Modeling operation and microarchitecture concurrency for communication architectures with application to retargetable simulation

In multiprocessor-based system-on-chips (SOCs), optimizing the communication architecture is often as important as, if not more than, optimizing the computation architecture. While there are mature platforms and techniques for the modeling and evaluation of computation architectures, the same is not true for the communication architectures. A major challenge in modeling the communication architecture is managing the concurrency at multiple levels: at the operation level, multiple communication operations may be active at any time; at the microarchitecture level, several microarchitectural components may be operating in parallel. Further, it is important to be able to clearly specify how the operation-level concurrency maps to the microarchitectural-level concurrency. This paper presents a modeling methodology and a retargetable simulation framework which fill this gap. This framework seeks to facilitate the design space exploration of the communication subsystem through a rigorous modeling approach based on a formal concurrency model, the operation state machine (OSM). Our OSM-based modeling methodology enables the entire system including both the computation and communication architectures to be modeled in a single OSM framework. This allows us to develop a tool set that can synthesize cycle-accurate system simulators for multiprocessing-element SOC prototypes. We show that, by simulation, critical system information such as timing and communication patterns can be obtained and evaluated. Consequently, system-level design choices regarding the communication architecture can be made with high confidence in early stages of design.     

浅谈集成电路的废气处理

集成电路的工业废气有含氟化物、硫酸雾的酸性废气,含氨的碱性废气,含异丙醇、光刻胶的有机废气,含SiO_2的含尘废气,以及含硅烷、磷烷的工艺尾气等,这些工业废气中大部分成分是有毒有害的,必须进行有效的处理才能排入大气中。主要讨论上述工业废气的分类、处理方式、应用范围及应用实例等。     

Synthesis and aqueous solution behaviors of sodium sulfonate‐terminated dendritic poly(ester‐amine)

Sodium sulfonate‐terminated dendritic poly(ester‐amine) (SPEA) was synthesized by sulfonation of acrylic double bond‐terminated dendritic poly(ester‐amine) (APEA) with sodium hydrogen sulfite (NaHSO₃) in mixture of diglycol and 2‐butanone under normal pressure. The structure of SPEA was characterized by IR, ¹H‐NMR, and elemental analysis. SPEA was water‐soluble. 1.0–40.0% (mass) SPEA aqueous solutions appeared as dilatant fluid. When pH value varied from 1.5 to 12.0, the viscosity of 1–5% (mass) SPEA aqueous solutions changed very small, and the electric conductivity almost kept stable within pH 3.0–10.0. The relationship between the viscosity and the concentration of SPEA water solutions was similar to that of NaCl water solutions. The surface tension of SPEA water solutions was lower than that of polyethylene glycol 2000 water solutions with the same concentration. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Molecular packing and phase transitions of side-chain liquid crystalline polymethacrylates based on p-methoxyazobenzene

The phase structures and transition behaviors of a series of side-chain liquid crystalline (LC) polymethacrylates based on p-methoxyazobenzene (PMnAzs, n = 6, 8, 10, 12) were studied using differential scanning calorimetry, one- and two-dimensional (1D and 2D) wide-angle X-ray diffraction, and Fourier transform infrared spectroscopic experiments. The LC phase transition of PMnAz follows the sequence of smectic A (SmA) ? nematic (N) ? isotropic (I). For PM10Az and PM12Az, the transition of SmA-to-N is not complete upon heating. In the low-temperature SmA phase, the polymers adopt a fully interdigitated side-chain packing with the smectic layer period almost identical to the side-chain length. For all the four samples, the first-order diffraction of the SmA structure only renders when the temperature approaches the transition of SmA ? N, with the intensity much lower than that of the second-order diffraction. The absence of the first-order diffraction at low temperatures is ascribed to the possible matching of the electron densities between the center portion of the side-chain sublayer and the main-chain sublayer of the SmA structure. Since only the mesogens from the same main-chain sublayer can stack parallel together, the distribution of the azobenzene domains may cause some sort of density undulation within the smectic layer. Among the samples, PM6Az presents the strongest undulation with some additional orders. We also examined the annealing effect on the H-aggregation of PMnAzs. It is found that isothermal annealing at a temperature slightly higher than the T_g of PM8Az and PM10Az can significantly enhance the UV absorption at 326 nm, indicating a further development of H-aggregation. However, for PM6Az and PM12Az, the UV–vis spectrum of the annealed sample is nearly identical to that without annealing.     

Synthesis and characterization of novel copolymer containing pyridylazo-2-naphthoxyl group via reversible addition–fragmentation chain transfer (RAFT) polymerization

A novel monomer containing pyridylazo-2-naphthoxyl group, 1-(1-(4-vinylbenzyloxy)naphthalen-2-yl)-2-(pyridin-2-yl)diazene (VBNPA), was successfully synthesized and copolymerized with styrene (St) in N,N-dimethyl formamide (DMF) via reversible addition–fragmentation chain transfer (RAFT) polymerization using 2-cyanoprop-2-yl-1-dithionaphthalate (CPDN) as RAFT agent. The polymerization behavior exhibited “living”/controlled characters. The obtained copolymer, poly(St-co-VBNPA), with pre-determinable molecular weight and narrow molecular weight distribution can be used as a carrier in metal ion detection and analysis via pre-concentration technique. The copolymer–metal ion (copper (Cu) and europium (Eu)) complexes were prepared and characterized.     

Synthesis,extraction, and adsorption properties of calix[4]arene‐poly(ethylene‐glycol) crosslinked polymer

Novel calix[4]arene‐poly(ethylene glycol) crosslinked polymer (CCP) has been synthesized by the polycondensation reaction between a p‐tert‐butylcalix[4]arene derivative and dihydroxyl capped poly(ethylene glycol) (DHPEG, M_n = 1000) catalyzed by neodymium tosylate. The hydrogel, consisted of 66.9% water and 33.1% CCP, can selectively extract aromatic organic molecules from aqueous solution according to the diameter of the guest molecules, which infers that the diameter of the calix[4]arene cavity is about 5.4 Å and the conformation of calix[4]arene units altered from cone conformation to 1,3‐alternate conformation during the polycondensation reaction. Furthermore, CCP can also adsorb naphthalene from gas phase, showing much higher capacity than active carbon does, which may have some potential applications in the field of separation and environment protection. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Dispersion characterization in layered double hydroxide/Nylon 66 nanocomposites using FIB imaging

Layered double hydroxides (LDHs), a newly emerging 2D host material, consist of cationic brucite-like layers and exchangeable interlayer anions. In this work, the morphology and dispersion of LDH particles in LDH/Nylon 66 (salt) nanocomposites has been investigated using focused ion beam (FIB) techniques, transmission electron microscopy (TEM) and X-ray diffraction (XRD). The FIB images show that LDHs are present in the polymer phase dispersed to different degrees, with partial intercalation, exfoliation, and aggregation all being observed. The most even dispersion was achieved in nanocomposites with the lowest loading (0.5 wt % LDH). Residual tactoids and agglomerates were most common in the samples made with the highest concentration of LDHs studied here (5 wt %). The dispersion observed using FIB was consistent with TEM and XRD analysis, yet this technique had significant benefits in terms of time and simplicity over these “conventional” technologies. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2008     

Polymer transcrystallinity induced by carbon nanotubes

In this work, we provide the evidence of polymer transcrystallinity in the presence of carbon nanotubes (CNTs). The interfacial morphology of carbon nanotube fiber-polypropylene matrix is investigated by means of polarized optical microscopy (POM), wide-angle X-ray diffraction (WAXD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The supramolecular microstructures of polypropylene transcrystals induced by the nanotube fiber are observed in the range of isothermal crystallization temperatures from 118 °C to 132 °C. The dynamic process of transcrystallization is analyzed by using the theory of heterogeneous nucleation. Microstructure analysis shows that the nanotubes can nucleate the growth of both α- and γ-transcrystal, and α-transcrystals dominate the overall interfacial morphology. Close to the nanotube fiber surface, a cross-hatched lamellar microstructure composed of mother lamellae and daughter lamellae is observed.     

组成对MgO-ZrO2-CaO系合成料结构与性能的影响

以脱硅锆、轻烧氧化镁、消石灰为原料，进行了MgO-ZrO2-CaO系原料的合成，研究了化学组成(包括ZrO2含量、CaO／ZrO2比)，烧成温度，杂质等对合成料性能和组织结构的影响。     

Low-Temperature Annealing Effect of RF Inductor With FeNi-SiO2 Granular Film

A low-temperature annealing process in vacuum is proposed to enhance the inductance of RF inductors with FeNi-SiO₂ magnetic granular films. Due to the great improvement of soft magnetic property in the 200degC and 350degC annealed film, the inductance is enhanced by 9.6% (200degC) and 8.3% (350degC), respectively, compared with the case of as-deposited film inductor. The peak value of quality factor, which is 9.18 for the as-deposited film inductor, is also increased to 9.27 (200degC ) and 12.27 (350degC), respectively.