Phosphate sources and their suitability for remediation of contaminated soils

Phosphate minerals and specifically apatite show promise for environmental cleanup because they can form stable compounds with a wide range of cationic contaminants. However, phosphate minerals naturally accumulate some heavy metals that may cause additional contamination of the environment if used improperly. Nine commercially available phosphate materials were evaluated for remediation of contaminated soil based on solubility, concentration of metal/metalloid impurities, and leachability of impurity metal/metalloids. The phosphate materials consisted of three groups: processed (i.e., fertilizers), mined (rock phosphates from different formations), and biogenic (ground fish bone). Processed and mined rock phosphates contained relatively high total concentrations of As, Co, Cr, and Cu but did not exceed the RCRA toxicity characteristic leaching procedure (TCLP) limits. Biogenic apatite contained much lower metal concentrations than processed and mined rock phosphate and was appreciably more soluble. By combining biogenic and mined phosphate it is possible to obtain a wide range of phosphate release rates, permitting rapid immobilization of contaminants while providing a slow release of phosphate for continued long-term treatment.     

Fractal Study on Raceway Boundary

  The raceway has been studied extensively both theoretically and experimentally. The raceway boundary is coarse and fragmentary, but all of previous studies are based on Euclidean geometry, which regards the dimension of raceway as an integer. The fractal method of calculating raceway size, which describes boundary with extremely irregular or fragmentary characteristic, is brought forward in physical model. The fractal theory is used to calculate the fractal dimension of raceway boundary and the precise surface area of ellipsoidal raceway boundary. The result shows that the surface area based on fractal is larger than that based on Euclidean. And the surface area increases with the rise of blowing rate.     

Impact factors of fractal analysis of porous structure

Characterization of pore structure is one of the key problems for fabrication and application research on porous materials. But, complexity of pore structure makes it difficult to characterize pore structure by Euclidean geometry and traditional experimental methods. Fractal theory has been proved effective to characterize the complex pore structure. The box dimension method based on fractal theory was applied to characterizing the pore structure of fiber porous materials by analyzing the electronic scannin...     

固定化乳酸菌发酵番茄饮料工艺研究

以番茄汁为主要原料,研究了用海藻酸钠包埋乳酸菌发酵番茄饮料的最佳工艺.研究结果表明,固定化乳酸菌发酵番茄饮料的最佳工艺条件为:海藻酸钠溶液浓度为1.5%,胶珠直径2～3mm;接种量6%,发酵温度33℃,番茄汁初始pH5.0,发酵时间36h,接着添加7%白砂糖、0.005%黄原胶和0.02%CMC-Na,以使感官指标达到最佳.连续发酵结果表明,固定化乳酸菌发酵番茄饮料可连续使用7次.     

Nitrogen-oxygen co-doped corrugation-like porous carbon for high performance supercapacitor

Nitrogen-oxygen co-doped corrugation-like porous carbon (NO-PC) has been developed by direct pyrolysis of formaldehyde-melamine polymer containing manganese nitrate. The melamine, formaldehyde and manganese nitrate act as nitrogen, oxygen source and pore-foaming agent, respectively. NO-PC exhibits favorable porous architecture for efficient ion transfer and moderate heteroatom doping for additional pseudocapacitance, which synergistically enhances the electrochemical performance of the NO-PC-based supercapacitor. The electrode delivers specific capacitance of 240 F/g at 0.3 A/g when tested in 6 mol/L KOH electrolyte, good rate capability (capacitance retention of 83.3% at 5 A/g) as well as stable cycling performance (capacitance remains ~96% after 10000 cycles at 3 A/g). The facile synthesis with unique architecture and chemistry modification offers a promising candidate for electrode material of energy storage devices.     

Digital Instruments-扫描探针显微镜(SPM)的世界开拓者

<正> 1987年,两位研究人员带着一个简单的目标开创了DI公司——制造大量操作简便的Scan-ning Probe Microscope(SPM),使科学家和工程师们能够对以前无法观察到的纳米尺度的物质表面结构及特性进行成像和探索。他们成功地制造了世界上第一台商用STM,并于同年生产出第一台Nanoscope,此后又在1989年推出第一台AtomicForce Microscope(AFM),为非导电性材料的深入     

Thermal denaturation and aggregation of Myosin subfragment 1 isoforms with different essential light chains

We compared thermally induced denaturation and aggregation of two isoforms of the isolated myosin head (myosin subfragment 1, S1) containing different "essential" (or "alkali") light chains, A1 or A2. We applied differential scanning calorimetry (DSC) to investigate the domain structure of these two S1 isoforms. For this purpose, a special calorimetric approach was developed to analyze the DSC profiles of irreversibly denaturing multidomain proteins. Using this approach, we revealed two calorimetric domains in the S1 molecule, the more thermostable domain denaturing in two steps. Comparing the DSC data with temperature dependences of intrinsic fluorescence parameters and S1 ATPase inactivation, we have identified these two calorimetric domains as motor domain and regulatory domain of the myosin head, the motor domain being more thermostable. Some difference between the two S1 isoforms was only revealed by DSC in thermal denaturation of the regulatory domain. We also applied dynamic light scattering (DLS) to analyze the aggregation of S1 isoforms induced by their thermal denaturation. We have found no appreciable difference between these S1 isoforms in their aggregation properties under ionic strength conditions close to those in the muscle fiber (in the presence of 100 mM KCl). Under these conditions kinetics of this process was independent of protein concentration, and the aggregation rate was limited by irreversible denaturation of the S1 motor domain.     

Minor components in the sex pheromone of legume podborer: Maruca vitrata development of an attractive blend

The legume podborer, Maruca vitrata (syn. M. testulalis) (F.) (Lepidoptera: Pyralidae) is a pantropical pest of legume crops. Sex pheromone was collected by gland extraction or trapping of volatiles from virgin female moths originating in India, West Africa, or Taiwan. Analysis by GC-EAG and GC-MS confirmed previously published findings that (E,E)-10,12- hexadecadienal is the most abundant EAG-active component with 2–5% of (E,E)-10,12-hexadecadienol also present. At least one other EAG response was detected at retention times typical of monounsaturated hexadecenals or tetradecenyl acetates, but neither could be detected by GC-MS. Laboratory wind-tunnel bioassays and a field bioassay of blends of (E,E)-10,12-hexadecadienal with (E,E)-10,12-hexadecadienol and a range of monounsaturated hexadecenal and tetradecenyl acetate isomers indicated greatest attraction of males was to those including (E,E)-10,12-hexadecadienol and (E)-10-hexadecenal as minor components. In subsequent trapping experiments in cowpea fields in Benin, traps baited with a three-component blend of (E,E)-10,12-hexadecadienal and these two minor components in a 100:5:5 ratio caught significantly more males than traps baited with the major component alone, either two-component blend, or virgin female moths. Further blend optimization experiments did not produce a more attractive blend. No significant differences in catches were found between traps baited with polyethylene vials or rubber septa, or between lures containing 0.01 and 0.1 mg of synthetic pheromone. Significant numbers of female M. vitrata moths, up to 50% of total catches, were trapped with synthetic blends but not with virgin females. At present there is no clear explanation for this almost unprecedented finding, but the phenomenon may improve the predictive power of traps for population monitoring.     

Application and Validation of a Multi-block Constitutive Model at Landslides of the Wenchuan Earthquake （特约稿）

A multi-block model and a corresponding computer program have been developed which predict the kinematics of landslides. Furthermore, a unique event for studying different models simulating the triggering and movement of landslides is the 2008 Wenchuan earthquake in the mountainous region in Sichuan Province of China, which caused a large number of rapid landslides. The purpose of the paper is two-fold:(a) to propose and incorporate into the multi-block model constitutive relations predicting soil response along slip surfaces, and (b) to apply the multi-block model with the constitutive relations at landslides triggered by the Wenchuan earthquake. The proposed constitutive equations predict the shape of the shear stress-displacement response measured in ring shear tests. In the application, four landslides caused by the Wenchuan earthquake were considered. Only in one of these landslides the shear resistance-displacement response along the slip surface has been measured in laboratory tests. At this landslide, the triggering and movement of the landslide was predicted. In the other landslides, back analyses were performed and it was observed that the multi-block model predicted reasonably well the final configuration of all slides. In addition, as the measured and back-estimated total friction angle of all landslides was less than 18°, and the materials along the slip surface were sandy, it is inferred that some, or all of the slip surface during these slides was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and movement of these landslides. Concluding, the paper (A) proposed and validated a multi-block constitutive model which can be applied to predict the triggering and movement of earthquake-induced slides and (B) by analyzing four landslides of the 2008 Wenchuan earthquake, it concludes that some, or all of the slip surface during these slides, was sheared in an undrained manner and excess pore pressures generated during sliding played a key role in the triggering and movement of these landslides.     

激光存储器——目前状况和将来的发展

未来的计算机存储器是使用莱塞光束和全息照相作为大容量的存储器。其主要优点是,能在较小的存储器上实现高的信息写入密度,消除了机械的磨损和损伤,並具有高速特性。