磁海地面公辅设施工程设计阶段投资控制

通过对磁海地面公辅设施工程投资控制的分析,阐述了工程设计阶段投资控制的重要性,以及在投资控制过程中存在的问题。

Microstructures and formation mechanism of headstand pyrocarbon cones developed by electromagnetic-field-assisted CVD

Novel headstand pyrocarbon cones （HPCs） with hollow structure were developed on the surfaces of pyrocarbon layers of the carbon/carbon （C/C） composites at 650-750 °C by the electromagnetic-field-assisted chemical vapor deposition in the absence of catalysts. The fine microstructures of the HPCs were characterized by high-resolution transmission electron microscopy. The results show that the textural features of the HPCs directly transfer from turbostratic structure in roots to a well-ordered high texture in stems. And the degree of high texture ordering decreases gradually from the stem to the tail of the HPCs. The formation mechanism of the HPCs was inferred as the comprehensive effect of polarization induction on electromagnetic fields and particle-filler property under disruptive discharge.

Ultrasonic-enhanced selective sulfide precipitation of copper ions from copper smelting dust using monoclinic pyrrhotite

The sulfide passivation film produced on the surface seriously prevents further reaction in the process of using monoclinic pyrrhotite(MPr)to treat heavy metal ions in wastewater.Ultrasonic technology was introduced to assist MPr to recover the copper ions.XPS result proves that CuS products exist on the surface of MPr.XRD and SEM results show that the CuS on the particles’surface is stripped under ultrasonic condition.The kinetics results indicate that the reaction under both conventional and ultrasonic conditions conform to the Avrami model.The reaction process changes from diffusion control to chemical reaction control under the ultrasonic condition as the solid layer is stripped off.The presence of ultrasonic significantly reduces the acidity and temperature required for the reaction and enhances the utilization efficiency of MPr;by controlling the amount of MPr,the removal rates of copper and arsenic in copper smelting dust leachate exceed 99%and 95%,respectively.

Static magnetic field-assisted synthesis of Fe3O4 nanoparticles and their adsorption of Mn(Ⅱ) in aqueous solution

A facile method for synthesis of the magnetic Fe_3O_4 nanoparticles was introduced.Magnetic nanoparticles were prepared via co-precipitation method with(PMF) and without(AMF) 0.15 T static magnetic field.The effects of magnetic field on the properties of magnetic nanoparticles were studied by XRD,TEM,SEM,VSM and BET.The results showed that the magnetic field in the co-precipitation reaction process did not result in the phase change of the Fe_3O_4 nanoparticles but improved the crystallinity.The morphology of Fe_3O_4 nanoparticles was varied from random spherical particles to rod-like cluster structure.The VSM results indicated that the saturation magnetization value of the Fe_3O_4 nanoparticles was significantly improved by the magnetic field.The BET of Fe_3O_4nanoparticles prepared with the magnetic field was larger than the control by 23.5%.The batch adsorption experiments of Mn(Ⅱ) on the PMF and AMF Fe_3O_4 nanoparticles showed that the Mn(II) equilibrium capacity was increased with the pH value increased.At pH 8,the Mn(Ⅱ) adsorption capacity for the PMF and AMF Fe_3O_4 was reached at 36.81 and 28.36 mg·g^(-1),respectively.The pseudo-second-order model fitted better the kinetic models and the Freundlich model fitted isotherm model well for both PMF and AMF Fe_3O_4.The results suggested that magnetic nanoparticles prepared by the magnetic field presented a fairly good potential as an adsorbent for an efficient removal of Mn(Ⅱ) from aqueous solution.

Novel Switched Reluctance Motor with Auxiliary Winding

The characteristics of the novel switched reluctance motor with auxiliary winding and four big swallow-tailed-slots in the internal surface of stator is analysed with the stator cross section and winding photo given, and the nlathematical model of the novel switched reluctance motor presented. To show that the auxiliary winding causes the electromotive force to improve current waveform and increase output power. The different effects of auxiliary winding on system performance under different speeds are analyzed and experimented. Simulation analyzing and experiments studying of the novel switched reluctance motor demonstrate validity of auxiliary winding improving current waveforms, increasing output power.

Surfactant-assisted synthesis and magnetic properties of monodispersed manganese ferrite nanocrystals

Monodispersed manganese ferrite （MnFe2O4） nanocrystals could be successfully synthesized in large quantities via a facile synthetic technique based on the pyrolysis of organometallic compound precursor, in which octadecene was used as solvent, and oleic acid and oleylamine were used as capping ligands. MnFe204 nanocrystals were obtained with size in a tunable range of 4- 15 nm and their morphologies could be tuned from spherical to triangle-shaped by varying the surfactants. The phase structure, morphology, and size of the products were characterized in detail by X-ray diffraction （XRD） and transmission electron microscopy （TEM）. Magnetic properties of MnFe2O4 nanocrystals with different morphologies were measured using a superconducting quantum interference device （SQUID）. Both monodisperse MnFe204 nanocrystals with spherical and triangle-shapes are superparamagnetic at room temperature while ferromagnetic at 2 K. The pyrolysis method may provide an effective route to synthesize other spinel ferrites or metal oxides nanocrystals.

Rectal cancer restaging using 3D CUBE vs.2D T2-weighted technique after neoadjuvant therapy:a diagnostic study

Objective.This study aimed to compare the accuracy of rectal cancer restaging after neoadjuvant therapy with 3D CUBE sequence with 2D T2-weighted fast spin-echo(FSE)sequence.Methods.This retrospective study comprised 72 patients with rectal cancer confirmed by colonoscopy and biopsy.After neoadjuvant therapy,all patients underwent pelvic magnetic resonance imaging(MRI)examination at 1.5T MRI sequences including a single coronal 3D CUBE T2-weighted FSE sequence with 1.4mmthickness and a 2D T2-weighted FSE sequence in the sagittal,coronal and axial planes with 5mmthickness.The total acquisition time of the two sequences was recorded.Results were compared with postsurgical pathology(gold standard).The diagnostic accuracy was evaluated;and receiver operating characteristic(ROC)curves and the area under the curves(AUC)were calculated.Results.The T category staging accuracy of 3D T2WI and 2D T2WI was 81.9% and 72.2%,respectively,for reviewer 1 and 86.1% and 75.0% for reviewer 2.The AUC of 3D was higher than that of 2D(0.878 vs.0.783 for reader 1 and 0.905 vs.0.796 for reader 2;both P<0.05)when judging whether the tumor broke through themuscle layer.There was no significant difference between 3D and 2D in judging whether lymph nodes weremalignant(AUC 0.719 vs.0.698 for reader 1 and 0.740 vs.0.698 for reader 2;both P>0.05).There were no significant differences in the visibility of the rectal wall layer,tumor lesion and the overall image quality(all P>0.05).Compared with 2D sequences,the 3D sequence had shorter acquisition time and higher signal intensity ratio(both P<0.05).Conclusion.3D CUBE T2-weighted sequences offer better diagnostic accuracy in rectal cancer restaging after neoadjuvant therapy when compared with 2D T2-weighted FSE sequences;it has a shorter scanning time and more versatility of orientation reconstruction.

整顿业务活动原始记录工作的几点体会

中国油脂公司为贯彻《国营商业统计制度》,曾于今年七、八月间先后以北京分公司和常德支公司为重点,协助整顿业务活动原始记录,弄清了业务环节,找出了问题的关键,拟定了业务活动原始记录试行办法,并总结了整顿原始记录中的一些经验.这种深入基层具体帮助的工作方法是值得提倡的.特将该公司在这一工作中的几点体会刊出,供同志们研究参考.