“基本型”视角下例谈几何问题解题思路的分析与探索

笔者以偶然得到的一个命题的解法为例,在“基本型”视角下对其解题思路进行分析和探索,通过提炼、总结切实感受,得出“基本型”在解决几何问题中的重要作用和价值.

Effects of Genotypes and Basic Medium on Culture of Maize Mature Embryos

[Objective]This study was to screen out suitable genotypes and basic medium for the culture of maize mature embryos.[Method]Using mature embryos of nine maize genotypes as explants,the effects of genotypes and basic medium on callus induction and subculture were investigated.[Result]The genotypes performed better in callus induction and subculture were found in turn 853-35,853-209,Dan 34 and 81162.MS medium is better than N6 medium in the callus induction from maize embryos,while N6 medium is more suitable for callus subculture.[Conclusion]Our study further improved the tissue culture system in maize with mature embryos as explants.

基于仿真的编队作战指挥系统设计方法及环境研究

首先研究了基于仿真的编队作战指挥系统设计方法的内涵,重点提出了基于仿真的编队作战指挥系统设计过程及所需的仿真系统,以此为基础,系统地提出了提高仿真模型和系统标准化、重用性以及开发的快速性的仿真支撑环境和"基本型"仿真应用环境,并对其组成、功能、应用流程进行了描述。该设计方法和支撑环境已成功地应用于某型舰作战指挥系统的研制过程中,取得了较好的效果。

Studies on Enhancing Yield of Embryos in Microspore Culture of Brassica napus L.

In ecological zone of Chengdu, Sichuan, microspore culture was carried out in Brassica napus L. to study the influencing factors on microspore culture. The results showed that the temperature on microspore formation stage, day and night temperature, disinfection solution of buds, cultivation concentration on microspore and strain-age were both important influencing factors on microspore culture. At a temperature below 5 ℃ or above 20 ℃, the material had a much lower embryo producing rate or even could not produce any embryo, but at the optimum temperature of 10 -15 ℃ the embryo yield was up to 300 pieces per bud; the best cultivation effect appeared when 0. 1% HgCl2 was used for disin- fection; the best density of microspore was 3 -4 buds per dish; In 2009, while strain-age was from 125 d to 150 d, the microspore embryo yield increased as strain-age increased. When stain-age was 150 days, the microspore embryo yield was up to the highest, but the yield declined after 150 days.

Study of Helicobacter pylori genotype status in saliva,dental plaques,stool and gastric biopsy samples

AIM:To compare genotype of Helicobacter pylori(H.pylori) isolated from saliva,dental plaques,gastric biopsy,and stool of each patient in order to evaluate the mode of transmission of H.pylori infection.METHODS:This cross-sectional descriptive study was performed on 300 antral gastric biopsy,saliva,dental plaque and stool samples which were obtained from patients undergoing upper gastrointestinal tract endoscopy referred to endoscopy centre of Hajar hospital of Shahrekord,Iran from March 2010 to February 2011.Initially,H.pylori strains were identified by rapid urease test(RUT) and polymerase chain reaction(PCR) were applied to determine the presence of H.pylori(ureC) and for genotyping of voculating cytotoxin gene A(vacA) and cytotoxin associated gene A(cagA) genesin each specimen.Finally the data were analyzed by using statistical formulas such as Chi-square and Fisher's exact tests to find any significant relationship between these genes and patient's diseases.P < 0.05 was considered statistically significant,RESULTS:Of 300 gastric biopsy samples,77.66% were confirmed to be H.pylori positive by PCR assay while this bacterium were detected in 10.72% of saliva,71.67% of stool samples.We were not able to find it in dental plaque specimens.The prevalence of H.pylori was 90.47% among patients with peptic ulcer disease(PUD),80% among patients with gastric cancer,and 74.13% among patients with none ulcer dyspepsia(NUD) by PCR assay.The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens.94.42% of H.pylori positive specimens were cagA positive and all samples had amplified band both for vacA s and m regions.There was significant relationship between vacA s1a/m1a and PUD diseases(P = 0.04),s2/m2 genotype and NUD diseases(P = 0.05).No statically significant relationship was found between cagA status with clinical outcomes and vacA genotypes(P = 0.65).The evaluation of vacA and cagA genes showed 6 differences between gastric biopsy and saliva specimens and 11 differences between gastric and stool specimens,CONCLUSION:Regard to high similarity in genotype of H.pylori isolates from saliva,stomach and stool,this study support the idea which fecal-oral is the main route of H.pylori transmission and oral cavity may serve as a reservoir for H.pylori,however,remarkable genotype diversity among stomach,saliva and stool samples showed that more than one H.pylori genotype may exist in a same patient.

Complete Spacelike Hypersurfaces with Constant Scalar Curvature in Locally Symmetric Lorentz Spaces

The complete space-like hypersurfaces with constant normal saclar curvature is discussed in a locally symmetric Lorentz space. A classified theorem is obtained by the operator L1 introduced by S Y Cheng and S T Yau [3].

A Geometric Model of Multiaxial Warp-knitted Preform for Composite Reinforcement

A new geometric model of Multiaxial Warp-Knitted (MWK) performs, which is based on the experimental observations and analysis of basic stitch, is developed to relate the geometric parameters and process variables. The fiber volume fraction and fibre orientation of MWK reinforced composites are described in terms of structural and processing parameters in the model. And this model provides a basis for the prediction of mechanical behavior of the MWK reinforced composites.

Collapse-type shrinkage characteristics in plantation-grown eucalypts： I . Correlations of basic density and some structural indices with shrinkage and collapse properties

Collapse-type shrinkage is one of highly refractory drying defects inlow-medium density plantation-grown eucalypt wood used as solid wood products. Basic density (BD),microfibril angle (MFA), double fibre cell wall thickness (DWT), proportion of ray parenchyma (RP),unit cell wall shrinkage, total shrinkage and residual collapse, which are associated withcollapse-type shrinkage characteristics, were investigated by using simple regression method forthree species of collapse-susceptible Eucalyptus urophyll,, E. grandis and E. urophyllaxE.grandis,planted at Dong-Men Forest Farm in Guangxi autonomous region, China. The results indicated that:unit cell wall shrinkage had a extremely strong positive correlation with BD, moderately strongpositive correlation with DWT, and a weakly or moderately negative correlation with RP and MFA;total shrinkage was positively correlated with BD, DWT and RP and negatively related to MFA, but notable to be predicted ideally by any examined factors alone owing to lower R^2 value (R^2≤0.5712);residual collapse was negatively correlated with BD and DWT, linearly positively correlated withMFA, and had strongly positive linear correlation with RP. It is concluded that BD can be used assingle factor (R^2≥ 0.9412) to predicate unit cell wall shrinkage and RP is the relatively soundindicator for predicting residual collapse

Efficient Property-Based Remote Attestation Scheme

In order to ensure the security of the property-based remote attestation scheme, an improved, more efficient, forrml security model of property-based remote attestation is proposed, with which we prove that the user platform satis- fies the security property requirements predefmed by a remote relying party. Under the co-Corrtautational Diffie-Helknan （CDH） assumption, the proposed scheme is proved to be secure in the random oracle model. Compared with the existing schemes, the proposed scheme has a short property certificate and signature size, and requires less computational cost.

Dynamic batch selective sampling based on version space analysis

A novel dynamic batch selective sampling algorithm based on version space analysis is presented. In the traditional batch selective sampling, example selection is entirely determined by the existing unreliable classification boundary; meanwhile, within a batch, examples labeled previously fail to provide instructive information for the selection of the rest. As a result, using the examples selected in batch mode for model refinement will jeopardize the classification performance. Based on the duality between feature space and parameter space under the SVM active learning fi：amework, dynamic batch selective sampling is proposed to address the problem. We select a batch of examples dynamically, using the examples labeled previously as guidance for further selection. In this way, the selection of feedback examples is determined by both the existing classification model and the examples labeled previously. Encouraging experimental results demonstrate the effectiveness of the proposed algorithm.

The Fundamental Theorem of Ultraproducts in Lattice valued Model for L_α Logic

In this paper we add some new corcollary and theorems to [1],in particular,we show the fundamental theorem of ultraproducts in lattice valued model for L α logic. As a corollary,we get the α compactness theorem for L_α logic.

Spring constitutive model of rigid pile composite foundation and application in design of raft foundation

The simplified analysis method based on the static equilibrium is generally adopted for raft design. The secondary stress of superstructure due to the differential settlement of the foundation is neglected, which leads to larger support moments and longitudinal bending of raft compared with real values. The spring constitutive relation of composite foundation is obtained by the flat plate loading tests in Karst region. The interaction between the spring and the raft is equivalent to the interaction between the composite foundation and the raft. The model for superstructure-raft-composite foundation interaction analysis is thus established and the raft is designed. This method not only considers the nonlinear properties of composite foundation but also analyzes the influence of superstructure on bending moment and deformation of raft. Compared with the inverted floor method, the calculated values of moment become more reasonable and uneven settlements are considered. This can be references to the design of raft foundation in similar regions.

Ontology Framework for Content-Based 3D Model Retrieval

The goal of the research on ontology framework for content-based 3D model retrieval is to develop a rich set of 3D model semantic representation so that both humans and machines can generate and understand model descriptions and processing for fast efficient retrieval from model collections. The purpose of ontology development for content-based 3D model retrieval is intended to describe model information regardless of storage, feature extraction and creation. The ontology includes the information on media features, low level visual descriptors, non media features of 3D model and their relationships. It is implemented in protege 3.1.

Study of front bumper process on the basis of hot stamping

The fitting method is used for obtaining the constitutive relation of ultra-high strength steel in this paper. At the same time, the forming limit of material is researched under different de/brmation conditions. Through experiments, the paper obtains stress-strain curve under different deformation temperatures and strain rates. On the basis of experimental data, the constitutive relation model is established which can reflect the de- fomlation capacity of ultra-high strength steel during process of hot stamping. Combining with finite element simulation results of hot stamping by the commercial software AUTOFORM, transfer path of load and matching law of strength, the paper determines the design criteria and forming process requirements of parts manufactured by hot stamping. Through setting different process parameters, such as punch velocity and friction coefficient, and blank shape, the paper finds that process parameters and blank shape have an essential effect on the quality of parts.

Research on goal-setting method of rock drivage based on the balance among period, cost and quality

On the basis of the analysis on the disadvantages of the original goal-setting about rock drivage, this paper defined the ＂life cycle quality＂. With project management theory and the Cobb-Douglas function, ＂quality-cost and quality-price curve model＂ and the ＂total cost-period prediction model＂ were built. Then the goal-setting method of the balance among quality, cost and period of rock drivage was constructed by finding ＂life cycle cost＂ through ＂life cycle quality＂ using ＂quality-cost and quality-price curve model＂ and ensuring period through ＂life cycle cost＂ using ＂total cost-period prediction model＂ （hereinafter referred to as the ＂three goals balance method＂）. ＂Value contribution＂ which is the value of the contribution to a mine because of rock drivage, was found in the process of constructing the ＂quality-cost and quality-price curve model＂. An industrial test was done in coal mine A with the research results, staff footage efficiency improved by 24.24%, the period shortened by 14.3%, the ＂life cycle cost＂ dropped by 2.09%, the ＂life cycle quality price＂ improved by 3.29%, and value contribution increased by 25.3%. The result shows that the new goal method setting on the basis of coal mine profit maximization can ensure construc- tion period. At the same time, it can realize cost and quality objectives and the optimization and balance of relationship among them; rewarding excavation teams by ＂value contribution＂ can combine organizational goal with personal goal, it significantly raise the employee＇s work efficiency.

Soil Uncertainties on Performance of Geotechnical Works

Performance-Based Design （PBD） is a more rational approach, particularly in seismic environments. In this approach it is relevant the performance required to structures and to geotechnical works, as well as the geotechnical constitutive models used to predict the performance. The parameters of the constitutive models are related in turn to soil properties. So soil properties are a key point for Performance-Based Design. Questions arising are： （i） which are the more relevant soil properties to solve a specific PBD geotechnical problem？ （ii） which are the more relevant model parameters and how they can be evaluated and/or correlated to soil properties？ （iii） which is the role of the soil parameters uncertainty in Performance-Based Design？ An answer to these questions is given in this paper, outlining the potential offered by the new advanced in-situ and laboratory tests and discussing the performance required by some geotechnical works.

Failure analysis of crush hammers based on damage fracture energy

To prolong the life-span of crush hammers in the pyrite concentrate workplace of Ganbazi Coal Preparation Plant of Chongqing Nantong Mining Ltd., we used a progressive damage constitutive model based on the ductile and shear damage fracture energy to analyze the hammer wear failure caused by the impact and abrasion on the hammer surface by pyrite, and carried out simulation analysis with the explicit algurithm on hammer leftovers from the plant during the process of coarser pyrite comminution. The simulation results are consistent with hammer wear failure caused by pyrite impact. Then we proposed corrective measures to prolong hammer life-span. Results of the production test in the Ganbazi Coal Preparation Plant showed that non-clearance hammers can avoid wear erosion, and adding steel bonded tungsten carbides F3002 prolonged the hammer life- span. The effect of austenitic manganese steel work-hardening was not prominent. Therefore, the hammer failure was mainly caused by superficial abrasion instead of fatigue cracks appearing when grains acted on the hardening layer.

Single nucleotide polymorphisms in the CDH17 gene of colorectal carcinoma

AIM:To investigate the relationship between c.343A>G and c.2216A>C polymorphism sites in the CDH17 gene and colorectal carcinoma.METHODS:Ninety-three non-consanguineous colorectal carcinoma patients admitted to the Department of Oncology at the First Affiliated Hospital of Zhengzhou University were included in this study.Ninety-three peripheral venous blood samples,of approximately one milliliter from each patient,were collected betweenDecember 2009 and August 2010.The genomic DNA of these peripheral venous blood samples were extracted and purified using a Fermentas Genomic DNA Purification Kit(Fermentas,CA) according to the manufacturer' s protocol.The single nucleotide polymorphisms(SNPs) of the liver-intestine cadherin(CDH17) gene c.343A>G and c.2216A>C were determined by the polymerase chain reaction-single strand conformation polymorphism method(PCR-SSCP) in 93 peripheral venous blood samples from patients suffering with colorectal carcinoma.Typical samples that showed different migration bands in SSCP were confirmed by sequencing.Directed DNA sequencing was used to check the correctness of the genotype results from the PCR-SSCP method.RESULTS:There was a significant association between the c.2216 A>C SNPs of the CDH17 gene and the tumor-node-metastasis(TNM) grade,as well as with lymph node status,in 93 peripheral venous blood samples from colorectal carcinoma patients.The genotype frequencies of A/C,A/A,and C/C were 12.90%,33.33% and 53.76%,respectively.There was a significant correlation between lymph node metastasis,TNM grade,and the genotype distribution(P < 0.05).The C/C genotype raised the risk of lymph node metastasis and the TNM grade.There was a significant difference in the TNM grade and lymph node metastasis between the A/A and C/C genotypes(P = 0.003 and P = 0.013,respectively).Patients with colorectal carcinoma carrying the C allele tended to have a higher risk of lymph node metastasis and have a higher TNM grade.The difference between the TNM grades,as well as the lymph node metastasis of the two alleles,was statistically significant(P < 0.01).CONCLUSION:The SNPs of the CDH17 gene c.2216 A>C might be clinically important in the prognosis of colorectal carcinoma.

Hierarchical Scene Analysis Method for Audio Sensor Networks

Abstract： A hierarchical method for scene analysis in audio sensor networks is proposed. This meth-od consists of two stages： element detection stage and audio scene analysis stage. In the former stage, the basic audio elements are modeled by the HMM models and trained by enough samples off-line, and we adaptively add or remove basic ele- ment from the targeted element pool according to the time, place and other environment parameters. In the latter stage, a data fusion algorithm is used to combine the sensory information of the same ar-ea, and then, a role-based method is employed to analyze the audio scene based on the fused data. We conduct some experiments to evaluate the per-formance of the proposed method that about 70% audio scenes can be detected correctly by this method. The experiment evaluations demonstrate that our method can achieve satisfactory results.

On the role of the constitutive model and basal texture on the mechanical behaviour of magnesium alloy AZ31B sheet

The recently developed elastic-viscoplastic self-consistent model with various self-consistent schemes was applied to study the effect of basal texture on the mechanical behavior of magnesium alloy AZ31B sheet. The influence of the basal texture was investigated using various initial textures generated by artificially tilting the measured texture of the reference AZ31B sheet around in a transverse direction. The material parameters for the various models were fitted to experimental uniaxial tension and compression along the rolling direction and were then used to study the effects of the basal texture on the yield stress, R value, ultimate stress and uniform strain under uniaxial tension. The effect of the basal texture on sheet metal forming was further assessed by calculating the limit strain under in-plane plane strain tension. An assessment of the predictive capability of polycrystal plasticity models was made based on comparisons of predictions and experimental observations. Among the available self-consistent approaches, the Affine self-consistent scheme resulted in the best overall performance.