Controlled Synthesis of Silver Nanoparticles Using Double Reductants and Its Voltammetric Characteristics Study

Constructing robust silver nanoparticles (AgNPs) with good shape and dispersibility is of particular interest in analytical applications. Herein, monodispersibility AgNPs with the average size of 20 nm have been successfully prepared via one-pot method using sodium borohydride and trisodium citrate as co-reductants. The introduction of sodium borohydride greatly accelerated the rate of nucleation, which can effectively solve the problem of broad size distribution. Both shape and dispersibility of AgNPs can be effectively adjusted by simple control of refluxing time or concentrations of the sodium borohydride. We also studied the voltammetric characteristics of the AgNPs using Ag/AgCl solid-state voltammetry. An intense and stable current peak at a low potential could be obtained, which could provide a unique advantage in analytical applications. Copyright © 2016 BCREC GROUP. All rights reserved Received: 5th November 2015; Revised: 21st January 2016; Accepted: 22nd January 2016 How to Cite: Duan, Y., Xu, Z., Jiang, X. (2016). Controlled Synthesis of Silver Nanoparticles Using Double Reductants and Its Voltammetric Characteristics Study. Bulletin of Chemical Reaction Engineering & Catalysis, 11 (1): 115-119. (doi:10.9767/bcrec.11.1.433.115-119) Permalink/DOI: http://dx.doi.org/10.9767/bcrec.11.1.433.115-11

BIOMEDICAL IMAGE RESOLUTION IMPROVEMENTS BY COMBINED USE OF FOCAL MODULATION, PUPIL ENGINEERING, AND SPARSITY PRIORS.

Ph.DDOCTOR OF PHILOSOPH

Calculation and Analysis of the Loads of Dou-Gong Brackets on Ming Dynasty Wooden Buildings in China

Constructions of Chinese ancient wooden buildings not only perform a seismic behavior but also benefit stability of the whole structures under static loads to protect Chinese ancient wooden buildings. Based on the surveying and mapping of JinciMirror Terrace and the collected data, load on the Mirror Terrace is calculated to provide the accurate value of the load, which can be used to determine the repair plan and provide a reference for later calculation of similar ancient buildings. The static stability is analyzed to determine whether the main components of the Mirror Terrace have good performance, discover the structural ideas of the ancients during construction, and provide a basis for the protection and maintenance of the buildings

H ∞ Model Reduction of 2D Markovian Jump System with Roesser Model

Abstract: This paper extends the results obtained for one-dimensional Markovian jump systems to investigate the problem of H ∞ model reduction for a class of linear discrete time 2D Markovian jump systems with state delays in Roesser model which is time-varying and mode-independent. The reduced-order model with the same randomly jumping parameters is proposed which can make the error systems stochastically stable with a prescribed H ∞ performance. A sufficient condition in terms of linear matrix inequalities (LMIs) plus matrix inverse constraints are derived for the existence of a solution to the reduced-order model problems. The cone complimentarity linearization (CCL) method is exploited to cast them into nonlinear minimization problems subject to LMI constraints. A numerical example is given to illustrate the design procedures

Incidence and Survival of Patients With Malignant Primary Spinal Cord Tumors: A Population-Based Analysis

Objective Epidemiological studies on spinal cord tumors are rare, and studies on primary intramedullary tumors are even rarer. The incidence and survival of patients with primary intramedullary spinal cord tumors have not been well documented. We aimed to study the incidence and survival of patients with primary spinal cord malignant and borderline malignant tumors based on data from the Surveillance, Epidemiology, and End Results (SEER) database and provide information for revealing the epidemiology and exploring the prognosis of patients with primary intramedullary tumors. Methods Patients in the SEER database with microscopically diagnosed malignant and borderline malignant primary spinal cord tumors from 2000 and 2019 were included in this study. We analyzed the distribution of patients according to the demographic and clinical characteristics. Then, we extracted the incidence rate and 5-year relative survival for the whole cohort and different subgroups of the cohort. Finally, multivariate Cox proportional hazards models were used to analyze the independent prognostic factors associated with overall survival. Results A total of 5,211 patients with malignant and borderline malignant primary spinal cord tumors were included in this cohort study. Ependymoma, astrocytoma (including oligodendrogliomas and glioblastoma), lymphoma and hemangioblastoma were the most common pathological types. The age-adjusted incidence rates of primary spinal cord ependymoma was 0.18 per 100,000. The incidence rate for females was significantly lower than that for males. The incidence rate was highest in Caucasian. The incidence rate of ependymoma was significantly higher than that of other pathological types. The incidence of astrocytoma was highest among people aged 0–19 years, the incidence of ependymoma was highest among people aged 40–59 years, and the incidence of lymphoma was highest among people aged 60 years or older. The 5-year observed survival and relative survival rates for the whole cohort were 82.80% and 86.00%, respectively. Patients diagnosed with ependymoma had significantly better survival than their counterparts. We also found the impact of surgery and chemotherapy on the prognosis of patients with different tumors varies a lot. Conclusion We conducted a population-based analysis of malignant and borderline malignant primary spinal cord tumors with the aim of revealing the epidemiology and survival of patients with primary intramedullary spinal cord tumors. Despite some shortcomings, this study provides valuable information to help us better understand the epidemiological characteristics of primary intramedullary spinal cord tumors

Pyrogenic carbon in Australian soils

Pyrogenic carbon (PyC), the combustion residues of fossil fuel and biomass, is a versatile soil fraction active in biogeochemical processes. In this study, the chemo-thermal oxidation method (CTO-375) was applied to investigate the content and distribution of PyC in 30 Australian agricultural, pastoral, bushland and parkland soil with various soil types. Soils were sampled incrementally to 50 cm in 6 locations and at another 7 locations at 0–10 cm. Results showed that PyC in Australian soils typically ranged from 0.27–5.62 mg/g, with three Dermosol soils ranging within 2.58–5.62 mg/g. Soil PyC contributed 2.0–11% (N = 29) to the total organic carbon (TOC), with one Ferrosol as high as 26%. PyC was concentrated either in the top (0–10 cm) or bottom (30–50 cm) soil layers, with the highest PyC:TOC ratio in the bottom (30–50 cm) soil horizon in all soils. Principal component analysis - multiple linear regression (PCA-MLR) suggested the silt-associated organic C factor accounted for 38.5% of the variation in PyC. Our findings suggest that PyC is an important fraction of the TOC (2.0–11%, N = 18) and chemically recalcitrant organic C (ROC) obtained by chemical C fractionation method accounts for a significant proportion of soil TOC (47.3–84.9%, N = 18). This is the first study comparing these two methods, and it indicates both CTO-375 and C speciation methods can determine a fraction of recalcitrant organic C. However, estimated chemically recalcitrant organic carbon pool (ROC) was approximately an order of magnitude greater than that of thermally stable organic carbon (PyC)

Classical imaging theory of a microlens with super-resolution

Super-resolution in imaging through a transparent spherical microlens has attracted lots of attention because of recent promising experimental results with remarkable resolution improvement. To provide physical insight for this super-resolution phenomenon, previous studies adopted a phenomenological explanation mainly based on the super-focusing effect of a photonic nanojet, while a direct imaging calculation with classical imaging theory has rarely been studied. Here we theoretically model the imaging process through a microlens with vectorial electromagnetic analysis, and then exclude the previously plausible explanation of super-resolution based on the super-focusing effect. The results showed that, in the context of classical imaging theory subject to the two-point resolution criterion, a microlens with a perfect spherical shape cannot achieve the experimentally verified sub-100 nm resolution. Therefore, there must be some other physical mechanisms that contribute to the reported ultrahigh resolution but have not been revealed in theory.Accepted Versio

Visualization 1: Hybrid wide-field and scanning microscopy for high-speed 3D imaging

Hybrid images with different pixel ratios Originally published in Optics Letters on 15 November 2015 (ol-40-22-5251