Relationship between paddy soil adhesion to steel and to rubber

Forty-three pairs of samples concerning adhesion of paddy soil to steel and to rubber are used to identify the relationship between these two groups of variables. Results show that there is no significant difference between them, implying that they are roughly equal to each other in engineering practice.     

Torsion pendulum automation by a single microcomputer

A new automated torsional pendulum is described. It uses a single photocell for the measurement of the period of oscillation and the logarithmic decrement. Data acquisition, data processing and temperature control are all performed by a single microcomputer. The result is that the instrument can be produced and operated more cheaply than before.The principles behind the design, the method of determining the shape factor, the calibration procedure and the software are discussed. Examples are given to illustrate the use of this instrument. A practical limitation is that the loss tangent should not exceed about 3.     

Visible light emission in collisions between O5+ ions and He atoms

Visible light emission spectra during collisions between O⁵⁺ ions and He atoms in the range of 200–800 nm at different projectile energies (4.06–5.31 keV-u⁻¹) have been measured. Emission spectra show that there are three channels of excitation in the O⁵⁺-He collision system: (i) single-electron capture into excited states; (ii) double-electron capture into excited states; (iii) direct excitation of target atoms. There are transitions between states with comparably high quantum numbersnl. The absolute emission cross-sections of every spectral line are calculated. The relations of these cross-sections with the energy of the projectiles are studied. Project supported by the National Natural Science Foundation of China and Chinese Association for Atomic and Molecular Dada.     

Raman scattering of high-temperature phase transition in KH2PO4

Raman scattering was applied to study the high-temperature phase transition (near 175°C) in KH₂PO₄. Drastic temperature-dependent changes were observed to take place in the normal modes of B₁ symmetry between 1000–3400 cm^?1. The disintegration of the dominant broad feature near 2500 cm^?1 when temperature rises beyond 150°C suggests that the alteration of the hydrogen-bond network is closely connected with this high-temperature phase transition.     

Synthetic Studies of Nitro-Chlorotropones and Trihalotropones

Nitration of 2-chlorotropone with fuming nitric acid gave 2-chloro- 4,7-dinitrotropone in good yield. 2,4,7-Trichlorotropone, a new compound, and 2,4,7-tribromotropone have been derived successfully from 2-chloro-4,7-dinitrotropone by heating with hydrogen chloride or hydrogen bromide in acetic acid. The structures of 2-chloro-4,7-dinitrotropone, 2,4,7-trichlorotropone and 2,4,7-tribromotropone have been confirmed on the basis of chemical facts together with the spectroscopical evidences. The chemical and physical properties of the above compounds have also been investigated.     

Synthesis, structure, and luminescent property of a heterometallic metal-organic framework constructed from rod-shaped secondary building blocks

A new heterometallic MOF compound, [ZnNa(m-BDC)2].NH2(CH3)2 (MOF-CJ2), has been solvothermally synthesized and characterized by single-crystal X-ray diffraction, X-ray powder diffraction, ICP, TGA, IR, and photoluminescence spectroscopy analyses. It crystallizes in monoclinic space group C2/c (No. 15) with a=13.277(6) A, b=14.323(7) A, c=11.328(6) A, and beta=111.73(2) degrees. Its framework is constructed from M-O-C (M=Na and Zn) rods composed of alternating six-coordinated Na(I) centers and four-coordinated Zn(II) centers. These rods are linked by m-BDC links to form primitive cubic (pcu) type rod packing. This framework exemplifies the first open-framework heterometallic MOF structure based on the assembly of infinite rod building units.     

Automatic knowledge extraction from survey data: learning <Emphasis Type="Italic">M</Emphasis>-of-<Emphasis Type="Italic">N</Emphasis> constructs using a hybrid approach

Data collected from a survey typically consist of attributes that are mostly if not completely binary-valued or binary-encoded. We present a method for handling such data where the underlying data analysis can be cast as a classification problem. We propose a hybrid method that combines neural network and decision tree methods. The network is trained to remove irrelevant data attributes and the decision tree is applied to extract comprehensible classification rules from the trained network. The conditions of the rules are in the form of a conjunction of M-of-N constructs. An M-of-N construct is a rule condition that is satisfied if (at least, exactly, at most) M of the N binary attributes in the construct are present. The effectiveness of the method is illustrated on data collected for a study of global car market segmentation. The results show that besides achieving high predictive accuracy, the method also allows meaningful interpretation of the relationships among the data variables.     

电子闪光灯光路变换的研究

本文主要论述了直接利用电子闪光灯为光源，产生垂直反射偏振光的原理、方法及在刑事摄影中的应用。通过理论研究和试验，设计出了电子闪光灯光路变换系统，解决了直接利用电子闪光灯为光源的拍摄案件现场某些光滑非金属物体时，物体表面产生强烈反射光线或反射光带和对人犯摄影、物证摄影时的强烈阴影干扰，以及无法直接用以电子闪光灯为光源，对遗留在案件现场上的痕迹进行垂直反射摄影的困难。