[Nondestructive Measurement of RDX Grain's Internal Pressure by Using Raman Spectrum Method].

RDX is a most widely used military explosive. As the development of new warheads, there are more and more applications of RDX with abnormal grain shapes. To ensure the operational effectiveness of the new warheads, it is necessary to find an on-line nondestructive methods that can measure the RDX grain's internal pressure. In this paper, we use Raman spectrum and first-principles methods to determine the characteristic spectral line of the RDX samples and have studied the shift of the Raman spectral lines under various pressures. In particular, we measured the RDX samples under the pressures of 10, 20 and 30 MPa, respectively, and checked the fitting errors by measuring the RDX samples under the pressures of 15, 25 and 35 MPa, respectively. It is found that the shift of the characteristic Raman spectral line has a good linear dependence on the external pressures. Therefore, we can at first calibrate the linear relation between the shift of the Raman spectral line of regular RDX and the pressures in laboratory and then measure the Raman spectral line shift of the RDX with abnormal shapes. Based on the calibrated linear relation and the measurement of Raman spectra, one can determine the internal pressure in RDX. In this way, we can realize the nondestructive detection of the internal pressure of RDX. The experiment results show that this method has the advantage of good sensitivity and reproducibility. The Raman spectrum method has been successfully tested in the warhead production line.

[Study on Raman spectra of multi-walled carbon nanotubes with different parameters].

In order to study the influencing factors on Raman spectroscopy, we research a series of comparative Raman spectroscopy of multi-walled carbon nanotubes (MWCNT) with different tube diameter and length. The results suggest that the G peak and D peak of MWCNT are all red-shifted as compared to that of polycrystalline graphite; In the same conditions, the peak intensity (G peak and D peak) is directly proportional to the diameter of the MWCNT, and inversely proportional to the length of the MWCNT; G peak frequency shift is closely related to the MWCNT diameter and length, which are inversely proportional to the diameter (with identical results of the single-walled carbon nanotube radial breathing modes) and direct proportional to the length. While, the influences of the diameter and length on D peak frequency shift are weak, and future analysis for the reason of this kind of phenomenon is as follows. Subsequently, we investigated the relation between D peak frequency shift and MWCNT aspect ratio, the relationship between G peak frequency shift and aspect ratio is nearly linear increase. Using the same analysis method, we plotted the different graphs of G peak and D peak intensity vs the aspect ratio of MWCNT, respectively. As the expected, the linear degression relation are existent in the two relationships.

Histological complete response after neoadjuvant XELOX in advanced gastric carcinoma.

We report on a case of a 65-year-old Chinese male with locally advanced gastric adenocarcinoma achieving pathological complete response after neoadjuvant chemotherapy with capecitabine and oxaliplatin (XELOX) regimen. He underwent esophagogastroduodenoscopy, which revealed a 6x5cm gastric ulcer. Biopsy of gastric ulcer revealed adenocarcinoma. Further workups with abdominal enhancement computed tomography (CT) staged his cancer as T4N2M0. He received 2 cycles of neoadjuvant chemotherapy with XELOX without severe toxicity. Afterwards, he underwent curative surgery consisting of total gastrectomy with extended D2 lymph node dissections and a Roux-en-Y esophagojejunostomy. On microscopic examination, no tumor cells were detected in the ulcer scar of the resected stomach and in the regional lymph nodes. The benefit of XELOX regimen as neoadjuvant chemotherapy in gastric cancer is worth further investigation.

[Raman spectrum study on synthesis mechanism of porous ZnO microspheres assisted with trisodium citrate].

Raman spectrum was applied to analyze the synthesis mechanism of nanostructure porous ZnO microspheres prepared via hydrothermal method assisted with trisodium citrate. The Raman spectrum characteristics of the sample revealed that the ZnO microspheres contained Zn-citrate complex, which was the complex of citrate acid group and Zn2+ in the reaction solution. The complex was chemisorbed on (204) and (503) faces of the Zn(OH)2 crystallite in the reacting solution, resulting in Zn(OH)2 nanosheet from the crystallite. Large quantities of Zn(OH)2 nanosheets aggregated as porous microspheres in hydrothermal process. Zn-citrate complex chemisorbed on the nanosheet improved the thermal stability of Zn(OH)2, which means a decomposition temperature over 200 degrees C. Nanostructure porous ZnO microspheres were obtained by heating Zn(OH)2 microspheres at 300 degrees C and the nanosheet structure was maintained.

[Experimental research on remote sensing spectrometer's instrument response function].

Remote sensing spectrometers were widely used in the fields such as spectral measure and trace gas supervision in atmosphere. The instrument response functions should be measured to eliminate the effect of the spectrometer. The instrument response functions of MCT detector and InSb detector in BLUKER TENSOR 37 passive FTIR spectrometer were measured in the present paper. The instrument response functions and background functions were offered with different temperature interval. The instrument response functions of MCT detector increased with temperature, but it was the reverse for InSb detector. The background functions of InSb detector increased with temperature, and the reverse for MCT detector.

Position-addressable digital laser scanning point fluorescence microscopy with a Blu-ray disk pickup head.

A compact and position-addressable blue ray scanning microscope (BSM) based on a commercially available Blu-ray disk pickup head (PUH) is developed for cell imaging with high resolution and low cost. The BSM comprises two objective lenses with numerical apertures (NAs) of 0.85 and 0.6 for focusing blue and red laser beams, respectively, on the sample slide. The blue and red laser beams are co-located adjacent to each other and move synchronously. A specially designed sample slide is used with a sample area and an address-patterned area for sample holding and address recognition, respectively. The blue laser beam is focused on the sample area and is used for fluorescent excitation and image capturing, whereas the red laser beam is focused on the address-patterned area and is used for address recognition and dynamic focusing. The address-patterned area is divided into 310 sectors. The cell image of each sector of the sampling area has a corresponding address pattern. Fluorescence images of monkey-derived kidney epithelial cells and fibroblast cells in which the F-actin is stained with fluorophore phalloidin CF 405 are measured by the BSM, with results comparable to those measured by a Leica TCS CP2 confocal microscope. The cell image of an area of interest can be easily tracked based on the coded address, and a large-area sample image can be accurately reconstructed from the sector images.