并联机床平面约束机构误差分析与建模

针对五轴数控机床平面约束机构进行了误差分析 ,指出了并联机床平面约束机构误差主要影响因素为机构的制造误差和安装误差·前者与由其引起的约束机构顶边中点沿x方向的位移成非线性关系 ,而后者则成线性关系·提出了一种依据测量数据反演非线性误差模型的建模方法 ,给出了五轴并联机床约束机构实测信息与模型输出间的多项式误差模型·比较仿真结果与测量结果可知 ,基于上述方法建立的误差模型精确 ,进而利用该模型对机床进行实时精度补偿 ,可使机床x方向定位精度大为提高

OPC服务器I/O DLL的开发

介绍了ＯＰＣ服务器中用于与硬件设备Ｉ／Ｏ交互的动态链接库的开发方法，并着重讨论了数据类型转换问题。

机器人化三腿磨削机床的研制

以钢坯修磨为实用目的研制的一台机器人化三腿机床，具有刚度大、负载能力强、机构简单、工作空间大、无运动耦合及奇异位形等优点，首次解决了钢坯局部修磨自动化问题，配以其它加工执行器还可实现多种工艺要求。建立了该机床的运动学逆、正解方程，对其工作空间和受力分析进行了介绍，并介绍了局部修磨自动化控制系统

企业经营系统的对象模型──资金流模型

本文阐述了大型工业企业综合自动化系统体系结构中经营管理层的对象模型（资金流模型）。首先论述了该模型在自动化体系结构中的地位和作用，然后分析了企业生产经营过程中发生的资金流，提出用借贷流程图方法表达资金流模型，并将这一方法与国际通用的借贷记帐法相联系，从而揭示了资金流模型与会计核算的内在联系．本文还对企业生产与经营活动的几个主要过程用借贷流程图进行了细化描述。

大型激光叠焊系统研究与开发

介绍一种新型激光叠焊系统,利用该系统可将尺寸范围为12.0m×1.5m厚度不等的两块不锈钢板重叠焊接在一起。针对大尺寸不锈钢板尺寸大、易变形等特点提出了主—辅式压紧机构,有效地控制了焊接过程中大尺寸板材的变形并消除了板材间隙;设计了ufxyz型四轴联动方案:u轴与x轴同向,u轴驱动钢板进行大范围运动,x轴驱动激光头小范围运动。u轴与x轴的复合运动提高系统精度的同时提高了系统焊接动态响应速度。对实际焊接板材进行试验验证,结果表明使用该系统进行焊接的钢板可承受压强最大能达到6.1MPa。

甘肃西峰黄土剖面500 ka以来的蜗牛化石记录及其古气候、古环境变化研究

The loess-paleosol sequences in China are among the best continental records of paleoclimate changes. Although numerous sedimentological and geochemical studies have contributed greatly to the understanding of past climate changes during this period, it is still necessary to decipher more details through investigating these sequences using various approaches including biological analyses. In this study, we analyze the mollusk fossil assemblages preserved in the upper part of the Xifeng section, from the fifth loess layer (L5) to the Holocene soil (S0), with the sampling interval of 10 cm. The main results and conclusions obtained are as follows: 1. A continuous terrestrial mollusk fossil record, covering the past 500 ka, has been obtained from the Xifeng loess-paleosol sequence, which provides important biological data for the study of paleoenvironmental changes in the Loess Plateau and its comparison with marine record during this period. A total of 475 mollusk assemblages were studied, and twenty-one species have been identified among the 210,000 mollusk individuals counted. Among these species, most have modern representatives and are found in previous terrestrial mollusk studies of Chinese loess-paleosol sequences. Thus, they can be grouped into cold-aridiphilous, thermo-humidiphilous, oriental, and cool-humidiphilous ecological groups, as defined by previous studies. 2. Comparison of mollusk assemblages between the last five glacials and four interglacials and Holocene shows very different climate conditions. The warmest period occurred at MIS 11, MIS 5e, and Holocene, respectively. The coldest period is the Last Glacial Maximam, rather than the MIS 12. 3. Our mollusk record provides insight into the climate conditions in the Loess Plateau during the MIS 11, interpreted as the closest analog to the present interglacial. S4 paleosol, equivalent of MIS 11, developed under two major different climate regimes: ranging from the very warm–humid early phase to the mild-cool late interval. Furthermore, a cooling spell has been documented at the interglacial optimum, reflecting unstable climate conditions. The early warm–humid conditions lasted over 30 ka, supporting that MIS 11 is a unique long interglacial in the Quaternary climate history. 4. Comparison of MIS 11 and Holocene climates based on the mollusk species compositions indicates major differences. The climate at the early part of MIS 11 was warmer and more humid than during the Holocene optimum period, but the conditions during the late part of MIS 11 were similar to or cooler than late Holocene. Our study indicates that the extent of warming during the Holocene might be significantly less than the conditions that prevailed during the early part of MIS 11 interglacial period. 5. Two strong summer monsoon events were observed during the MIS 12 and MIS 10. They correspond to the maximam values of insolation gradient between low and high latitudes, suggesting a causal linkage. 6. Our study, combined with the previously investigated Luochuan land snail record, reveals that the climate in the Loess Plateau during MIS 3 experienced three stages: relatively warm, humid climate prevailed during MIS 3c, relatively cold, dry climate during MIS 3b, and relatively warm-humid period during MIS 3a. Climate at this time fluctuated frequently in Luochuan, and changed from warm-cool to cold-dry in Xifeng. Our results reveal that the relatively warm-humid climate during MIS 3c may be resulted from an increasing insolation gradient controlled by obliquity. Our result also reveals that obvious regional difference existed in the Loess Plateau during MIS 3. A greater climate gradient occurred during this time compared with today’s climate pattern in the Loess Plateau.

苏丹被动裂谷盆地的油气成藏机理和成藏模式

The research area of this paper covers the maximum exploration projects of CNPC, including Blocks 1/2/4 and Block 6 of the Muglad basin and the Melut basin in Bocks 3/7 in Sudan. Based on the study of the evolution history of the Central African Shear Zone (CASZ), structural styles and filling characteristics of the rift basins, it is put forward that the rift basins in Sudan are typical passive rift basins undergoing the strike-slip, extension, compression and inversion since the Cretaceous. The three-stage rift basins overlapped obliquely. The extension and rifting during the Early Cretaceous is 50-70% of the total extension. The features of the passive rift basins decided that there is a single sedimentary cycle and one set of active source rocks within the middle. Influenced by the three-stage rifting and low thermal gradient, hydrocarbon generation and charging took place very late, and the oil pool formation mechanism is very unique from the Lower Cretaceous rift sequences to the Paleogene. The reservoir-seal assemblages are very complicated in time and space. The sealing capacity of cap rocks was controlled by the CASZ. In general the oils become heavier towards the CASZ and lighter far away. The oil biodegradation is the reason causing the high total acid number. The determination of effective reservoir depth ensures that all discovered fields up to now are high-production fields. The propagation and growth of boundary faults in the rift basins can be divided into a simple fault propagation pattern and a fault growth-linkage pattern. It is firstly found that the linkage of boundary fault segments controls the formation of petroleum systems. Three methods have been established to outline petroleum systems. And a new classification scheme of rift-type petroleum system has been put forward: pre-rift, syn-rift (including passive and active) and post-rift petroleum systems. This scheme will be very important for the further exploration of rift basins. This paper firstly established the formation models of oil pools for the passive rift basins in Sudan: the coupling of accommodation zones and main plays for the formation of giant fields. The overlapping of late rifting broke the anticlines to be several fault-blocks. This process determined that anti-fault blocks are the main traptypes in the cretaceous sequences and anticlines in the Paleogene. This can explain why the traptypes are different between the Muglad and Mefut basins, and will provide theoretic guidance for the exploration strategy. The established formation mechanism and models in this paper have had great potential guidance and promotion for the exploration in Sudan, and resulted in significant economic and social benefit. A giant field of 500 million tons oil in place was found 2003. The cost in Blocks 3/7 is only 0.25

A homogeneous DNA hybridization system by using a new luminescence terbium chelate

Homogeneous DNA hybridization assay based on the luminescence resonance energy transfer (LRET) from a new luminescence terbium chelate, N,N,N-1,N-1-[2,6-bis(3'-aminomethyl-1'-pyrazolyl)-4-phenylpyridine]tetrakis(acetic acid) (BPTA)-Tb3+ (lambda(ex) = 325 nm and lambda(em) = 545 nm) to an organic dye, Cy3 (A,. = 548 nm and A,. = 565 nm), has been developed. In the system, two DNA probes whose sequences are complementary to the two different consecutive sequences of a target DNA are used; one of the probes is labeled with the Tb3+ chelate at the T-end, and the other is with Cy3 at the 5'-end. Labeling of the Tb3+ chelate is accomplished via the linkage of a biotin-labeled DNA probe with the Tb3+ chelate-labeled streptavidin. Strong sensitized emission of Cy3 was observed upon excitation of the Tb3+ chelate at 325 run, when the two probe DNAs were hybridized with the target DNA. The sensitivity of the assay was very high compared with those of the previous homogeneous-format assays using the conventional organic dyes; the detection limit of the present assay is about 30 pM of the target DNA strand.

Business service quality in an e-commerce environment

Yang, Y., Humphreys, P., & McIvor, R. (2006). Business service quality in an e-commerce environment. Supply Chain Management: An International Journal, 11 (3), 195-201. RAE2008

An association mapping approach to identify flowering time genes in natural populations of Lolium perenne (L.)

Sk?t, L., Humphreys, M. O., Armstead, I. P., Heywood, S., Sk?t, K. P., Sanderson, R., Thomas, I. D., Chorlton, K. H., & Sackville Hamilton, N. R. (2005). An association mapping approach to identify flowering time genes in natural populations of Lolium perenne (L.). Molecular Breeding, 15(3), 233-245. Sponsorship: BBSRC RAE2008

Estimation of long-run parameters in unbalanced cointegration

This paper analyses the asymptotic properties of nonlinear least squares estimators of the long run parameters in a bivariate unbalanced cointegration framework. Unbalanced cointegration refers to the situation where the integration orders of the observables are different, but their corresponding balanced versions (with equal integration orders after filtering) are cointegrated in the usual sense. Within this setting, the long run linkage between the observables is driven by both the cointegrating parameter and the difference between the integration orders of the observables, which we consider to be unknown. Our results reveal three noticeable features. First, superconsistent (faster than √ n-consistent) estimators of the difference between memory parameters are achievable. Next, the joint limiting distribution of the estimators of both parameters is singular, and, finally, a modified version of the ‘‘Type II’’ fractional Brownian motion arises in the limiting theory. A Monte Carlo experiment and the discussion of an economic example are included.

Genome-wide association study for subclinical atherosclerosis in major arterial territories in the NHLBI's Framingham Heart Study

INTRODUCTION:Subclinical atherosclerosis (SCA) measures in multiple arterial beds are heritable phenotypes that are associated with increased incidence of cardiovascular disease. We conducted a genome-wide association study (GWAS) for SCA measurements in the community-based Framingham Heart Study.METHODS:Over 100,000 single nucleotide polymorphisms (SNPs) were genotyped (Human 100K GeneChip, Affymetrix) in 1345 subjects from 310 families. We calculated sex-specific age-adjusted and multivariable-adjusted residuals in subjects tested for quantitative SCA phenotypes, including ankle-brachial index, coronary artery calcification and abdominal aortic calcification using multi-detector computed tomography, and carotid intimal medial thickness (IMT) using carotid ultrasonography. We evaluated associations of these phenotypes with 70,987 autosomal SNPs with minor allele frequency [greater than or equal to] 0.10, call rate [greater than or equal to] 80%, and Hardy-Weinberg p-value [greater than or equal to] 0.001 in samples ranging from 673 to 984 subjects, using linear regression with generalized estimating equations (GEE) methodology and family-based association testing (FBAT). Variance components LOD scores were also calculated.RESULTS:There was no association result meeting criteria for genome-wide significance, but our methods identified 11 SNPs with p < 10-5 by GEE and five SNPs with p < 10-5 by FBAT for multivariable-adjusted phenotypes. Among the associated variants were SNPs in or near genes that may be considered candidates for further study, such as rs1376877 (GEE p < 0.000001, located in ABI2) for maximum internal carotid artery IMT and rs4814615 (FBAT p = 0.000003, located in PCSK2) for maximum common carotid artery IMT. Modest significant associations were noted with various SCA phenotypes for variants in previously reported atherosclerosis candidate genes, including NOS3 and ESR1. Associations were also noted of a region on chromosome 9p21 with CAC phenotypes that confirm associations with coronary heart disease and CAC in two recently reported genome-wide association studies. In linkage analyses, several regions of genome-wide linkage were noted, confirming previously reported linkage of internal carotid artery IMT on chromosome 12. All GEE, FBAT and linkage results are provided as an open-access results resource at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007.CONCLUSION:The results from this GWAS generate hypotheses regarding several SNPs that may be associated with SCA phenotypes in multiple arterial beds. Given the number of tests conducted, subsequent independent replication in a staged approach is essential to identify genetic variants that may be implicated in atherosclerosis.

The Framingham Heart Study 100K SNP genome-wide association study resource: overview of 17 phenotype working group reports

BACKGROUND:The Framingham Heart Study (FHS), founded in 1948 to examine the epidemiology of cardiovascular disease, is among the most comprehensively characterized multi-generational studies in the world. Many collected phenotypes have substantial genetic contributors; yet most genetic determinants remain to be identified. Using single nucleotide polymorphisms (SNPs) from a 100K genome-wide scan, we examine the associations of common polymorphisms with phenotypic variation in this community-based cohort and provide a full-disclosure, web-based resource of results for future replication studies.METHODS:Adult participants (n = 1345) of the largest 310 pedigrees in the FHS, many biologically related, were genotyped with the 100K Affymetrix GeneChip. These genotypes were used to assess their contribution to 987 phenotypes collected in FHS over 56 years of follow up, including: cardiovascular risk factors and biomarkers; subclinical and clinical cardiovascular disease; cancer and longevity traits; and traits in pulmonary, sleep, neurology, renal, and bone domains. We conducted genome-wide variance components linkage and population-based and family-based association tests.RESULTS:The participants were white of European descent and from the FHS Original and Offspring Cohorts (examination 1 Offspring mean age 32 +/- 9 years, 54% women). This overview summarizes the methods, selected findings and limitations of the results presented in the accompanying series of 17 manuscripts. The presented association results are based on 70,897 autosomal SNPs meeting the following criteria: minor allele frequency [greater than or equal to] 10%, genotype call rate [greater than or equal to] 80%, Hardy-Weinberg equilibrium p-value [greater than or equal to] 0.001, and satisfying Mendelian consistency. Linkage analyses are based on 11,200 SNPs and short-tandem repeats. Results of phenotype-genotype linkages and associations for all autosomal SNPs are posted on the NCBI dbGaP website at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007.CONCLUSION:We have created a full-disclosure resource of results, posted on the dbGaP website, from a genome-wide association study in the FHS. Because we used three analytical approaches to examine the association and linkage of 987 phenotypes with thousands of SNPs, our results must be considered hypothesis-generating and need to be replicated. Results from the FHS 100K project with NCBI web posting provides a resource for investigators to identify high priority findings for replication.

Genome-wide association with bone mass and geometry in the Framingham Heart Study

BACKGROUND:Osteoporosis is characterized by low bone mass and compromised bone structure, heritable traits that contribute to fracture risk. There have been no genome-wide association and linkage studies for these traits using high-density genotyping platforms.METHODS:We used the Affymetrix 100K SNP GeneChip marker set in the Framingham Heart Study (FHS) to examine genetic associations with ten primary quantitative traits: bone mineral density (BMD), calcaneal ultrasound, and geometric indices of the hip. To test associations with multivariable-adjusted residual trait values, we used additive generalized estimating equation (GEE) and family-based association tests (FBAT) models within each sex as well as sexes combined. We evaluated 70,987 autosomal SNPs with genotypic call rates [greater than or equal to]80%, HWE p [greater than or equal to] 0.001, and MAF [greater than or equal to]10% in up to 1141 phenotyped individuals (495 men and 646 women, mean age 62.5 yrs). Variance component linkage analysis was performed using 11,200 markers.RESULTS:Heritability estimates for all bone phenotypes were 30-66%. LOD scores [greater than or equal to]3.0 were found on chromosomes 15 (1.5 LOD confidence interval: 51,336,679-58,934,236 bp) and 22 (35,890,398-48,603,847 bp) for femoral shaft section modulus. The ten primary phenotypes had 12 associations with 100K SNPs in GEE models at p < 0.000001 and 2 associations in FBAT models at p < 0.000001. The 25 most significant p-values for GEE and FBAT were all less than 3.5 x 10-6 and 2.5 x 10-5, respectively. Of the 40 top SNPs with the greatest numbers of significantly associated BMD traits (including femoral neck, trochanter, and lumbar spine), one half to two-thirds were in or near genes that have not previously been studied for osteoporosis. Notably, pleiotropic associations between BMD and bone geometric traits were uncommon. Evidence for association (FBAT or GEE p < 0.05) was observed for several SNPs in candidate genes for osteoporosis, such as rs1801133 in MTHFR; rs1884052 and rs3778099 in ESR1; rs4988300 in LRP5; rs2189480 in VDR; rs2075555 in COLIA1; rs10519297 and rs2008691 in CYP19, as well as SNPs in PPARG (rs10510418 and rs2938392) and ANKH (rs2454873 and rs379016). All GEE, FBAT and linkage results are provided as an open-access results resource at http://www.ncbi.nlm.nih.gov/projects/gap/cgi-bin/study.cgi?id=phs000007.CONCLUSION:The FHS 100K SNP project offers an unbiased genome-wide strategy to identify new candidate loci and to replicate previously suggested candidate genes for osteoporosis.

A genome-wide association study for blood lipid phenotypes in the Framingham Heart Study

BACKGROUND:Blood lipid levels including low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides (TG) are highly heritable. Genome-wide association is a promising approach to map genetic loci related to these heritable phenotypes.METHODS:In 1087 Framingham Heart Study Offspring cohort participants (mean age 47 years, 52% women), we conducted genome-wide analyses (Affymetrix 100K GeneChip) for fasting blood lipid traits. Total cholesterol, HDL-C, and TG were measured by standard enzymatic methods and LDL-C was calculated using the Friedewald formula. The long-term averages of up to seven measurements of LDL-C, HDL-C, and TG over a ~30 year span were the primary phenotypes. We used generalized estimating equations (GEE), family-based association tests (FBAT) and variance components linkage to investigate the relationships between SNPs (on autosomes, with minor allele frequency [greater than or equal to]10%, genotypic call rate [greater than or equal to]80%, and Hardy-Weinberg equilibrium p [greater than or equal to] 0.001) and multivariable-adjusted residuals. We pursued a three-stage replication strategy of the GEE association results with 287 SNPs (P < 0.001 in Stage I) tested in Stage II (n ~1450 individuals) and 40 SNPs (P < 0.001 in joint analysis of Stages I and II) tested in Stage III (n~6650 individuals).RESULTS:Long-term averages of LDL-C, HDL-C, and TG were highly heritable (h2 = 0.66, 0.69, 0.58, respectively; each P < 0.0001). Of 70,987 tests for each of the phenotypes, two SNPs had p < 10-5 in GEE results for LDL-C, four for HDL-C, and one for TG. For each multivariable-adjusted phenotype, the number of SNPs with association p < 10-4 ranged from 13 to 18 and with p < 10-3, from 94 to 149. Some results confirmed previously reported associations with candidate genes including variation in the lipoprotein lipase gene (LPL) and HDL-C and TG (rs7007797; P = 0.0005 for HDL-C and 0.002 for TG). The full set of GEE, FBAT and linkage results are posted at the database of Genotype and Phenotype (dbGaP). After three stages of replication, there was no convincing statistical evidence for association (i.e., combined P < 10-5 across all three stages) between any of the tested SNPs and lipid phenotypes.CONCLUSION:Using a 100K genome-wide scan, we have generated a set of putative associations for common sequence variants and lipid phenotypes. Validation of selected hypotheses in additional samples did not identify any new loci underlying variability in blood lipids. Lack of replication may be due to inadequate statistical power to detect modest quantitative trait locus effects (i.e., < 1% of trait variance explained) or reduced genomic coverage of the 100K array. GWAS in FHS using a denser genome-wide genotyping platform and a better-powered replication strategy may identify novel loci underlying blood lipids.