基于非线性机会约束规划的多基雷达系统稳健功率分配算法

现有多基雷达系统(MSRS)功率分配算法都假设目标的雷达散射截面(RCS)信息先验已知。针对上述问题,该文将目标的RCS建模为分布未知的随机变量,提出一种基于非线性机会约束规划(NCCP)的MSRS稳健功率分配算法,用于处理RCS参数的不确定性。该文首先推导了目标跟踪误差的贝叶斯克拉美罗界(BCRLB)。然后以最小化MSRS各个时刻发射功率为目标,在满足BCRLB不大于给定误差的概率超过某一置信水平的条件下建立了NCCP模型,并用条件风险价值(CVaR)松弛结合抽样平均近似(SAA)算法对此问题进行了求解。最后,仿真实验验证了算法的有效性和稳健性。

多基质土壤混合层技术系统(MSL)对猪场废水的处理效果

通过室内试验模拟研究多基质土壤混合层技术系统(multi-soil-layering system,MSL)在水力负荷为50、100、200和300L.m-2.d-1条件下对猪场废水的处理效果,并初步探讨该系统对有机物、氮、磷的去除途径。结果表明:在4个水力负荷下,化学需氧量(CODCr)平均去除率分别为74.8%、72.6%、59.5%和33.4%,微生物分解是MSL系统去除有机物的主要途径;氨氮平均去除率分别为82.1%、71.0%、30.0%和18.9%,硝化/反硝化作用是MSL系统去除氮的主要途径;磷的平均去除率分别为61.4%、56.0%、39.1%和23.0%,基质吸附作用是MSL系统去除磷的主要途径;水力负荷对MSL系统处理养猪废水的效果特别是对氮的去除有很大影响,控制适当的水力负荷是提高MSL系统污水处理效果的重要手段。MSL系统对猪场废水的处理是一种高效无动力的处理技术,具有较高的实用价值。

基于多基表示的滑动窗口椭圆曲线多标量乘算法

标量乘运算从整体上决定了椭圆曲线密码体制的快速实现效率,在一些椭圆曲线公钥密码体制中需要计算多标量乘。多基数链的标量表示长度更短、非零比特数目更少,较好地适用于椭圆曲线标量乘的快速计算。为了提高椭圆曲线密码的效率,在已有的二进制域和素域的标量乘算法的基础上,结合滑动窗口技术、多基算法,提出新的更高效的多标量乘算法。实验结果表明,新算法与传统Shamir算法和交错NAF算法相比,其所需的运算量更少,能有效地提高椭圆曲线多标量乘算法的效率,使多标量乘的运算更高效。相比于其他算法,新算法的计算效率比已有的多标量乘算法提高了约7.9%～20.6%。

多基雷达定位中站址误差影响分析

本文针对多基雷达系统站址测量误差对飞行目标定位精度的影响 ,给出了评估此项误差的数学模型。分析表明 ,其影响是各站址误差的线性组合。主站的站址误差起着主要作用 。

Cooperative navigation and localization for multiple UUVs

The authors proposed a moving long baseline algorithm based on the extended Kalman filter （EKF） for cooperative navigation and localization of multi-unmanned underwater vehicles （UUVs）. Research on cooperative navigation and localization for multi-UUVs is important to solve navigation problems that restrict long and deep excursions. The authors investigated improvements in navigation accuracy. In the moving long base line （MLBL） structure, the master UUV is equipped with a high precision navigation system as a node of the moving long baseline, and the slave UUV is equipped with a low precision navigation system. They are both equipped with acoustic devices to measure relative location. Using traditional triangulation methods to calculate the position of the slave UUV may cause a faulty solution. An EKF was designed to solve this, combining the proprioceptive and exteroceptive sensors. Research results proved that the navigational accuracy is improved significantly with the MLBL method based on EKF.

高轨辐射源被动雷达空-时积累海面动目标检测技术

被动雷达作为一种特殊的双(多)基雷达体制,具有低成本、反隐身和抗干扰能力强等显著优势;与传统辐射源相比,地球同步轨道(geosynchronous earth orbit,GEO)卫星具有覆盖面积广、重访周期短、地面功率密度高等特性,将其作为辐射源构成高轨辐射源被动雷达,在广域持续隐蔽探测中具有显著优势。本文针对一发多收的高轨辐射源被动雷达系统,为解决多基目标回波的高精度融合问题,提出了一种基于空-时联合积累的高轨辐射源被动雷达海面运动目标检测技术。首先,利用Keystone变换和去调频傅里叶变换实现目标回波能量跨距离单元和跨多普勒单元现象的校正,并将各站目标回波能量积累到多普勒参数域;然后,根据目标角度、距离、多普勒参数与多基构型间的解析形式,建立各站目标回波域、多普勒参数域间各自映射关系,从而解决了多基间目标距离和多普勒参数的差异性问题,完成了多基间目标回波能量的对齐和积累,实现了高轨辐射源被动雷达动目标检测和定位。

Using RAPD Method on Systematic Evolution of Four Species in Anura

The phylogenetic relationships of four species,Bufo melanostictus,Hyla chinensis,Rana limnocharis and Rana guentheri,which belong to three differrent families of Anura,were detected with RAPD technique.The genomic DNA of each species was amplified with 19 random primers.16 primers given clear amplified bands were used for analysis and the genetic distances between four species were calculated.The results show that RAPD bands obtained by all 16 primers evinced different degree polymorphisms.The genetic distance between R.limnocharis and R.guentheri is the nearest,that between B.melanostictus and H.chinensis is the second nearest,and that between B.melanostictus and R.guentheri is the furthest.The different distances also indicated that the relationship between Bufoidae and Hylidae is closer than that between Bufonidae and Ranidae at genomic DNA level.In concordant with the conclusion of the morphology,chromosomal and mitochondrial DNA studies,our results provide a new evidence of the systematic evolution of the three families of Anura at DNA molecular level.

A simple rectification method for linear multi-baseline stereovision system

The linear multi-baseline stereo system introduced by the CMU-RI group has been proven to be a very effective and robust stereovision system. However, most traditional stereo rectification algorithms are all designed for binocular stereovision system, and so, cannot be applied to a linear multi-baseline system. This paper presents a simple and intuitional method that can simultaneously rectify all the cameras in a linear multi-baseline system. Instead of using the general 8-parameter homography transform, a two-step virtual rotation method is applied for rectification, which results in a more specific transform that has only 3 parameters, and more stability. Experimental results for real stereo images showed the presented method is efficient.

Study on Origin and Evolution of Polyploids in Parakmeria Hu et Cheng Using LEAFY Gene

[Objective] This study aimed to explore the origin and evolution of poly- poids in Parakmeria Hu et Cheng through LEAFY gene clone and sequence analysis. [Method] In this study, LEAFY gene in Parakmeria species and its relative genera was cloned and sequenced using molecular biology methods. With reference to LEAFY gene sequence published by NCBI, the origin pattern of polypoids in Parakmeria was explored and reasons for the distribution layout of different polypoids were analyzed through sequence alignment and phylogenetic analysis. [Result] Different Magnoliaceae species can be distinguished using the LEAFY gene, and there was a length polymorphism found in the 3＋ end of the LEAFY gene, which can be used to divide Magnoliaceae plants of different species or in different genera, thus of high application value. [Conclusion] Most Parakmeria tetraploids are produced by polyploidization of homologous chromosomes, while Parakmeria hexaploids are chiefly produced by both polyploidization of homologous chromosomes and heterologous hybridization.

Association of Fas-670 gene polymorphism with inflammatory bowel disease in Chinese patients

AIM: Recent studies suggest that Fas-mediated apoptosis is involved in the pathogenesis of inflammatory bowel disease (IBD). It has been hypothesized that either increased apoptosis of intestinal epithelium or decreased apoptosis of lamina propria lymphocytes may induce inflammation of gut. The aim of this study was to determine whether the Fas gene promoter polymorphism at position-670 was associated with IBD in Chinese patients.METHODS: Fifty unrelated Chinese patients with IBD (38patients with ulcerative colitis and 12 with Crohn's disease)and 124 healthy controls were genotyped for the Fas-670polymorphism by PCR-restriction fragment length polymorphism method. The PCR product was digested by Mva I restriction enzyme.RESULTS: Distribution of the Fas-670 gene polymorphism was 33% for the AA genotype, 52% for the AG genotype and 15% for the GG genotype in 124 healthy subjects. In patients with IBD, 30% was for the AA genotype, 42% for the AG genotype and 28% for the GG genotype respectively. However, there was no significant difference in the genotype (P= 0.1498), allele frequencies (P= 0.3198)and carriage frequencies (P = 0.4133) between healthy controls and IBD patients. Furthermore, we did not find any difference between the left-sided colitis and total colitis (P = 0.8242).CONCLUSION: Fas-670 polymorphism is not associated with IBD in Chinese patients.

Short Baseline Positioning with an Improved Time Reversal Technique in a Multi-path Channel

The existence of a multi-path channel under the water greatly decreases the accuracy of the short baseline positioning system.In this paper,the application of a time reversal mirror to the short baseline positioning system was investigated.The time reversal mirror technique allowed the acoustic signal to better focus in an unknown environment,which effectively reduced the expansion of multi-path acoustic signals as well as improved the signal focusing.The signal-to-noise ratio（SNR） of the time reversal operator greatly increased and could be obtained by ensonifying the water.The technique was less affected by the environment and therefore more applicable to a complex shallow water environment.Numerical simulations and pool experiments were used to demonstrate the efficiency of this technique.

Multistatic radar analysis based on ambiguity function and Cramér-Rao lower bounds

The primary goal of this work is to characterize the impact of weighting selection strategy and multistatic geometry on the multistatic radar performance. With the relationship between the multistatic ambiguity function （AF） and the multistatie Cram6r-Rao lower bound （CRLB）, the problem of calculating the multistatic AF and the multistatic CRLB as a performance metric for multistatic radar system is studied. Exactly, based on the proper selection of the system parameters, the multistatic radar performance can be significantly improved. The simulation results illustrate that the multistatic AF and the multistatic CRLB can serve as guidelines for future multistatic fusion rule development and multistatic radars deployment.

Genetic Structure of Tetraploid Italian and Westerwolds Ryegrasses （Lolium spp,） as Revealed by Enzyme and ISSR Polymorphism

The genetic variation of Italian ryegrass （Lolium multiflorum Lain.） and westerwolds ryegrass （L. westerwoldicum Breakw.） was investigated in eight tetraploid cultivars originated from Poland. The 337 individual seedlings, cultivated in uniform greenhouse conditions, were tested with horizontal gel electrophoresis according to five enzyme systems： diaforase （DIA）, superoxide dismutase （SOD）, glutamate oxalacetate transaminase （GOT）, peroxidise （PX） and phosphogluco isomerise （PGI）, which were used to array allelic diversity at five polymorphic loci. The estimation of genetic diversity in 64 plants of the same cultivars was studied using inter simple sequence repeats （ISSRs） as molecular marker. The genetic variation described by ISSR suggests that the polymorphism detected appears to be poorly informative at the taxonomic level. For statistical analysis, unweighted pair group method with arithmetic mean （UPGMA） based dendrograms and minimum spanning trees were constructed using Nei＇s distance and Jaccard＇ s similarity coefficient.

Diversity and Bioactivity of Actinomycetes from Marine Sediments of the Yellow Sea

Among the 116 actinomycetes collected from marine sediments of the Yellow Sea,56 grew slowly and appeared after 2?3 weeks of incubation.Among the 56 strains,only 3 required seawater(SW) for growth,and 21 grew well in the medium prepared with SW rather than distilled water(DW),while the remaining 32 grew well either with SW or with DW.Six representatives with different morphological characteristics,including 1 SW-requiring strain and 5 well-growing with SW strains,were selected for phy-logenetic analysis based on 16S rRNA gene.Two strains belong to Micrococcaceae and Nocardiopsaceae respectively.The other 4 strains belong to the family of Streptomycetaceae.In the analyzed 6 strains,one was related to Nocardiopsis spp.and the other three were related to Streptomyces spp.,representing new taxa.Bioactivity testing of fermentation products from 3 SW-requiring strains and 21 well-growing with SW strains revealed that 17 strains possessed remarkable activities against gram-positive pathogen or/and tumor cells,suggesting that they were prolific resources for natural drug discovery.

A Preliminary Phylogenetic Analysis of Luidia (Paxillosida: Luidiidae) from Chinese Waters with Cytochrome Oxidase Subunit I (COI) Sequences

Luidia Forbes （Paxillosida： Luidiidae） are common soft bottom sea stars with 49 described species. Because of substan- tial morphological diversity, the taxonomy of the genus is complex and hasn＇t been resolved definitely. In order to resolve general taxonomic issues, and determine species boundaries and phylogenetic relationships within the genus Luidia, the sequences of tyro- chrome oxidase subunit I （COI） gene from 24 specimens of Luidia, belonging to eight taxa in Chinese waters, were studied. Three sequences of two species in genus Luidia from GenBank were used to analyze the phylogenetie relationships. The molecular phy- logeny exhibited three main clades, each with strong bootstrap support： Clade A including Luidia quinaria from the Sea of Japan; Clade B including seven nominal species （L. quinaria von Martens, L. yesoensis Goto, L. ehangi Liu, Liao and Li, L. orientalis Fisher, L. avicularia Fisher, L. longispina Sladen and L. hardwicki Gray） from Chinese waters; and Clade C including L. maculata Miiller ＆ Troschel from Chinese waters. Our molecular phylogeny results support the morphological Quinaria-Group and Alter- nata-Group assigned by D6derlein. Seven nominal species we sampled do not exhibit genetic distances that are large enough to rec- ognize them as separate species. Cryptic species may exist in ＇Luidia quinaria＇ from the Yellow Sea and the Sea of Japan. Meaning- ful morphological characters need further investigation in Luidia.

Crohn's disease genotypes of patients in remission vs relapses after infliximab discontinuation

AIM： To investigate genetic differences between Crohn＇s disease （CD） patients with a sustained remission vs relapsers after discontinuing infliximab while in cortico- steroid-free remission. METHODS： Forty-eight CD patients received infliximab and were in full corticosteroid-free clinical remission but then discontinued infliximab for reasons other than a loss of response, were identified by review of an electronic database and charts. Infliximab-associated remis- sion was defined as corticosteroid-free plus normaliza- tion of clinical disease activity [CD activity index （CDAI） 〈 150] during follow-up visits based on physician global assessments. A CD relapse （loss of infliximab-induced remission） was clinically defined as a physician visit for symptoms of disease activity （CDAI 〉 220） and a thera- peutic intervention with CD medication（s）, or a hospital- ization with complications related to active CD. Genetic analyses were performed on samples from 14 patients （n = 6 who had a sustained long term remission after stopping infliximab, n -- 8 who rapidly relapsed after stopping infliximab）. Nucleotide-binding oligomerization domain 2 （NOD2）/caspase activation recruitment do- main 15 （CARD15） polymorphisms （R702W, G908R and L1007fs） and the inflammatory bowel disease 5 （IBDS） polymorphisms （IGR2060a1 and IGR3081a1） were ana- lyzed in each group. RESULTS： Five single nucleotide polymorphisms of IBD5 and NOD2/CARD15 genes were successfully analyzed for all 14 subjects. There was no signifcant increase in frequency of the NOD2/CARD15 polymor- phisms （R702W, G908R and L1007fs） and the IBD5 polymorphisms （IGR2060al and IGR3081a1） in either group of patients; those whose disease relapsed rap- idly or those who remained in sustained long term remission following the discontinuation of infliximab. Nearly a third of patients in full clinical remission who stopped infliximab for reasons other than loss of re- sponse remained in sustained clinical remission, while two-thirds relapsed rapidly. There was a marked dif- ference in the duration of clinical remission following discontinuance of infliximab between the two groups. The patients who lost remission did so after 1.0 years 4- 0.6 years, while those still in remission were at the time of this study, 8.1 years 4- 2.6 years post-discon- tinuation of infliximab, P 〈 0.001. The 8 patients who had lost remission after discontinuing infiiximab had a mean number of 5 infusions （range 3-7）, with a mean treatment time of 7.2 mo （range 1.5 mo-15 mo）. The mean duration of time from the last infusion of inflix- imab to the time of loss of remission was 382 d （range 20 d-701 d）. The 6 patients who remained in remission after discontinuing infliximab had a mean number of 6 infusions （range 3-12）, with a mean treatment dura- tion of 12 mo （range 3.6 mo-32 too） （P = 0.45 relative to those who lost remission）. CONCLUSION： There are no IBD5 or NOD2/CARD15 mutations that predict which patients might have sus- tained remission and which will relapse rapidly after stopping infliximab.

Diversity and Antimicrobial Activity of Cultivable Halophilic Archaea from Three Algerian Sites

Hypersaline environments are colonized by communities of microorganisms, which developed adaptations from halotolerant to extreme halophilic lifestyles. Twenty-four halophilic archaeal strains were isolated from three Algerian hypersaline sites, including the solar salterns in Ichekaben and two natural salt lakes at Ouargla and Oran. Almost full-length 16S rRNA genes were amplified using archaeal-specific primers, sequenced and phylogenetically analyzed. Three isolates from the salt lake of Ouargla were affiliated to Halorubrum sp., while six isolates from Ichekaben were Natrinema sp.. The remaining strains belonged to the genus Haloarcula, which was identified in the three Algerian sites. A phylogenetic tree of Haloarcula sp. including the two copies of the 16S rRNA gene, showed that two strains group with Haloarcula hispanica, while the other 13 cluster with OHF-1/OHF-2 isolated from French commercial salt. Both Natrinema sp. and Haloarcula sp. were persistent at Ichekaben. For the six Natrinema sp. isolates, this observation correlates with their capacity to produce antimicrobial compounds, and a DNA fragment closely related to the halocin C8 gene was amplified for five strains.

GyrB Gene Acts as a Phylogenetic Discriminator for Bacterial Diversity in Acid Mine Drainage

To study the efficiency ofDNA gyrase subunit B （gyrB） gene as means of diversity analysis, diversities of gyrB genes in three AMD samples collected from Dabaoshan Mine were studied by analyzing gyrB gene library. Many novel gyrB sequences and groups were detected. The results show that Acidithiobacillusferrooxidans-like bacteria represented 88.0% of the bacterial population in a sample. However, other two samples showed much high diversities. These diversities were characterized by the reciprocal of Simpson＇s index （l/D）, and show ferrous ion strongly influenced the composition of the microbial communities. The study indicate that gyrB Gene as a phylogenetic discriminator is a good tool to study different strains in same species that were difficult to be distinguished by 16S genes. But now gyrB Gene cannot define clearly unknown sequences to certain lineage, due to the incompleteness of the gyrB database.

Single Nucleotide Polymorphism Genotyping of Calpastatin Gene Using the ARMS Compared with the RFLP

Calpastatin is an endogenous inhibitor of calpain which is responsible for the breakdown of myofibrillar proteins, The association of Single Nucleotide Polymorphism （SNP） in the calpastatin gene with meat tenderness is an important topic in meat production. Therefore efficient procedure to investigate the SNP is necessary. The objectives of this study were to detect the SNP of calpastatin gene at domain L marker （G/C transversion） of the Kamphaengsaen beef breed （KPS cattle; n = 26） by the Amplification Refractory Mutation System （ARMS） compared with the Restriction Fragment Length Polymorphism （RFLP） methods and to determine the genotypes of the KPS cattle at that marker. Genomic DNA of calpastatin gene extracted from blood of the KPS cattle was detected with ARMS and RFLP methods. The ARMS system has utilized two primer pairs to amplify the two different alleles of a polymorphism in single PCR reaction to detected single base mutation. In this method, the alleles-specific primers had a mismatch at 3＇ terminal base and a second deliberate mismatch at position -2 from 3＇ terminus. While the RFLP method detected a polymorphism using PCR-base technique follow by RsaI restriction enzyme. Amplification of the ARMS method revealed that the results were not different from the conventional method of RFLP. Analysis of genotypes revealed that the KPS cattle inherited the CC, CG and GG genotypes at domain L marker. These were reliable when verified by nucleotide sequence analysis of PCR products. The animals were genotyped and determined for tenderness phenotype with this marker that predicted variation of an intronic polymorphism at domain L of the calpastatin gene. Therefore, the ARMS method was simple, efficient technique, and suitable for detecting SNP at domain L marker of the calpastatin gene.

Settlement monitoring system of pile-group foundation

In order to realize information construction on settlement of pile-group foundation of Sutong Bridge, the monitoring instruments of high-precision micro-pressure sensor and hydrostatic leveling and settlement profiler were integrated synthetically. A set of practical multi-scale monitoring system on settlement of super-large pile-group foundation in deep water was put forward. The reliable settlement results are obtained by means of multi-sensor data fusion. Finite element model of pile-group foundation is established. By analysis of finite element simulated calculation of pile-group foundation, rules of settlement and uneven settlement obtained by monitoring and calculation results are coincident and the absolute error of settlement between them is 4.7 mm. The research shows that it is reasonable and feasible to monitor settlement of pile-group foundation with the system, and it can provide a method for the same type pile-group foundation in deep water.