化学发光法快速测定硝化甘油化学安定性研究

本文介绍用化学发光法测定硝化甘油安定性,它一方面继承了以NO_x气体使试纸显线条为衡量标准的硝甘安定性经典方法(阿贝尔试验);另一方面快准的测定硝甘热分解时的NO_x浓度,从定性分析发展到定量分析,从间断的试纸变色分析发展至连续的电信号分析,更准确地反映了硝甘安定性好坏;建立了用化学发光法测定硝甘化学安定性的判断标准。

Determination the Vigor of Rice Seed with Different Degrees of Aging with Ultraweak Chemiluminescence During Early Imbibition

用高灵敏度的单光子计数系统探测人工老化 (40℃ ,相对湿度 90 % ) 0、7、14和 2 1d的水稻种子吸胀初期的超弱化学发光强度变化 ,首次观测到水稻 (OryzasativaL .)种子吸胀初期超弱化学发光强度与其老化程度有关。加水激活水稻种子的超弱化学发光 ,其强度依赖于种子的老化程度。实验结果表明水稻种子的人工老化时间越短 ,则吸胀初期 (2 0～ 30min)超弱化学发光的强度越强 ,萌发率越高。水稻种子萌发率与超弱化学发光强度呈显著正相关。观测水稻种子吸胀初期超弱化学发光强度的变化可望成为检测种子老化程度的一种快速、简便、无损伤的新方法。

HEURISTIC PARTICLE SWARM OPTIMIZATION ALGORITHM FOR AIR COMBAT DECISION-MAKING ON CMTA

Combining the heuristic algorithm （HA） developed based on the specific knowledge of the cooperative multiple target attack （CMTA） tactics and the particle swarm optimization （PSO）, a heuristic particle swarm optimization （HPSO） algorithm is proposed to solve the decision-making （DM） problem. HA facilitates to search the local optimum in the neighborhood of a solution, while the PSO algorithm tends to explore the search space for possible solutions. Combining the advantages of HA and PSO, HPSO algorithms can find out the global optimum quickly and efficiently. It obtains the DM solution by seeking for the optimal assignment of missiles of friendly fighter aircrafts （FAs） to hostile FAs. Simulation results show that the proposed algorithm is superior to the general PSO algorithm and two GA based algorithms in searching for the best solution to the DM problem.

Preparation and characterization of aluminum foams with ZrH_2 as foaming agent

Aluminum foams were fabricated by melt-based route using ZrH2 as a foaming agent. The factors which affected the foaming of aluminum foams during casting process were investigated. The powdered zirconium hydride with content of 0.6%-1.4% （mass fraction） was added to the molten pure aluminum and the foaming condition was controlled in a temperature range from 933 to 1 013 K, Ca amount of 1.5%-3.0% （mass fraction）, stirring time of 0.5-2.5 min and holding time of 1.5-4.0 min to obtain homogeneous aluminum foams. The fabricated aluminum foams were characterized by XRD, SEM and Image-pro plus. The mechanical properties of the aluminum foams with different relative density were tested. The result indicates that the foaming agent （ZrH2） is suitable for the preparation of small aperture aluminum foams with average pore diameter of 1 mm. Inter-metallic compounds and Al2O3 have effect on the melt viscosity. The aluminum foams experience linear elastic, platforms and densification process and had a higher efficiency of energy absorption.

Field Measurement of NO2 and RNO2 by Two-Channel Thermal Dissociation Cavity Ring Down Spectrometer

A two-channel thermal dissociation cavity ring down spectroscopy （CRDS） instrument has been built for in situ, real-time measurement of NO2 and total RNO2 （peroxy nitrates and alkyl nitrates） in ambient air, with a NO2 detection limit of 0.10 ppbv at 1 s. A 6-day long measurement was conducted at urban site of Hefei by using the CRDS instrument with a time resolution of 3 s. A commercial molybdenum converted chemiluminescence （Mo-CL） instrument was also used for comparison. The average RNO2 concentration in the 6 days was measured to be 1.94 ppbv. The Mo-CL instrument overestimated the NO2 concentration by a bias of ＋1.69 ppbv in average, for the reason that it cannot distinguish RNO2 from NO2. The relative bias could be over 100% during the afternoon hours when NO2 was low but RNO2 was high.

Experimental studies on pillar failure characteristics based on acoustic emission location technique

Acoustic emission （AE） technique is a useful tool for investigating rock damage mechanism, and is used to study the temporal-spatial evolution process of microcracks during the similar pillar material experiment. A combined AE location algorithm was developed based on the Least square algorithm and Geiger location algorithm. The pencil break test results show that the location precision can meet the demand of microcrack monitoring. The 3D location of AE events can directly reflect the process of initiation, propagation and evolutionary of microcracks. During the loading process, stress is much likely concentrated on the area between pillar and roof of the specimen, where belongs to danger zone of macroscopic failure. When rock reaches its plastic deformation stage, AE events begin to decrease, which indicates that AE quiet period can be seen as precursor characteristic of rock failure.

Preliminary Studies on High-performance Liquid Chro-matography Chemiluminescence Determination of theSaturated Fatty Acids(C_(16) C_(18))in Human Serum

The peroxyoxalate chemiluminescence(CL)detection of fatty acids in human se- rum combined with high-performance liquid chromatography (HPLC)is described.Some fatty acids in serum were extracted with a 1 :1(v/v)mixture of chloroform-n-heptane.2-(4-Hydrazinocarbonyl- phenyl)-4,5-diphenylimidazole (HCPI) was used as a fluorescent labelling reagent of the fatty acids. The labelling reaction was carried out at 30℃ for 1 h at pH 6.5 and the resulting reaction mixture was sudjected to HPLC. The labelled fatty acid C_(17)(P-C_(17))was used as the internal standard. The la- belled fatty acids C_(16) and C_(18) were separated within 18 min on an ODS-8OTM column (150 mm× 6 mm ID,5μm,Tosoh Japan).The calibrlation curves of fatty acids from the spiked control serum were Y_1=-0.003 7 + 0.0028X_1,r=0.994 for FA C_( 16) and Y_2=0.00 1 2 + 0.00098X_2,r=0.999 for FA C_( 18),respectively.The average recoveries of facids from the spiked contrl serum were 107.2%(n=8,RSD=4.3%)for FA C_(16) and 97.35%(n=8, RSD=4.0%)for FA C_(18),respectively.The lower detection limits of fatty acids after reaction were 12μmol per 20μl injection for FA C_(16) and 18 μmol per 20μl injection for FA C_(18),respectively(signal to noise ratio, S/N=2).The HPLC/CL method was applied to the determination of FA C_(16) and FA C_(18) in normal human serum and the results showed that the concentrations of fatty acids in normal human serum were 0.134 ± 0.009 μ mol/ml serum(n=5) for FA C_(16) and 0.052±0.028 μmol/ml serum(n=5)for FA C_(18),respectively.

Numerical modeling of anisotropy paradoxes in direct current resistivity and time-domain induced polarization methods

Based on an analytical solution for the current point source in an anisotropic half-space,we study the apparent resistivity and apparent chargeability of a transversely isotropic medium with vertical and horizontal axes symmetry,respectively.We then provide a simple derivation of the anisotropy paradoxes in direct current resistivity and time-domain induced polarization methods.Analogous to the mean resistivity,we propose a formulation for deriving the mean polarizability.We also present a three-dimensional finite element algorithm for modeling the direct current resistivity and time-domain induced polarization using an unstructured tetrahedral grid.Finally,we provide the apparent resistivity and apparent chargeability curves of a tilted,transversely isotropic medium with diff erent angles,respectively.The subsequent results illustrate the anisotropy paradoxes of direct current resistivity and time-domain induced polarization.

Purification and characterization ofα-L-fucosidase from human primary hepatocarcinoma tissue

AIM: To purify and characterizeα-L-fucosidase from human liver cancer tissue and to detect the localization ofα-L-fucosidase in tumor tissue. METHODS: Cation exchange chromatography on CM-52 and ultrafiltration were used to separateα-Lfucosidase (AFU) from crude extract of liver cancer tissue. 4-methylumbelliferyl-α-L-fucopyranoside was used as a fluorescent substrate to quantify the purified AFU activity in each step. A polyclonal antibody (pAb) against the purified AFU was obtained by anion exchange chromatography on DEAE-52 after ammonium sulfate fractionation and ultrafiltration. Immuohistochemical staining was used to observe the expression of AFU in malignant and adjacent liver tissues. RESULTS: Humanα-L-fucosidase was purified 74-fold to apparent homogeneity with 15% yield. SDSPAGE indicated the presence of one subunit of molecular weight of 55 Ku. The specific activity of AFU in pooled fraction by chromatography was 10085 IU/mg. Western blot analysis indicated that the pAb could recognize one protein band of molecular weight of 55 Ku. The expression of AFU was observed in cytoplasm membrane of liver cancer tissue but not in that of adjacent tissue. CONCLUSION: The purifiedα-L-fucosidase from primary hepatocarcinoma (PHC) is different in its properties fromα-L-fucosidase in human other organs. The polyclonal antibody prepared in this experiment can be applied to the diagnosis of PHC.

A Filtering Approach Based on MMAE for a SINS/CNS Integrated Navigation System

This paper explores multiple model adaptive estimation(MMAE) method, and with it, proposes a novel filtering algorithm. The proposed algorithm is an improved Kalman filter— multiple model adaptive estimation unscented Kalman filter(MMAE-UKF) rather than conventional Kalman filter methods,like the extended Kalman filter(EKF) and the unscented Kalman filter(UKF). UKF is used as a subfilter to obtain the system state estimate in the MMAE method. Single model filter has poor adaptability with uncertain or unknown system parameters,which the improved filtering method can overcome. Meanwhile,this algorithm is used for integrated navigation system of strapdown inertial navigation system(SINS) and celestial navigation system(CNS) by a ballistic missile's motion. The simulation results indicate that the proposed filtering algorithm has better navigation precision, can achieve optimal estimation of system state, and can be more flexible at the cost of increased computational burden.

Effect of compression ratio on microstructure evolution of Mg−10%Al−1%Zn−1%Si alloy prepared by SIMA process

A new Mg−10%Al−1%Zn−1%Si alloy with non-dendritic microstructure was prepared by strain induced melt activation(SIMA)process.The effect of compression ratio on the evolution of semisolid microstructure of the experimental alloy was investigated.The results indicate that the average size ofα-Mg grains decreases and spheroidizing tendency becomes more obvious with the compression ratios increasing from 0 to 40%.In addition,the eutectic Mg2Si phase in the Mg−10%Al−1%Zn−1%Si alloy transforms completely from the initial fishbone shape to globular shape by SIMA process.With the increasing of compression ratio,the morphology and average size of Mg2Si phases do not change obviously.The morphology modification mechanism of Mg2Si phase in Mg−10%Al−1%Zn−1%Si alloy by SIMA process was also studied.

Prevalence of gastric varices and results of sclerotherapy with N-butyl 2 cyanoacrylate for controlling acute gastric variceal bleeding

AIM： To study the prevalence, predictors and control of bleeding following N-butyl 2 cyanoacrylate （NBC） sclerotherapy of gastric varix （GV）. METHODS： We analyzed case records of 1436 patients with portal hypertension, who underwent endoscopy during the past five years for variceal screening or upper gastrointestinal （GI） bleeding. Fifty patients with bleeding GV underwent sclerotherapy with a mean of 2 mL NBC for control of bleeding. Outcome parameters were primary hemostasis （bleeding control within the first 48 h）, recurrent bleeding （after 48 h of esophagogastro-duodenoscopy） and in-hospital mortality were analyzed. RESULTS： The prevalence of GV in patients with portal hypertension was 15% （220/1436） and the incidence of bleeding was 22.7% （50/220）. Out of the 50 bleeding GV patients, isolated gastric varices （IGV-Ⅰ） were seen in 22 （44%）, gastro-oesophageal varices （GOV） on lesser curvature （GOV-Ⅰ） in 16 （32%）, and GOV on greater curvature （GOV-Ⅱ） in 15 （30%）. IGV-Ⅰ was seen in 44% （22/50） patients who had bleeding as compared to 23% （39/170） who did not have bleeding （P 〈 0.003）. Primary hernostasis was achieved with NBC in all patients. Re-bleeding occurred in 7 （14%） patients after 48 h of initial sclerotherapy. Secondary hemostasis was achieved with repeat NBC sclerotherapy in 4/7 （57%）. Three patients died after repeat sclerotherapy, one during transjugular intrahepatic portosystemic stem shunt （TIPSS）, one during surgery and one due to uncontrolled bleeding. Treatment failure-related mortality rate was 6% （3/50）. CONCLUSION： GV can be seen in 15% of patients with portal hypertension and the incidence of bleeding is 22.7%. NBC is highly effective in controlling GV bleeding. In hospital mortality of patients with bleeding GV is 6%.

False Human Immunodeficiency Virus Test Results Associated with Rheumatoid Factors in Rheumatoid Arthritis

Objective To investigate if immunological factors associated with rheumatoid arthritis(RA) affect the result of human immunodeficiency virus(HIV) screening by electrochemiluminescence immunoassay(ECLIA) and enzyme-linked immunosorbent assay(ELISA). Methods 100 RA cases were enrolled from January 2012 to February 2013 into this study. HIV screening was conducted with ECLIA detecting both HIV-1 p24 antigen, HIV-1 and HIV-2 antibodies, with ELISA and colloidal gold method detecting HIV-1 and HIV-2 antibodies. The samples producing positive results were submitted to the Center for Disease Control for confirmation using Western blotting method. The antibody titers of rheumatoid factors(RF) including RF-IgG, RF-IgM, RF-IgA, and CCP-IgG were analyzed by ELISA. Results The HIV positive-rate determined by ECLIA was significantly higher than that by ELISA and colloidal gold method(P<0.01). The false-positive rate of HIV screening was associated with antibody titers of RF-IgG, RF-IgM, RF-IgA, and CCP-IgG in RA(P<0.01). Conclusion Immunological factors, including RF and anti-CCP antibody, may influence the screening of HIV by ECLIA, producing false-positive result.

Results of percutaneous sclerotherapy and surgical treatment in patients with symptomatic simple liver cysts and polycystic liver disease

AIM: To evaluate the results of the treatment of simple liver cysts (solitary and multiple) and polycystic liver disease (PLD) using percutaneous sclerotherapy and/or surgical procedures in a single tertiary referral centre. METHODS: Retrospective analysis of 54 patients referred for evaluation and possible treatment of simple liver cysts (solitary and multiple) and PLD, from January 1997 to July 2006. RESULTS: Simple liver cysts were treated in 41 pts (76/) with a mean size of 12.6 cm. The most common reason for referral was abdominal pain or discomfort (85/). Percutaneous sclerotherapy was performed as initial treatment in 30 pts, showing cyst recurrence in 6 pts (20/). Surgical treatment was initially performed in 11 pts with cyst recurrence in 3 pts (27/). PLD was treated in 13 pts (24/) with a mean size of the dominant cyst of 13 cm. Percutaneous sclerotherapy for PLD was performed in 9 pts with recurrence in 7 pts (77.8/). Surgical treatment for PLD was undertaken in 4 pts (30.8/) with recurrence in all. Eventually, 2 pts with PLD in the presence of polycystic kidney disease underwent liver-and kidney transplantation because of deterioration of liver and kidney function. CONCLUSION: The majority of patients with simple liver cysts and PLD are referred for progressive abdominal pain. As initial treatment, percutaneous sclerotherapy is appropriate. Surgical deroofing is indicated in caseof cyst recurrence after percutaneous sclerotherapy. However, the results of percutaneous sclerotherapy and surgical treatment for PLD are disappointing. Partial liver resection is indicated when there is suspicion of a pre-malignant lesion.

Synthesis and growth mechanism of SiC/SiO2 nanochains by catalyst-free thermal evaporation method in Ar/CO atmosphere

SiC/SiO2 nanochains were synthesized on a carbon fiber substrate by a catalyst-free thermal evaporation method in the Ar/CO atmosphere.X-ray diffraction(XRD),Fourier-transform infrared spectroscopy(FT-IR),scanning electron microscopy(SEM)and transmission electron microscopy(TEM)revealed that the as-synthesized SiC/SiO2 nanochains are composed of single-crystalline SiC nanowires and amorphous SiO2 beads.The introduction of CO can promote the formation of SiO2,so that the SiC/SiO2 nanochains are subsequently formed during cooling.In addition,the photoluminescence spectrum of SiC/SiO2 nanochains showed a broad emission peak at around 350 nm,which is ascribed to the oxygen discrepancy in the SiO2 beads as well as the SiC/SiO2 interfacial effect.These findings can provide guidance for further study of the vapor growth of 1D SiC-based materials.

Analysis of volatile chemical components of Radix Paeoniae Rubra by gas chromatography-mass spectrometry and chemometric resolution

The volatile chemical components of Radix Paeoniae Rubra (RPR) were analyzed by gas chromatography-mass spectrometry with the method of heuristic evolving latent projections and overall volume integration. The results show that 38 volatile chemical components of RPR are determined, accounting for 95.21% of total contents of volatile chemical components of RPR. The main volatile chemical components of RPR are (Z, Z)-9,12-octadecadienoic acid, n-hexadecanoic acid, 2-hydroxy- benzaldehyde, 1-(2-hydroxy-4-methoxyphenyl)-ethanone, 6,6-dimethyl-bicyclo[3.1.1] heptane-2-methanol, 4,7-dimethyl-benzofuran, 4-(1-methylethenyl)-1-cyclohexene-1-carboxaldehyde, and cyclohexadecane.

Heuristic Genetic Algorithm for Discretization of Continuous Attributes in Rough Set Theory

Discretization based on rough set theory aims to seek the possible minimum number of the cut set without weakening the indiscemibility of the original decision system. Optimization of discretization is an NP-complete problem and the genetic algorithm is an appropriate method to solve it. In order to achieve optimal discretization, first the choice of the initial set of cut set is discussed, because a good initial cut set can enhance the efficiency and quality of the follow-up algorithm. Second, an effective heuristic genetic algorithm for discretization of continuous attributes of the decision table is proposed, which takes the significance of cut dots as heuristic information and introduces a novel operator to maintain the indiscernibility of the original decision system and enhance the local research ability of the algorithm. So the algorithm converges quickly and has global optimizing ability. Finally, the effectiveness of the algorithm is validated through experiment.

Preparation and in vitro Studies of Stealth PEGylated PLGA Nanoparticles as Carriers for Arsenic Trioxide

The aim of this study was to prepare arsenic trioxide （ATO）-loaded stealth PEGylated PLGA nanoparticles （PEG-PLGA-NPs） and to assess the merits of PEG-PLGA-NPs as drug carriers for ATO delivery. PEG-PLGA copolymer was synthesized with methoxypolyethyleneglycol （Mw=5000）, D, L-lactide, and glycolide by the ring-opening polymerization method. Amorphous ATO was transformed into cubic crystal form to increase its solu-bility in the organic solvent. ATO-loaded PEG-PLGA-NPs were prepared by the modified spontaneous emulsification solvent diffusion （SESD） method, and the main experimental factors influencing the characteristics of nanopar- ticles were investigated, to optimize the preparation. To confirm the escape of PEG-PLGA-NPs from phagocytosis by phagocytes, PEG-PLGA-NPs labeled rhodamine B uptake by murine peritoneal macrophages （MPM） were analyzed by flow cytometry. The results showed that the physicochemical characteristics of PEG-PLGA-NPs were affected by the type and concentration of the emulsifiers, polymer concentration, and drug concentration. ATO-loaded PEG-PLGA-NPs, with particle size of 120.8nm, zeta potential of-10.73mV, encapsulation efficiency of 73.6%, and drug loading of 1.36%, were prepared under optimal conditions. The images of transmission electron micros-copy （TEM） indicated that the optimized nanoparticles were near spherical and without aggregation or adhesion. The release experiments in vitro showed the ATO release from PEG-PLGA-NPs exhibited consequently sustained release for more than 26d, which was in accordance with Higuchi equation. The uptake of PEG-PLGA-NPs by MPM was found to decrease markedly compared to PLGA-NPs. The experimental results showed that PEG-PLGA-NPs were potential nano drug delivery carriers for ATO.

Optimization of total harmonic current distortion and torque pulsation reduction in high-power induction motors using genetic algorithms

This paper presents a powerful application of genetic algorithm （GA） for the minimization of the total harmonic current distortion （THCD） in high-power induction motors fed by voltage source inverters, based on an approximate harmonic model. That is, having defined a desired fundamental output voltage, optimal pulse patterns （switching angles） are determined to produce the fundamental output voltage while minimizing the THCD. The complete results for the two cases of three and five switching instants in the first quarter period of pulse width modulation （PWM） waveform are presented. Presence of harmonics in the stator excitation leads to a pulsing-torque component. Considering the fact that if the pulsing-torques are at low frequencies, they can cause troublesome speed fluctuations, shaft fatigue, and unsatisfactory performance in the feedback control system, the 5th, 7th, 1 lth, and 13th current harmonics （in the case of five switching angles） are constrained at some pre-specified values, to mitigate the detrimental effects of low-frequency harmonics. At the same time, the THCD is optimized while the required fundamental output voltage is maintained.

Inorganic Elemental Determinations of Marine Traditional Chinese Medicine Meretricis concha from Jiaozhou Bay:The construction of Inorganic Elemental Fingerprint Based on Chemometric Analysis

The goal of this paper is to explore the relationship between the inorganic elemental fingerprint and the geographical origin identification ofMeretricis concha, which is a commonly used marine traditional Chinese medicine （TCM） for the treatment of asthma and scald bums. For that, the inorganic elemental contents ofMeretricis concha from five sampling points in Jiaozhou Bay have been determined by means of inductively coupled plasma optical emission spectrometry, and the comparative investigations based on the contents of 14 inorganic elements （A1, As, Cd, Co, Cr, Cu, Fe, Hg, Mn, Mo, Ni, Pb, Se and Zn） of the samples from Jiaozhou Bay and the previous reported Rushan Bay were performed. It has been found that the samples from the two bays are ap- proximately classified into two kinds using hierarchical cluster analysis, and a four-factor model based on principle component analysis could explain approximately 75% of the detection data, also linear discriminant analysis can be used to develop a prediction model to distinguish the samples from Jiaozhou Bay and Rushan Bay with accuracy of about 93%. The results of the present investi- gation suggested that the inorganic elemental fingerprint based on the combination of the measured elemental content and chemom- etric analysis is a promising approach for verifying the geographical origin ofMeretricis concha, and this strategy should be valuable for the authenticity discrimination of some marine TCM.