Improvement of magnetic properties and read/write characteristics in SmCo5 perpendicular thin films

An SmCo₅ alloy is a promising candidate for ultra-high density magnetic recording media because of its strong uniaxial magnetocrystalline anisotropy, whose constant, K_u, is more than 1.1×10⁸ erg/cm³. Recently, we successfully obtained high perpendicular magnetic anisotropy for a sputter-deposited SmCo₅ thin film by introducing a Cu/Ti dual underlayer. However, it is necessary to improve magnetic properties and read/write (R/W) characteristics for applying SmCo₅ thin films to perpendicular magnetic recording media. In this study, we focused on reduction of magnetic domain size and change of a magnetization reversal process of SmCo₅ perpendicular magnetic thin films by introducing carbon (C) atoms into the constituent Cu underlayer. The magnetic domain size became small and the ratio of coercivity (H_c) against magnetic anisotropy (H_k) which is an index of the magnetization reversal process was increased by adding C atoms. We also evaluated the R/W characteristics of SmCo₅ double-layered media including C atoms. The medium noise was decreased and signal-to-noise ratio increased by introducing the C. The addition of C into the Cu underlayer is effective for changing the magnetization reversal process, reducing medium noise and increasing SNR.     

Identification of evolutionarily conserved Momordica charantia microRNAs using computational approach and its utility in phylogeny analysis

Momordica charantia (bitter gourd, bitter melon) is a monoecious Cucurbitaceae with anti-oxidant, anti-microbial, anti-viral and anti-diabetic potential. Molecular studies on this economically valuable plant are very essential to understand its phylogeny and evolution. MicroRNAs (miRNAs) are conserved, small, non-coding RNA with ability to regulate gene expression by bind the 3′ UTR region of target mRNA and are evolved at different rates in different plant species. In this study we have utilized homology based computational approach and identified 27 mature miRNAs for the first time from this bio-medically important plant. The phylogenetic tree developed from binary data derived from the data on presence/absence of the identified miRNAs were noticed to be uncertain and biased. Most of the identified miRNAs were highly conserved among the plant species and sequence based phylogeny analysis of miRNAs resolved the above difficulties in phylogeny approach using miRNA. Predicted gene targets of the identified miRNAs revealed their importance in regulation of plant developmental process. Reported miRNAs held sequence conservation in mature miRNAs and the detailed phylogeny analysis of pre-miRNA sequences revealed genus specific segregation of clusters.     

基于JdbcTemplate的数据库访问处理

Spring JdbcTemplate简化了对数据库的访问处理,详细讨论了JdbcTemplate实现对数据库表格的增、删、改、查询的操作处理方法。分别针对多行数据结果集、单值结果的查询需求,给出相应的JdbcTemplate的不同方法调用。在数据更新处理中,讨论了完整SQL和带参数填充的SQL的方法调用形式。最后,结合文件内容的保存与恢复处理实例,介绍了大容量数据的读写,通过LobCreator对象的setBlobAsBinaryStream方法实现LOB数据的写入,通过LobHandler接口提供的系列方法可获取LOB数据。     

Density Estimation under Constraints

Abstract

We suggest a general method for tackling problems of density estimation under constraints. It is, in effect, a particular form of the weighted bootstrap, in which resampling weights are chosen so as to minimize distance from the empirical or uniform bootstrap distribution subject to the constraints being satisfied. A number of constraints are treated as examples. They include conditions on moments, quantiles, and entropy, the latter as a device for imposing qualitative conditions such as those of unimodality or “interestingness.” For example, without altering the data or the amount of smoothing, we may construct a density estimator that enjoys the same mean, median, and quartiles as the data. Different measures of distance·give rise to slightly different results.     

移动通信网络干扰问题的分析与解决方案

主要介绍了移动通信网络干扰的成因及快速查找网络干扰的方法,并提供了多种行之有效的解决方案。对提高移动通信高层次服务水平,满足用户对通信质量的高要求奠定了基础。     

Effective march algorithms for testing single-order addressed memories

Today's commonly used macro generators provide for read/write memories of type SRAM, Register File, Multi-Port RAM, Single-Order Addressed Memory (e.g. FIFO), CAM (Content Addressable Memory), etc. In addition to automatically generating the required momory, the appropriate test, which may be applied externally or internally as a BIST, has to be determined.Current literature provides tests for most memory types; however, tests for single-order addressed (SOA) memories, whereby the address can only change in one direction (e.g. from address 0 ton-1) have not been published yet. SOA memories are used in FIFOs and in applications where the BIST area overhead and/or speed penalty for normal (dual) order addressing are not acceptable.This article illustrates the testing problems and presents a family of march algorithms optimized for testing SOA memories.     

45nm工艺下8管双阈值SRAM单元的研究

比较分析了8管SRAM单元在不同双阈值组合情形下的性能,为不同需求的设计者提供了在静态噪声容限(SNM)、漏功耗和延迟之间做出合理权衡的参考。仿真结果表明,组合C8具有最大的SNM,高阈值晶体管Mnl可以有效抑制漏电流。最后,分析了不同组合下的读写延迟时间,并给出了延迟差异的原因。     

Contaminant-induced current decline in capillary array electrophoresis

High-throughput capillary array electrophoresis (CAE) instruments for DNA sequencing suffer to varying degrees from read length degradation associated with electrophoretic current decline and inhibition or delay in the arrival of fragments at the detector. This effect is known to be associated with residual amounts of large, slow-moving fragments of template or genomic DNA carried through from sample preparation and sequencing reactions. Here, we investigate the creation and expansion of an ionic depletion region induced by overloading the capillary with low-mobility DNA fragments, and the effect of growth of this region on electrophoresis run failure. Slow-moving fragments are analytically and experimentally shown to reduce the ionic concentration of the downstream electrolyte. With injection of large fragments beyond a threshold quantity, the anode-side boundary of the nascent depletion region begins to propagate toward the anode at a rate faster than the contaminant DNA migration. Under such conditions, the depletion region expands, the capillary current declines dramatically, and the electrophoresis run yields a short read length or fails completely.     

A new asymmetric 6T SRAM cell with a write assist technique in 65 nm CMOS technology

A new asymmetric 6T-SRAM cell design is presented for low-voltage low-power operation under process variations. The write margin of the proposed cell is improved by the use of a new write-assist technique. Simulation results in 65 nm technology show that the proposed cell achieves the same RSNM as the asymmetric 5T-SRAM cell and 77% higher RSNM than the standard 6T-SRAM cell while it is able to perform write operation without any write assist at V_DD=1 V. Monte Carlo simulations for an 8 Kb SRAM (256×32) array indicate that the scalability of operating supply voltage of the proposed cell can be improved by 10% and 21% compared to asymmetric 5T- and standard 6T-SRAM cells; 21% and 53% lower leakage power consumption, respectively. The proposed 6T-SRAM cell design achieves 9% and 19% lower cell area overhead compared with asymmetric 5T- and standard 6T-SRAM cells, respectively. Considering the area overhead for the write assist, replica column and the replica column driver of 2.6%, the overall area reduction in die area is 6.3% and 16.3% as compared with array designs with asymmetric 5T- and standard 6T-SRAM cells.