Effects of rare earth on inclusions and corrosion resistance of 10PCuRE weathering steel

The types,morphologies and distributions of nonmetallic inclusions in Cu-P weathering steels with and without rare earth were analyzed through a quantitative image analyzer,scanning electron microscopy(SEM)and energy dispersive spectroscopy(EDS)attached to SEM.Solid-soluble content of rare earth in the steels was analyzed by non-aqua electroanalysis and ICP.The results showed that rare earth modified the types and the morphologies of inclusions in the weathering steels.The small spherical rare earth oxysulfides and rare earth sulphides replaced the elongated MnS inclusions in the RE weathering steels.The rare earth inclusions dispersedly distributed and most inclusions were smaller than 2 μm in size.The optimum content of RE was 0.0065%-0.016% for 10PCuRE weathering steels containing about0.002% oxygen and 0.004% sulfur.Solid-soluble content of rare earth in steels was(14-20)x 10-6,which can act as a micro-alloying element.The corrosion resistance of 10PCuRE weathering steels and Q235 were studied by dry-wet cyclic immersion test.Their corrosion rates were obtained respectively.The polarization curves and pitting corrosion behaviors of weathering steels with and without rare earth were measured by electrochemical methods.The corrosion resistance of Cu-P weathering steels was improved by adding an appropriate amount of rare earth.Less and fewer rare earth inclusions largely decreased pitting susceptibility and rate of pit propagation.The pitting potential and the resistance against pitting corrosion of the RE weathering steel were significantly improved due to the modification of rare earth to inclusions.     

Lanthanide NIR luminescence for telecommunications, bioanalyses and solar energy conversion

Present-day advanced technologies heavily rely on the exciting magnetic and spectroscopic properties of lanthanide ions. In particular, their ability to generate well-characterized and intense near-infrared (NIR) luminescence is exploited in any modern fiber-optic telecommunication network. In this feature article, we first summarize the whereabouts underlying the design of highly luminescent NIR molecular edifices and materials. We then focus on describing the main trends in three applications related to this spectral range: telecommunications, biosciences, and solar energy conversion. In telecommunications, efforts concentrate presently on getting easily processable polymer-based waveguide amplifiers. Upconversion nanophosphors emitting in the visible after NIR excitation are now ubiquitous in many bioanalyses while their application to bio-imaging is still in its early stages; however, highly sensitive NIR-NIR systems start to be at hand for both in vitro and in vivo imaging, as well as dual probes combining magnetic resonance and optical imaging. Finally, both silicon-based and dye-sensitized solar cells benefit from the downconversion and upconversion capabilities of lanthanide ions to harvest UV and NIR solar light and to boost the overall quantum efficiency of these next-generation devices.     

Evaluation of D113 cation exchange resin for the removal of Eu(Ⅲ) from aqueous solution

Batch adsorption experiments were conducted for the adsorption of Eu(Ⅲ) ions from aqueous solution by D113 resin. The results indicated that D113 resin could adsorb Eu(Ⅲ) ion effectively from aqueous solution. The adsorption was strongly dependent on pH of the medium with enhanced adsorption as the pH turned from 3.50 to 7.00 and the optimal adsorption condition was in HAc-NaAc medium with pH value of 6.50. The maximum uptake capacity of Eu(Ⅲ) ions was 290.9 mg/g D113 at 298 K, at an initial pH value of 6.50. The overall adsorption process was best described by Lagergren-first-order kinetics. When Freundlich and Langmuir isotherms were tested, the latter had a better fit with the experimental data. The thermodynamic parameters such as free energy (G) which were all negative, indicated that the adsorption of Eu(Ⅲ) ions onto D113 resin was spontaneous and the positive value of enthalpy (H) showed that the adsorption was endothermic in nature. Thomas model was applied to experimental column data to determine the characteristic parameters of column useful for process design. Furthermore, Eu(Ⅲ) could be eluted by using 3.0 mol/L HCl solution and the D113 resin could be regenerated and reused.     

Phase structure and temperature dependent luminescence properties of Sr2LiSiO4F: Eu2+ and Sr2MgSi2O7: Eu2+ phosphors

Green-emitting Sr2LiSiO4F:Eu2+ and blue-emitting Sr2MgSi2O7:Eu2+ phosphors were synthesized by the conventional high temperature solid-state route,respectively.Their structures and photoluminescenee properties were comparatively investigated.It was found that the mixture phases of Sr2MgSi2O7 and SrF2 were obtained when a part of Sr2+ in Sr2LiSiO4F was replaced by some amount of Mg2+ in order to design the possible SrMgLiSiO4F:Eu2+ phosphor.Based on the photoluminescence analysis,Sr2LiSiO4F:Eu2+ phosphor exhibited a green broad emission band of main peak at 513 nm under the excitation of 365 nm,while the Sr2MgSi2O7:Eu2+ and SrMgLiSiO4F:Eu2+ phosphor showed blue emission centered at 467 nm.The temperature dependent photoluminescence properties and room temperature decay time for the three kinds of phosphors were also discussed in this paper.     

Er3+-substituted W-type barium ferrite: preparation and electromagnetic properties

Er3+-substituted W-type barium ferrites Ba1-xErx(Zn0.3Co0.7)2Fe16O27(x=0.00,0.05,0.10,0.15,0.20)were synthesized by polymer adsorbent combustion method.Samples were characterized by X-ray diffraction analysis(XRD),X-ray fluorescence(XRF),scanning electron microscopy(SEM)and network analyzer to investigate the relationships among Er3+concentration,crystal structure,surface mcrphology and electromagnetic properties.All the XRD patterns showed pure phase of W-type barium ferrite when x≤0.15,while the impurity phase of ErFeO3 appeared when x=0.20.The pure W-type barium ferrite showed a hexagonal flake shape.In addition,the microwave electromagnetic properties of samples were analyzed in the frequency range of 2-18 GHz.It was indicated that the electromagnetic properties were significantly improved when Er3+doping content was 0.10.The reasons were also discussed using electromagnetic theory.The optimized ferrite exhibited excellent microwave absoption performance.The maximum of reflection loss(RL)reached about-27.4 dB and RL was below-10dB at the frequency range from 8.4 GHz to 18 GHz,when the thickness was 2.6 mm.     

EXAFS investigation and luminescent properties of nanosized Tb: Lu2O3 phosphors

Nanosized terbium doped Lu2O3 phosphors were synthesized via a modified co-precipitation processing.The as-prepared Tb:Lu2O3 phosphors was consisted of well crystallized nanosized sphere particles with a diameter of about 30 nnx Local structure of Tb ions in Lu2O3 lattice was investigated by an analytical approach based on Fourier transformation of the extended X-ray absorption fine structure(EXAFS) data.X-ray near edge structure (XANES) spectra suggested that all Tb ions doped were tervalonce.EXAFS results indicated that Tb ions have entered the Lu2O3 cubic lattice by means of solid solution.The coordination number and first shell Tb-O distance dropped with the increasing of Tb concentration.Emission spectra of the phosphors was shown to be typical for Tb3+ with main components at 542,550 and 490 nm,derived from irradiative relaxation of 5D4 level.The emission intensity decreased severely with the increasing of Tb concentration from 1 mol.% to 15 tool.%,suggesting a significant concentration quenching above 1 mol.% Tb.The reduction of emission intensity was interpreted by higher distortion derived relaxation among the surface state resident Tb3+ ions.     

Multi-Pass Simulation of Heavy Plate Rolling Including Intermediate Forced Cooling

Thermomechanical Controlled Processing (TMCP) including accelerated cooling after the final hot rolling pass is a well-established technology,widely applied in HSLA steel plate production.However,there are still certain limitations,especially for thicker plate.The rolling schedule includes a long holding period (HP) after the roughing stage to allow the temperature to fall sufficiently for optimised TMCP during finishing.Intermediate Forced Cooling (IFC) applied during the HP can increase productivity by decreasing the required hold time,can restrict austenite grain growth,and can also improve the subsequent strain penetration in thick plate with further metallurgical benefits.Multi-pass plane strain compression (PSC) tests have been performed on the thermomechanical compression (TMC) machine at Sheffield University including different severities of IFC.Clearly it is impossible to simulate all aspects of the temperature and strain gradients present in thick plates in laboratory specimens,and most of the tests were conducted at temperatures and strains calculated by Finite Element modelling as relevant to specific positions through the plate thickness.However,some aspects of the gradients were addressed with tests using cold platens.The results have indeed shown that IFC can shorten the HP and reduce austenite grain growth and its variation across thick plate.     

Overview of Particles and Bubbles in Continuously Cast Steel

This paper gives an overview of phenomena associated with particles and bubbles in continuously cast steel. During steel processing from deoxidation to solidification the inclusion population undergoes changes with opportunities of removal. Flotation is an important separation mechanism. Inclusion particles may accumulate in the solidifying strand, thus forming enriched bands, which depend on the type of casting machine. Bubbles are created during inert gas injection. They also change in size, can float out, but also form accumulation bands. The interaction of bubbles and particles is discussed. Internal structure that recently has been observed on the inner surface of bubbles will be reviewed.     

烦恼 快乐 艺术——池莉“人生三部曲”解读

池莉的"人生三部曲"--<烦恼人生>、<不谈爱情>、<太阳出世>诉尽了普普通通的市民烦恼,小说中主人公被柴米油盐、吃喝拉撒、老婆孩子等琐事所烦着,从而构成他们的"烦恼人生".然而池莉通过自己的艺术创作,以积极的人生态度,又让读者体会到生活本身的快乐,"烦恼人生"中包含着"快乐人生".     

属性块在工程图形中的研究与应用

介绍了在工程图形中用属性块标注表面粗糙度的方法.采用属性块不仅能避免大量重复性的工作,还能节省大量的存储空间,具有提高绘图速度、质量,便于修改,资源共享等应用价值.     

Evolution of the epidemic process as a form of solution to its internal contradictions

The author formulated the main contradition of the epidemic process consisting of contradiction between the interaction of the motive forces of the epidemic process, since this contradiction at the same time served as the imperative condition of the origination and as the cause of the subsequent arrest of the spread of infection. The main contradiction of the epidemic process is expressed in reduction of the number and limited activity of the sources of infection, attenuation or arrest of the mechanism of transmission of the causative agents, formation of immunity in the population, the appearance of hereditary resistance in the hosts to the causative agent of the infection. The action of the principal internal contradiction of the epidemic process in the course of evolution conditions genetic variability of the causative agents of the infectious diseases, intensification of the mechanisms of excretion of the parasites from the host organism, and increase of their resistance in the external environment, formation of latent forms of infection.     

Current problems in organizing the donor system in the Armed Forces

In the work the factors, rendering essential influence on organization of donorship in modern army conditions are systematized. The organization of donorship should be connected to functioning of territorial system of medical maintenance of the Armed Forces of RF. It assumes presence of four organizational levels: central, district, zone and garrison. Perfecting the system of organization of donorship, we should be guided by the following conducting principles: maximum maintenance of safety of donorship; wide introduction of a method of plasmacytopheresis in work of establishments and subdivisions of blood supply service; organization of autodonorship and quota of the donors of an emergency reserve in each military-medical establishment; reliable maintenance of revealing of markers of hemotransmissible infections at inspection of the donors.     

Critical periods in the development of mutants in scute Drosophila melanogaster

Thermosensitive periods of the development of germs of separate pairs of macrochaetae were studied in two lines of mutation of scute Drosophila melanogaster (y/sc4B and cs7). The experiments have revealed the following three features which had not been observed earlier in similar investigations in other mutants of drosophila: 1) change of thermosensitivity in mutants sc7 in different periods of ontogenesis; 2) different sensitivity in mutants of both lines in different critical periods of the same pair of macrochaetae; 3) discrete sensitivity of separate macrochaetae in mutants of both lines at different stages of oogenesis when there are no germs of these organs yet. The change of penetrability of the mutation of scute for scuttellar macrochaetae in mutants y/sc4B caused by the 90-minute-long heating of larvae on the 4th day of their life (critical period of development) is inherited in 15 observed generations of the maternal line. One may consider these periods of the increased thermosensitivity to be tje periods of stepwise determination of germs of separate pairs of macrochaetae.     

Means to improve therapeutic care in the Armed Forces

The article describes dynamics of diseases of therapeutic field in the Armed Forces in 1991-1996. The analysis of therapeutic sick rate has confirmed, that a major problem of military therapy remains acute pneumonia, which sick rate in 1993-1996 has increased twice. The sick rate of ulcer has increased equally. The main directions of perfection of organization of the therapeutic care in the Armed Forces are etiologic diagnostics and prophylaxis of acute pneumonia in the soldiers, creation of system of prophylaxis, active revealing and centralized high-specialized treatment of the patient with ischemic heart disease among officers, perfection of system of rendering of the specialized care to the patient of endocrinological field, introduction of modern methods of anti-relapse treatment of ulcer, active revealing of the persons, infected by virus of hepatitis, perfection of work of an out-patient department link.     

Topical diagnostic methods in primary hyperparathyroidism

The efficiency of USI of the neck, scintigraphy of the parathyroid glands (PTG) with selen-methionine and selective catheterization of veins (SCV) of the neck and mediastinum for preoperative determination of the localization of the source of hyperproduction of the parathyroid hormone was analyzed on the basis of results of examination of 149 patients including 51 patients with primary hyperparathyroidism confirmed during the operation. It was noted that none of the methods of topical diagnostics used in the work is thought to be universal for different clinical situations. A method of their complex use is proposed which foresee USI of the neck as the first step. In case of insufficient information of the results of USI the authors propose SCV of the neck and mediastinum as a method of choice which allows the size and level of the altered PTG to become more exact and which makes further search with the help of other methods of topical diagnostics more purposeful and effective.     

The mechanical properties of materials from iron powder obtained by the reduction of martite ore

Conclusions The article presents the results of an investigation of the mechanical properties of samples of iron powder obtained by reducing martite ore by converted natural gas.The use of this raw material for producing iron powder for the needs of the powder metallurgy industry permits a considerable extension of the raw material reserves.As a result of the investigations the authors determined the characteristics of strength, plasticity and fatigue strength of material of varying porosity.The regularities of deformation of such materials and the strength characteristics of the duration of load application were studied.The results show that the strength and plasticity of metal powder materials of similar composition made of other kinds of iron powders.     

STG-12变辊距型钢矫直机的设计计算

针对变辊距矫直机具有不同于恒辊距矫直机的结构特点 ,给出变辊距型钢矫直机辊数、辊距的确定方法 ,并计算出各辊的弯曲力矩及矫直力 ,最后求得设备电机功率。通过设备的具体运行证明 ,变辊距结构对改善设备的受力状况及提高型钢矫直质量十分有利     

Evolution of gypsy-group retrotransposons: phylogenetic analysis of domains included in the pol-polyprotein

Transposons of gypsy group are assigned to LTR-containing retrotransposons present in the genomes of invertebrates, fungi, and plants. In this work, a theoretical analysis of the potential products of ORFs of these retrotranposons was conducted. Alignments were obtained and trees of similarity were constructed for domains of the POL region. On the basis of the obtained data, two hypothetically monophyletic subgroups of transposons were distinguished within the framework of the gypsy group, settling the genomes of taxonomically related organisms (the subgroup of "true" gypsy of insects and the subgroup of gypsy-like transposons of plants and fungi). A number of peculiarities of the topology of these trees hypothetically indicate cases of genetic conversion and recombination of domains accompanying the evolution of this group. The amino acid substitution fixation rate was evaluated on the basis of comparison of sequences of the protein products of ORFs. Estimates of the time of divergence of subgroups of gypsy-group transposons are significantly less than estimates of the times of divergence of their host species. One explanation for this discrepancy might be the hypothesis of settlement by transposons of the genomes of isolated host species.     

Change in neutrophils in liquidators of the consequences of the accident at the Chernobyl Atomic Electric Power Station

In result of own researches and analysis of the literature? the information about high sensitivity of neutrophils of peripheric blood to infringements of constancy of internal state of body, arising as reply to radiating influence, are received. Ionized radiation modulates greatly properties and functions of neutrophilic granulocytes, which are the most sensitive and high-modulated cells of non-specific resistance system. The changes of the functional-metabolic status of neutrophils in participants of liquidation of consequences of Chernobyl disaster have been saving during 10 years after influence of the extreme, including radiating, factors of failure.     

Basal encephalocoele: imaging and exposing the hernia

The effects of daily injections, over the course of 14 days, of 45 micrograms of phenamine, 5 micrograms of haloperidol and naloxone, 15 micrograms of leu-enkephalin and its analog, a tetrapeptide, into the rostral neostriatum have been studied. The chronic stimulation of the dopaminergic system of the striatum induced facilitation of the realization of an active avoidance conditioned reflex, and stimulated exploratory stereotypy, while its blockade led to suppression of conditioned reflex activity against the background of a clearcut rigid akinetic syndrome. The microinjections of leu-enkephalin and naloxone did not substantially alter the behavior, but the injection of the tetrapeptide was accompanied by changes in behavior, with symptoms of catalepsy and hyperkinesia. Injections of phenamine and haloperidol were accompanied by a decrease in the content of dopamine in the striatum and an increase in the level of DOPAC; the injections of enkephalin and naloxone induced changes of the reverse order. The possible causes of the noncorrespondence of the behavioral and neurochemical shifts in the presence of a direct chronic pharmacological action on the mediator of the neostriatum.