黄药和巯基苯并噻唑作捕收剂对金和毒砂浮选效率的比较

用巯基苯并噻唑(NaBMT)作捕收剂对来自赛尔西尼(Salsigne)矿床的两种难选含金矿石试样进行了浮选试验.结果表明,用KAX(钾黄药)(25%)和NaMBT(75%)的混合药剂取代常规的混合捕收剂,即使其用量较小,仍可使毒砂、尤其是金的浮选得到明显的改善.浮选选择性相回收率的改善,必须是在有关作业协同的有效作用下进行,这些作业为,强力浮选把毒砂和金回收到粗精矿中,再对粗精矿进行有效的精选和单体石英的弱浮选.     

Dynamic proteome in enigmatic preeclampsia: an account of molecular mechanisms and biomarker discovery

The coevolution of genomics and proteomics has led to advancements in the field of diagnosis and molecular mechanisms of disease. Proteomics is now stepping into the field of obstetrics, where early diagnosis of pregnancy complication such as preeclampsia (PE) is imperative. PE is a multifactorial disease characterized by hypertension with proteinuria, which is a leading cause of maternal and neonatal morbidity and mortality occurring in 5-7% of pregnancies worldwide. This review discusses the probable molecular mechanisms that lead to PE and summarizes the proteomics research carried out in understanding the pathogenicity of PE, and for identifying the candidate biomarker for diagnosis of the disease.     

Progress towards using the speed of ultrasound for beef leanness classification

Following the observation of a high correlation between the reciprocal of the speed of ultrasound and lean proportion in beef carcasses, commercial equipment (VOSI) was developed and its performance alongside a smaller assembly (Mini G) is reported. The speed of ultrasound was measured through six sites on beef carcasses within 1 h of stunning: three sites with VOSI and three sites with Mini G. Sides were also scored for fatness and conformation using the EAAP system, and subcutaneous fat depth was measured at 25,50 and 75% of the width of M. longissimus thoracis from the midline at the last rib. All sides were dissected into subcutaneous fat, intermuscular fat, muscle and bone. The reciprocal speed averaged over the three VOSI sites (RV346) was the best single predictor of the proportion of lean in the side. Multiple regression analyses, in predicting per cent lean, showed that addition of conformation score improved the precision of fat score and fat depth for a group of 26 sides. It did not provide a significant improvement over RV346. However, in another group of 50 sides showing more variation in side mass and conformation, conformation score did significantly improve RV346. The best prediction of per cent lean, involving RV346 and tissue thicknesses, gave a residual standard deviation of 1·35%, and conformation score did not significantly improve this regression.     

Estimation of lamb carcass composition from measurements of the speed of ultrasound in the soft tissues of live animals and carcasses

The application of the velocity of sound (VOS) technique to lamb carcasses in a previous study (Fisher & Page, 1986) measured composition at a hind limb and neck site but was not as precise as fat scores in predicting lean proportion. This study examines VOS measurements made at sites in the hind limbs and along the vertebral column in live sheep and carcasses. A group (A) comprising five breeds of males and females (n = 61) and a sub-group (B) of Scottish Blackface castrated males (n = 34) were studied, and the reciprocal velocity of ultrasound (RV) was measured on the live sheep immediately behind the shoulder and over the last rib using a fixed-distance transducer assembly operating at 5 MHz, and in the hind limbs at 2·25 MHz using the apparatus described by Miles et al. (1984). Corresponding measurements were made on the carcasses which were classified by a Meat and Livestock Commission fatstock officer and then dissected. Standard deviations of lean proportion were 4·48% (A) and 3·39% (B). The residual standard deviations (rsds) for groups A and B respectively were obtained using the following predictors: live mass (LM) 4·27% and 2·96%; LM + breed (B) 3·08% (group A only); LM + mean RV 2·36% and 2·07%; LM + B + mean RV 1·99% (group A only). Using carcass measurements: carcass mass (CM) 4·25% and 2·90%; CM + MLC fat score 2·99% and 2·12%; CM + RV last rib 2·89% and 2·02%. These data show that VOS measurements through dorsal sites of live sheep provide encouragingly precise estimates of carcass lean proportion. For carcasses, dorsal sites provide a less precise estimate of carcass lean but when carcass mass is included in multiple regression the precision of the correlation is comparable with that of multiple regression of fat score with carcass mass.     

Design and construction of an experimental pervious paved parking area to harvest reusable rainwater

Pervious pavements are sustainable urban drainage systems already known as rainwater infiltration techniques which reduce runoff formation and diffuse pollution in cities. The present research is focused on the design and construction of an experimental parking area, composed of 45 pervious pavement parking bays. Every pervious pavement was experimentally designed to store rainwater and measure the levels of the stored water and its quality over time. Six different pervious surfaces are combined with four different geotextiles in order to test which materials respond better to the good quality of rainwater storage over time and under the specific weather conditions of the north of Spain. The aim of this research was to obtain a good performance of pervious pavements that offered simultaneously a positive urban service and helped to harvest rainwater with a good quality to be used for non potable demands.     

Photonic content-addressable memory system that uses a parallel-readout optical disk

We describe a high-performance associative-memory system that can be implemented by means of an optical disk modified for parallel readout and a custom-designed silicon integrated circuit with parallel optical input. The system can achieve associative recall on 128 × 128 bit images and also on variable-size subimages. The system's behavior and performance are evaluated on the basis of experimental results on a motionless-head parallel-readout optical-disk system, logic simulations of the very-large-scale integrated chip, and a software emulation of the overall system.     

High-speed framing camera with an ellipsoidal scanner

A new type of rotating-mirror framing-camera optical system is proposed. A study is reported of the feasibility of the use of an aspherical mirror, with its surface in the shape of a prolate ellipsoid of revolution, in the scanning system of the camera. Starting from the aberration minimization conditions, the optimization of the parameters of the optical system is carried out. An aspherical mirror of this kind performs not only the scanning function, but also acts as a condenser, thus greatly simplifying construction of the camera.     

Subnanosecond switching, plasma electrode pockels cell for high-contrast imaging with partially coherent light

A high-contrast optical switch for imaging partially coherent light (~150 times the diffraction limit) requires that it have a large angular acceptance. We describe the development of a high-speed Pockels cell that uses a thin crystal to simultaneously achieve high-contrast (greater than 1800:1) and large-angular acceptance (greater than 7 mrad for a 5-mm aperture). A KD*P crystal was used in a longitudinal-mode configuration with plasma discharges forming low-resistance, high optical transmission electrodes to couple the switching voltage. Rise times of the switched optical pulse of the order of 500 ps were observed. Characterization of the device in the near and far fields was also performed.