Investigation into high-pressure behavior of MnTiO_3:X-ray diffraction and Raman spectroscopy with diamond anvil cells

The structural stability of manganese titanate MnTiO3 at high pressure was investigated by X-ray diffraction and Raman spectroscopy with diamond anvil cells. Ilmenite-type MnTiO3 is stable at least to 26.6 GPa, and lithium niobate type MnTiO3 reversibly transforms at room temperature to perovskite at 2.0 GPa. Bulk moduli （K300） of ilmenite, lithium niobate and perovskite are 174（4） GPa, 179 （8） GPa, and 208（5） GPa, respectively （at fixed first pressure derivative K＇ = 4）. The Griineisen parameter T has been estimated to be 1.28 for ilmenite and 1.75 for perovskite. In ilmenite phase, TiO6 octahedra become more regular with increasing pressure. In perovskite phase structural distortion increases with pressure increase.

Modeling and Numerical Solution of a Cancer Therapy Optimal Control Problem

A mathematical optimal-control tumor therapy framework consisting of radio- and anti-angiogenesis control strategies that are included in a tumor growth model is investigated. The governing system, resulting from the combination of two well established models, represents the differential constraint of a non-smooth optimal control problem that aims at reducing the volume of the tumor while keeping the radio- and anti-angiogenesis chemical dosage to a minimum. Existence of optimal solutions is proved and necessary conditions are formulated in terms of the Pontryagin maximum principle. Based on this principle, a so-called sequential quadratic Hamiltonian (SQH) method is discussed and benchmarked with an “interior point optimizer—a mathematical programming language” (IPOPT-AMPL) algorithm. Results of numerical experiments are presented that successfully validate the SQH solution scheme. Further, it is shown how to choose the optimisation weights in order to obtain treatment functions that successfully reduce the tumor volume to zero.

Subsolidus Phase Relations in the System MgO-SiO_2-Cr-O and Thermodynamic Properties of Related Cr^(2+)-Containing End-members

Subsolidus phase relations have been determined in the systems SiO2-Cr-O and MgO-SiO2-Cr-O in equilibrium with metallic Cr, at 1100 to 1500℃ and 0 to 2.88 GPa. The results show that there are no ternary phases in the SiO2-Cr-O system at these conditions, i.e., only the assemblage eskolaite-Cr-metal-quartz (or tridymite) is found. In the MgO-containing system, however, extensive substitution of Cr2+ for Mg is observed in (Mg, Cr2+)2SiO4 olivine, (Mg, Cr2+)2Si2O6 pyroxene, and (Mg, Cr2+)Cr2O4 spinel. Cr3+ levels in olivine and pyroxene are below detection limits. The pyroxene is orthohombic at XCrPx2+ < 0.2, monoclinic at higher XCrPx2+ . Thestructure of the spinels becomes tetragonally distorted at XCr2+Sp >0.2. The experimental datahave been fitted to a thermodynamic model, and the authors obtained the mixing parameter (W) of Mg-Cr2+ in olivine, pyroxene and spinel, and the relation between temperatures and free energies of formation for the end-members: Cr2+-olivine (Cr2SiO4), Cr2+-pyroxene (Cr2Si2O6) and Cr2+-spinel (Cr3O4).

The Plastid Envelope CHLOROPLAST MANGANESE TRANSPORTER1 Is Essential for Manganese Homeostasis in Arabidopsis

The transition metal manganese （Mn） is indispensable for photoautotrophic growth since photosystem II （PSII） employs an inorganic Mn4CaOs cluster for water splitting. Here, we show that the Arabidopsis membrane protein CHLOROPLAST MANGANESE TRANSPORTER1 （CMT1） is involved in chloroplast Mn homeostasis. CMT1 is the closest homolog of the previously characterized thylakoid Mn transporter PHOTOSYNTHESIS-AFFECTED MUTANT71 （PAM71）. In contrast to PAM71, CMT1 resides at the chloro- plast envelope and is ubiquitously expressed. Nonetheless, like PAM71, the expression of CMT1 can also alleviate the Mn-sensitive phenotype of yeast mutant qomrl. The cmtl mutant is severely suppressed in growth, chloroplast ultrastructure, and PSII activity owing to a decrease in the amounts of pigments and thylakoid membrane proteins. The importance of CMT1 for chloroplast Mn homeostasis is demonstratedby the significant reduction in chloroplast Mn concentrations in cmtl-1, which exhibited reduced Mn binding in PSII complexes. Moreover, CMT1 expression is downregulated in Mn-surplus conditions. The pam71 cmtl-ldouble mutant resembles the cmtl-f single mutant rather than pare71 in most respects. Taken together, our results suggest that CMT1 mediates Mn2 uptake into the chloroplast stroma, and that CMT1 and PAM71 function sequentially in Mn delivery to PSII across the chloroplast envelope and the thylakoid membrane.

Factors shaping community structure of endophytic fungi–evidence from the Pinus-Viscum-system

Endophytic fungal communities have been shown to be highly diverse in almost every host plant species analyzed so far.However,the factors shaping their compositions are largely unknown.To elucidate the impact of various factors,10 independent replicates of DNA extracts from each of 17 surface-sterilized leaf and stem samples were analyzed by pyrosequencing of fungal ITS1 rRNA gene amplicons.Altogether,154 fungal OTUs(operational taxonomic units),represented by 953,385 sequences,were found in at least 2 samples from Viscum album ssp.austriacum and/or its host Pinus sylvestris.Deviating from earlier,cultivation-based assessments,the communities were dominated by OTUs related to the genus Mortierella and OTUs not assignable to a certain fungal phylum.However,Ascomycota were still the most diverse group in terms of OTU richness and already hypothesized organ and host preferences of certain endophytic Xylariaceae isolated from the Pinus-Viscum-system could be confirmed.Host species and organ type were also the major factors shaping the detected fungal communities.The two plant species clearly differed according to the endophytic fungal communities,but only stems and needles of Pinus were inhabited by significantly different fungal assemblages.Interestingly,only the 1 and 3 year old stem sections differed according to the endophytic fungal community,while differently aged leaves of both plants were indistinguishable in this regard.Size of the organs had no impact on fungal communities in Pinus,but shorter internodes and smaller leaves showed at least a tendency to differ from the corresponding larger organs in Viscum.Fungal communities also differed slightly between the two sampling sites,lying 200 km apart,and between the three sampling campaigns.Because the samples were drawn within 15 days,this finding indicates that seasonal shifts clearly outweigh aging effects in host plant with perennial leaves.The results therefore provide strong evidence against a linear development of the endophytic fungal communities in Pinus sylvestris and Viscum album over the years.The communities seem to establish themselves already in the year the respective organs emerge.Further study is required to clarify whether they predominantly establish anew each year,or if the core community persists throughout subsequent years.The most abundant endophytic OTUs are known from soil and/or dead plant material and are supposed to represent latent decomposers.The study reveals for the first time that host and/or organ preferences of putatively saprotrophic fungi are predominantly responsible for compositional differences in the endophytic fungal communities between host plants and organs.While the analyses are shown to provide rather robust results,the significance of genetic abundance,as revealed by high-throughput sequencing analyses,remains an unsettled issue.This is discussed in detail,as well as the challenges in assigning taxonomic names to OTUs.

Enhanced power conversion efficiency in iridium complexbased terpolymers for polymer solar cells

By introducing various low concentrations of Iridium complexes to the famous donor polymer of PTB7-Th backbone,new heavy metal containing terpolymers have been demonstrated.When blended with PC71BM,an obvious increase of power conversion efficiency(PCE)is obtained in 1 mol%Ir containing polymer for different photovoltaic devices either using Ca or PDIN as cathode interface layers.The impact of molecular weight on the photovoltaic performance has been particularly considered by using three batches of control polymer PTB7-Th to ensure a fair and more convincing comparison.At similar molecular weight conditions(Mn:~60 kg mol−1,M_(w):100-110 kg mol^(−1)),the 1 mol%Ir containing PTB7-ThIr1/PC71BM blends exhibits enhanced PCE to 9.19%compared with 7.92%of the control PTB7-Th.Through a combination of physical measurement,such as optoelectrical characterization,GIWAXS and pico-second time-resolved photoluminescence,the enhancement are contributed from comprehensive factors of higher hole mobility,less bimolecular recombination and more efficient slow process of charge separation.

Finite morphisms of projective and K■hler manifolds

In this paper we study finite morphisms of projective and compact K■hler manifolds, in particular,positivity properties of the associated vector bundle,deformation theory and ramified endomorphisms.

The maximal size of 6-and 7-arcs in projective Hjelmslev planes over chain rings of order 9 Dedicated to Professor Feng Keqin on the Occasion of his 70th Birthday

We complete the determination of the maximum sizes of （k,n）-arcs, n ≤ 12, in the projective gjelmslev planes over the two （proper） chain rings Z9 = Z/9Z and S3 = F3[X]/（X2） of order 9 by resolving the hitherto open cases n = 6 and n = 7. Parts of our proofs rely on decidedly geometric properties of the planes such as Desargues＇ theorem and the existence of certain subplanes.

Chemical diffusion and oxygen exchange of LaNi_(0.4)Fe_(0.6)O_(3-δ)ceramics

Oxygen surface exchange and oxygen chemical diffusion coefficients of LaNi_(0.4)Fe_(0.6)O_(3-δ)ceramics are determined via conductivity relaxation method after stepwise change of temperature in the range of 700-950℃in air and Ar/O2 gas flow at oxygen partial pressures(p_(o2))of 4 Pa,18 Pa,37 Pa,47 Pa and 59 Pa.The highest conductivity(about 160 S·cm^(-1))is found at 950℃in air.No oxygen exchange(δ=0)below 700℃is observed in the investigated p_(o2) range.The oxygen exchange coefficients determined in reduction mode are higher than those determined in oxidation mode.This is explained by clusterization of oxygen vacancies on the surface of the sample investigated in oxidation mode.The opposite tendency is found for chemical diffusion coefficients.Unlike surface,the oxygen vacancies of the volume region are probably not clustered and have predetermined the higher oxygen diffusion mobility of the sample treated in oxidation mode.

On Generalised Abundance,Ⅱ

In our previous work,we introduced the Generalised Nonvanishing Conjecture,which generalises several central conjectures in algebraic geometry.In this paper,we derive some remarkable nonvanishing results for pluricanonical bundles which were not predicted by the Minimal Model Program,by making progress towards the Generalised Nonvanishing Conjecture in every dimension.The main step is to establish that a somewhat stronger version of the Generalised Nonvanishing Conjecture holds almost always in the presence of metrics with generalised algebraic singularities,assuming the Minimal Model Program in lower dimensions.