Search

The present study investigates the effect of beta grain size on the stability of the beta phase in terms of trigger stress and the resultant mechanical properties of metastable beta titanium alloy. The trigger stress has a complex U-shaped relation concerning the beta grain size, which could be due to alternant mechanisms from interface friction and elastic energy. Nevertheless, the residual stress/strain could affect the trigger stress in the small grain size scale. More interestingly, dominant deformation modes are altered by a change of grain size with predominant stress-induced martensite (SIM) at small grain size and prime dislocation at large grain size, leading to grain size-dependent tensile behaviour of a metastable beta titanium alloy.

The present study investigates the effect of beta grain size on the stability of the beta phase in terms of trigger stress and the resultant mechanical properties of metastable beta titanium alloy. The trigger stress has a complex U-shaped relation concerning the beta grain size, which could be due to alternant mechanisms from interface friction and elastic energy. Nevertheless, the residual stress/strain could affect the trigger stress in the small grain size scale. More interestingly, dominant deformation modes are altered by a change of grain size with predominant stress-induced martensite (SIM) at small grain size and prime dislocation at large grain size, leading to grain size-dependent tensile behaviour of a metastable beta titanium alloy.

The problems of stability and controllability of the finite deformation are investigated for a pre-stressed hyperelastic cylindrical tube subjected to the axial compression. The tube is assumed to be composed of an incompressible neo-Hookean material. Based on the theory of small deformation superposed on large elastic deformation, the mathematical model is formulated by a system of incremental equilibrium equations and incremental boundary conditions. Moreover, the general solutions describing the finite deformation of the tube are obtained by the form of Bessel functions. Finally, the system of nonlinear equations governing the stability of the tube are given, the criteria of the stability discussed in terms of the corresponding numerical simulations.

The use of bonding for joining composite materials in high-performance structures has increased significantly, as this joining method offers improved stress distributions and capability of joining dissimilar materials. However, the use of adhesive bonding for this purpose might lead to delamination failure, caused by peel stresses acting on the generally weaker transverse direction of the composite adherends. This work focused on improving the resistance to delamination of composite adhesive joints by using a novel composite with a reinforced high toughness resin on the surfaces. Single-lap joints using the novel composite material as adherends, were found to have 22% higher failure loads when compared with the specimens using carbon fiber reinforced polymer only adherends, with the failure mode changing from delamination of the adherends to cohesive failure in the adhesive. The lap shear strength was also close to that attained when using high strength steel adherends. A finite element analysis, using cohesive elements, was performed with the objective of reproducing the experimental results and better understanding the failure mechanism. Using this model, it has been determined that the change of failure mode and the plasticity on the surface layers are the two key factors underlying the increase in strength obtained with the novel adherends.

Background/Objectives:Prenatal growth, which is widely marked by birthweight, may have a pivotal role in affecting the lifelong risk of cardiometabolic disorders; however, comprehensive evaluation of its relations with childhood cardiometabolic risk patterns and the ethnic and gender disparities in national representative populations is still lacking. The aim of this study was to evaluate the associations between birthweight and comprehensive patterns of cardiometabolic risk in a nationally representative sample of children and adolescents.Subjects/Methods:Prospective analyses were performed using data from 28 153 children 0 to 15 years in the National Health and Nutrition Examination Survey from 1999 through 2014. We defined childhood cardiometabolic disorders using standard definitions for obesity, high blood pressure, hyperglycemia and dyslipidemia.Results:Five birthweight categories <2.5, 2.5–3.0, 3.0–3.5, 3.5–4.2 and ⩾4.2 kg accounted for 8.2%, 17.9%, 35.7%, 27.9% and 10.4% of the population, respectively. In all children, with increasing birthweight, we observed significantly increasing trends of the risk of general and central obesity (P for trend <0.01) and significantly decreasing trends of the risk of high systolic blood pressure (SBP), high HbA1c and low high-density lipoprotein cholesterol (HDL-C) (P for trend <0.05). The associations were independent of current body mass index (BMI). In addition, we found that the relations of birthweight with high waist circumference in Black children showed U-shape, as well as high SBP in Mexican and Hispanic children. Moreover, we found that the associations of low birthweight with high SBP and low HDL-C appeared to more prominent significant in boys, whereas the inverse association with high HbA1c was more evident in girls.Conclusions:Our data indicate that birthweight is significantly related to childhood cardiometabolic risk, independent of current BMI, and the associations exhibit race and gender-specific patterns.

•A novel and robust method that both enhances boiling heat transfer and suppresses film boing using the dielectrophoretic effect.•Completely bypass film boiling and switch to nucleate boiling.•Heat transfer efficiency can be adjusted dynamically during the thermal system operation.•Heat flux enhancement up to 200% can be achieved using dielectrophoretic effect.

TIM‐3–Gal‐9 negative T cell costimulation promotes hepatic homeostasis and cytoprotection against innate immune‐driven ischemia reperfusion injury in mouse liver transplants.

Ischemia-reperfusion injury (IRI), an innate immunity-driven local inflammation, remains the major problem in clinical organ transplantation. T cell immunoglobulin and mucin domain (TIM-3)–Galectin-9 (Gal-9) signaling regulates CD4+ Th1 immune responses. Here, we explored TIM-3–Gal-9 function in a clinically relevant murine model of hepatic cold storage and orthotopic liver transplantation (OLT). C57BL/6 livers, preserved for 20 h at 4°C in UW solution, were transplanted to syngeneic mouse recipients. Up-regulation of TIM-3 on OLT-infiltrating activated CD4+ T cells was observed in the early IRI phase (1 h). By 6 h of reperfusion, OLTs in recipients treated with a blocking anti-TIM-3 Ab were characterized by: (1) enhanced hepatocellular damage (sALT levels, liver Suzuki’s histological score); (2) polarized cell infiltrate towards Th1/Th17-type phenotype; (3) depressed T cell exhaustion markers (PD-1, LAG3); and (4) elevated neutrophil and macrophage infiltration/activation. In parallel studies, adoptive transfer of CD4+ T cells from naïve WT, but not from TIM-3 Tg donors, readily recreated OLT damage in otherwise IR-resistant RAG−/−test recipients. Furthermore, pre-treatment of mice with rGal-9 promoted hepatoprotection against preservation-association liver damage, accompanied by enhanced TIM-3 expression in OLTs. Thus, CD4+ T cell-dependent “negative” TIM-3 costimulation is essential for hepatic homeostasis and resistance against IR stress in OLTs.

Polymer films with patterned microstructure have been widely applied in various industrial areas such as micro reactors, chemical sensors and micro-molded template etc. In this paper, a self-supporting polymer film with regular honeycomb microstructure is fabricated by self-organization via evaporation of polyphenylene oxide (PPO) solution in which carbon disulfide is used as solvent under humid ambience. Apart from investigation of self-organization mechanism of PPO honeycomb including nucleation, growth of water droplets condensed upon liquid supporting substrate, the quantitative relationship between honeycomb microstructure and ambient conditions is built through tremendous self-organization experiments. The controllable formation of honeycomb microstructure with desirable hydrophobicity was achieved by use of built quantitative relationship. Moreover, hydrophobicity mathematical model of self-organized honeycomb thin film was proposed, and its validation was experimentally verified.

A series of new sensors (1, 2, 3 and 4) bearing aromatic hydroxyl group shows the strongest binding ability for AcO- by UV-vis, fluorescence, 1H NMR titrations and theoretical investigation. The sensitivity for AcO- can be tuned by electron push-pull properties of the substituents on the aromatic ortho position of the sensor. Especially, sensor 4 containing nitro group shows the best sensitivity. The excellent sensitivity of 4 for AcO- is attributed to the structure match of host-guest. In addition, the interacted process of host-guest accompanies color changes and can be used as new colorimetric chemosensors. Real life experimental result indicates that sensor 4 can be used to qualitatively detect the fluoride in toothpaste.

Blinking and time correlation between fluorescences of neighboring negatively charged CdSe/CdS and CdSe/ZnS colloidal quantum dots have been studied experimentally. A tendency of synchronous blinking, that is, a bunching effect, is clearly observed from two neighboring QDs with a spatial separation up to 1.1 μm. We believe that our observations will help to better understand the mechanisms for the blinking.

Wheat end-use product quality is highly influenced by the composition and quantity of high- and low-molecular-weight glutenin subunits (HMW-GS and LMW-GS). In the present study, 224 Chinese wheat cultivars and advanced lines were characterised for the HMW-GS and LMW-GS with allele-specific PCR markers and sodium-dodecyl-sulfate polyacrylamide gel electrophoresis (SDS-PAGE). The results showed that 56 cultivars (25.0%) carried the allele Glu-D1-1d(Dx5), while 80 cultivars (35.7%) with the allele Glu-B1-2a(By8) produced a 527-bp specific band. Fourteen genotypes (6.3%) with the allele Glu-B1e(Bx20) yielded a 701-bp amplicon with the marker Marand a 753-bp specific PCR fragment with the marker ZSBy9aF1/R3. Glu-B1h(Bx14+By15) was present in only 1 genotype, and 2 cultivars contained the allele Glu-B1f(Bx13+By16) identified with the marker ZSBy9F2/R2. Four genotypes (1.8%) with the allele Glu-B1-1d(Bx6) gave 695-bp and 830-bp bands, and 5 genotypes (2.2%) with the allele Glu-B1i(Bx17+By18) amplified a 659-bp fragment using the marker Bx. One hundred and six cultivars (47.3%) had the allele Glu-B1-2b(By9), amplifying a 663-bp fragment with the marker ZSBy9aF1/R3; 34 genotypes (15.8%) contained the allele Glu-B3d, generating a 662-bp PCR fragment with the marker gluB3d. Fifteen cultivars (7.0%) with the allele Glu-B3byielded 1570-bp and 750-bp PCR amplicons with the markers gluB3band gluB3bef, respectively. The allele Glu-B3hwas found in 7 cultivars, generating a 1022-bp PCR fragment with the marker gluB3h. The genotypes detected by SDS-PAGE were mostly consistent with those identified by molecular markers, confirming the utility of the molecular markers. The information for the HMW-GS and LMW-GS in Chinese wheat cultivars will be useful in wheat breeding programs.

Cytoplasmic transfer is an assisted reproductive technique that involves the infusion of ooplasm from a donor oocyte into a recipient oocyte of inferior developmental competence. Although this technique has shown some success for couples with recurrent in vitro fertilization failure, it results in mitochondrial heteroplasmy in the offspring, defined as the presence of two different mitochondrial genomes in the same individual. Because the long-term health consequences of mitochondrial heteroplasmy are unknown, there is a need for appropriate animal models to evaluate any physiological changes of dual mtDNA genotypes. This longitudinal study was designed as a preliminary screen of basic physiological functions for heteroplasmic mice (NZB mtDNA on a BALB/cByJ background). The mice were tested for cardiovascular and metabolic function, hematological parameters, body mass analysis, ovarian reserve, and tissue histologic abnormalities over a period of 15 mo. Heteroplasmic mice developed systemic hypertension that corrected over time and was accompanied by cardiac changes consistent with pulmonary hypertension. In addition, heteroplasmic animals had increased body mass and fat mass compared with controls at all ages. Finally, these animals had abnormalities in electrolytes and hematological parameters. Our findings suggest that there are significant physiological differences between heteroplasmic and control mice. Because ooplasm transfer appears to be consistently associated with mitochondrial heteroplasmy, children conceived through ooplasm transfer should be closely followed to determine if they are at risk for any health problems.

Background: Rac1 GTPase, a member of the Ras‐related Rho GTPase family, is the major Rac isoform present in platelets and has been shown to be involved in cell actin cytoskeleton reorganization and adhesion. Agonists that induce platelet secretion and aggregation also activate Rac1 GTPase, raising the possibility that Rac1 GTPase may be involved in regulation of platelet function. Objectives: To rigorously define the role of Rac1 in platelet regulation. Methods: We have used a dual approach of gene targeting in mice and pharmacologic inhibition of Rac1 by NSC23766, a rationally designed specific small molecule inhibitor, to study the role of Rac1 in platelet function. Results: Platelets from mice as well as human platelets treated with NSC23766 exhibited a significant decrease in: (i) active Rac1 species and phosphorylation of the Rac effector, p21‐activated kinase; (ii) expression of P‐selectin and secretion of adenosine triphosphate induced by thrombin or U46619; and (iii) aggregation induced by adenosine 5′‐diphosphate, collagen, thrombin and U46619, a stable analog of thromboxane A2. NSC23766 did not alter the cAMP or cGMP levels in platelets. Consistent with the requirement of Rac1 for normal platelet function, the bleeding times in Rac1–/–mice or mice given NSC23766 were significantly prolonged. Conclusions: Our data show that deficiency or inhibition of Rac1 GTPase blocks platelet secretion. The inhibition of secretion, at least in part, is responsible for diminished platelet aggregation and prolonged bleeding times observed in Rac1knockout or Rac1 inhibitor‐treated mice.

Lanzou Alkaline Stretched Noodles (LASN) was a traditional staple food in northwest China for nearly 90 years. LASN specialty wheat breeding has become an important target since 1990s. In order to discover the LASN specialty wheat quality requirement for allelic variations at Glu-3of northwest China spring wheats. Two northwest China spring wheat cultivars and 39 elite F6 breeding lines were adopted to determine the low-molecular-weight glutenin subunits (LMW-GS) composition by one step one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) basing on the protocol of Singh et al. (1991). The results showed that Glu-A3dand Glu-B3gwere correlated to high protein content, high volume of SDS-sediment and super dough strength (W). While Glu-A3awas bad to dry gluten content and SDS-sediment as well as dough properties such as dough strength (W) and dough tenacity (P). Moreover, Glu-B3jhas not significant influence on flour quality, but it has the negative effect on dough strength (W) and dough extensibility (L). As for LASN quality, Glu-A3dand Glu-B3gwere beneficial alleles and Glu-A3awas unbeneficial alleles for LASN quality.

Although the relationship between androgens and the immune system has been well established, the immunomodulatory function of different kinds of androgens on the cellular immunity remains to be defined. In the present study, the in vitro influences of testosterone, dehydroisoandrosterone and androstenedione on the Con A induced proliferation of thymocyte were determined. The results showed that both dehydroisoandrosterone and testosterone suppressed the Con A induced proliferation of thymocyte, while dehydroisoandrosterone was less potent than testosterone. In contrast, relatively high doses of androstenedione augmented the proliferative activities of thymocytes. Taken together, these data implied that small structural changes of androgens result in markedly different biological effects. These findings suggest that the balance between these steroids may be a significant determinant in maintaining immune homeostasis.

A fluoroquinolone prodrug, PA2808, was prepared and shown to convert to the highly active parent drug PA2789. In vitro and in vivo activation of PA2808 by alkaline phosphatase was demonstrated using disk diffusion and rat lung infection models. The water solubility of PA2808 showed a marked increase compared to PA2789 over a pH range suitable for aerosol drug delivery. A total of 48 analogues based on PA2789 were prepared and screened against a panel of Gram-positive and Gram-negative pathogens. Incorporating a cyclopropane-fused pyrrolidine (amine g) at C-7 resulted in some of the most active analogues.

Starting from a known linear route and a proposed convergent route, we have successfully developed a new hybrid convergent route to MIV-150 that takes advantage of the robust chemistry for the preparation of a fluoroketal and the stereospecific Negishi coupling of an iodocyclopropane moiety to a benzene ring. Stereoselective β- and cis-iodination chemistry was developed for the preparation of an enantiomerically pure iodocyclopropanecarboxylate. Following the Negishi coupling, proven chemistry from the linear route was incorporated, thus ensuring a similar high-purity profile for the final active pharmaceutical ingredient (API). In addition, we have prepared and evaluated a series of basic inorganic and organic MIV-150 salts that have drastically increased water solubility over the parent compound.

Wholly aromatic poly(aryl ethers) containing triphenylmethane and tetraphenylmethane moieties were successfully synthesized by aromatic nucleophilic substituting polycondensation from masked bisphenols and decafluorobiphenyl followed by sulfonation with chlorosulfonic acid. The sulfonation took place only at the para positions on the pendant phenyl rings due to the novel biphenol structures designed. For the synthesized polymers, the sulfonation content can be easily controlled and the water-takeup can be conveniently tailored by changing the amount of sulfonation agent. These sulfonated polymers are soluble in polar organic solvents, such as NMP, dimethylacetamide, dimethyl sulfoxide, dimethylformamide, and ethylene glycol monomethyl ether and can be readily cast into tough and smooth films from solutions. The films exhibited very high water absorption ability and superior mechanical strength. These polymers also showed high glass transition temperatures ranging from 176 to 203 °C compared with Nafion. The sulfonated polymers can be potentially used as the proton-exchange membranes for fuel cells.

In this paper, a new type of soluble polyimide/silica (PI/SiO2) hybrid was prepared by the sol−gel process. The coupling agent γ-glycidyloxypropyltrimethoxysilane (GOTMS) was chosen to enhance the compatibility between the polyimide (PI) and silica (SiO2). Furthermore, the effects of the coupling agent on the morphologies and properties of the PI/SiO2 hybrids were investigated using UV−vis and FTIR spectroscopies and SEM. The densities and solubilities of the PI/SiO2 hybrids were also measured. The results show that the size of the silica particle was markedly reduced by the introduction of the coupling agent, which made the PI/SiO2 hybrid films become transparent. The solubility of the PI/SiO2 hybrid was also improved by the coupling agent. In addition, all of these effects became even more pronounced with increased amounts of the coupling agent. The thermal properties of the compatibilized PI/SiO2 hybrids were investigated by DSC and TGA. Moreover, their mechanical properties were also characterized. The results showed that the glass transition temperatures (Tg) of the hybrids were higher than those of their counterparts without the coupling agent. The thermal stability was lowered by the addition of the coupling agent, but it was still higher than that of the pure polyimide. The compatibility of the two components was effectively improved by the coupling agent; this resulted in the markedly improved mechanical properties.

The transport rate of an organic cation, malachite green (MG), across a unilamellar bilayer (~105 nm) of the dioleoylphosphatidylglycerol (DOPG) liposome has been studied by the SHG technique. This is the first time to our knowledge that the effects of anions on molecular cation transport have been observed. Our studies show four results. First, in the presence of sodium chloride (NaCl) or sodium bromide (NaBr), the time constant for transport of MG across the DOPG bilayer increases with the increase in the concentration of the counterion (i.e., Cl^- or Br^-). Second, with the organic electrolytes, sodium citrate (NaCitrate) and sodium ethanesulfonate (NaEtSO3), the transport rate is independent of the concentration of the counterion (i.e., Citrate^- and EtSO3^-). Third, at the same counterion concentration, the transport rate depends on the species of the counterion used. The rate of MG transport is the slowest with Cl^-, faster with Br^-, and the fastest with the two organic counterions, Citrate^- and EtSO3^-. Last, at the low counterion concentration of 1mM, the transport rates of MG were found to approach the same value for the four anions. A brief discussion of a possible mechanism is presented.

The static absorption and ultrafast solvation dynamics of a tricarbocyanine dye IR144 at the silica/acetonitrile and the silica/butanol interfaces were investigated by using steady-state second harmonic generation (SHG) spectroscopy and pump−probe time-resolved SHG (TRSHG) experiments. At both interfaces, the peak wavelength for the S0 → S1 transition of adsorbed IR144 is significantly red-shifted with respect to the maximum absorption wavelength in the corresponding bulk solvent. Because IR144 is negatively solvatochromic, this shift is indicative of a smaller polarity at the interface. A theoretical model of TRSHG is discussed which allows extraction of the solvation dynamics correlation function from the time dependence of the TRSHG signal measured in the pump−probe experiment at a chosen probe wavelength. The time constant for the diffusive component of solvation at the silica/acetonitrile interface was found to be 1.05 ± 0.14 ps. It is somewhat shorter, although of the same order of magnitude, than the time constant for the diffusive solvation in bulk acetonitrile, 2.23 ps. At the silica/butanol interface, a time constant of 1.20 ± 0.15 ps was extracted, whereas in the bulk butanol, the corresponding diffusive solvation is biexponential with times of 3.5 and 33 ps.

Studies probing the molecular dynamics of C60 in various environments, and conditions, have been generating a great deal of attention since these investigations have the potential of providing baseline information that might be useful in predicting similar behavior in other members of the fullerene family. We have used ¹³C spin−lattice relaxation measurements to analyze the rotational motion of C60 in toluene-d8 and have compared these results with data obtained in carbon disulfide and 1,2-dichlorobenzene-d4. We found that the reorientational times, τc, of C60 in these solvents did not conform to conventional viscosity arguments but were better correlated to the strength of solute−solvent interactions. Consequently, our attempt at theoretically duplicating our correlation times via hydrodynamic-based models proved unsuccessful. Nevertheless, our observations suggest that the success of any future theoretical models will be critically dependent on whether solvent effects are included in the analysis of this type of motion.

A combination of pulsed THz transmission and FTIR spectroscopy was employed to measure the normalized frequency dependent absorption coefficient of HCl in spherical, dipolar, and linear solvents (CCl4, CHCl3, and alkanes, respectively) in the 0−350 cm^-1 portion of the far-infrared spectral region. The analysis applied to the measured spectra describes the interaction between the quantum mechanical rigid rotator motion of HCl and the solvent through explicit consideration of the anisotropic potential between HCl and the bath. Nominally, the theory requires two adjustable parameters to fit the solvated HCl absorbance spectra. However, a compilation of experimental results for HCl dissolved in various solvents of high symmetry reveals a quadratic dependence of one parameter, the mean square field of the bath, on solvent polarizability. It is shown that dipole−induced dipole (DID) interactions account for the observed quadratic form. This observation introduces a constraint that reduces the number of adjustable parameters so that unique values for the second fitting parameter, the exponential decay rate of the anisotropic potential time correlation function, may be extracted from the measured absorbance curves. The analysis of HCl−alkane solution spectra reveals a more subtle aspect of this dependence. Only a very weak polarizability dependence was found for solvents of large aspect ratio such as the alkanes. This difference indicates that the molecular polarizability density, not simply the molecular polarizability, dictates the strength of the solvent mean square field. Last, a simple scheme for classifying nonpolar solvents based on DID interactions between the solute and the bath is established.

Heterochromatin differentiation, including band size, sites, and Giemsa staining intensity, was analyzed by the HKG (HCl-KOH-Giemsa) banding technique in the A genomes of 21 diploid (Triticum urartu, T. boeoticum and T. monococcum), 13 tetraploid (T. araraticum, T. timopheevi, T. dicoccoides and T. turgidum var. Dicoccon, Polonicum), and 7 cultivars of hexaploid (T. aestivum) wheats from different germplasm collections. Among wild and cultivated diploid taxa, heterochromatin was located mainly at centromeric regions, but the size and staining intensity were distinct and some accessions' genomes had interstitial and telomeric bands. Among wild and cultivated polyploid wheats, heterochromatin exhibited bifurcated differentiation. Heterochromatinization occurred in chromosomes 4At and 7At and in smaller amounts in 2At, 3At, 5At, and 6At within the genomes of the tetraploid Timopheevi group (T. araraticum, and T. timopheevi) and vice versa within those of the Emmer group (T. dicoccoides and T. turgidum). Similar divergence patterns occurred among chromosome 4Aa and 7Aa of cultivars of hexaploid wheat (T. aestivum). These dynamic processes could be related to geographic distribution and to natural and artifical selection. Comparison of the A genomes of diploid wheats with those of polyploid wheats shows that the A genomes in existing diploid wheats could not be the direct donors of those in polyploid wheats, but that the extant taxa of diploids and polyploids probably have a common origin and share a common A-genomelike ancestor.

In the microsporocytes of a haploid of Trilicum monococcum(x = 7), foldback and other nonhomologous pairing was observed at pachytene. At the diplotene equivalent stage of meiosis, nonhomologous chromosomes were connected by their telomeres in associations involving two to seven chromosomes. Telomeric connections were Feulgen‐positive for DNA and were disjoined by metaphase I. These connections may have resulted from earlier base‐pairing of repeated sequences of guanine‐rich telomere overhangs of nonhomologous chromosomes. Recent molecular studies of several widely divergent organisms have shown that all telomeres of nonhomologous chromosomes in a genome are identical, and telomere structure is conserved among widely divergent eukaryotes. Chromosome distribution at anaphase I fitted theoretical expectations of random movement of each of the seven chromosomes to one or the other of the two poles as did pollen fertility (stainability) resulting from such distribution. A single bivalent in 3.78% of the metaphase I cells provided evidence for a duplication in the genome of Triticum monococcum.

Optical nonlinearities (including nonlinear absorption and nonlinear refraction) and the temporal properties of the nonlinear refraction of hypocrellin A (HA) in its resonant region have been investigated by using single-beam Z-scan and time-resolved two-color Z-scan techniques with picosecond pulses. The reverse saturable absorption effect can be attributed to the efficient absorption of excited states of both the normal and tautomeric forms, S1 and S1‘, with the contribution of S1 as the dominant mechanism. The change of the refractive index of HA increases with increasing irradiance I0 at low irradiances (&lt;5 GW/cm²), while it hardly changes with I0 at high irradiances. The explanation for such an experimental phenomenon is that the averaged population densities of both S1 and S1‘ increase with I0 at low irradiance, while those of these two states become saturated at high irradiance. The refractive nonlinearities exhibit a very slowly decaying tail, which is attributed to the contributions of S1, S1‘, and the triplet state of the normal form, T1, and is dependent on the rise times and lifetimes of these intermediate states. The kinetic model for HA allows for the determination of the absorption cross sections of the ground state of the normal form of HA S0, the ground state of its tautomer S0‘, the excited state of its tautomer S1‘, and the refractive nonlinearities of S1, S1‘, and T1. The close match between the theory and experiment not only shows the completeness of the five-level kinetic model but also demonstrates the close relationship between the optical nonlinearities of HA and the dynamics involved in excited-state intramolecular proton transfer.

We have employed the Hubbard relation to acquire semiquantitative information on the¹³C spin−lattice relaxation rate of buckminsterfullerene in CS2. We found the spin rotation mechanism to be operative and its contribution to be significant at all temperatures studied here. With the exception of values at 303 K, we found very different chemical shift and spin rotation contributions in this solvent than in 1,2-dichlorobenzene-d4. In fact, the respective contributions were reversed at 313 K. This observation indicates that solvent effects play a critical role in determining how effective these mechanisms will be in a given solvent. Three hydrodynamic-based models were applied in an attempt at theoretically describing the rotational motion of the title molecule in CS2. The Stokes−Einstein−Debye (SED) model proved superior in duplicating our experimental findings. The agreement between the SED predictions and our experimental reorientational times suggests that C60 reorients in the “stick” limit where solute−solvent velocities are predicted to be similar. We, however, believe that the velocity coherence is not due to their separate matched velocities but rather originates from the presence of intermolecular interactions.

NASICON-type lithium-ion conducting solid electrolyte for Li1+xAlxGe0.2Ti1.8-x(PO4)3 were prepared with solid-state method at 900 degC for 7 h. In this paper, we have studied the property of Li1+xAlxGe0.2Ti1.8-x(PO4)3 solid electrolyte systems with various numbers of Al replaced Ti. The highest total electrical conductivity of the sintered pellets for Li1.45Al0.45Ge0.2Ti1.35(PO4)3 at 25 degC was 1.0x10-3 S/cm, which has NASICON-type crystalline structure without impurity phase. And the sintered pellet as x=0.45 in Li1+xAlxGe0.2Ti1.8-x(PO4)3 systems also has highest relative density of 95.6% and highest three-point strength of 90 Nmm[?]2, respectively.

The advances in the Terahertz (THz) technology drive the needs for the design and manufacture of waveguide devices that integrate complex three-dimensional (3D) miniaturized components with meso- and micro-scale functional features and structures. Typical dimensions of the waveguide functional structures are in the range from 200 μm to 50 μm and dimensions decrease with the increase in the operating frequency of the waveguide devices. Technological requirements that are critical for achieving the desired microwave filtering performance of the waveguides include geometrical accuracy, alignment between functional features and surface integrity. In this context, this paper presents a novel manufacturing route for the scaled-up production of THz components that integrate computer numerical control (CNC) milling and laser micromachining. A solution to overcome the resulting tapering of the laser-machined structures while achieving a high accuracy and surface integrity of the machined features is applied in this research. In addition, an approach for two-side processing of waveguide structures within one laser machining setup is described. The capabilities of the proposed manufacturing process chain are demonstrated on two THz waveguide components that are functionally tested to assess the effects of the achieved machining results on devices' performance. Experimental results show that the proposed process chain can address the manufacturing requirements of THz waveguide filters, in particular the process chain is capable of producing filters with geometrical accuracy better than 10 μm, side wall taper angle deviation of less than 1 deg from vertical (90 deg), waveguide cavities corner radius better than 15 μm, and surface roughness (Sa) better than 1.5 μm. The manufacturing efficiency demonstrated in this feasibility study also provides sufficient evidences to argue that the proposed multistage manufacturing technique is a very promising solution for the serial production of small to medium batches of THz waveguide components. Finally, analyses of the manufacturing capabilities of the proposed process chain and the photoresist-based technologies were performed to clearly demonstrate the advantages of the proposed process chain over current waveguide fabrication solutions.

ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.