The role of microstructural evolution during spark plasma sintering on the soft magnetic and electronic properties of a CoFe–Al2O3 soft magnetic composite

Journal of Materials Science - For transformers and inductors to meet the world’s growing demand for electrical power, more efficient soft magnetic materials with high saturation magnetic...     

以太网供电技术的发展

面向以太网供电（PoE）的IEEE802．3af标准将以太网网络连接引向了一个全新的方向，即以10／100／1000Mbps数据速率一并输送DC功率。伴随PoE而出现的一组独特的问题和崭新的思维方式是许多拥有以太网设备设计经验的工程师过去所并不熟悉的。目前，PoE一般用于VoIP电话、无线接入点和安全摄像机。而随着PoE技术的进步，改进标准的呼声渐起，旨在造就新兴的应用。     

Cognitive-behavioral therapy and relationship therapy in the treatment of children referred for antisocial behavior.

112 children (aged 7-13 yrs) were randomly assigned to one of three treatments: problem-solving skills training (PSST), problem-solving skills training with in vivo practice (PSST-P), which included therapeutically planned activities to extend training to settings outside of treatment, or client-centered relationship therapy (RT). PSST and PSST-P children showed significantly greater reductions in antisocial behavior and overall behavior problems, and greater increases in prosocial behavior than RT children. These effects were evident on measures obtained immediately after treatment and at a 1-year follow-up, and on measures of child performance at home and at school. PSST-P children showed greater changes than PSST children on measures of functioning at school at posttreatment, but these differences were no longer evident at follow-up. Children in both PSST conditions showed significant reductions in deviant behavior and improvements in prosocial behavior from pretreatment to follow-up, whereas RT children tended to remain at their pretreatment level of functioning. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Nanostructured polymer blends: Synthesis and structure

Nanostructured polymer blends prepared via anionic ring opening polymerizations of cyclic monomers in the presence of a pre-made polymer melt exhibit a number of special properties over traditional polymer blends and homopolymers. Here, we report on a simple and versatile method of in situ polymerization of macrocyclic carbonates in the presence of a maleic anhydride polypropylene (mPP) matrix and a surface-active compatibilizer (i.e. PC grafted onto a mPP backbone generated in situ) to yield a micro- and nanostructured polymer blends consisting of a polycarbonate (PC) minor phase, and a polypropylene (PP) major phase. By varying the processing conditions and concentration of the macrocyclic carbonate it was possible to reduce the size of the PC dispersions to an average minor diameter of 150 nm. NMR and TEM characterizations indicate that the PC dispersions do not influence crystal content in the PP phase. Overall, the results point to a simple strategy and versatile route to new polymeric materials with enhanced benefits.     

Critical Infrastructure in the Face of a Predatory Future: Preparing for Untoward Surprise

The editors of this special issue asked Todd LaPorte to reflect on the issues that emerge from the discussions in this special issue and, more in general, from the discussions that have proliferated in the wake of recent crises and disasters. In his contribution, Professor LaPorte contemplates what political leaders can do to prepare for catastrophic surprises. A crucial initiative, he argues, would be the initiation of a public discussion about the level of distress that a society is willing to accept in the pursuit of efficient, reliable critical infrastructures.     

Molecular basis of resistance to HIV-1 protease inhibition: a plausible hypothesis

The binding thermodynamics of the HIV-1 protease inhibitor acetyl pepstatin and the substrate Val-Ser-Gln-Asn-Tyr-Pro-Ile-Val-Gln, corresponding to one of the cleavage sites in the gag, gag-pol polyproteins, have been measured by direct microcalorimetric analysis. The results indicate that the binding of the peptide substrate or peptide inhibitor is entropically driven; i.e., it is characterized by an unfavorable enthalpy and a favorable entropy change, in agreement with a structure-based thermodynamic analysis based upon an empirical parameterization of the energetics. Dissection of the binding enthalpy indicates that the intrinsic interactions are favorable and that the unfavorable enthalpy originates from the energy cost of rearranging the flap region in the protease molecule. In addition, the binding is coupled to a negative heat capacity change. The dominant binding force is the increase in solvent entropy that accompanies the burial of a significant hydrophobic surface. Comparison of the binding energetics obtained for the substrate with that obtained for synthetic nonpeptide inhibitors indicates that the major difference is in the magnitude of the conformational entropy change. In solution, the peptide substrate has a higher flexibility than the synthetic inhibitors and therefore suffers a higher conformational entropy loss upon binding. This higher entropy loss accounts for the lower binding affinity of the substrate. On the other hand, due to its higher flexibility, the peptide substrate is more amenable to adapt to backbone rearrangements or subtle conformational changes induced by mutations in the protease. The synthetic inhibitors are less flexible, and their capacity to adapt is more restricted. The expected result is a more pronounced effect of mutations on the binding affinity of the synthetic inhibitors. On the basis of the thermodynamic differences in the mode of binding of substrate and synthetic inhibitors, it appears that a key factor to understanding resistance is given by the relative balance of the different forces that contribute to the binding free energy and, in particular, the balance between conformational and solvation entropy.