Permeability of Zirconia, Hafnia, and Thoria to Oxygen

The permeability to oxygen of 4 wt% lime-stabilized zirconia and hafnia and of pure thoria was determined between 1100° and 2050°C. The permeability constant (permeability multiplied by the thickness) at 25 torr oxygen pressure is given by:
A 1/4-power oxygen pressure dependence of the permeability was found for zirconia and hafnia and a variable power dependence was found for thoria. The diffusivities for zirconia and hafnia were determined from the time dependence of permeation. These are given by:
A transport mechanism suggested for zirconia and hafnia involves migration of oxygen ion vacancies and electron holes.     

Plant Responses to Herbivory,Wounding, and Infection

Plants have various self-defense mechanisms against biotic attacks, involving both physical and chemical barriers. Physical barriers include spines, trichomes, and cuticle layers, whereas chemical barriers include secondary metabolites (SMs) and volatile organic compounds (VOCs). Complex interactions between plants and herbivores occur. Plant responses to insect herbivory begin with the perception of physical stimuli, chemical compounds (orally secreted by insects and herbivore-induced VOCs) during feeding. Plant cell membranes then generate ion fluxes that create differences in plasma membrane potential (Vm), which provokes the initiation of signal transduction, the activation of various hormones (e.g., jasmonic acid, salicylic acid, and ethylene), and the release of VOCs and SMs. This review of recent studies of plant–herbivore–infection interactions focuses on early and late plant responses, including physical barriers, signal transduction, SM production as well as epigenetic regulation, and phytohormone responses.     

Developmental, Gustatory, and Behavioral Responses of Leafroller Larvae, Choristoneura rosaceana, to Tannic Acid and Glucose

Soluble sugars are essential nutrients generally perceived as phagostimulants to most insects studied. However, tannins are known as digestibility reducers, hence deleterious to caterpillar development, and as deterrents as well. Previous work demonstrated that larvae of the polyphagous oblique-banded leafroller, Choristoneura rosaceana, performed better when reared on a control + 0.5% tannic acid diet than on the standard control diet and that larvae reared on a control + 5% glucose diet had slower development and reduced survival. This study was designed to elucidate the behavioral and neurophysiological components of the larval responses to tannic acid and glucose. C. rosaceana larvae were reared individually from the first to the sixth instar on one of four different artificial diets: (1) control; (2) control + 5% glucose; (3) control + 0.5% tannic acid; (4) control + 5% glucose + 0.5% tannic acid. After 14 days, larvae reared on the control + 5% glucose diet had not developed past the fourth instar, whereas a considerable proportion of larvae reared on the control + 0.5% tannic acid diet had already attained the pupal stage. Insects reared on the control or the control + 5% glucose + 0.5% tannic acid diet had intermediate development, with most larvae in the fifth instar. In addition, once the mid-sixth instar was reached, the feeding preferences to 25 and 300 mM glucose, 25 mM tannic acid, and 25 mM glucose + 25 mM tannic acid over water were assessed in two-choice tests. Feeding affected preference. Control-reared insects preferred feeding on treatments containing glucose and were not deterred by tannic acid. However, larvae that had been exposed to tannic acid during their development were deterred by tannic acid and their glucose discrimination was impaired. The sensitivity to glucose was also examined from neurophysiological recordings by stimulating the sugar-sensitive cell (cell 1) on the lateral styloconic sensillum of the maxillary galea with increasing concentrations of glucose (1, 10, 25, 50, 100, 200, 300, and 500 mM). We also determined whether tannic acid was phagostimulatory, since insects develop relatively quickly on a diet containing this compound, by testing 1 mM tannic acid, 1 mM tannic acid + 300 mM glucose, and 300 mM glucose on the lateral styloconic sensilla. The traces indicated that 1 mM tannic acid was not detected by any of the four chemosensory cells in these sensilla. The combination of tannic acid and glucose produced no spikes from the sugar-sensitive cell, whereas a prominent spike activity resulted with 300 mM glucose. We concluded that, although C. rosaceana larvae develop faster on a tannic acid diet, this compound is not a phagostimulant. The converse is true for glucose; i.e., it stimulates the sugar-sensitive cell in the lateral styloconica in a concentration-dependent fashion. Previous dietary experience changes the sensory and behavioral responses of C. rosaceana to glucose. Our findings imply that not all compounds that are phagostimulatory are necessarily beneficial to an insect's fitness. Therefore, developmental studies should be interpreted in conjunction with behavioral and physiological data.     

A simple,economical, and catalyst-free oxidation of thiols to disulfides

A simple, rapid, and highly efficient method for the preparation of symmetrical aliphatic, aromatic, and heteroaromatic disulfides is reported. Addition of NBS to an alkyl- or arylthiol under catalyst-free conditions in dichloromethane solution produces the corresponding disulfides in nearly quantitative yields.     

Convenient access both to highly antimalaria-active 10-arylaminoartemisinins, and to 10-alkyl ethers including artemether, arteether, and artelinate

An economical phase-transfer method is used to prepare 10-arylaminoartemisinins from DHA and arylamines, and artemether, arteether, and artelinate from the corresponding alcohols. In vivo sc screens against Plasmodium berghei and P. yoelii in mice reveal that the p-fluorophenylamino derivative 5 g is some 13 and 70 times, respectively, more active than artesunate; this reflects the very high sc activity of 10-alkylaminoartemisinins. However, through the po route, the compounds are less active than the alkylaminoartemisinins, but still approximately equipotent with artesunate.     

成虫饲料对斜纹夜蛾蛾子健康以及温度对蛹、卵生长发育的影响

以10％白糖、10％糖醋（4：1）、10％蜂蜜和10％糖蜜（1：1）为饲料喂养成虫，用低温冷藏蛹和卵块，高温处理卵块，结果表明，对蛾子寿命的影响以10％糖醋（4：1）组最差，产卵量以10％蜂蜜组相对较好，孵化率4组成虫饲料与对照CK均无显著差异，低温对蛹的羽化展翅、高温，低温对卵孵化率均有明显影响。     

Physicochemical, mineralogical, and morphological characteristics of concrete exposed to elevated temperatures

Concrete cubes prepared from ordinary Portland cement (OPC) of known chemical, mineralogical, and physical performance characteristics and fired to various temperature regimes up to 1000 °C in steps of 100 °C for a constant period of 5 h have been studied by using X-ray diffraction (XRD) and DTA/TGA to establish the effect of elevated temperatures on the mineralogical changes occurring in the hydrated phases of concrete. The changes in physical state of concrete were studied by measuring ultrasonic pulse velocity (UPV) and consequent deterioration in the compressive strength with increase in temperature. Scanning electron microscopy (SEM) studies showed distinct morphological changes corresponding to deterioration of concrete exposed to higher temperatures.     

Orientation of Sugarcane Rootstalk Borer Weevil, Diaprepes abbreviatus, to Weevil, Frass, and Food Odors

Adults of the sugarcane rootstalk borer weevil, Diaprepes abbreviatus, form aggregations on citrus trees, where they feed on new foliage. The relative roles of male and female weevils, frass, food, and combinations of these odor sources in aggregation formation were studied using a y-tube olfactometer. Female and male D. abbreviatus were attracted by food, males, females, and female or male frass. Females were most often attracted by damaged food (broken green beans), whereas males were similarly attracted to damaged food and either female frass, male frass, or heterosexual pairs. No enhancement of attraction by either sex was found when males and male frass were combined with damaged food.     

Yield and leaf composition of sunflower in relation to N,P, K,and lime treatments

Sunflower (Helianthus annus L), a drought resistant crop, is cultivated widely throughout the world. Still, few studies on the fertility requirements of the crop have been published, particularly in relation to cultivation on highly weathered soils and in terms of using foliar analysis as a tool in diagnosing nutritional needs.Two 3⁴ (N, P, K, lime) factorial experiments (high and low fertility levels) with trace elements as split plots were conducted on Farningham clay loam, a Typic Haplorthox. No significant yield response to added N or micronutrients was found on either experiment. Liming and P fertilization increased seed yields in the low fertility experiment. Increased K application gave significant yield increases in both experiments.Preliminary foliar diagnostic norms were developed using the Diagnosis and Reccommendation Integrated System (DRIS). The prognostic value of these norms was tested using the low fertility experiment. In 32 of the 37 cases where the DRIS analysis could be checked against actual experimental yield results, application of the nutrient diagnosed as the most yield limiting resulted in a positive yield response. These data suggest that sunflowers can be a successful crop on Oxisols provided fertility is adequate.     

Nanoconjugates of methacrylic polymers: Synthesis,characterization, and immobilization to leather

Imparting superhydrophobicity to surfaces has direct implications for developing water-repellent materials. Most hydrophobic materials cannot be applied directly to specific surfaces like leather because of noncompatibility. Although methacrylic polymers are compatible to leather, their inherent hydrophilic characteristics make it challenging to use for introducing hydrophobicity or superhydrophobicity. In this article, we present a strategy of introducing hydrophobicity in various degrees as well as superhydrophobicity to different surfaces, particularly leather and glass surfaces by using conjugates of methacrylic polymers and various carbon nanomaterials. The covalent functionalization of methacrylate polymers with carbon nanotubes and fullerenes was performed by radical polymerization in the presence or absence of chain transfer agents (CTAs). CTA was used during polymerization to introduce carboxylic acid group, necessary for chromium-assisted binding to leather to avoid leaching. A balance between the compatibility of the polymer nanoconjugates with the leather and the amount necessary for coating stabilization was studied by a rheometer. While water contact angle measurement indicated the mild hydrophobicity in most cases, we were delighted to observe superhydrophobicity in one case presumably due to increased roughness because of the presence of specific nanomaterial to overcome inherent hydrophilicity of methacrylic polymers. © 2019 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2020 , 137, 48627.     

Flame-ionization detector response to methyl, ethyl, propyl, and butyl esters of fatty acids

The concept of theoretical response factors is not directly applicable to methyl esters of short-chain fatty acids (FA), since their carbon deficiency is larger than expected from theory. Substituting the methyl group by an ethyl, propyl, or butyl group improved the flame-ionization efficiency of fatty acid esters gradually, up to the point where the empirical response factors of the butyl esters were identical within experimental error to the theoretical values. Butyl esters of FA have a uniform flame-ionization detection (FID) response irrespective of the number of carbon atoms contained in the FA. They exhibit a carbon deficiency of 1.0, i.e. the carbonyl carbon atom does not respond, as expected from theory. Compared to methyl esters, which have a carbon deficiency of 1.4–1.5 for short-chain FA, use of butyl esters has the advantage that a precalculation of the FID response enables the analyst to judge whether the analytical system employed works properly and the data produced are accurate and reliable. Both acid (BF₃ or H₂SO₄)-and alkali (butoxide)-catalyzed butyl ester preparation were equally effective, giving the analyst a choice of methods so that different analytical needs can be addressed efficiently. Computing response factors and comparing the theoretically expected values with those obtained experimentally gives the experimenter an indication whether the analytical system employed for FA profiling (transesterification plus the subsequent gasliquid chromatographic separation and quantitation by FID) works properly. This setup is particularly useful for an accurate analysis of the FA profile of milk fat.     

高耐磨亲水亲油易清洁纳米涂层的制备及性能

高耐磨亲水亲油易清洁纳米涂层是以硅酸盐、硅溶胶和纳米氧化锆分散液等为原料,磷酸铝作固化剂,按照合适的比例混合,经喷涂烘烤制备的涂层。经试验,以n(SiO_2)︰n(M~+)︰n(PO_4~(3-))=8.3︰1.7︰1,添加0.5%质量分数的纳米氧化锆分散液制备的涂层,在湿度93%、温度55℃、时间96小时的恒温恒湿测试条件下能够保持良好的表面状态而不出现白斑;经过3万次的百洁布摩擦未出现刮痕、磨损、脱落或者易清洁性降低的现象;与去离子水的接触角平均值为7.4°,与大豆油的接触角平均值为19.0°;涂层具有优异的长效保护和易清洁性能。