利用注册表增强计算机系统的安全性

计算机系统的安全问题一直是各单位计算机工程技术人员所重点考虑和首要解决的问题。文章根据工作实际，阐述了利用WIN98注册表增强系统安全性的方法。     

When ancillary services decrease with more wind in ERCOT

The extant literature predicts that increasing penetration of variable generation resources should have a profound effect on ancillary services for maintaining system frequency and reliability. However, a study of the ERCOT market found that between 2014 and 2017, the procured quantities of ancillary services continuously declined, while annual wind generation output increased by 26 million MWh. This article discusses potential reasons for the phenomenon of declining need for ancillary services and its implications.     

稳态瑞雷波勘探在地震安评中的应用

介绍了稳态瑞雷波法的工作原理和工作方法,介绍了SM98-24B瑞雷波仪的参数,以及在地震安评项目的波速测试中,稳态瑞雷波法勘探与钻孔波速测试的对比结果.     

院系网站总体设计与技术细节──中山大学数学与计算科学学院网站建设

中山大学数学与计算科学学院网站构建以FRONTPAGE98为主要开发工具,以HTML和DHTML为主要开发语言,以WINDOWSNT4.0为网站服务器操作系统,以IIS3.0为WEB服务器,提供了HTTP和FTP两种服务。同时还运用了VB、JAVA、JavaScript语言为网站提供各种HTML、DHTML所无法实现的扩展功能。该文从网站的总体设计思想、设计过程与技术细节来阐述整个网站的设计过程。     

Characteristics of Retinitis Pigmentosa Associated with ADGRV1 and Comparison with USH2A in Patients from a Multicentric Usher Syndrome Study Treatrush

In contrast to USH2A, variants in ADGRV1 are a minor cause of Usher syndrome type 2, and the associated phenotype is less known. The purpose of the study was to characterize the retinal phenotype of 18 ADGRV1 patients (9 male, 9 female; median age 52 years) and compare it with that of 204 USH2A patients (111 male, 93 female; median age 43 years) in terms of nyctalopia onset, best corrected visual acuity (BCVA), fundus autofluorescence (FAF), and optical coherence tomography (OCT) features. There was no statistical difference in the median age at onset (30 and 18 years; Mann–Whitney U test, p = 0.13); the mean age when 50% of the patients reached legal blindness (≥1.0 log MAR) based on visual acuity (64 years for both groups; log-rank, p = 0.3); the risk of developing advanced retinal degeneration (patch or atrophy) with age (multiple logistic regression, p = 0.8); or the frequency of cystoid macular edema (31% vs. 26%, Fisher’s exact test, p = 0.4). ADGRV1 and USH2A retinopathy were indistinguishable in all major functional and structural characteristics, suggesting that the loss of function of the corresponding proteins produces similar effects in the retina. The results are important for counseling ADGRV1 patients, who represent the minor patient subgroup.     

基于Windows的气辅注射注气的实时控制方案

本文针对气体辅助注射成型注气控制这样一个实时性要求较高的计算机控制系统,分析了控制系统的任务要求。通过分析基于Win98平台进行实时控制的技术限制,指出采用Win98的定时器不能满足实时控制要求,并提出了实现高精度实时控制的5种方案。通过对这5种方案的分析比较,并根据实际情况,确定在本注气控制系统中采用WINSOWS系统的多媒体扩展库所提供的多媒体定时函数来实现实时控制要求。本文提出了使用该函数编写控制软件的应注意的问题。该控制系统在气体辅助注塑成型注气控制系统上能可靠运行并达到了预期目标。     

Spin–charge separation and electron pairing instabilities in Hubbard nanoclusters

Electron charge and spin pairing instabilities in various cluster geometries for attractive and repulsive electrons are studied exactly under variation of interaction strength, electron doping and temperature. The exact diagonalization, level crossing degeneracies, spin–charge separation and separate condensation of paired electron charge and opposite spins yield intriguing insights into the origin of magnetism, ferroelectricity and superconductivity seen in inhomogeneous bulk nanomaterials and various phenomena in cold fermionic atoms in optical lattices. Phase diagrams resemble a number of inhomogeneous, coherent and incoherent nanoscale phases found recently in high-_Tc$T_c$ cuprates, manganites and multiferroic nanomaterials probed by scanning tunneling microscopy. Separate condensation of electron charge and spin degrees at various crossover temperatures offers a new route for superconductivity, different from the BCS scenario. The calculated phase diagrams resemble a number of inhomogeneous paired phases, superconductivity, ferromagnetism and ferroelectricity found in Nb and Co nanoparticles. The phase separation and electron pairing, monitored by electron doping and magnetic field surprisingly resemble incoherent electron pairing in the family of doped high-_Tc$T_c$ cuprates, ruthenocuprates, iron pnictides and spontaneous ferroelectricity in multiferroic materials.     

Photonic theory of noise

The paper proposes that 1/f noise in materials and devices under non-equilibrium conditions is of electromagnetic origin rather than being related to charge carriers. For samples represented by simple resistors the analysis shows that the noise is due to the discrete nature of photons constituting the impinging electromagnetic flux from the source feeding the resistor. The paper presents detailed analysis of the external and internal electromagnetic fields of the resistor environment, with appropriate interpretation in terms of discrete photons. From quantum theory photons are known to retain their energy under interactions in linear environments. This property implies a departure from macroscopic electromagnetics in that photons cannot be partially transmitted and partially reflected, a phenomenon requiring appropriate modifications of boundary conditions at the resistor surface. These special demands call for inclusion of a supplementary internal resistor mode, serving as a lossless idler which is active only for matching purposes. At the resistor terminals the impinging photons give rise to excitation of RF current and voltage noise with an exact 1/f frequency distribution, which is in agreement with all available experimental measurements. The paper presents detailed formulae for noise spectral densities under general drive conditions from DC and RF sources of arbitrary internal resistance. The presented theoretical noise formulae have the same form as earlier empirical formulae for 1/f noise. With an RF source at frequency f₀ the analysis predicts noise with 1/|f-f₀| frequency distribution, which is compatible with available experimental observations.     

Decarbonization of the U.S. electricity sector: Are state energy policy portfolios the solution?

State governments have taken the lead on U.S. energy and climate policy. It is not yet clear, however, whether state energy policy portfolios can generate results in a similar magnitude or manner to their presumed carbon mitigation potential. This article seeks to address this lack of policy evidence and contribute empirical insights on the carbon mitigation effects of state energy portfolios within the U.S. electricity sector. Using a dynamic, long-term electricity dispatch model with U.S. power plant, utility, and transmission and distribution data between 2010 and 2030, this analysis builds a series of state-level policy portfolio scenarios and performs a comparative scenario analysis. Results reveal that state policy portfolios have modest to minimal carbon mitigation effects in the long run if surrounding states do not adopt similar portfolios as well. The difference in decarbonization potential between isolated state policies and larger, more coordinated policy efforts is due in large part to carbon leakage, which is the export of carbon intensive fossil fuel-based electricity across state lines. Results also confirm that a carbon price of $50/metric ton CO₂e can generate substantial carbon savings. Although both policy options – an energy policy portfolio or a carbon price – are effective at reducing carbon emissions in the present analysis, neither is as effective alone as when the two strategies are combined.