数控机床的发展趋势及国内发展现状

简要分析了数控机床高速化、高精化、复合化、智能化、开放化、并联驱动化、网络化、极端化、绿色化等发展趋势,并指出了我国数控机床发展中存在的问题。

针织新技术发展现状与趋势

为加快智能化针织技术的研发与应用,介绍了国内外针织技术的发展现状,阐述了我国针织产业在新常态下的发展特征。从针织装备高精技术、针织智能生产技术、针织服饰成形技术、针织立体编织技术和针织智能穿戴技术5个方面对最新针织技术、典型产品、前沿应用进行全面的解析。同时,基于目前市场需求低迷、成本持续攀升、环保形势严峻、产品同质化严重,我国针织产业比较优势下降,下行压力加大等问题,对针织产业未来发展提出展望,认为针织行业应抢占先机,加快融入"互联网+"概念,深入开展两化融合,促进针织产业模式的转型升级,提高国际竞争力。

浅谈柔性制造技术在数控机床中的应用

进入21世纪,中国制造业既面临提升机械制造水平的需求而引发的制造装备发展的良机,同时也面临着市场竞争的压力。本文分析了以高效柔性制造技术为核心的数控技术,从中探讨高效柔性制造技术对促进机床制造业发展的作用。

谈我国数控机床的发展趋势

从高精化、高速化、高效化、柔性化、智能化、集成化、适用性和经济性等方面阐述我国数控机床的发展趋势。

Assessment of Contemporary Theoretical Methods for Bond Dissociation Enthalpies

The density functional theory （DFT） is the most popular method for evaluating bond dis- sociation enthalpies （BDEs） of most molecules. Thus, we are committed to looking for alternative methods that can balance the computational cost and higher precision to the best for large systems. The performance of DFT, double-hybrid DFT, and high-level com- posite methods are examined. The tested sets contain monocyclic and polycyclic aromatic molecules, branched hydrocarbons, small inorganic molecules, etc. The results show that the mPW2PLYP and G4MP2 methods achieve reasonable agreement with the benchmark val- ues for most tested molecules, and the mean absolute deviations are 2.43 and 1.96 kcal/mol after excluding the BDEs of branched hydrocarbons. We recommend the G4MP2 is the most appropriate method for small systems （atoms number≤20）; the double-hybrid DFT methods are advised for large aromatic molecules in medium size （20≤atoms number≤50）, and the double-hybrid DFT methods with empirical dispersion correction are recommended for long-chain and branched hydrocarbons in the same size scope; the DFT methods are ad- vised to apply for large systems （atoms number〉50）, and the M06-2X and B3P86 methods are also favorable. Moreover, the differences of optimized geometry of different methods are discussed and the effects of basis sets for various methods are investigated.

PRMT5 regulates Golgi apparatus structure through methylation of the golgin GM130

Maintenance of the Golgi apparatus （GA） structure and function depends on Golgi matrix proteins. The posttranslational modification of Golgi proteins such as phosphorylation of members of the golgin and GRASP families is important for determining Golgi architecture. Some Golgi proteins including golgin-84 are also known to be methylated, but the function of golgin methylation remains unclear. Here, we show that the protein arginine methyltransferase 5 （PRMT5） localizes to the GA and forms complexes with several components involved in GA ribbon formation and vesicle tethering. PRMT5 interacts with the golgin GM130, and depletion of PRMT5 causes defects in Golgi ribbon formation. Furthermore, PRMT5 methylates N-terminal arginines in GM130, and such arginine methylation appears critical for GA ribbon formation. Our findings reveal a molecular mechanism by which PRMT5-dependent arginine methylation of GM130 controls the maintenance of GA architecture.

Well-controlled stirring tank leaching to improve bio-oxidation efficiency of a high sulfur refractory gold concentrate

For the high sulfur refractory gold concentrate with 41.82%sulfur and 15.12 g/t gold,of which 82.11%was wrapped in sulfide,a well-controlled stirring tank leaching was carried out to improve the bio-oxidation efficiency.Results show that bio-oxidation pretreatment can greatly improve the gold recovery rate of high-sulfur refractory gold concentrate,and at the optimum pH 1.3 in this study,compared with the process without pH control,the oxidation rate of sulfur increased from 79.31%to 83.29%,while the recovery rate of gold increased from 76.54%to 83.23%;under this condition the activity of mixed culture could be sustained and the formation of jarosite could diminish.The results also displayed that for the high sulfur refractory gold concentrate,the recovery of gold is positively correlated with the oxidation rate of sulfur,and the recovery rate of gold increases with the increase of sulfur oxidation rate within a certain range.

High dimension feature extraction based visualized SOM fault diagnosis method and its application in p-xylene oxidation process

Purified terephthalic acid(PTA) is an important chemical raw material. P-xylene(PX) is transformed to terephthalic acid(TA) through oxidation process and TA is refined to produce PTA. The PX oxidation reaction is a complex process involving three-phase reaction of gas, liquid and solid. To monitor the process and to improve the product quality, as well as to visualize the fault type clearly, a fault diagnosis method based on selforganizing map(SOM) and high dimensional feature extraction method, local tangent space alignment(LTSA),is proposed. In this method, LTSA can reduce the dimension and keep the topology information simultaneously,and SOM distinguishes various states on the output map. Monitoring results of PX oxidation reaction process indicate that the LTSA–SOM can well detect and visualize the fault type.

Multistep hepatocarcinogenesis from a dysplastic nodule to well-differentiated hepatocellular carcinoma in a patient with alcohol-related liver cirrhosis

We describe a rare case of the transformation of a dysplastic nodule into well-differentiated hepato- cellular carcinoma (HCC) in a 56-year-old man with alcoholrelated liver cirrhosis. Ultrasound (US) disclosed a 10 mm hypoechoic nodule and contrast enhanced US revealed a hypovascular nodule, both in segment seven. US-guided biopsy revealed a high-grade dysplastic nodule characterized by enhanced cellularity with a high N/C ratio, increased cytoplasmic eosinophilia, and slight cell atypia. One year later, the US pattern of the nodule changed from hypoechoic to hyperechoic without any change in size or hypovascularity. US-guided biopsy revealed well-differentiated HCC of the same features as shown in the first biopsy, but with additional pseudoglandular formation and moderate cell atypia. Moreover, immunohistochemical staining of cyclase- associated protein 2, a new molecular marker of well- differentiated HCC, turned positive. This is the first case of multistep hepatocarcinogenesis from a dysplastic nodule to well-differentiated HCC within one year in alcohol-related liver cirrhosis.

On the effectiveness of the ideological and political education in higher vocational colleges

The ideological and political education in vocational colleges has ＂employment oriented＂, ＂practicability＂ and ＂practicalness＂ and other features, while facing the practical difficulties that the cultural spirit is insufficient, the specialization of the teachers is not strong, and the students lack their own active participation and so on. The higher vocational colleges must deepen the concepts of running higher vocational education, strengthen the construction of the team of the ideological and political theory education, pay more attention to the combination of the ideological and political education with the practice, cultivate the people-oriented model of the ideological and political education, and improve the effectiveness of the ideological and political education.

Collegian Cultural Form of the American Entrepreneurial Universities and Its Enlightenment

The cultural form of entrepreneurial university has the academic entrepreneurial characteristics, which agrees with the background of economic era. MIT and Stanford University are the models of American entrepreneurial universities, and the spiritual culture, system culture, material culture and behavior culture elements of academic entrepreneurial characteristics depend on each other, influence each other and have a good cycle of cultural form, which is the internal driving mechanism of MIT and Stanford University towards entrepreneurial university development. In this cultural structure, the contradictory unity of academic and entrepreneurship, tile interaction between science and hummaity, the mutual promotion of innovation and entrepreneurship have the enlightenment significance for the construction of entrepreneurial university.

Arginine-mediated synthesis of cube-like platinum nanoassemblies as efficient electrocatalysts

Controllable self-assembly of noble metal nanocrystals is of broad interest for the development of highly active electrocatalysts. Here we report an efficient arginine-mediated hydrothermal approach for the high-yield synthesis of cube-like Pt nanoassemblies （Pt-CNAs） with porous cavities and rough surfaces based on the self-assembly of zero dimensional Pt nanocrystals. In this process, arginine acts as the reductant, structure directing agent, and linker between adjacent nanocrystals. Interestingly, the Pt-CNAs exhibit single-crystal structures with dominant {100} facets, as evidenced by X-ray diffraction. Based on electrocatalytic studies, the as-synthesized Pt-CNAs exhibit improved electrocatalytic activity as well as good stability and CO tolerance in the methanol oxidation reaction. The Pt-CNA＇s good performance is attributed to their unique morphology and surface structure. We believe that the synthetic strategy outlined here could be extended to other rationally designed monometallic or bimetallic nanoassemblies for use in high performance fuel cells.

A modified highly precise direct integration method for a class of linear time-varying systems

It is always a bottleneck to design an effective algorithm for linear time-varying systems in engineering applications.For a class of systems,whose coefficients matrix is based on time-varying polynomial,a modified highly precise direct integration(VHPD-T method)was presented.Through introducing new variables and expanding dimensions,the system can be transformed into a timeinvariant system,in which the transfer matrix can be computed for once and used forever with a highly precise direct integration method.The method attains higher precision than the common methods(e.g.RK4 and power series)and high efficiency in computation.Some numerical examples demonstrate the validity and efficiency of the method proposed.

A Batesian mimic and its model share color production mechanisms

Batesian mimics are harmless prey species that resemble dangerous ones （models）, and thus receive protection from predators. How such adaptive resemblances evolve is a classical problem in evolutionary biology. Mimicry is typically thought to be difficult to evolve, especially if the model and mimic produce the convergent phenotype through different proximate mecha- nisms. However, mimicry may evolve more readily if mimic and model share similar pathways for producing the convergent phenotype. In such cases, these pathways can be co-opted in ancestral mimic populations to produce high-fidelity mimicry with- out the need for major evolutionary innovations. Here, we show that a Batesian mimic, the scarlet kingsnake Larnpropeltis elap-soides, produces its coloration using the same physiological mechanisms as does its model, the eastern coral snake Micrurus fulvius. Therefore, precise color mimicry may have been able to evolve easily in this system. Generally, we know relatively little about the proximate mechanisms underlying mimicry .