主要目标法在工业缝纫机送料机构最优综合中的应用

以全转动副式工业缝纫机送料机构为研究对象,为使机构能在若干无确定内在联系的位置上分别满足不同工艺要求而构造了机构位态图,提出位态分析的方法。在此基础上采用主要目标法对机构可调参数进行了优化综合。本文的研究成果不但为GK0001串联双针链式工业缝纫机样机的开发与研制提供了必要的理论依据,而且对同类机型的分析与设计也具有重要的参考价值。

Modeling GPS multipath effect based on spherical cap harmonic analysis

Most GPS positioning errors can be eliminated or removed by the differential technique or the modeling method,but the multipath effect is a special kind of system or gross error,so it is difficult to be simulated or eliminated.In order to improve the accuracy of GPS positioning,the single-epoch pseudorange multipath effects at GPS station were calculated,and firstly modeled based on the spherical cap harmonic（SCH）,which is the function of satellite longitude and latitude with the robust method.The accuracy of the kinematic point positioning technique was improved by correcting pseudorange observations with the multipath effect calculated by the SCH model,especially in the elevation direction.The spherical cap harmonic can be used to model the pseudorange multipath effect.

Ku80 gene G-1401T promoter polymorphism and risk of gastric cancer

AIM:To evaluate the possible relationship between the Ku80 gene polymorphism and the risk of gastric cancer in China.METHODS:In this hospital-based case-control study of gastric cancer in Jiangsu Province,China,we investigated the association of the Ku80 G-1401T (rs828907) polymorphism with gastric cancer risk.A total of 241 patients with gastric cancer and 273 age-and sexmatched control subjects were genotyped and analyzed by polymerase chain reaction-restriction fragment length polymorphism.RESULTS:The frequencies of genotypes GG,GT and TT were 65.6%,22.8% and 11.6% in gastric cancer cases,respectively,and 75.8%,17.6% and 6.6% in controls,respectively.There were significant differences between gastric cancer and control groups in the distribution of their genotypes (P=0.03) and allelic frequencies (P=0.002) in the Ku80 promoter G-1401T polymorphism.CONCLUSION:The T allele of Ku80 G-1401T may be associated with the development of gastric cancer.

Taxonomy of the lesser jerboa Jaculus jaculus (Dipodidae,Rodentia) based on allozymic and morphological variation

The lesser Egyptian jerboa Jaculus jaculus, is a member of the subfamily Dipodinae, known to have a number of subspecies. Previous studies of J. jaculus from North Africa found various morphological forms of unknown taxonomic status, which are frequently grouped into two taxa： J. jaculus and J. deserti. We assessed the taxonomic status of this taxon in Tunisia using allozymic （phylogenetic analysis of 23 genetic loci encoding 16 enzymatic proteins） and morphological （multivariate analysis of 13 craniodental characters） analyses of 136 J. jaculus specimens collected from seven localities within its distribution range. Allozymic analysis clearly indicated the existence of two distinct groups of J. jaculus, with a mean genetic distance （D） value of 0.99 and FΩ=0.52. Individuals within the two groups did not show any obvious geographical structuration, even within the Matmata locality which represents the meeting point for the two groups where they were found in sympatry. Additionally, morphometric analysis of 13 craniodental characters was clearly separated the two groups. These results were obtained over a very restricted area of the total distribution of J. jaculus and strongly suggest the occurrence of two separate and often sympatric species within the currently accepted J.jaculus in Tunisia： J.jaculus and J. deserti

Characteristics of Multipath Effects in GPS Dynamic Deformation Monitoring

ABSTRACT The multipath has long been considered a major error source in GPS applications .The characteristics 0f the GPS signal multipath effects are analyzed. based on which an experiment that considers the characteristics of dynamic deformation monitoring has been carried out. The solution results of observation data in two successive days are processed by a method,which combines the wavelet filtering and the differential correction betweentwo successive days. The research demonstrates that the multipath errors have stronger repeatability on successive days;after significantly mitigating the influence of multipath effects,the accuracy of three-dimensional positioning for GPS dynamic deformation monitoring can attain the mm level,an obvious accuracy improving particularly invertical component.The characteristics of GPS signal multipath,th eexperimental scheme and the qualitative and quantitative analysis of results are detailed.

Spatial and seasonal variations in the trophic spectrum of demersal fish assemblages in Jiaozhou Bay, China

Trophic structure of fish communities is fundamental for ecosystem-based fisheries management, and trophic spectrum classifies fishes by their positions in food web, which provides a simple summary on the trophic structure and ecosystem function. In this study, both fish biomass and abundance trophic spectra were constructed to study the spatial and seasonal variations in the trophic structure of demersal fish assemblages in Jiaozhou Bay, China. Data were collected from four seasonal bottom trawl surveys in Jiaozhou Bay from February to November in 2011. Trophic levels(TLs) of fishes were determined by nitrogen stable isotope analysis. This study indicated that most of these trophic spectra had a single peak at trophic level(TL) of 3.4–3.7, suggesting that demersal fish assemblages of Jiaozhou Bay were dominated by secondary consumers(eg. Pholis fangi and Amblychaeturichthys hexanema). The spatial and seasonal variations of trophic spectra of Jiaozhou Bay reflected the influence of fish reproduction, fishing pressure and migration of fishes. Two-way analysis of variance(ANOVA) showed that seasonal variations in trophic spectra in Jiaozhou Bay were significant(P <0.05), but variations among different areas were not significant( P >0.05). The trophic spectrum has been proved to be a useful tool to monitor the trophic structure of fish assemblages. This study highlighted the comprehensive application of fish biomass and abundance trophic spectra in the study on trophic structure of fish assemblages.

Variation of DRB1 Gene in Tibetan Sheep

It reveals that the MHC （major histocompatibility complex） gene product always involved in the control of immune response and disease resistance. Nowadays many studies have indicated the OLA （ovine lymphocyte antigen） DRB1 gene is associated with some sheep diseases. Tibetan sheep is one of the three major shag sheep breeds in China, and also have the largest number of China＇s sheep breeds. But till now no report has been seen on studying DRB1 gene in Tibetan sheep of China. To understand the evolution and provide the basis for sheep disease resistance, polymorphism in the exon2 ofDRB1 gene in Tibetan sheep was analyzed. The PCR-SSCP, cloning and sequencing were used to analyse DRB1 gene variation in 600 Tibetan sheep of China. And the genetic relationship and evolutionary significance of the alleles had also been analyzed. Total of 31 alleles were identified, in which 15 alleles had not been reported before. And there were 70 SNPs （single nucleotide polymorphisms） sites in 31 sheep DRB1 gene haplotypes, the proportion was 29.5% to the whole exort2 sequence. All of this indicated that DRB1 exon2 is highly polymorphic in Tibetan sheep. The variation identified here might have an impact on both the function and level of expression of the OLA-DRB1.

Seismic Response of a Structure under Various Subsoi Models

Three types of the soil-structure interaction are used for structure analysis loaded by seismic effects. An example of the real RC building is used to demonstrate differences in the dynamic response results in the calculation of internal forces and displacements. Variant three options of the soil models were used as a building supporting structure. In the case of soil model A, the soil was modelled by using of equivalent stiffness values, stemming from the theory of a rigid circular disc on an elastic homogeneous half-space. Non-uniformly modelled vertical stiffness of the soil according to the Boussinesq model was used for model B. Both models A and B are characterised by the ＂averaged＂ soil model on the bases of spring constants. Model C was used for the soil better corresponding to its actual composition by the Winkler-Pasternak theory. Model C, where the actual layered soil is considered, is modelled more accurately than for the ＂averaged＂ soil of models A and B. The dynamic response of models operating with ＂averaged＂ values of rigid and soft soil layers is markedly shifted to the conservative smaller values of internal forces. The building response tbr model C in dynamic displacements is significantly higher than for the both models A and B.

Risk analysis of dynamic control of reservoir limited water level by considering flood forecast error

Flood control forecast operation mode is one of the main ways for determining the upper bound of dynamic control of flood limited water level during flood season. The floodwater utilization rate can be effectively increased by using flood forecast information and flood control forecast operation mode. In this paper, Dahuofang Reservoir is selected as a case study. At first, the distribution pattern and the bound of forecast error which is a key source of risk are analyzed. Then, based on the definition of flood risk, the risk of dynamic control of reservoir flood limited water level within different flood forecast error bounds is studied. The results show that, the dynamic control of reservoir flood limited water level with flood forecast information can increase the floodwater utilization rate without increasing flood control risk effectively and it is feasible in practice.

Ground State Properties of Ds Isotopes Within the Relativistic Mean Field Theory

The ground state properties of Ds(Z=110) isotopes(N=151-195) are studied in the framework of the relativistic mean field(RMF) theory with the effective interaction NL-Z2.The pairing correlation is treated within the conventional BCS approximation.The calculated binding energies are consistent with the results from finite-range droplet model(FRDM) and Macroscopic-microscopic method(MMM).The quadrupole deformation,α-decay energy,α-decay half-live,charge radius,two-neutron separation energy and single-particle spectra are analyzed for Ds isotopes to find new characteristics of superheavy nuclei(SHN).Among the calculated results it is rather distinct that the isotopic shift appears evidently at neutron number N=184.