Unified framework for microstruture evolution and property quantification

In this study, a novel unified framework for the study of both microstructural evolution and the mechanical property quantification is proposed. The multistate Potts model is used to simulate the microstructural evolution, whereas a volume-compensated particle method (VCPM) is used for the mechanical property quantification of the steady state microstructure. The VCPM proposed by Chen and colleagues was originally developed for the investigation of the fracture phenomenon of solid materials. The model was also successfully extended to study the elastoplastic properties of solids by introducing a volume conservation scheme. In the VCPM framework, the domain of interest is discretized into regular unit cells according to the triangle and square packing for 2D and simple cubic, body centered cubic and face-centered cubic packing for 3D. Both local pair-wise and nonlocal multibody potential are proposed to account for the interactions between particles. The multistate Potts models have been used extensively to model a variety of microstructural phenomena, such as the grain growth in a single or multiple-phase system, recrystallization, solidification, and many others. The space-filling array of regular cells is used to represent the Potts domain which is the same as the one used in VCPM. The microstructure evolves such that the system Hamiltonian is minimized. To consider different external effects on the states of the microstructure, different energy terms can be introduced into the system Hamiltonian, such as surface energy to account for the interface effect and strain energy for the grain orientation. Once the final steady state is obtained using the multistate Potts model, usually some other techniques, such as FEM, are used to calculate the effective properties of the microstructural system. It requires the mapping between the FEM meshes and the microstructure. The mapping is very difficult, especially for the interface mapping when the microstructure is very complex. In this study, the VCPM is coupled with the multistate Potts model to simulate the microstructural evolution and quantify the effective mechanical properties of the system within one framework. No mapping between these two models is required since they share the same underlying domain structures. The nonlocal potential proposed in VCPM is introduced into the multistate Potts model as an alternative of the original strain energy term. By doing this, effective simulation of the microstructure evolution for multiple-phase materials can be achieved. Given the final microstructure, the VCPM simulation is carried out to calculate the effective properties of the obtained system

Real-time threshold voltage and mobility compensation for large-size AMOLED displays

A new real-time compensation method of Vth and fj for large size AMOLED display named linear charging sensing (LCS) has been developed. This compensation method can accomplish the Vth and и sensing within tens or hundreds microseconds which can realize the sensing for all the pixels of FHD (1920* 1080) AMOLED display within one frame time in theory. By simulation analysis, LCS compensation method has very high accuracy for Vth sensing with a tiny error of 0.07V for AVth=0.5V and no error for AVth=-0.5V. Further verified in FHD AMOLED panel, the method can make a great improvement for image sticking and luminance uniformity

Protective effect of delayed remote limb ischemic postconditioning: role of mitochondrial KATP channels in a rat model of focal cerebral ischemic reperfusion injury

Delayed remote ischemic postconditioning (DRIPost) has been shown to protect the rat brain from ischemic injury. However, extremely short therapeutic time windows hinder its translational use and the mechanism of action remains elusive. Because opening of the mitochondria KATP channel is crucial for cell apoptosis, we hypothesized that the neuroprotective effect of DRIPost may be associated with KATP channels. In the present study, the neuroprotective effects of DRIPost were investigated using adult male Sprague-Dawley rats. Rats were exposed to 90 minutes of middle cerebral artery occlusion followed by 72 hours of reperfusion. Delayed remote ischemic postconditioning was performed with three cycles of bilateral femoral artery occlusion/reperfusion for 5 minutes at 3 or 6 hours after reperfusion. Neurologic deficit scores and infarct volumes were assessed, and cellular apoptosis was monitored by terminal deoxynucleotidyl transferase nick-end labeling. Our results showed that DRIPost applied at 6 hours after reperfusion exerted neuroprotective effects. The KATP opener, diazoxide, protected rat brains from ischemic injury, while the KATP blocker, 5-hydroxydecanote, reversed the neuroprotective effects of DRIPost. These findings indicate that DRIPost reduces focal cerebral ischemic injury and that the neuroprotective effects of DRIPost may be achieved through opening of KATP channels

Generation of highly retrievable atom photon entanglement with a millisecond lifetime via a spatially multiplexed cavity

Qubit memory that is entangled with photonic qubit is the building block for long distance quantum repeaters. Cavity enhanced and long lived spin wave photon entanglement has been demonstrated by applying dual laser beams onto optical-lattice atoms. However, owing to cross readouts by two beams, retrieval efficiency of spin wave qubit is decreased by one quarter compared to that of single mode spin wave at all storage times. Here, by coupling cold atoms to two modes of a polarization interferometer based cavity, we achieve perfect qubit retrieval in cavity enhanced and long lived atom photon entanglement. A write laser beam is applied onto cold atoms, we then create a magnetic field insensitive spin wave qubit that is entangled with the photonic qubit encoded onto two arms of the interferometer. The spin wave qubit is retrieved by a read beam, which avoids the cross readouts. Our experiment demonstrates 540$\mu$s storage time at 50% intrinsic qubit retrieval efficiency, which is 13.5 times longer than the best reported result

Submarine fresh groundwater discharge into Laizhou Bay comparable to the Yellow River flux

Near- and off-shore fresh groundwater resources become increasingly important with the social and economic development in coastal areas. Although large scale (hundreds of km) submarine groundwater discharge (SGD) to the ocean has been shown to be of the same magnitude order as river discharge, submarine fresh groundwater discharge (SFGD) with magnitude comparable to large river discharge is never reported. Here, we proposed a method coupling mass-balance models of water, salt and radium isotopes based on field data of 223Ra, 226Ra and salinity to estimate the SFGD, SGD. By applying the method in Laizhou Bay (a water area of 6000 km2), we showed that the SFGD and SGD are 0.57 - 0.88 times and 7.35 - 8.57 times the annual Yellow River flux in August 2012, respectively. The estimate of SFGD ranges from 4.12 x 10^7 m3/d to 6.36 x 10^7 m3/d, while SGD ranges from 5.32 x 10^8 m3/d to 6.20 x 10^8 m3/d. The proportion of the Yellow River input into Laizhou Bay was less than 14% of the total in August 2012. Our method can be used to estimate SFGD in various coastal waters

Down-Regulation of MiR-127 Facilitates Hepatocyte Proliferation during Rat Liver Regeneration

Liver regeneration (LR) after partial hepatectomy (PH) involves the proliferation and apoptosis of hepatocytes, and microRNAs have been shown to post-transcriptionally regulate genes involved in the regulation of these processes. To explore the role of miR-127 during LR, the expression patterns of miR-127 and its related proteins were investigated. MiR-127 was introduced into a rat liver cell line to examine its effects on the potential target genes Bcl6 and Setd8, and functional studies were undertaken. We discovered that miR-127 was down-regulated and inversely correlated with the expression of Bcl6 and Setd8 at 24 hours after PH, a time at which hypermethylation of the promoter region of the miR-127 gene was detected. Furthermore, in BRL-3A rat liver cells, we observed that overexpression of miR-127 significantly suppressed cell growth and directly inhibited the expression of Bcl6 and Setd8. The results suggest that down-regulation of miR-127 may be due to the rapid methylation of its promoter during the first 24 h after PH, and this event facilitates hepatocyte proliferation by releasing Bcl6 and Setd8. These findings support a miRNA-mediated negative regulation pattern in LR and implicate an anti-proliferative role for miR-127 in liver cells

Noise mitigation in low leakage MTCMOS circuits

The critical dimensions of semiconductor devices are miniaturized with complementary metal-oxide-semiconductor (CMOS) technology scaling. Increasing numbers of transistors are crammed onto integrated circuits, thereby enhancing the operating frequency and functionality. The power consumption of integrated circuits increases with larger number of transistors and higher operating frequency. Excessive power consumption is a primary hindrance to the advancement of CMOS integrated circuits. Leakage currents are important sources of power consumption in modern nanoscale CMOS integrated circuits. Suppressing subthreshold leakage currents in large scale integrated circuits is essential for achieving green computing and facilitating the proliferation of portable electronics. Multi-threshold CMOS (MTCMOS), which is also known as power/ground gating, is the most commonly used leakage power suppression technique in state-of-the-art integrated circuits. Significant power and ground distribution network noise is produced when an MTCMOS circuit block transitions from sleep mode to active mode. Mode transition noise is the most important reliability issue in MTCMOS circuits. The generation mechanisms of mode transition noise in MTCMOS circuits are explored in this dissertation. The effectiveness of different noise-aware combinational MTCMOS circuit techniques to deal with the mode transition noise phenomenon is evaluated. An intermediate relaxation mode is investigated to gradually dump the charge stored on the virtual ground wire to the real ground distribution network during the sleep to active mode transitions. Novel noise-aware sequential MTCMOS circuits are presented. A low-leakage data retention sleep mode is implemented with smaller centralized sleep transistors to suppress the mode transition noise produced during the reactivation events in sequential MTCMOS circuits. Threshold voltage tuning techniques are typically utilized for leakage power reduction or performance enhancement in integrated circuits. A new application of the threshold voltage tuning methodology is proposed to lower the reactivation noise with smaller sleep transistors and shorter reactivation delay in MTCMOS circuits. The principal mechanism of noise reduction and silicon area compaction in threshold voltage tuned MTCMOS circuits is investigated. Threshold voltage tuning is also effective in mitigating the reactivation noise in sequential MTCMOS circuits. A new dynamic forward body bias technique is presented to alleviate the mode transition noise in sequential MTCMOS circuits without sacrificing the data retention capability in low-leakage sleep mode. Sleep signal slew rate modulation is an alternative technique that is effective for suppressing the reactivation noise in MTCMOS circuits. A triple-phase sleep signal slew rate modulation technique with a novel digital sleep signal generator is proposed in this dissertation. With the new digital triple-phase sleep signal slew rate modulation technique, fast and energy efficient mode transitions are achieved with negligible reactivation noise in MTCMOS circuits. The leakage currents that are produced by on-chip memory increase the power consumption of high performance microprocessors. Furthermore, the data stability and write ability of static random-access memory (SRAM) cells are degraded with lower supply voltage, shrinking dimensions of transistors, and exacerbated process variations in each new CMOS technology generation. Compact, robust, and energy efficient memory design is pivotal in deeply scaled CMOS integrated circuits. The application of MTCMOS technique to SRAM circuits for leakage power suppression is investigated in this dissertation. Various novel asymmetrically ground-gated MTCMOS SRAM circuits are proposed for providing a low-leakage sleep mode with data retention capability. With the new asymmetrical power and ground gating techniques, the data stability is significantly enhanced during both read operations and idle status. Specialized write assist circuitry are also proposed to provide wider write voltage margins with the new memory cells

Threshold Voltage Tuning for Faster Activation With Lower Noise in Tri-Mode MTCMOS Circuits

A new threshold voltage tuning methodology is explored in this paper to minimize the peak power/ground bouncing noise with smaller sleep transistors in multi-threshold CMOS (MTCMOS) circuits. Different circuit techniques with the threshold voltage tuning strategy lower the activation noise, the activation delay, and the size of the additional sleep transistors by up to 27.76%, 32.66%, and 85.71%, respectively, as compared to a previously published noise-aware MTCMOS circuit with standard zero-body-biased high threshold voltage sleep transistors in a UMC 80-nm CMOS technology