is also presented

In vivo consequences of deleting EGF repeats 8–12 including the ligand binding domain of mouse Notch1

<p>Abstract</p> <p>Background</p> <p>Notch signaling is highly conserved in the metazoa and is critical for many cell fate decisions. Notch activation occurs following ligand binding to Notch extracellular domain. <it>In vitro </it>binding assays have identified epidermal growth factor (EGF) repeats 11 and 12 as the ligand binding domain of Drosophila Notch. Here we show that an internal deletion in mouse Notch1 of EGF repeats 8–12, including the putative ligand binding domain (lbd), is an inactivating mutation <it>in vivo</it>. We also show that maternal and zygotic <it>Notch1</it>^{<it>lbd</it>/<it>lbd </it>}mutant embryos develop through gastrulation to mid-gestation.</p> <p>Results</p> <p><it>Notch1</it>^{<it>lbd</it>/<it>lbd </it>}embryos died at mid-gestation with a phenotype indistinguishable from <it>Notch1 </it>null mutants. In embryonic stem (ES) cells, Notch1^lbdwas expressed on the cell surface at levels equivalent to wild type Notch1, but Delta1 binding was reduced to the same level as in <it>Notch1 </it>null cells. In an ES cell co-culture assay, Notch signaling induced by Jagged1 or Delta1 was reduced to a similar level in <it>Notch1</it>^{<it>lbd</it><it/>}and <it>Notch1 </it>null cells. However, the <it>Notch1</it>^{<it>lbd</it>/<it>lbd </it>}allele was expressed similarly to wild type Notch1 in <it>Notch1</it>^{<it>lbd</it>/<it>lbd </it>}ES cells and embryos at E8.75, indicating that Notch1 signaling is not essential for the <it>Notch1 </it>gene to be expressed. In addition, maternal and zygotic <it>Notch1 </it>mutant blastocysts developed through gastrulation.</p> <p>Conclusion</p> <p>Mouse Notch1 lacking the ligand binding domain is expressed at the cell surface but does not signal in response to the canonical Notch ligands Delta1 and Jagged1. Homozygous <it>Notch1</it>^{<it>lbd</it>/<it>lbd </it>}mutant embryos die at ~E10 similar to <it>Notch1 </it>null embryos. While Notch1 is expressed in oocytes and blastocysts, Notch1 signaling via canonical ligands is dispensable during oogenesis, blastogenesis, implantation and gastrulation.</p

The Core Values of Principals in School Management under Chinese Education Reform

The values of principals in school management play a pivotal role in shaping school leadership, teacher behaviours, and student performance. However, research studies focusing on principals’ values are relatively abundant in Western countries, yet still limited in the Chinese context. To fill this gap, this paper adopts a qualitative research approach to investigate the fundamental values of Chinese principals in leading and managing primary schools within the current education reform landscape. The findings reveal that the principals in the study emphasised nine core values: equity, fairness, openness, respect, empowerment, encouragement, recognition, trust, and democracy. These values were found to contribute to a positive school climate that promoted the growth of teachers, students, and the school. The results have significant implications for policy makers and principals in China, suggesting the necessity to foster ethical and relational skills among principals and to acknowledge the invaluable contributions of teacher leaders and teachers in school development. Keywords: principals, values, school management, education reform DOI: 10.7176/JEP/14-24-09 Publication date:August 31st 202