The Design and Analysis of Successive Decoding for Channels With Memory

Many communication systems have to cope with channels with unknown and time-varying state, including fading, inter-symbol interference, and more general finite-state Markov channels. This work proposes a novel successive decoding paradigm, or more specifically, a time-multiplexed transmission of multiple codes with multi-staged reception, to address the two fundamental aspects of these channels: the estimation of achievable information rate and the design of a practical coding system. The first part of this work shows that successive decoding under a deep rectangular interleaver essentially decomposes the original channel into a set of asymptotic memoryless subchannels with semi-infinite preceding training symbols. The achievable information rate of the original channel under a given input distribution can be efficiently computed from this set. Furthermore, the conventional coding system that separates estimation from decoding can operate on these memoryless channels without loss of mutual information. These results allow us to characterize accurately the binary-input capacity of correlated fading channels and to operate within 1.1 dB to the binary-input capacity using AWGN channel optimized LDPC codes. The second part of this work deals with the design of more practical successive decoding with a small number of levels. The main idea is to incorporate an irregular interleaving pattern and when necessary iterative estimation decoding within each level. These techniques provide a more flexible configuration of successive decoding for balancing the performance and the delay. The analysis of the achievable rate and the extrinsic information transfer (EXIT) charts are proposed for code rate allocation and for the efficient optimization of interleavers. Both the optimal random interleaver and a good construction of the deterministic interleaver are numerically shown to have performance very close to its binary-input capacity with a small number of levels.</p

Hydrogenation-Assisted Graphene Origami and Its Application in Programmable Molecular Mass Uptake, Storage, and Release

The malleable nature of atomically thin graphene makes it a potential candidate material for nanoscale origami, a promising bottom-up nanomanufacturing approach to fabricating nanobuilding blocks of desirable shapes. The success of graphene origami hinges upon precise and facile control of graphene morphology, which still remains as a significant challenge. Inspired by recent progresses on functionalization and patterning of graphene, we demonstrate hydrogenation-assisted graphene origami (HAGO), a feasible and robust approach to enabling the formation of unconventional carbon nanostructures, through systematic molecular dynamics simulations. A unique and desirable feature of HAGO-enabled nanostructures is the programmable tunability of their morphology via an external electric field. In particular, we demonstrate reversible opening and closing of a HAGO-enabled graphene nanocage, a mechanism that is crucial to achieve molecular mass uptake, storage, and release. HAGO holds promise to enable an array of carbon nanostructures of desirable functionalities by design. As an example, we demonstrate HAGO-enabled high-density hydrogen storage with a weighted percentage exceeding the ultimate goal of US Department of Energy

Hydrogenation-Assisted Graphene Origami and Its Application in Programmable Molecular Mass Uptake, Storage, and Release

The malleable nature of atomically thin graphene makes it a potential candidate material for nanoscale origami, a promising bottom-up nanomanufacturing approach to fabricating nanobuilding blocks of desirable shapes. The success of graphene origami hinges upon precise and facile control of graphene morphology, which still remains as a significant challenge. Inspired by recent progresses on functionalization and patterning of graphene, we demonstrate hydrogenation-assisted graphene origami (HAGO), a feasible and robust approach to enabling the formation of unconventional carbon nanostructures, through systematic molecular dynamics simulations. A unique and desirable feature of HAGO-enabled nanostructures is the programmable tunability of their morphology <i>via</i> an external electric field. In particular, we demonstrate reversible opening and closing of a HAGO-enabled graphene nanocage, a mechanism that is crucial to achieve molecular mass uptake, storage, and release. HAGO holds promise to enable an array of carbon nanostructures of desirable functionalities by design. As an example, we demonstrate HAGO-enabled high-density hydrogen storage with a weighted percentage exceeding the ultimate goal of US Department of Energy

Research on the Abnormal Isothermal Adsorption of Shale

The adsorption content of the shale sample and pure clay minerals decreased at a high pressure and clearly declined for pure clay minerals. With the increase in the test pressure, the degree of deviation between the gaseous phase CH₄ density increment rate and the adsorbed phase CH₄ mass increment rate decreased, which resulted in a decrease in the methane adsorption values calculated at a high pressure. As the test pressure increased, the measurement volume of the shale sample and the pure clay minerals decreased. In the adsorption measurement, the diameter of CH₄ is larger than that of He, with the development of the micropores in shale; the actual measurement volume was larger compared to that in the buoyancy measurement. Accompanied by the increase in the test pressure and adsorption, the volume of the adsorbed phase CH₄ should also be considered in the calculation performed in the adsorption measurement. All of these factors have reinforced the calculated degree of reduction of methane adsorption at a high pressure. Besides the adsorption capacities of different pure clay minerals being different, the content and types of pure clay minerals also affected the adsorption capacity of shale at a high pressure

Data_Sheet_1_Mixed-Mode Bacterial Transmission via Eggshells in an Oviparous Reptile Without Parental Care.PDF

Symbiotic microorganisms play important roles in maintaining health and facilitating the adaptation of the host. We know little about the origin and transgenerational transmission of symbiotic bacteria, especially in egg-laying species without parental care. Here, we investigated the transmission of bacterial symbionts in the Chinese three-keeled pond turtle (Mauremys reevesii), a species with no post-oviposition parental care, by evaluating contributions from potential maternal and environmental sources to eggshell bacterial communities. Using 16S rRNA amplicon sequencing, we established that the bacterial communities of eggshells were similar to those of the maternal cloaca, maternal skin, and nest soil, but distinct from those of surface soil around nest and pond water. Phylogenetic structure analysis and source-tracking models revealed the deterministic assembly process of eggshell microbiota and high contributions of the maternal cloaca, maternal skin, and nest soil microbiota to eggshell bacterial communities. Moreover, maternal cloaca showed divergent contribution to eggshell microbiota compared with two other main sources in phylogenesis and taxonomic composition. The results demonstrate a mixture of horizontal and vertical transmission of symbiotic bacteria across generations in an oviparous turtle without parental care and provide insight into the significance of the eggshell microbiome in embryo development.</p

Additional file 1 of Autologous blood patch intraparenchymal injection reduces the incidence of pneumothorax and the need for chest tube placement following CT-guided lung biopsy: a systematic review and meta-analysis

Additional file 1. Fig. S1: Sensitivity analysis of the incidence of pneumothorax

Additional file 11: of Compositional and mutational rate heterogeneity in mitochondrial genomes and its effect on the phylogenetic inferences of Cimicomorpha (Hemiptera: Heteroptera)

A series of in-house shell scripts used in this study. (TXT 664 bytes