全站仪测量点位坐标的偏心改正

由界址点测量的特点和其高精度的要求可知,利用全站仪测定界址点的坐标是最有效的方法,但在观测时由于棱镜中心经常不能准确地放在界址点的铅垂线上,造成了界址点坐标测量的偏心。文中分析了界址点坐标偏心的各种类型、大小以及利用全站仪偏心测量功能加以改正的方法,并在实测中应用,取得了满意的结果。

数字化测图中有关精度问题的分析与探讨

本文为近年来应用数字化测图的实践,对使用全站仪进行全野外数据采集过程中测量误差的来源进行分析,统计出数字化测图的数学精度。在国家测绘主管部门尚未颁布相应测绘技术标准的情况下,提供一点仅供参考的实践经验,并提出几点自己的看法。

Hydrothermal Synthesis of Rhombus-like SmCO3OH Microplates and Its Photoluminescence Property Doped with Eu^3＋

Rhombus-like SmCO3OH microplates with the edge lengths ranging from 5 μm to 10 μm and the thickness about 1.5 μm were synthesized through a simple hydrothermal method using urea as the precipitance. The structure and properties of the rhombus-like SmCO3OH microplates were characterized by X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy, and X-ray photoelectron spectroscopy. The optical property of the rhombus-like SmCO3OH microplates doped with Eu^3＋ was investigated by photoluminescence. A broad and strong emission band at 677 nm was obtained, which can be contributed to producing light conversion film.

Prediction of valid acidity in intact apples with Fourier transform near infrared spectroscopy

To develop nondestructive acidity prediction for intact Fuji apples, the potential of Fourier transform near infrared (FT-NIR) method with fiber optics in interactance mode was investigated. Interactance in the 800 nm to 2619 nm region was measured for intact apples, harvested from early to late maturity stages. Spectral data were analyzed by two multivariate calibra- tion techniques including partial least squares (PLS) and principal component regression (PCR) methods. A total of 120 Fuji apples were tested and 80 of them were used to form a calibration data set. The influences of different data preprocessing and spectra treatments were also quantified. Calibration models based on smoothing spectra were slightly worse than that based on derivative spectra, and the best result was obtained when the segment length was 5 nm and the gap size was 10 points. Depending on data preprocessing and PLS method, the best prediction model yielded correlation coefficient of determination (r2) of 0.759, low root mean square error of prediction (RMSEP) of 0.0677, low root mean square error of calibration (RMSEC) of 0.0562. The results indicated the feasibility of FT-NIR spectral analysis for predicting apple valid acidity in a nondestructive way.

Some Suggestions Improving Apollo Lunar Laser Retroreflector Arrays

According to our engineering research on satellite-borne laser retroreflector array, some suggestions are proposed on how to manufacture a new Apollo LLRA that can make us measure one illuminating point and unilluminating area on the moon's surface. These suggestions are: to control the dihedral angle offset within ± 0.1″; to use the larger aperture of the transparent face of cube corner prisms; to investigate how to separate out Apollo's reflected laser from mixed beam hitting on the LLR system.

New Environmental Friendly Yellow Ceramic Pigments of the Type （Fe^ⅢM^Ⅴ）-TiO2

The family of Cr（Ⅲ） and Fe（Ⅲ）-doped rutile pigments of nominal composition （M^ⅢM^V）xTi1-2xO2, with M^Ⅲ = Cr（Ⅲ） or Fe（Ⅲ） and M＇（V） = Sb, Nb, Ta, with x = 0.03, 0.15 and 0.25 were investigated as ceramic pigments covering the yellow-ochre-brown palette. The formulations containing Fe（Ⅲ） are novel compositions not included in the commercial rutile pigments. The materials were characterized by XRD （X-ray diffraction） analysis and FTIR （Fourier transformed infrared spectroscopy）. The transition temperature from anatase-to-rutile was estimated by the evolution of the spectral patterns. This crystal phase transition is responsible of the color formation. A higher distortion of TiO6 octahedra is observed in the case of （FeSb） containing cells which contribute to the enhancement of the light absorption. The coloring performance of all the formulations were evaluated by enameling the mixtures containing 5% pigments and commercial frits representative of single and double firing industrial processes. The chromatic values obtained are in the yellow to brown domain of the chromatic plot, depending on the composition of the pigment-frit batch. In the case of the Fe-glazes, and particularly the combination （FeNb）, the chromatic values are close to the best yellow tinting. This new FeNb-rutile pigment could be a more benign substitute of Cr-yellow pigments. The homogeneity of the enamels was confirmed by SEM （scanning electron microscopy）-EDAX （energy dispersive X-ray analysis） microscopy.

Enzymatic saccharification of cellulose using an ionic liquid [Amim] [COOH] pretreatment

In this study we used l-allyl-3-methyl imidazole formate （[Amim][COOH]） as ionic liquid to pre-treat the cellulose and determined the rate of polymerization and enzymatic hydrolysis. The results showed that pretreatment with （[Amim][COOH]） significantly decreased the cellulose polymerization. As the pretreatment temperature went up, the enzymatic hydrolysis rate was first increased and then decreased The maximal enzymatic hydrolysis rate was achieved when the pretreatment temperature was 90 ℃. Under the ultrasonic condition, the initial rate of enzmatic hydrolysis for the ionic liquid-treated cellulose was up to 11.10 gL-1h-1, which was 33% increase compared to the untreated cellulose. Scanning Electronic Microscopy （SEM） and Fourier Transform Infrared-Raman Spectroscop （FT-IR） analysis showed that ionic liquidtreated cellulose started to depolymerize. In addition, the cr3＇stallinity of the cellulose was significantly decreased after pretreatment with ionic liquid.

呼噜

周丽丽打开化妆盒,给自己描了眉,涂了口红,又对着盒镜仔细打量着,瞧着眼角上熟悉的鱼尾纹,兀自露出无奈的笑容。她盖上化妆盒,又为自己换了身淡蓝色连衣裙,站到立镜前展开裙摆,摆了几个姿式又旋了一个圈,给镜中的自己扮了个鬼脸。她昨天刚过46周岁生日,但身材依旧苗条,风韵犹在。丈夫5年前因车祸不幸去世后,她就把心思全部花在了女儿身上。

Dynamic deformation behavior of a face-centered cubic FeCoNiCrMn high-entropy alloy

In this study, mechanical tests were conducted oil a face-centered cubic FeCoNiCrMn high-entropy alloy, both in tension and compression, in a wide range of strain rates （10^-4-10^4 s^-1） to systematically investigate its dynamic response and underlying deformation mechanism. Materials with different grain sizes were tested to understand the effect of grain size, thus grain boundary volume, on the mechanical prop-erties. Microstructures of various samples both before and after deformation were examined using elec-tron backscatter diffraction and transmission electron microscopy. The dislocation structure as well as deformation-induced twins were analyzed and correlated with the measured mechanical properties. Plastic stability during tension of the current high-entropy alloy （HEA）, in particular, at dynamic strain rates, was discussed in lights of strain-rate sensitivity and work hardening rate. It was found that, under dynamic conditions, the strength and uniform ductility increased simultaneously as a result of the mas-sive formation of deformation twins. Specifically, an ultimate tensile strength of 734 MPa and uniform elongation of-63% are obtained at 2.3×10^3 s^-1, indicating that the alloy has great potential for energy absorption upon impact loading.

Cold-temperature deformation of nano-sized tungsten and niobium as revealed by in-situ nano-mechanical experiments

We constructed and developed an in-situ cryogenic nanomechanical system to study small-scale mechanical behavior of materials at low temperatures. Uniaxial compression of two body-centered-cubic （bcc） metals, Nb and W, with diameters between 400 and 1300 rim, was studied at room temperature and at 165 K. Experiments were conducted inside of a Scanning Electron Microscope （SEM） equipped with a nanomechanical module, with simultaneous cooling of sample and diamond tip. Stress-strain data at 165 K exhibited higher yield strengths and more extensive strain bursts on average, as compared to those at 298 K. We discuss these differences in the framework of nano-sized plasticity and intrinsic lattice resistance. Dislocation dynamics simulations with surface-controlled dislocation multiplication were used to gain insight into size and temperature effects on deformation of nano-sized bcc metals.

Fabrication of porous scaffolds with protein nanogels

A novel type of porous scaffold was fabricated from single protein nanogels. The nanogels with single protein as core and crosslinked polymer network as shell were prepared through a two-step procedure including surface acryloylation and in situ radical polymerization. The formation of single protein nanogels was verified by matrix assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometer, transmission electron microscopy (TEM) and dynamic light scattering (DLS) analyses. Subsequently, the porous scaffolds were fabricated through a solvent evaporating process of aqueous nanogel solutions. The porous scaffolds were characterized by Fourier transform infrared (FTIR), scanning electronic microscopy (SEM), atomic force microscopy (AFM), and fluorescence microscopy. Interestingly, the obtained porous nanogel scaffolds presented multi-level porous morphologies with macro and nano scale pores, providing better spaces and microenvironments than normal macro porous scaffolds. Cell proliferation assay of nanogels showed low cytotoxicity. Considering that both the protein species and polymer constitutes can be pre-designed and adjusted, these multi-level porous nanogel scaffolds are promising candidates for tissue culture applications.

Occurrence, Structure and Mineral Phases of Nanoparticles in an Anthrosol

Soils contain various kinds of crystalline to amorphous solid particles with at least one dimension in the nanoscale （〈 100 nm）. These nanoparticles contribute greatly to dynamic soil processes such as soil genesis, trace element cycling, contaminant transport, and chemical reaction. The nano-sized fraction of an Anthrosol was obtained to determine the occurrence, chemical composition, structure, and mineral phases of nanoparticles using high-resolution transmission electron microscopy （HRTEM） equipped with an energy-dispersive X-ray spectroscopy. Selected area electron diffraction or the fast Fourier transform of high-resolution images was used in structural characterization of the nanoparticles with HRTEM. Two nanoscale mineral types, i.e., mineral nanoparticles and nanomi- nerals, were observed in the Anthrosol. Mineral nanoparticles in soil included well crystalline aluminumsilicate nanosheets, nanorods, and nanoparticles. Nanosheets with a length of 120-150 nm and a width of about 10-20 nm were identified as chlorite/vermiculite series. The presence of clear lattice fringe spacing in HRTEM image of nanoparticles indicated that mineral nanoparticles had a relatively good crystallinity. The nanomineral ferrihydrite also existed in the Anthrosol. The HRTEM images and the particle size distribution histogram suggested that these ferrihydrite nanoparticles were quite homogeneous, and had a narrow size distribution range （1-7 nm） with a mean diameter of 3.6 4- 1.6 nm. Our HRTEM observation indicated that mineral nanoparticles and nanominerals were common and widely distributed in Anthrosols. HRTEM and selected area diffraction or lattice fringe spacing characterization provided further proofs to the structure of nanoparticles formed in soil.