广义共轭延拓矩阵的奇异值分解

定义广义共轭延拓矩阵的概念,利用复矩阵的实分量矩阵,分别建立广义行共轭延拓矩阵和列共轭延拓矩阵与其母矩阵的实分量矩阵的奇异值和奇异向量之间的定量关系.所得行或列延拓矩阵的奇异值等于母矩阵的实分量矩阵奇异值的2^(1/2)倍,相应的右或左奇异向量矩阵是实正交矩阵.

Real-time instance segmentation based on contour learning

Instance segmentation plays an important role in image processing.The Deep Snake algorithm based on contour iteration deforms an initial bounding box to an instance contour end-to-end,which can improve the performance of instance segmentation,but has defects such as slow segmentation speed and sub-optimal initial contour.To solve these problems,a real-time instance segmentation algorithm based on contour learning was proposed.Firstly,ShuffleNet V2 was used as backbone network,and the receptive field of the model was expanded by using a 5×5 convolution kernel.Secondly,a lightweight up-sampling module,multi-stage aggregation(MSA),performs residual fusion of multi-layer features,which not only improves segmentation speed,but also extracts effective features more comprehensively.Thirdly,a contour initialization method for network learning was designed,and a global contour feature aggregation mechanism was used to return a coarse contour,which solves the problem of excessive error between manually initialized contour and real contour.Finally,the Snake deformation module was used to iteratively optimize the coarse contour to obtain the final instance contour.The experimental results showed that the proposed method improved the instance segmentation accuracy on semantic boundaries dataset(SBD),Cityscapes and Kins datasets,and the average precision reached 55.8 on the SBD;Compared with Deep Snake,the model parameters were reduced by 87.2%,calculation amount was reduced by 78.3%,and segmentation speed reached 39.8 frame·s−1 when instance segmentation was performed on an image with a size of 512×512 pixels on a 2080Ti GPU.The proposed method can reduce resource consumption,realize instance segmentation tasks quickly and accurately,and therefore is more suitable for embedded platforms with limited resources.

频率域航空电磁法视电阻率转换在岩性构造填图中的应用

以固定翼航空电磁系统正演公式为基础,介绍了实虚分量法、幅值飞行高度法等均匀半空间模型下的视电阻率转换方法。将内蒙古某测区实测的高、中、低3个频率的航空电磁数据转换为视电阻率,即Hρs、Mρs、Lρs,并对3个频率的视电阻率填图效果进行了试验对比,最后选用Hρs等值线图进行岩性构造填图,与地质图吻合程度较高。提高了航空视电阻率填图的实际意义和应用,为后期资料解释提供了理论基础。

High resolution GPR and its experimental study

We develop a high resolution ground penetrating radar system （LANRCS-GPR） based on the E5071B Vector Network Analyzer （VNA）. This system takes advantage of a wideband and adjustable frequency domain ground penetrating radar system and adds the characteristics of a network analyzer with ultra-wideband and high precision measurement. It adopts the LAN mode to concatenate system control that reduces construction cost and makes the system easy to expand. The high resolution ground penetrating radar system carries out real time imaging using F-K migration with high calculation efficiency. The experiment results of the system indicate that the LANRCS-GPR system provides high resolution and precision, high signal-to-noise ratio, and great dynamic range. Furthermore, the LANRCS-GPR system is flexible and reliable to operate with easy to expand system functions. The research and development of the LANRCS-GPR provide the theoretical and experimental foundation for future frequency domain ground penetrating radar production and also can serve as an experimental platform with high data gathering precision, enormous information capability, wide application, and convenient operation for electromagnetic wave research and electromagnetic exploration.

电磁探矿仪野外找矿可行性试验研究

使用自制的电磁探矿仪进行野外找矿试验 ,剖面试验是在已知矿体上进行 ;根据剖面试验结果再选取最佳收、发距 ,最佳工作频率进行小面积试验 ,目的是对仪器的主要技术指标进行检验 ,同时对仪器投入野生产的可行性进行论证。

基于K中心点聚类分析的大地电磁阻抗识别

在大地电磁场复杂的观测环境中,信号会受到不同类型或程度的噪声干扰。传统阻抗估计或提取方法(如功率谱法、Robust法等)难以获得稳定的阻抗值。利用大地电磁阻抗的实虚分量特性,受噪声干扰小的信号阻抗分布集中,受噪声干扰严重的信号阻抗分布散乱。引入K中心点聚类分析对阻抗进行提取与识别,并利用阻抗欧氏距离来描述阻抗间的相似性,依据相似性把受干扰小的信号阻抗划分到一类,受干扰大的信号阻抗划分到不同的类。依据相干度准则和紧凑性准则等类的选取准则,甄别出干扰环境中阻抗所在的最佳类。通过仿真实验和实例分析,验证了K中心点聚类分析能在噪声环境中识别出高质量的信号,恢复出真实阻抗值。

Prediction of Distillation Column Performance by Computational Mass Transfer Method

A computational mass transfer model is proposed for predicting the concentration profile and Murphree efficiency of sieve tray distillation column. The proposed model is based on using modified c＇2 -εc＇ two equations formulation for closing the differential turbulent mass transfer equation with improvement by considering the vapor injected from the sieve hole to be three dimensional. The predicted concentration distributions by using proposed model were checked by experimental work conducted on a sieve tray simulator of 1.2 meters in diameter for desorbing the dissolved oxygen in the feed water by blowing air. The model predictions were confirmed by the experimental measurement. The validation of the proposed model was further tested by comparing the simulated result with the performance of an industrial scale sieve tray distillation column reported by Kunesh et al. for the stripping of toluene from its water solution. The predicted outlet concentration of each tray and the Murphree tray efficiencies under different operating conditions were in agreement with the published data. The simulated turbulent mass transfer diffusivity on each tray was within the range of the experimental result in the same sieve column reported by Cai et al. In addition, the prediction of the influence of sieve tray structure on the tray efficiency by using the proposed model was demonstrated.

Preparation and coking properties of coal maceral concentrates

The concentrates with different maceral contents were obtained from Kailuan coking coals with different coal ranks(Ro;ranvarying from 0.88%to 1.73%)by float–sink separation in lab.Then these concentrates were characterized by proximate analysis,ultimate analysis,petrography analysis and coking index determination.The results show that the vitrinite is characterized as nature of lower carbon content,higher hydrogen content,higher volatile matter and stronger caking property compared to inertinite.The relationships between variation rate of volatile matter and maximum volatile matter and coal ranks are identified,and a linear model is developed for fast determination of the maceral contents.Compared to inertinite-rich concentrate,the blending ratio of vitrinite-rich concentrate is increased by 13%,which is considered to be a potential technique based on maceral separation for expanding the coking coal resources.

Crossing point temperature of coal

A further understanding of the self-heating of coal was obtained by investigating the crossing point temperature（CPT） of different ranks of coal.The tests were carried out using a self-designed experimental system for coal self-heating.50 g（±0.01 g） of coal particles ranging from 0.18 mm to 0.38 mm in size were put into a pure copper reaction vessel attached to the center of a temperature programmed enclosure.The temperature program increased the temperature at a rate of 0.8℃/min.Dry air was permitted to flow into the coal reaction vessel at different rates.The surrounding temperature and the coal temperature were monitored by a temperature logger.The results indicate that CPT is affected by coal rank,moisture,sulfur, and the experimental conditions.Higher ranked coals show higher CPT values.A high moisture content causes a delay phenomenon during the self-heating of the coal.Drying at 40℃decreases the effects of moisture.The reactivity of sulfur components in the coal is low under dry and low-temperature conditions. These components form a film that covers the coal surface and slightly inhibits the self-heating of the coal. The flow rate of dry air,and the heating rate of the surroundings,also affect the self-heating of the coal.The most appropriate experimental conditions for coal samples of a given weight and particle size were determined through contrastive analysis.Based on this analysis we propose that CPTs be determined under the same,or nearly the same conditions,for evaluation of the spontaneous combustion of coal.

Microstructural evolution and mechanical properties of Ti-5Al-5Mo-5V-3Cr alloy by heat treatment with continuous temperature gradient

A new high throughput heat-treatment method with a continuous temperature gradient between 600 and 700 ？C was utilized on the Ti-5553 alloy（Ti-5 Al-5 Mo-5 V-3 Cr, mass fraction, %）. The temperature gradient was induced by the variation of the axial section of sample, which was heated by the direct current. The variation of continuous cooling rates on the treated sample was realized by using the end quenching method. The microstructural evolution and mechanical properties under different heat treatment conditions were evaluated. The results show that the pseudo-spinodal decomposition of the alloy occurs at（617±1） ？C, and the size of the precipitated α phase is around 300 nm. Moreover, the highest microhardness is obtained after the heat treatment at the pseudo-spinodal decomposition temperature for 4 h. These indicate that the high throughput method is efficient and fast to determine the phase transformation temperature and corresponding microstructural evolution of alloys.

Xeno-free derivation and culture of human embryonic stem cells： current status, problems and challenges

Human embryonic stem cells （hESC） not only hold great promise for the treatment of degenerative diseases but also provide a valuable tool for developmental studies. However, the clinical applications of hESC are at present limited by xeno-contamination during the in vitro derivation and propagation of these cells. In this review, we summarize the current methodologies for the derivation and the propagation of hESC in conditions that will eventually enable the generation of clinical-grade cells for future therapeutic applications.

Characterization and expression of sweetfish （Plecoglossus altivelis） cathepsin D

Cathepsin D （CTSD） is a lysosomal acidic endoproteinase that plays an important role in immune response, In this study, we obtained sweetfish （Plecoglossus altivelis） CTSD （PaCTSD） via de-novo transcriptome sequencing of sweetfish macrophages. The full length cDNA sequence of PaCTSD was 1955 bp encoding a propeptide of 397 amino acids. The deduced protein had a calculated molecular weight of 43.17x 103. Multiple alignment with other known CTSD amino acid sequences revealed amino acid conservation through the teleosts. Phylogenetic tree analysis showed that PaCTSD grouped tightly with other fish CTSD, and was close to that of Atlantic salmon and rainbow trout. Subsequently, PaCTSD was prokaryotically expressed and refolded by the urea gradient method on a nickel-nitrilotriacetic acid column. Enzyme activity analysis showed that PaCTSD exhibited pH-dependent proteolytic activity. Quantitative real-time PCR showed that PaCTSD mRNA was expressed in all detected tissues in healthy sweetfish. The highest expression was observed in the spleen and white blood cells, followed by liver, head-kidney, kidney, intestine, gill, and muscle. After Listonella anguillarum infection, PaCTSD transcripts were up-regulated significantly in liver, spleen, white blood cells, and head-kidney of sweetfish. In summary, PaCTSD has proteolytic activity and is closely involved in the immune response of sweetfish.

MicroRNA-15a/b are up-regulated in response to myocardial ischemia/reperfusion injury

Objective Several studies have indicated that miR-15a,miR-15b and miR-16 may be the important regulators of apoptosis.Since attenuate apoptosis could protect myocardium and reduce infarction size,the present study was aimed to find out whether these miRNAs participate in regulating myocardial ischemia reperfusion （I/R） injury.Methods Apoptosis in mice hearts subjected to I/R was detected by TUNEL assay in vivo,while flow cytometry analysis followed by Annexin V/PI double stain in vitro was used to detect apoptosis in cultured cardiomyocytes which were subjected to hypoxia/reoxygenation （H/R）.Taqman real-time quantitative PCR was used to confirm whether miR-15a/15b/16 were involved in the regulation of cardiac I/R and H/R.Results Compared to those of the controls,I/R or H/R induced apoptosis of cardiomyocytes was significantly iucreased both in vivo （24.4％ ± 9.4％ vs.2.2％ ± 1.9％,P ＜ 0.01,n =5） and in vitro （14.12％ ±0.92％ vs.2.22％ ± 0.08％）.The expression of miR-15a and miR-15b,but not miR-16,was increased in the mice I/R model,and the results were consistent in the H/R model.Conclusions Our data indicate miR-15 and miR-15b are up-regulated in response to cardiac I/R injury,therefore,down-regulation of miR- 15a/b may be a promising strategy to reduce myocardial apoptosis induced by cardiac I/R injury.

Coupled Reaction/Distillation Process for Hydrolysis of Methyl Acetate

A process composed of a fixed-bed and a distillation column with a side withdraw, mainly methanol, is developed to hydrolyze methyl acetate (MA) as a typical byproduct in polyvinyl alcohol (PVA) and pure terephthalic acid (PTA) factory. The process is simulated by employing the equilibrium stage model RadFrac and plug flow model Rplug in Aspen Plus. Experiments are also carried out in a lab-scale to evaluate the process. The results show that at the molar ratio of water to methyl acetate about 4.0-5.0 in the feed stream and the volume ratio of distillate to feed MA above a critical value, the side product contains more than 80% (by mass) (MeOH) and less than 2% (by mass) MA, while the bottom contains more than 46% (by mass) acetic acid (HAc) and less than 0.5% (by mass) methanol with almost complete conversion of MA. Compared with the old catalytic distillation process we proposed before, this process can cut down 47.6% energy consumption and a distillation column.

Effects of China's OFDI on Host Countries' Environmental Quality

From a FDI source country perspective, this paper reveals the effect of Chinas OFDI on host countries' environmental quality. Based on the Copeland-Taylor model, this paper creates a theoretical mechanism to demonstrate how Chinas OFDI affects host countries' pollution intensity and environmental quality and carries out an empirical analysis based on Chinas OFDI data of 2003-2014 and the economic development index data of 168 host countries. Since Chinas OFDI is differentiated for countries of various income levels, this paper f Urther conducts a sub-sample empirical test on the income level of host countries. The result shows that Chinas OFDI growth generally induces an increase in total pollution emissions in host countries but significantly reduces per capita emissions and thus improves local environmental quality. Sub-sample regression result shows that whether in terms of total or per capita emissions, Chinas OFDI has a much more significant effect in improving the environmental quality of high-income countries.

Identification and expression analysis of bovine ANGPTL gene family

Encoded by seven genes, angiopoietin-like （ANGPTL） family members structurally similar to the angiogenic regulating factor angiopoietin are known to possess biological activities in angiogenesis and metabolism. Here we reports for the first time the identification and expression analysis of all the seven members of bovine ANGPTL gene family, which were designated bANGPTL1 to bANGPTL7 in order. The seven bANGPTL genes consist of 4-9 exons, span 3800M-3000 bp and are located on different chromosomes. The deduced amino acid sequences of the members all possess an N-terminal coiled-coil domain and a C-terminal fibrinogen-like domain, both characteristics of angiopoietins. Phylogenetic analysis showed that the 32 identified ANGPTL homologs from 9 species could be classified into two major groups. Real-time quantitative PCR （Q-PCR） analysis revealed that the bANGPTL family members have different expression patterns. This study will be helpful for investigation on the biological role of the bANGPTL family in this economically important species. Furthermore, it provides an insight into the molecular evolution of the emerging ANGPTL family

Performance analysis of jig for coal cleaning using 3D response surface methodology

Beneficiation of coal of -4.76 mm + 3 mm size fraction was investigated in a laboratory model Denver jig.Process variables were studied to analyze their effect on the performance of jig in terms of yield and ash content of clean coal. Three-factor three-level Box-Behnken design of experiments with response surface methodology(RSM) was employed to understand the performance behavior of jig. From the study, the bed height was found to be the most significant parameter affecting the yield and ash content of clean coal. It was possible to reduce the ash content from 24.32% in feed to an ash content of 16.55% in clean coal at 2 L/min water flow rate and 10 min jigging time. Influence of operating variables of the jig on responses was presented and discussed in 3D surface plots. The developed model was found to be significant within the range of parameters under investigation with correlation of co-efficient values as 0.99(yield) and 0.98(ash).

cDNA clone and expression analysis of a-Tropomyosin during Japanese flounder （Parafichthys ofivaceus） metamorphosis

Tropomyosin （TM） plays a critical role in skeletal and cardiac muscle development and function. To assess the fimctional significance of a-TM in Japanese flounder （Paralichthys olivaceus） development and metamorphosis, cDNA from Japanese flounder was cloned and a-TM mRNA measured during development and metamorphosis. The full-length cDNA is 1 191 bp, including a 5＇- untranslated region of 114 bp, a Y-UTR of 222 bp, and an open reading frame of 855 bp encoding a polypeptide of 284 amino acids. Real-time quantitative PCR revealed that a-TM mRNA is initially expressed in unfertilized ovum, indicating the a-TM gene is maternal. Relatively low mRNA levels were observed in different embryonic stages. A higher level of a-TM mRNA was detected 3 days post hatching （dph）, while the highest level was measured at 29 dph （metamorphic climax） after which it declined towards the end of metamorphosis. The expression of a-TM mRNA was up-regulated in thyroid hormone-treated larvae at 36 dph, but there was no marked difference at other stages when compared to control animals. After thiourea treatment, the expression of a-TM mRNA declined slightly. These data provide basic information that can be utilized in further studies into the role of a-TM in P olivaceus development and metamorphosis.

Experimental and numerical analysis of secondary disasters induced by oxygen rich combustion within a tunnel

Various physical parameters, including gas concentrations (O2, CO, CH4, and H2) and temperatures at dif- ferent air velocities, were determined for full scale wood fires in the Chongqing Coal Research Institute fire test tunnel. Both experimental measurements and numerical simulations are discussed. The numer- ical analysis was performed with the computational fluid dynamics software package ''FLUENT''. The results show that the experimental data agree with the simulation results. The results verify that Roberts' theory of burning is correct. They also prove that the air velocity is the key factor that determines the type of combustion. Also, it is shown that secondary disasters are unlikely for oxygen rich combustion with a limited fire load.

Relationship between Ponkan Mandarin Fruit Quality and Nutrient Concentrations

Five age groups of trees were carried out in order to study relationships between the deterioration of Ponkan mandarin fruit quality and changes in tissues nutrient concentrations with tree age.Fruit quality and nutrient concentrations in fruits and leaves were measured.Comprehensive fruit quality decreased in the order:5-year-old > 13-year-old > 38-year-old > 8-year-old >18-year-old.In 18-year-old trees,calcium(Ca) concentrations of fruit and leaf were lower,while potassium(K) and boron(B) concentrations of fruit and magnesium(Mg) and manganese(Mn) concentrations of leaf were higher.Negative relationships were observed between fruit total soluble solids and leaf B,while positive relationships were observed between fruit total soluble solids and leaf and fruit Ca concentrations,and between titratable acidity and leaf Mn.Fruit quality decreasing with tree age most likely resulted from an imbalance of high K,Mg and B but lower Ca concentrations in leaves and fruits.