Far infrared reflection spectra in narrow-gap semiconductors

Far infrared reflection spectra of Cd_XHg_1?X Se are measured in the region 20 to 600 cm^?1 at temperatures between 5 and 77 K. Reflection spectra are explained well by the dynamic dielectric function which is constructed as a sum of Γ₈?Γ₈ interband, intraband and phonon contributions. The plasmon-LO phonon coupling effect is also discussed.     

Preparation of silica fibers and non-woven cloth by electrospinning

Silica fibers, which can potentially be used as filters and media for catalysts immobilization, were successfully spun via electrospinning process with precursor prepared through the sol–gel synthesis. Spinnable sols can be obtained only when the molar ratio of water to TEOS is less than 2 which is consistent with the retrospective results derived for other spinning methods. It was confirmed for the first time that the reaction time can be drastically reduced by introducing humidified air, controlled by KCl saturated aqueous solution, during sol–gel process. The size of obtained silica fibers is about 4.5 μm and has a certain degree of flexibility and mechanical strength. Although the specific surface area of as spun fiber was 7.7 m²/g, which is apparently small comparing to generic silica, treatment by boiling water only for 5 min could increase the specific surface area to be about 500 m²/g.     

Bimodal Momentum Distribution of the High-Density Supersolid State

By performing exact quantum Monte Carlo simulations, we study the momentum distribution of the supersolid state in the two-dimensional extended Bose-Hubbard model with the nearest-neighbor repulsion. For strong nearest-neighbor repulsions, the supersolid state is stable in a broad region up to large hopping amplitudes and high particle densities. In the supersolid state, the momentum distribution shows a bimodal structure with two peaks related to the superfluidity and solidity respectively. By our calculations, we show that the bimodal structure becomes clearer as the chemical potential (or the particle density) is increased.     

Carbon nanotube enables quantum leap in oil recovery

A novel sealing material based on a CNT-rubber composite was developed for use in producing oil from deep, hot reservoirs. Fully dispersed and better bondings are two critical advances that enhance its mechanical properties. Authors solved the critical issues and clarified the mechanism of nano network reinforcement using test data. The resulting sealing solution underwent field tests around the world, and it marks a rare success story for the use of nanotechnology in the oilfield.     

Texture,sensory and swallowing characteristics of high-pressure-heat-treated pork meat gel as a dysphagia diet

To develop a soft meat product for a dysphagia diet, high-pressure technology was applied. Pressure-heat-treated ground pork meat (PH) was prepared from ground pork mixed with water (ground meat: water, 1:0.5 or 1:1) and salt (1.5%). PH-gels were made from these meat homogenates by treatment at 400 MPa for 20 min, followed by heat treatment. Heat-treated pork meat homogenates (H) were also prepared. The hardness and adhesiveness of the 1:1PH-gel was lower than those of the 1:1H-gel. The PH-gel scored higher in sensory evaluations of elasticity, smoothness and ease of swallowing. Scanning electron micrographs indicated that the superior textural property of the 1:1PH-gel was caused by a network of myosin filaments. Videofluoroscopic examination of swallowing revealed that the 1:1PH-gel was easy to swallow and left little residue in the oropharynx. These results proved the utility of pressurization in creating a dysphagia meat diet.     

Investigation of ochratoxin a, B and citrinin contamination in various commercial foods

Ochratoxin A (OTA), ochratoxin B (OTB) and citrinin (CIT) in commercial foods were simultaneously determined and confirmed with high-performance liquid chromatography (HPLC) and liquid chromatography coupled with tandem mass spectrometry (LC/MS/MS). The samples examined were made up of cereal, fruit, coffee, and cacao products. The limits of quantification (S/N> or =10) of OTA, OTB and CIT were 0.1 microg/kg or less. Aflatoxins (AF), deoxynivalenol (DON) and fumonisins were also surveyed. Of 157 samples examined, 44 were contaminated with OTA at levels of 0.11 to 4.0 microg/kg. At least 2 positive samples were labeled as domestics. In most positive samples, the OTA level was low, less than 1 microg/kg. The highest incidence of OTA was observed in cacao powder (10/12), followed by instant coffee (5/7), cocoa (5/8) and raisin (6/13). OTB was found in fruit and cacao products containing relatively high levels of OTA. Co-occurrence of OTA, CIT and DON was found in cereal products, and co-occurrence of OTA and AF was found in cacao products. Approximately 30% of naturally contaminated OTA in roasted coffee bean moved into the extract solution when brewed with paper filter.     

Effect of hydroxypropyl-beta-cyclodextrin on the degradation of pentachlorophenol by potassium monopersulfate catalyzed with iron(III)-porphyrin complex

A novel biomimetic catalytic system containing a supramolecular complex between iron(III)-tetrakis(p-sulfonatophenyl)porphyrin [Fe(III)-TPPS] and hydroxypropyl-beta-cyclodextrin (HP-beta-CD) was examined for the potassium monopersulfate catalyzed oxidation of pentachlorophenol (PCP). In the absence of HP-beta-CD, the percentage of PCP disappearance and the numbers of chlorine atoms released from PCP increased to 50% and 1.5 for a 1-day reaction period, respectively. However, in the presence of HP-beta-CD, the PCP completely disappeared and the number of chlorine atoms from PCP was increased to 3.1. o-Tetrachloroquinone, 2- and 4-hydroxyl-nonachlorodiphenyl ethers, and octachlorodibenzo-p-dioxin were detected among the oxidation products. In the absence of HP-beta-CD, the percentage of PCP conversion to oxidation products increased and then reached plateau. In the presence of HP-beta-CD, the amount of oxidation products produced initially increased for the first 10 min and thereafter decreased gradually. These results suggest that the addition of HP-beta-CD results in the further degradation of oxidation products. In addition, the mineralization of PCP to CO2 was investigated using 14C6-labeled PCP. After a 1-day reaction period, 24% of the 14C6-labeled PCP was converted to 14CO2 in the presence of HP-beta-CD, although significant 14CO2 generation was not observed in its absence. The effect of HP-beta-CD on the facilitation of PCP degradation can be attributed to the fact that the self-oxidation of Fe(III)-TPPS is prevented by the formation of a stable supramolecular complex between HP-beta-CD and Fe(III)-TPPS.     

几种预处理方法转化木质纤维原料制乙醇的对比

为提供木质纤维原料转化乙醇的预处理方法的参考,以水稻秸秆、白酒丢糟分别为原料,对丁酮稀溶液、液氨、蒸汽爆破和浓硫酸水解的预处理工艺制乙醇效果进行了对比,并对水洗与烘干脱毒方式进行了探讨。当分别用丁酮稀溶液、液氨、蒸汽爆破和浓硫酸水解处理原料时,分别采用烘干、不脱毒、水洗并回收洗水与中和等方法,可得到相应预处理方法的最高乙醇产率。其中,丁酮稀溶液爆破法的丢糟与秸秆的酶解总糖收得率分别为86%与88%,乙醇产率为25.2 g/(100 g绝干丢糟)与26.3 g/(100 g绝干秸秆)。其乙醇产率较液氨、蒸汽爆破法高,但比实验室水平的浓硫酸水解工艺低。     

Toxicity and tetramine contents of salivary glands from carnivorous gastropods

Salivary glands from 29 species of marine carnivorous gastropods in nine families were examined for lethal activity against mice and tetramine content. Mouse lethality was assayed by intravenous injection of buffer extracts into mice, and was detected in 14 species. Heat-stability tests confirmed that toxins in four species were thermolabile, while those in eight species were thermostable. Based on the tetramine contents determined by the colorimetric method using methanolic extracts, the thermostable toxins in seven species (Neptunea eulimatalamellosa, N. vinosa, N. arthritica, N. bulbacea, N. intersculpta f. pribiloffensis, N. intersculpta f. frater pilsbry and Hemifusus tuba) were considered to be tetramine contained at high levels (more than 900 micrograms/g salivary gland), but that in one species (Buccinum opisthoplectum) appeared to be a low-molecular-weight compound differing from tetramine. It is interesting that one (Hemifusus tuba) of the seven species containing high amounts of tetramine belongs to the family Melongenidae, although the other six Neptunea species are members of the family Buccinidae, as expected from previous studies.     

Biosynthesis of p-anisaldehyde by the white-rot basidiomycete Pleurotus ostreatus

The white-rot basidiomycete Pleurotus ostreatus produced sweet flavor compounds on a liquid medium. The major and minor compounds identified by GC-MS analysis were p-anisaldehyde (4-methoxybenzaldehyde) and 3-chloro-p-anisaldehyde (3-chloro-4-methoxybenzaldehyde), respectively. p-Anisaldehyde was only produced under static culture conditions. Differences in the type and quantity of flavor compounds produced among wild strains of P. ostreatus were observed. Aryl alcohol oxidase and manganese peroxidase activities increased parallel to the production of p-anisaldehyde. These results indicated that the biosynthesis of p-anisaldehyde is concerned in generating H2O2-activated peroxidase in the lignin-degradation system. Addition of L-tyrosine to the culture led to higher production of p-anisaldehyde. The flavor extract, which contains p-anisaldehyde, exhibited antimicrobial activity against Bacillus subtilis, Pseudomonas aeruginosa, Aspergillus niger and Fusarium oxysporum.