High tension cyclic hydrocarbons synthesized from biomass-derived platform molecules for aviation fuels in two steps

Synthesizing ring structure aviation fuels from biomass-derived platform molecules is challenging,especially for bridged ring structure aviation fuels which are typically achieved from fossil-derived chemicals.Herein,we report the synthesis of a series of ring structure biofuels in two steps by a combination of a solvent-free Michael-cyclization reaction and a hydrodeoxygenation(HDO)reaction from lignocellulosederived 5,5-dimethyl-1,3-cyclohexanedione.These biofuels are obtained with high overall yields up to 90%,which exhibit high densities of 0.81 g cm^(-3)-0.88 g cm^(-3)and high volumetric neat heat of combustion(VNHOC)values of 36.0 MJ L^(-1)-38.6 MJ L^(-1).More importantly,bridged-ring structure hydrocarbons can also be achieved in two steps by a combination of a Robinson annulation reaction and an HDO reaction to afford the final products at high overall yields up to 90%.The bridged-ring structure products have comparable high densities and high VNHOC values to the best artificial fuel JP-10(0.94 g cm^(-3)and 39.6 MJ L^(-1)).The results demonstrate a promising way for the synthesis of high-density aviation fuels with different fuel properties at high yields.

Feedback Cache Mechanism for Dynamically Reconfigurable VLIW Processors

Very Long Instruction Word （VLIW） architectures are commonly used in application-specific domains due to their parallelism and low-power characteristics. Recently, parameterization of such architectures allows for runtime adaptation of the issue-width to match the inherent Instruction Level Parallelism （ILP） of an application. One implementation of such an approach is that the event of the issue-width switching dynamically triggers the reconfiguration of the data cache at runtime. In this paper, the relationship between cache resizing and issue-width is well investigated. We have observed that the requirement of the cache does not always correlate with the issue- width of the VLIW processor. To further coordinate the cache resizing with the changing issue-width, we present a novel feedback mechanism to ＂block＂ the low yields of cache resizing when the issue-width changes. In this manner, our feedback cache mechanism has a coordinated effort with the issue-width changes, which leads to a noticeable improvement of the cache performance. The experiments show that there is 10% energy savings as well as a 2.3% cache misses decline on average achieved, compared with the cache without the feedback mechanism. Therefore, the feedback mechanism is proven to have the capability to ensure more benefits are achieved from the dynamic and frequent reconfiguration.

P-Type Chemical Doping-Induced High Bipolar Electrical Conductivities in a Thermoelectric Donor–Acceptor Copolymer

Typically,conducting polymers transfer either electrons or holes.It is rare to see high bipolar(p-and n-type)electrical conductivities within a single bulk doped organic polymer without the assistant of gate voltage.Herein,we report that FeCl3-doped solutionprocessable D–A copolymer poly(2,5-bis(2-octyldo decyl)-3,6-di(thiophen-2-yl)diketopyrrolo[3,4-c]pyrrole-1,4-dione-alt-thieno[3,2-b]thiophen)(DPPTTT)could exhibit a high p-type electrical conductivity of 130.6 S/cm and a good n-type electrical conductivity of 14.2 S/cm by engineering the doping level.