The novel low temperature synthesis of nanocrystalline MgAl2O4 spinel using “gel” precursors

Nanocrystalline MgA1₂O₄ was synthesized by pyrolysis of the homogeneous spinel precursor, Mg(C₄H₅O₂)₂·(H₂O):Al₂(OH)₃(C₃H₃O₂)₃·(H₂O)₂:NH₄(C₃H₃O₂)·(H₂O). The spinel precursor gel is composed of a mixture of magnesium and aluminum acrylate salts dissolved in an ammonium acrylate gel. The reaction of acrylic acid with magnesium hydroxide in water produced magnesium methacrylate, and a similar reaction of basic aluminum acetate produced the aluminum salt of acrylic acid. The reaction of acrylic acid with ammonium hydroxide produced the ammonium acrylate gel. Ammonium acrylate gel was found to absorb many times its own weight of water. Although similar properties have been identified in PMMA and in the polymer of sodium acrylate, only the ammonium acrylate gel exists as an unpolymerized monomer. The spinel precursor gel is a pre-ceramic material that yields an amorphous oxide phase at 425°C that begins to crystallize to the MgAl₂O₄ spinel at 600°C and is fully crysta1line at 1030°C with a uniform particle size of 7-100 nm. The spinel precursor gel and the nanocrystalline MgA1₂O₄ spinel were characterized by XRD and TEM.     

Reduction of lipid peroxidation and H2O2‐mediated DNA damage by a red alga (Grateloupia filicina) methanolic extract

The antioxidant activity of an extract of Grateloupia filicina was evaluated using linoleic acid and fish oil as substrates in an induct period at 65 °C. Furthermore, the algal extract was subjected to comet assay to evaluate its protecting ability for H₂O₂‐induced DNA damage in rat lymphocytes. Progression of oxidation was examined using weight gain, peroxide value (PV), 2‐thiobarbituric acid reactive substances and conjugated diene data. Effectiveness of the extract at 0.03 and 0.05% levels was superior to that of α‐tocopherol at 0.01% and the activity of 0.05% extract was higher than that of butylated hydroxyanisole and butylated hydroxytoluene at 0.01%. Also, the algal extract significantly inhibited H₂O₂ induced DNA damage in comet assay. The maximum DNA damage inhibition (68.9%) was recorded from the 50 µg ml⁻¹ alga extract when the rat lymphocyte cells were treated with 50 µM H₂O₂. Copyright © 2005 Society of Chemical Industry     

Priority inheritance in soft real-time databases

Due to resource sharing among tasks, priority inversion can occur during priority-driven preemptive scheduling. In this work, we investigate solutions to the priority inversion problem in a soft real-time database environment where two-phhse locking is employed for concurrency control. We examine two basic schemes for addressing the priority inversion problem, one based on priority inheritance and the other based on priority abort. We also study a new scheme, called conditional priority inheritance, which attempts to capitalize on the advantages of each of the two basic schemes. In contrast with previous results obtained in real-time operating systems, our performance studies, conducted on an actual real-time database testbed, indicate that the basic priority inheritance protocol is inappropriate for solving the priority inversion problem in real-time database systems. We identify the reasons for this performance. We also show that the conditional priority inheritance scheme and the priority abort scheme perform well for a wide range of system workloads.This work was supported by the National Science Foundation under Grant IRI-8908693 and by the U.S. Office of Naval Research under Grant N00014-85-K0398.A previous version of this paper appeared in Real-Time Systems Symposium, Dec. 1991.     

Interpreting Presuppositions Using Active Logic: From Contexts to Utterances

Presupposition is a pervasive feature of human language. It involves many interesting interactions between the utterances of a discourse and the context of the discourse. In this paper we focus on issues of logical form connected with the interaction of presupposition and discourse context, and illustrate our theory with some implementational work using the active logic framework. After reviewing some of the major issues in presupposition theory we turn to a largely successful unified approach of Heim. We show how the main principles of this theory can be implemented in active logic. But we also find two serious difficulties. These consist in (a) a straightforward counterexample and (b) a type of discourse that we call a garden‐path discourse. We maintain that both the counterexample and the garden‐path type of discourse can be handled by our active‐logic version of Heim's theory. This requires us to reformulate and extend Heim's theorey. Although this work is largely theoretical, both Heim's theory and ours have important things to say about the incremental processing of the utterances that make up discourse. And we present our theory as a specification of a processing device that takes logical form of a sentence along with current discourse context as input and delivers an updated discourse context as output. As an experiment, we have implemented portions of this device.     

Electric nerve stimulation (ENS): 70 clinical cases of bi-block aided by an electric bipolar signal

The paper describes medical informatics discipline and deals with decision support systems in more details. It describes the process of decision making using diagnostic and therapeutic decision making cycle and two sources of medical knowledge-scientific and empirical knowledge. It shows different approaches for development of computer supported decision systems and presents some examples of their use in medical practice.     

Small Solutions to Polynomial Equations, and Low Exponent RSA Vulnerabilities

We show how to find sufficiently small integer solutions to a polynomial in a single variable modulo N, and to a polynomial in two variables over the integers. The methods sometimes extend to more variables. As applications: RSA encryption with exponent 3 is vulnerable if the opponent knows two-thirds of the message, or if two messages agree over eight-ninths of their length; and we can find the factors of N=PQ if we are given the high order bits of P. Received 21 December 1995 and revised 11 August 1996     

Synthesis of Silver Nanocrystallites by a New Thermal Decomposition Method and Their Characterization

We formed silver nanocrystallites by the thermal decomposition of a Ag+¹‐oleate complex, which was prepared by a reaction with AgNO₃ and sodium oleate in a water solution. The resulting monodispersed silver nanocrystallites were produced by controlling the temperature (290 °C). Transmission electron microscopic (TEM) images of the particles showed a 2‐dimensional assembly of the particles with a diameter of 9.5 ± 0.7 nm, demonstrating the uniformity of these nanocrystallites. An energy‐dispersive X‐ray (EDX) spectrum and X‐ray diffraction (XRD) peaks of the nanocrystallites showed the highly crystalline nature of the silver structure. We analyzed the decomposition of the Ag⁺¹‐oleate complex using a Thermo Gravimetric Analyzer (TGA) and observed the crystallization process using XRD.     

黄河小浪底工程泥沙问题的研究

本文系统地研究了原型沙和模型沙（电木粉）的基本运动特性。首次提出了可应用于高含沙水流模型试验的相似关系，据此理论建造了黄河小浪底枢纽１:８０的正态泥沙模型。研究了小浪底工程不同运用阶段的泥沙问题。同时，还重点研究了高含沙异重流和泄水建筑物的防淤堵问题。     

A robust continuous model for evidential reasoning

A 2-D model for evidential reasoning is proposed, in which the belief function of evidence is represented as a belief density function which can be in a continuous or discrete form. A vector form of mutual dependency relationship of the evidence is considered and a dependency propagation theorem is proved. This robust method can resolve the conflicts resulting from either the mutual dependency among evidences or the structural dependency in an inference network due to the evidence combination order. Belief conjunction, belief combination, belief propagation procedures, and AND/OR operations of an inference network based on the proposed 2-D model are all presented, followed by some examples demonstrating the advantages of this method over the conventional methods.