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The trajectory tracking performance of an actual robot is usually used as an important standard to evaluate a nonlinear controller algorithm. The aim of this article is to design a new experimental robot system based on the Robot Operating System-MATLAB framework. To validate the performance, a nonlinear tracking controller includes the following features. Firstly, the surface robot model is in Lie algebra S O (3) format, which keeps the potential of cooperation control between space vehicles. Secondly, the nonlinear controller has good robustness under unknown disturbances. Thirdly, the control algorithm focuses on the practical robot, Turtlebot2. The robot system experimental results demonstrate the effectiveness of the proposed controller for trajectory tracking under unknown disturbance. The controller's potential applications include autonomous robots for indoor examination, extreme condition rescuing, and cooperation between unmanned aerial vehicle and unmanned surface vehicle autodrives. [ABSTRACT FROM AUTHOR]

Understanding how metabolic reactions translate the genome of an organism into its phenotype is a grand challenge in biology. Genome-wide association studies (GWAS) statistically connect genotypes to phenotypes, without any recourse to known molecular interactions, whereas a molecular mechanistic description ties gene function to phenotype through gene regulatory networks (GRNs), protein-protein interactions (PPIs) and molecular pathways. Integration of different regulatory information levels of an organism is expected to provide a good way for mapping genotypes to phenotypes. However, the lack of curated metabolic model of rice is blocking the exploration of genome-scale multi-level network reconstruction. Here, we have merged GRNs, PPIs and genome-scale metabolic networks (GSMNs) approaches into a single framework for rice via omics’ regulatory information reconstruction and integration. Firstly, we reconstructed a genome-scale metabolic model, containing 4,462 function genes, 2,986 metabolites involved in 3,316 reactions, and compartmentalized into ten subcellular locations. Furthermore, 90,358 pairs of protein-protein interactions, 662,936 pairs of gene regulations and 1,763 microRNA-target interactions were integrated into the metabolic model. Eventually, a database was developped for systematically storing and retrieving the genome-scale multi-level network of rice. This provides a reference for understanding genotype-phenotype relationship of rice, and for analysis of its molecular regulatory network.

Understanding farmers' participation is crucial for achieving an effective impact on rural living environmental governance and promoting sustainable development. Taking Sandu Town in eastern China as a case study, in-depth semi-structured interviews with farmers, village cadres, and town managers were conducted in this study. Then, a conceptual framework incorporating comprehensive factors is presented to analyze the driving factors and mechanisms of farmer participation in rural domestic waste management. The results show that farmers' participation in pro-environmental actions is a response to an integrated network of both internal and external factors. Life inertia, loss of personal interests, and objective conditions are the barriers to farmers deciding to participate. Meanwhile, environmental awareness can increase farmers' internal motivations, and factors such as household benefits, social-cultural influences, and appraisal systems, including household possession protection, very low economic costs, better life experiences, demonstrations from society, "following the crowd", peer pressure, and reward and criticism measures, are the external forces that mobilize farmers to participate in rural environmental governance. Policy recommendations are proposed based on the findings. [ABSTRACT FROM AUTHOR]

In systems biology, inference of functional associations among genes is compelling because the construction of functional association networks facilitates biomarker discovery. Specifically, such gene associations in human can help identify putative biomarkers that can be used as diagnostic tools in treating patients. Although biomedical literature is considered a valuable data source for this task, currently only a limited number of webservers are available for mining gene-gene associations from the vast amount of biomedical literature using text mining techniques. Moreover, these webservers often have limited coverage of biomedical literature and also lack efficient and user-friendly tools to interpret and visualize mined relationships among genes. To address these limitations, we developed GAIL (Gene-gene Association Inference based on biomedical Literature), an interactive webserver that infers human gene-gene associations from Gene Ontology (GO) guided biomedical literature mining and provides dynamic visualization of the resulting association networks and various gene set enrichment analysis tools. We evaluate the utility and performance of GAIL with applications to gene signatures associated with systemic lupus erythematosus and breast cancer. Results show that GAIL allows effective interrogation and visualization of gene-gene networks and their subnetworks, which facilitates biological understanding of gene-gene associations. GAIL is available at . [ABSTRACT FROM AUTHOR]

Identification of cancer patient subgroups using high throughput genomic data is of critical importance to clinicians and scientists because it can offer opportunities for more personalized treatment and overlapping treatments of cancers. In spite of tremendous efforts, this problem still remains challenging because of low reproducibility and instability of identified cancer subgroups and molecular features. In order to address this challenge, we developed Integrative Genomics Robust iDentification of cancer subgroups (InGRiD), a statistical approach that integrates information from biological pathway databases with high-throughput genomic data to improve the robustness for identification and interpretation of molecularly-defined subgroups of cancer patients. We applied InGRiD to the gene expression data of high-grade serous ovarian cancer from The Cancer Genome Atlas and the Australian Ovarian Cancer Study. The results indicate clear benefits of the pathway-level approaches over the gene-level approaches. In addition, using the proposed InGRiD framework, we also investigate and address the issue of gene sharing among pathways, which often occurs in practice, to further facilitate biological interpretation of key molecular features associated with cancer progression. The R package "InGRiD" implementing the proposed approach is currently available in our research group GitHub webpage ( https://dongjunchung.github.io/INGRID/ ). [ABSTRACT FROM AUTHOR]

Multi-arm multi-stage designs, in which multiple active treatments are compared to a control and accumulated information from interim data are used to add or remove arms from the trial, may reduce development costs and shorten the drug development timeline. As such, this adaptive update is a natural complement to Bayesian methodology in which the prior clinical belief is sequentially updated using the observed probability of success. Simulation is often required for planning clinical trials to accommodate the complexity of the design and to optimize key design characteristics. This paper addresses two key limiting factors in simulations, namely the computational burden and the time needed to obtain results. We first introduce a generic process for simulating Bayesian multi-arm multi-stage designs with binary endpoints. Then, to address the computational burden and time, we optimize the method for calculating the posterior probability and posterior predictive probability of success. [ABSTRACT FROM AUTHOR]

Abstract China's fallow compensation policy is known to be relatively simple and unsophisticated, and in much need of improvement. In seeking such improvement, this paper designed some alternative compensation schemes that include recultivation insurance, priority right of participation in the fallowing work or free agricultural inputs, but lower income subsidy, and reported on a choice experiment of alternatives with 421 peasant-farming households in Chaling County, Hunan Province – a fallow area of heavy-metal-contaminated farmland. A mixed logit model was used to compare the choices made between pilot and non-pilot villages, and the influencing factors involved. The results showed that most farmers preferred the alternative compensation schemes to the current policy, and income subsidy was not the only factor affecting their choices, which indicated recultivation insurance and a longer period of free agricultural inputs were also important. However, the preferences differed between pilot and non-pilot village farmers, in which the pilot village farmers were more willing to accept less income subsidy in favor of increased recultivation insurance and an extended period of free agricultural inputs. By contrast, non-pilot village farmers preferred to adopt an alternative compensation scheme with a priority right of participation in the fallowing work and high level of income subsidy. The possible reason for the differences was that the publicity and training activities provided by the government had changed the preferences of pilot village farmers. Generally, the effects of various forms of economic compensation and single cash payment were different about fallow compensation policy, and the preferences of farmers from different backgrounds might also vary from person to person. Different regions needed to design the fallow compensation policy according to practical problems in the use of farmland and farmers' preferences. Highlights • Choice experiment is used to compare the preference between pilot and non-pilot village farmers. • The effects of various forms of economic compensation and single cash payment are different. • The preferences of farmers from different backgrounds may be different. • Extra attention should be given to works such as fallow publicity and training. [ABSTRACT FROM AUTHOR]

A calix[4]arene (C4A)-functionalized (phthalocyaninato)(porphyrinato) europium(iii) triple-decker compound (Pc)Eu(Pc)Eu[T(C4A)PP] (1) is firstly designed, synthesized and prepared into well-organized films using a simple solution-processing quasi-Langmuir-Shäfer (QLS) method. The QLS film of 1 on an ITO (film 1/ITO) electrode, serving as a host–guest electrochemical recognition layer, is able to establish specific responses/interactions toward organic molecules with biological and drug interest including dopamine (DA), uric acid (UA), tyrosine (Tyr), tryptophan (Trp) and Acetaminophen (APAP), depending mainly on the matching degree of molecular dimensions between the analytes and the C4A cavity in addition to their chemical nature. More significantly, the film 1/ITO electrode shows a wide linear range of electrochemical detection (from 0.1 to 100 μM) to DA and APAP, with a high sensitivity of 53.0 and 94.3 μA mM−1 and a very low detection limit of 25 and 11 nM for DA and APAP, respectively, representing the best result among the nonenzymatic organic semiconductor-based biosensors. In particular, the film 1/ITO electrode exhibits excellent stability, reproducibility, high selectivity, and anti-interference nature for the detection of both DA and APAP, indicating the great potential of calix[n]arene macrocycle-modified tetrapyrrole rare earth sandwich compounds in the field of ultrasensitive and specific nonenzymatic sensors. [ABSTRACT FROM AUTHOR]

Two photon absorption (2PA) is of great interest across many disciplines and there has been a large effort to increase the two-photon cross section (σ2) via synthetic modification, especially by enhancing intramolecular charge-transfer (ICT). This work takes the previously studied (7-benzothiazol-2-yl-9,9-diethylfluoren-2-yl)diphenylamine (AF240), an asymmetric D–π–A chromophore, and intentionally appends a functional group (–OH, AF240-OH or –OCH3, AF240-OMe) to the 6-position of the fluorenyl π-bridge of the new chromophores. Electrochemical results in both dichloromethane and acetonitrile support stabilization of the highest occupied molecular orbital in the derivatives due to inductive electron donating effects of the hydroxy and methoxy groups. The lowest unoccupied molecular orbital is stabilized via intramolecular hydrogen bonding to the benzothiazole moiety in the case of AF240-OH. As previously observed for AF240, the steady-state emission spectra show significant solvatochromism as they broaden and red shift with increasing solvent polarity. The fluorescence lifetimes and quantum yields show that the non-radiative rate constant is increased for AF240-OH in all solvents, especially in nonpolar media. The results suggest there is forced intramolecular hydrogen bonding to the benzothiazole in nonpolar solvents because the solvent poorly solubilizes the hydroxy group. This increases the non-radiative decay rate constant (knr) via additional vibrational decay pathways. While not as dramatic, the increase in knr in polar solvents supports some deactivation via hydrogen bonding to the solvent. Steric effects are also observed in the methoxy derivative, which inhibits planarization of the benzothiazole with the fluorene, increasing the energy of the excited state. Ultrafast transient absorption spectroscopy in tetrahydrofuran solution supports stabilization of the excited state in a few ps as solvent and structural reorganizations occur. In the case of AF240-OH, no evidence of proton transfer is observed. The decrease in emission energies in the case of AF240-OH support increased ICT driven by higher degree of coplanarity and the quinoidal structure in the excited state. However, a moderate increase in the intrinsic 2PA cross-section is resulted. It is likely because of the two possible and competing solvent-stabilized ICT processes (PICT and TICT) in AF240-OH. Nevertheless, the strategic presence of a hydroxide group capable of intramolecular hydrogen bonding in AF240-OH provides a much broader 2PA sensitivity window than AF240. [ABSTRACT FROM AUTHOR]

The maximal procedure is a restricted randomization method that maximizes the number of feasible allocation sequences under the constraints of the maximum tolerated imbalance and the allocation sequence length. It assigns an equal probability to all feasible sequences. However, its implementation is not easy due to the lack of the Markovian property of the conditional allocation probabilities. In this paper, we propose the asymptotic maximal procedure, which replaces the sequence-length-dependent conditional allocation probabilities with their asymptotic values. The new randomization procedure is compared with the original maximal procedure and few other randomization procedures with the maximum tolerated imbalance via simulations and is found to be a practical choice for future clinical trials. [ABSTRACT FROM AUTHOR]

The two-photon absorbing dye AF240 [1, (7-benzothiazol-2-yl-9,9-diethylfluoren-2-yl)diphenylamine] is modified by adding bulky alkyl groups to the diphenylamino moiety. Three new compounds are synthesized which have ethyl groups in both ortho positions of each phenyl ring (2), t-butyl groups in one ortho position of each phenyl ring (3), and t-butyl groups in the para position of each phenyl ring (4). The dyes are examined in several aprotic solvents with varying polarity to observe the effects of the sterically hindering bulky groups on the ground and excited-state photophysical properties. While the ground state shows minimal solvent dependence, there is significant dependence on the fluorescence quantum yield and lifetime, as well as the excited-state energy levels. This effect is caused by the formation of an intramolecular charge-transfer (ICT) state, which is observed in the solvents more polar than n-hexane and supported by TD-DFT calculations. Electronic effects of ortho or para alkyl substitution should be similar, yet drastic differences are observed. A red shift in the fluorescence maximum is observed in 4 relative to 1, yet a blue shift occurs in 2 and 3 because the substituents at the sterically sensitive ortho-positions inhibit excited-state geometric relaxation and result in less ICT character than 1. Coupled with theoretical calculations, the data support a planar ICT (PICT) excited state where the diphenylamino nitrogen in an sp2-like geometry is integral with the plane containing the fluorene and benzothiazole moieties. Ultrafast transient absorption experiments show that ICT occurs rapidly (＜150 fs) followed by geometric and solvent relaxation in ∼1–4 ps to form the PICT or solvent-stabilized ICT (SSICT) state. This relaxation is not observed in non-polar n-hexane because the solvent dependent ICT state energy lies higher than the locally-excited (LE) state. Finally, formation of a triplet state (T1) is only efficiently observed in n-hexane for all four dyes. [ABSTRACT FROM AUTHOR]

Two series of new Schiff base compounds were synthesized. For Schiff base compounds with a pyridine nitrogen atom in 4-position (7a–e), their supramolecular hydrogen bonding complexes show good liquid crystal properties. However, no liquid crystal property is observed for8a–e. Results of theoretical calculations demonstrate that it is the intermolecular hydrogen bond of Schiff base compounds (8a–e) that prevents the formation of supramolecular hydrogen bonding. The Schiff base compounds, with terminal alkoxy chains, can recognize Cu2+selectively with a color change. Nevertheless, others cannot recognize Cu2+. [ABSTRACT FROM AUTHOR]

Summary: Integration of genetic studies for multiple phenotypes is a powerful approach to improving the identification of genetic variants associated with complex traits. Although it has been shown that leveraging shared genetic basis among phenotypes, namely pleiotropy, can increase statistical power to identify risk variants, it remains challenging to effectively integrate genome-wide association study (GWAS) datasets for a large number of phenotypes. We previously developed graph-GPA, a Bayesian hierarchical model that integrates multiple GWAS datasets to boost statistical power for the identification of risk variants and to estimate pleiotropic architecture within a unified framework. Here we propose a novel improvement of graph-GPA which incorporates external knowledge about phenotype-phenotype relationship to guide the estimation of genetic correlation and the association mapping. The application of graph-GPA to GWAS datasets for 12 complex diseases with a prior disease graph obtained from a text mining of biomedical literature illustrates its power to improve the identification of risk genetic variants and to facilitate understanding of genetic relationship among complex diseases. [ABSTRACT FROM AUTHOR]

The influence of a variety of factors on the photomechanical output of azo-CP2- xx systems is studied, primarily focusing on a sample with a higher crosslink density (30 mol%) and two new, structurally related crosslinked polyimides with modified backbone flexibility/rigidity. This work elucidates the strong coupling between geometrical considerations (reciprocal aspect ratio of cantilever) and the visualized mechanical response (e.g., flexural-torsional response of a cantilever). [ABSTRACT FROM AUTHOR]

A series of poly(arylene ether)s, (PAEs), carrying a pendant diphenyl phosphoryl group were prepared via the nucleophilic aromatic substitution (NAS) reactions of 3,5-difluorotriphenylphosphine oxide, 6. The difluoro monomer 6 was synthesized via two-step reaction sequence and subsequently characterized by 1H, 13C, 19F, and 31P NMR spectroscopy, GC/MS, and elemental analysis. The reactivity of the electrophilic sites in 6, activated by only a diphenylphosphoryl group located in the meta-position, in 6 was probed via NMR spectroscopy and model reactions and was determined to be sufficient to undergo typical NAS reactions. High molecular weight, amorphous, organic soluble poly(arylene ether)s, bearing a pendant diphenylphosphoryl group, were prepared via the reaction of 6 with a variety of bis-phenols under typical NAS conditions. The poly(arylene ether)s were characterized for structure via the use of 1H, 13C, and 31P NMR spectroscopy while their thermal properties were evaluated using DSC and TGA analysis. The glass transition temperatures ( Tg) of the synthesized PAEs ranged from 143 to 175 °C, while their 5% weight loss temperatures ranged from 467 to 510 °C under nitrogen and from 470 to 526 °C in air. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 [ABSTRACT FROM AUTHOR]

An alternative approach to an AB2 monomer, N-[3,5-bis(4-hydroxybenzoyl)benzene]-4-fluorophthalimde, 4, for hyperbranched poly(arylene ether ketone imide)s has been developed. The key steps were a para-position selective electrophilic aromatic substitution of fluorobenzene with 5-nitroisophthaloyl dichloride and a subsequent clean conversion of the aryl fluorides to phenol groups using potassium hydroxide as the nucleophile. The overall yield for the synthesis of 4 was 51.6%. [ABSTRACT FROM AUTHOR]

The requisition–compensation balance of farmlands (RCBF) is a strict Chinese policy that aims to ensure food security. However, the process of supplementing arable land has substantially damaged the ecological environment through the blind development of grasslands, woodlands, and wetlands to supplement arable land. Can arable land alone ensure food security? To answer this question, this study introduced the concepts of arable land equivalent unit (ALEU) and food equivalent unit (FEU) based on the idea of food security. Zhoushan City in Zhejiang Province, China was selected as the research area. This study analyzed the ALEU supply and demand capabilities in the study area and presented the corresponding policy implications for the RCBF improvement. The results showed that the proportion of ALEU from arable land and waters for aquaculture is from 46:54 in 2009 to 31:69 in 2015, thereby suggesting that aquaculture waters can also be important in food security. Under three different living standards (i.e., adequate food and clothing, well-off, and affluence), ALEU from arable land can barely meet the needs of the permanent resident population in the study area. However, ALEU from aquaculture waters can provide important supplementation. Therefore, we suggest that food supply capability from land types other than the arable land be taken seriously. Furthermore, RCBF can be improved with ALEU as core of the balance. [ABSTRACT FROM AUTHOR]

[Display omitted] • We evaluated urban land-use intensity from input, density and output. • The spillover effects of urban land-use intensity on CO 2 emissions were explored. • A machine learning method (BPNN) was proposed to predict CO 2 emissions. Currently, China will promote county towns' urbanization, and few studies have analyzed spatial effects of urban land-use intensity on CO 2 emissions and predicted CO 2 emissions at the county level accurately. Here, taking data from 2010 to 2015 at the county level of Zhejiang Province as an example, we analyzed the spatial effect of urban land-use intensity from three aspects of input, density and output on CO 2 emissions by the spatial Durbin model (SDM). And then a machine learning method of Back Propagation Neural Network (BPNN) was proposed to predict CO 2 emissions for 2035 nonlinearly under the different promotions of urban land-use intensity. The main result and conclusion showed that: (1) The spillover effects of urban land-use density were negatively related to CO 2 emissions, and urban land-use output intensity showed positive spillover effects on CO 2 emissions; (2) The prediction of BPNN showed that the improvement of urban land-use intensity would not be effective in CO 2 emissions reductions for southwestern counties with both low levels of urbanization and urban land-use intensity; (3) It was effective in CO 2 emissions reduction by slowing down the growth rate of urban land-use capital input intensity, especially for the northeast region which was developed by the port economy. Our study encouraged a regional differentiated urban land-use intensity improvement strategy for Zhejiang to achieve low carbon development. [ABSTRACT FROM AUTHOR]

Abstract: Two new Schiff base compounds, tailed by the fluoroalkoxy, were synthesized in a three-step process. Those supramolecular structures constructed by hydrogen bonding show good liquid crystal properties with higher clear points and wider mesomorphic phase ranges than other analogs containing a terminal alkoxy chain. Investigation of the optical textures by polarizing microscopy reveals that terminal fluorinated substituents convert the nematic phase of supramolecular hydrogen-bonding complexes with terminal alkoxy chains into the smectic A phase of those with terminal fluoroalkoxy chains. [Copyright &y& Elsevier]

In an effort to probe the influence of structural isomerism on the excited-state properties of a naphthalene-based donor-acceptor (D-A) system, four 1-naphthalenecarbonitrile compounds with amine substituents in the 2-, 3-, and 4-positions were synthesized and their photophysical properties were examined. Specifically, the molecules 2-dimethylamino-1-naphthalenecarbonitrile ( 2DA ), 2-(1-piperidinyl)-1-naphthalenecarbonitrile ( 2P ), 3-dimethylamino-1-naphthalenecarbonitrile ( 3DA ), and 4-(1-piperidinyl)-1-naphthalenecarbonitrile ( 4P ) were studied. The substitution position of the amine donor has a significant impact on both the ground-state absorption and excited-state properties of the complexes in toluene solution. The energy, band shape, and extinction coefficient of the ground-state absorption spectra are highly dependent on the substitution position of the amine donor. All of the derivatives exhibit fluorescence at room temperature. The fluorescence observed from 2DA, 2P, and 3DA demonstrates a vibronic structure with all three molecules possessing Stokes shifts on the order of 40 nm, whereas the fluorescence observed from 4P is broad and has a Stokes shift 2 times greater than the other derivatives. The fluorescence lifetimes, fluorescence quantum yields, and intersystem crossing quantum yields vary greatly with the substitution position of the amine donor. 2DA and 2P display intermediate fluorescence lifetimes (2.7 ns) and fluorescence quantum yields (0.20) while possessing the greatest intersystem quantum yield (0.80). 3DA has a much greater fluorescence lifetime (16.9 ns) and fluorescence quantum yield (0.82) at the expense of the intersystem crossing quantum yield (0.12). 4P has the shortest lifetime (0.53 ns), with the lowest fluorescence and intersystem crossing quantum yields (<0.05). The singlet-triplet energy gaps are nearly identical for 2DA, 2P, and 3DA with values on the order of 0.70 eV. This singlet-triplet gap is larger in 4P, with a calculated value of 0.94 eV. The triplet-triplet absorption spectra of 2DA, 2P, and 3DA are similar. Broad peaks in the UV and visible regions with maxima around 330 and 500 nm characterize all three spectra. The triplet excited-state extinction coefficient values for 3DA were found to be 1.5 times larger than those in 2DA and 2P. The triplet-triplet absorption spectrum of 4P is markedly different from the triplet-triplet absorption spectra of the other derivatives. The spectrum is broad, with the four local maxima observed at 374, 445, 624, and 774 nm. All four molecules display delayed fluorescence and laser-power-dependent triplet excited-state decay kinetics, indicating the involvement of triplet-triplet annihilation in the deactivation of the triplet excited states. Both the intrinsic triplet lifetimes and triplet-triplet annihilation rate constants were determined. These values are similar for all of the derivatives with triplet lifetimes on the order of 100 μs and diffusion-controlled rates of triplet-triplet annihilation.

The maximal procedure is a restricted randomization method that maximizes the number of feasible allocation sequences under the constraints of the maximum tolerated imbalance and the allocation sequence length. It assigns an equal probability to all feasible sequences. However, its implementation is not easy due to the lack of the Markovian property of the conditional allocation probabilities. In this paper, we propose the asymptotic maximal procedure, which replaces the sequence-length-dependent conditional allocation probabilities with their asymptotic values. The new randomization procedure is compared with the original maximal procedure and few other randomization procedures with the maximum tolerated imbalance via simulations and is found to be a practical choice for future clinical trials.

A facile approach was developed for preparing the multilayer hybrid films of mixed (phthalocyaninato) (porphyrinato) europium(III) triple-decker compound (Pc)Eu(Pc)Eu[trans-T(COOCH 3 ) 2 PP] (1) and graphene oxide (GO) using the solution-processing QLS method. The combination of the nature of relatively high conductivity and great surface area for GO with the electroactive and semiconductive triple-decker compound in ITO electrode renders the hybrid film excellent sensing property for H 2 O 2 , due to the optimized triple-decker molecular packing in the uniform-sized nanoparticles (ca. 70 nm) formed on the GO surface. The amperometric responses are linearly proportional to the concentration of H 2 O 2 in the range of 0.05-1800 μM with a fast response time of 0.03 s μM -1 , a low detection limit of 0.017 μM, and good sensitivity of 7.4 μA mM -1 . The present work represents the best result of tetrapyrrole-based nonenzymatic electrochemical sensor for H 2 O 2 . Nevertheless, the triple-decker/GO/ITO also shows excellent stability, reproducibility, and selectivity, indicating the great potential of electroactive tetrapyrrole rare earth sandwich compounds in combination with GO in the field of nonenzymatic electrochemical sensors.

Herein reported is a fundamentally new strategy for the design of high-power and high energy-density devices. This approach is based on the exchange of lithium ions between the surfaces (not the bulk) of two nanostructured electrodes, completely obviating the need for lithium intercalation or deintercalation. In both electrodes, massive graphene surfaces in direct contact with liquid electrolyte are capable of rapidly and reversibly capturing lithium ions through surface adsorption and/or surface redox reaction. These devices, based on unoptimized materials and configuration, are already capable of storing an energy density of 160 Wh/kg(cell), which is 30 times higher than that (5 Wh/kg(cell)) of conventional symmetric supercapacitors and comparable to that of Li-ion batteries. They are also capable of delivering a power density of 100 kW/kg(cell), which is 10 times higher than that (10 kW/kg(cell)) of supercapacitors and 100 times higher than that (1 kW/kg(cell)) of Li-ion batteries.

A supercapacitor with graphene-based electrodes was found to exhibit a specific energy density of 85.6 Wh/kg at room temperature and 136 Wh/kg at 80 °C (all based on the total electrode weight), measured at a current density of 1 A/g. These energy density values are comparable to that of the Ni metal hydride battery, but the supercapacitor can be charged or discharged in seconds or minutes. The key to success was the ability to make full utilization of the highest intrinsic surface capacitance and specific surface area of single-layer graphene by preparing curved graphene sheets that will not restack face-to-face. The curved morphology enables the formation of mesopores accessible to and wettable by environmentally benign ionic liquids capable of operating at a voltage >4 V.

The water-induced aggregation behavior of rod-coil diblock copolymers based on poly(ethylene oxide) (PEO) and poly{(+)-2,5-bis[4'-((S)-2-methylbutoxy)phenyl]styrene} (PMBPS), PEO104-b-PMBPS53, was investigated in the common solvent THF and in the selective solvent dioxane. Before adding water, PEO104-b-PMBPS53 stayed as single polymer chains no matter what conformation the PEO block took (i.e., either the random coil conformation in THF or the compact globule conformation in dioxane). The critical water content ( approximately 6 wt %) at which PEO104-b-PMBPS53 began to aggregate was also similar in both solvents, indicating that PMBPS dominated the aggregation process. However, the size, the size distribution, and the morphology of aggregates in THF/water were quite different from those in dioxane/water. Narrowly distributed spheres with Rh approximately 20 nm were observed in dioxane, whereas in THF, a bimodal distribution peaked at 3 and approximately 300 nm, was observed. The results from 2D wide-angle X-ray diffraction and polarized optical microscopy demonstrated that the PMBPS blocks packed in a parallel pattern upon aggregation in dioxane/water. The anisotropic disclike structures observed in THF/water also indicated the orientation of the PMBPS blocks upon forming aggregates in dilute solution.

Free radical polymerization of (+)-2,5-bis[4'-((S)-2-methylbutyloxy)phenyl]styrene yields a chiral polymer with memory of optical activity after the initial stereogenic center in the side group of the monomer is chemically removed.