间甲苯胺制备高纯间甲酚的工艺改进

以间甲苯胺为原料,经过重氮化、水解合成了高纯度的间甲酚,主要研究了由间甲苯胺制备间甲酚的合成工艺,通过试验确定了较佳的工艺条件,在此条件下合成间甲酚的收率可达90%,产品纯度为99.7%。     

间氨基酚的产业现状及发展动态

简要介绍间氨基酚的几种主要生产工艺,并分别对其优缺点进行了讨论。概述了美国、西欧和日本间氨基酚的应用领域及市场现状;同时还分析了国内间氨基酚的生产现状及在各领域的应用情况,并对国内外的间氨基酚装置情况进行了全面总结。最后对国内间氨基酚的发展提出了建议。     

气相扩散法制备石墨层间化合物述评

本文从碱金属-石墨层间化合物、碱土金属-石墨层间化合物、稀土金属-石墨层间化合物、金属卤化物-石墨层间化合物、卤素-石墨层间化合物以及其他类型的石墨层间化合物六个方面简要介绍了气相扩散法在石墨层间化合物制备中的应用,指出了气相扩散法存在的问题和进一步的发展方向.     

职业卫生技术服务机构实验室间能力比对的分析与思考

实验室间能力比对是实验室外部质量控制的有效形式,本文介绍了实验室间能力比对的常用评定方法,阐述了实验室间能力比对工作中注意事项和应对策略,分析概括了实验室间能力比对未来趋势和走向,从而提出实验室间能力比对工作的思考和建议。     

间苯二甲胺的合成与应用

综述了间苯二甲胺的合成方法,分析了以间苯二甲腈为原料、经Co和Ni为主催化剂催化加氢制备间苯二甲胺的工艺。对间苯二甲胺在环氧树脂固化剂、聚氨酯等产品生产中的应用进行了阐述。     

层间水膜对3D打印混凝土界面性能的影响

混凝土材料的制备与性能优化是建筑3D打印结构化发展与应用的基础。3D打印混凝土材料的宏观力学性能、长期耐久性能均与界面细观结构直接相关。本文明确了3D打印混凝土层间界面水分状态(水膜)的形成机制,测试了不同打印层厚条带的水膜随时间的演化规律,通过CT扫描技术研究了层间间隔时间、打印层厚、环境状态对层间界面孔隙特征的影响,揭示了层间界面水分状态、层间界面孔隙特征及层间黏结性能三者之间的相互影响机制。结果表明：层间界面孔隙率随单位面积上层间界面水分质量的增长而降低,层间界面水分质量是较打印参数而言更直接的层间界面状态影响因素;层间水分状态和界面细观孔隙特征直接影响着3D打印混凝土材料的宏观力学强度。     

基于数字图像相关方法的复合材料层间剪切性能研究

层间剪切强度是评价复合材料层合板层间力学性能的一项重要指标。首先,按照ASTM D 2344开展了复合材料层合板短梁剪切试验,研究了CCF300/5228复合材料层合板层间剪切性能。其次,基于数字图像相关方法得到了不同载荷作用下层间全场位移和应变分布。最后,利用ABAQUS建立了复合材料层合板有限元模型,分析了复合材料层合板层间位移及应变分布,并与数字图像相关计算结果进行了对比。研究表明,数字图像相关方法试验结果与有限元分析结果具有较好的一致性。数字图像相关方法能够实时监测层合板层间应变分布,进而预测层间剪切破坏位置,为复合材料层间剪切性能研究提供有效的全场应变监测手段。     

煤化工动力车间DCS配置方案分析

分析了某企业煤化工动力车间工艺系统的特点及其与常规单元制机组的差异,设计了符合动力车间运行特点的DCS配置方案,给出了某煤化工动力车间DCS配置的具体实例。     

间戊二烯石油树脂改性研究进展

介绍了间戊二烯石油树脂改性技术的进展动态,综述了间戊二烯石油树脂各种改性方式,针对我国间戊二烯石油树脂产量小、品种单一、牌号少、应用范围小的现状,提出了建议。     

间苯二甲胺合成工艺研究

以间苯二甲腈为原料,雷尼镍为催化剂,进行催化加氢制间苯二甲胺,探讨了各种因素对反应结果的影响,即:间苯二甲腈原料纯度、催化剂、反应助剂、反应温度、反应压力及反应溶剂等对催化加氢反应的影响。提出间苯二甲腈催化加氢制间苯二甲胺工艺的最佳控制条件。指出对原料间苯二甲腈的纯化及催化剂的研究是今后间苯二甲腈催化加氢制备间苯二甲胺实现工业化的研究重点。     

Olfactory-based behavioral interactions among five species in the southern pine bark beetle group

Olfactory-mediated behavioral interactions were investigated among the five scolytid species comprising the southern pine bark beetle group. Behavioral response, as determined from field trap catch data, showed that each species was attracted in greatest numbers to the pheromonal blend produced by conspecifies. Interspecifically,D. frontalis displayed no cross-attractancy toIps pheromonal blends, but was weakly attracted to the pheromonal blend of femaleD. terebrans. ThreeIps species displayed varying degrees of cross-attraction as well as to theDendroctonus pheromonal blends. More specifically,I. calligraphus was attracted toI. avulsus and, to a very limited extent, also to the maleD. terebrans pheromonal blend.I. avulsus was somewhat more cross-attractive thanI. calligraphus and showed attraction to the pheromonal blends of femaleD. frontalis, male and femaleD. terebrans, maleI. calligraphus, and maleI. grandicollis. I. grandicollis showed the greatest degree of cross-attraction, particularly in response to theDendroctonus pheromonal blends.Research support in part by CSRS grant 86-CRCR-1-2270, NATO grant CRG.0710/86 and Texas Agricultural Experiment Station project MS1525 (while M.T.S. and T.L.P. were with Texas A&M University). The findings, opinions, and recommendations expressed herein are those of the authors and not necessarily those of the U.S. Department of Agriculture.     

Density-Dependent Reduction and Induction of Milkweed Cardenolides by a Sucking Insect Herbivore

The effect of aphid population size on host-plant chemical defense expression and the effect of plant defense on aphid population dynamics were investigated in a milkweed-specialist herbivore system. Density effects of the aposematic oleander aphid, Aphis nerii, on cardenolide expression were measured in two milkweed species, Asclepias curassavica and A. incarnata. These plants vary in constitutive chemical investment with high mean cardenolide concentration in A. curassavica and low to zero in A. incarnata. The second objective was to determine whether cardenolide expression in these two host plants impacts mean A. nerii colony biomass (mg) and density. Cardenolide concentration (microgram/g) of A. curassavica in both aphid-treated leaves and opposite, herbivore-free leaves decreased initially in comparison with aphid-free controls, and then increased significantly with A. nerii density. Thus, A. curassavica responds to aphid herbivory initially with density-dependent phytochemical reduction, followed by induction of cardenolides to concentrations above aphid-free controls. In addition, mean cardenolide concentration of aphid-treated leaves was significantly higher than that of opposite, herbivore-free leaves. Therefore, A. curassavica induction is strongest in herbivore-damage tissue. Conversely, A. incarnata exhibited no such chemical response to aphid herbivory. Furthermore, neither host plant responded chemically to herbivore feeding duration time (days) or to the interaction between herbivore initial density and feeding duration time. There were also no significant differences in mean colony biomass or population density of A. nerii reared on high cardenolide (A. curassavica) and low cardenolide (A. incarnata) hosts.     

Ancestral semiochemical attraction persists for adjoining populations of siblingIps bark beetles (Coleoptera: Scolytidae)

Three species ofIps pine bark beetles in Hopping's group IX (S.L. Wood'sgrandicollis group),Ips confusus, I. lecontei, andI. paraconfusus, are parapatrically distributed in the American Southwest. They share post-Pleistocene altitudinal ecotones with their host pines. Adjacent to these areas of host overlap, we tested the hypothesis that aggregation pheromones produced by male beetles and/or host volatiles are sufficient to elicit the speciesspecific colonization behaviors typical of these threeIps species in nature. A more distantly related species,I. pini (Hopping's group IV, S.L. Wood'spini group) was used for outgroup comparison. Under the influence of pheromone, males ofI. confusus andI. paraconfusus do not discern among unin-fested log bolts of host and nonhost pine prior to bark contact. Males responding to pheromones emanating from infested bolts are similarly undiscriminating. Females ofI. confusus andI. lecontei olfactorily discern the combination of conspecific males in host pine from other possible beetlepine combinations; females ofI. paraconfusus do not. FemaleI. pini discerned conspecific pheromone from that ofI. lecontei. The bark beetle predator,Enoclerus lecontei, is attracted by, but does not discriminate among, the male-produced volatiles of these Group IXIps species. These results support a hypothesis that divergence in pheromonal responses by these group IXIps species has evolved following their speciation, having been manifested first in the female sex. Evolutionarily, the derived pheromonal messages have preceded their behavioral discrimination by these beetles. Additional speciesspecific cues may operate between the sexes in the field that may preclude heterospecific pairings.     

Interspecific response to sex pheromones,and calling behavior of severalAttagenus species (Coleoptera: Dermestidae)

Females of severalAttagenus species demonstrated calling behaviors similar to those previously reported forA. elongatulus. Attagenus rufipennis females did not call until they were 12–14 days old. OtherAttagenus species called at approx. 4 days of age. All species exhibited diurnal periods of calling activity. Interspecific pheromone responses were tested, withA. megatoma megatoma, A. megatoma canadensis, A. megatoma japonicus, andA. schaefferi spurcus showing equal cross-responses. Male response to females was demonstrated inA. rufipennis andA. bicolor. Attagenus rufipennis, bicolor, andelongatulus males responded only to female extracts of their own species.Mention of a proprietary product does not constitute an endorsement by the USDA.     

国外生物降解聚合物的种类及主要组分

据１９９６～１９９８年国外有关文献的汇集,由美,日,德等国主要研制,生产的生物降解聚合物种类为：１,单一型生物降解聚合物;（１）合成酯（酸）类;（２）淀粉基材料;（３）天然高分子材料;２、复合型生物降解聚合物;（１）不同种类的烃基互聚物;（２）烃酯（酸）／聚酯（３）脂肪族聚酯／芳香族聚酯共聚物;（３）淀粉基复合型,（５）光／生物降解聚合物;３、可生物降解水溶性聚合物。     

Allelopathic interactions among algae

Five species of green algae isolated from the Cleveland County, Oklahoma, area and a commercially obtained yellow-green alga were tested for allelopathic interactions. Axenic cultures ofPandorina morum Bory were stimulated in three sterile filtrates from nonaxenic cultures ofScenedesmus incrassatulus var.mononae G.M. Smith, with the oldest filtrate showing the least stimulation. By measuring the growth of axenic cultures inoculated into sterile filtrates of old cultures, instances of inhibition and stimulation were recorded in three screening experiments.Cosmarium vexatum West filtrate was inhibitory to the five other species, a characteristic probably important in its role of producing waterblooms in ponds and swamps. The allelopathic effects of filtrates of the five other species onBolrydium becherianum Vischer could be a key to its restriction to terrestrial sites. Instances of heat lability of the active substances were noted. These interactions, both allelopathic and stimulatory, probably play a significant role in the succession of algal blooms in nature.     

Plant-determined variation in the cardenolide content,thin-layer chromatography profiles,and emetic potency of monarch butterflies,Danaus plexippus L. Reared on milkweed plants in California: 2.Asclepias speciosa

The pattern of variation in gross cardenolide concentration of 111Asclepias speciosa plants collected in six different areas of California is a positively skewed distribution which ranges from 19 to 344 g of cardenolide per 0.1 g dry weight with a mean of 90 g per 0.1 g. Butterflies reared individually on these plants in their native habitats ranged from 41 to 547 g of cardenolide per 0.1 g dry weight with a mean of 179 g. Total cardenolide per butterfly ranged from 54 to 1279 g with a mean of 319 g. Differences in concentrations and total cardenolide contents in the butterflies from the six geographic areas appeared minor, and there were no differences between the males and the females, although the males did weigh significantly more than females. The uptake of cardenolide by the butterflies was found to be a logarithmic function of the plant concentration. This results in regulation: larvae which feed on low-concentration plants produce butterflies with increased cardenolide concentrations relative to those of the plants, and those which feed on high-concentration plants produce butterflies with decreased concentrations. No evidence was adduced that high concentrations of cardenolides in the plants affected the fitness of the butterflies. The mean emetic potencies of the powdered plant and butterfly material were 5.62 and 5.25 blue jay emetic dose fifty units per milligram of cardenolide and the number of ED₅₀ units per butterfly ranged from 0.28 to 6.7 with a mean of 1.67. Monarchs reared onA. speciosa, on average, are only about one tenth as emetic as those reared onA. eriocarpa. UnlikeA. eriocarpa which is limited to California,A. speciosa ranges from California to the Great Plains and is replaced eastwards byA. syriaca L. These two latter milkweed species appear to have a similar array of chemically identical cardenolides, and therefore both must produce butterflies of relatively low emetic potency to birds, with important ecological implications. About 80% of the lower emetic potency of monarchs reared on A. speciosa compared to those reared onA. eriocarpa appears attributable to the higher polarity of the cardenolides inA. speciosa. Thin-layer Chromatographie separation of the cardenolides in two different solvent systems showed that there are 23 cardenolides in theA. speciosa plants of which 20 are stored by the butterflies. There were no differences in the cardenolide spot patterns due either to geographic origin or the sex of the butterflies. As when reared onA. eriocarpa, the butterflies did not store the plant cardenolides withR _f values greater than digitoxigenin. However, metabolic transformation of the cardenolides by the larvae appeared minor in comparison to when they were reared onA. eriocarpa. AlthoughA. eriocarpa andA. speciosa contain similar numbers of cardenolides and both contain desglucosyrioside, the cardenolides ofA. speciosa overall are more polar. ThusA. speciosa has no or only small amounts of the nonpolar labriformin and labriformidin, whereas both occur in high concentrations inA. eriocarpa. A. speciosa plants and butterflies also contain uzarigen, syriogenin, and possibly other polar cardenolides withR _f values lower than digitoxin. The cardenolide concentration in the leaves is not only considerably less than inA. eriocarpa, but the latex has little to immeasurable cardenolide, whereas that ofA. eriocarpa has very high concentrations of several cardenolides. Quantitative analysis ofR _f values of the cardenolide spots, their intensities, and their probabilities of occurrence in the chloroform-methanol-formamide TLC system produced a cardenolide fingerprint pattern very different from that previously established for monarchs reared onA. eriocarpa. This dispels recently published skepticism about the predictibility of chemical fingerprints based upon ingested secondary plant chemicals.Lepidoptera: Danaidae.Apocynales: Asclepiadaceae.This study was supported by U.S. National Science Foundation grants DEB 75-14265 and 78-10658 to Amherst College and BSR-8119382 to the University of Florida with L.P. Brower as Principal Investigator and DEB75-14266, DEB78-15419, and DEB-81-19391 to the University of California at Davis with J.N. Seiber as Principal Investigator.     

Modified dynamic matrix control

DMC (Dynamic Matrix Control) has been used successfully in industry for the last decade. It can deal with constraints and unusual dynamic behavior directly. It also shows a good control performance for the servo problem. Relatively, it can’t reject disturbances systematically. We propose a modified DMC method to control the regulatory process more efficiently. The proposed DMC method makes the control output by subtracting the estimated disturbance from the control output of the original DMC. Here, the disturbance is estimated by a new disturbance estimator. It shows better control performances than the original DMC.     

Soil nutrient depletion by agricultural production in Southern Mali

The degree of soil mining by agricultural production in Southern Mali is assessed by calculating nutrient balances: differences between the amount of plant nutrients exported from the cultivated fields, and those added to the fields. Export processes include extraction by crops, losses due to leaching, to erosion, and to volatilization and denitrification. Inputs include applications of fertilizer and manure, restitution of crop residues, nitrogen fixation, atmospheric deposition of nutrients in rain and dust, and enrichment by weathering of soil minerals. Nutrient balances are calculated for N, P, K, Ca, and Mg. Both pessimistic and optimistic estimates are given.The resulting figures indicate, even when the most optimistic estimates are used, large deficits for nitrogen, potassium and magnesium. For the region as a whole, the calculated deficits are -25 kg N/ha,-20 kg K/ha, and -5 kg Mg/ha. Further, acidification is to be expected, in particular in areas where cotton is grown. The deficits are caused by traditional cereal crops, but also by cotton and especially by groundnut. The latter two crops are fertilized, but insufficiently. It is important to note, that the negative figures are not automatic recommendations for application of a specific amount of additional fertilizer. For phosphorus and calcium the balance of the region as a whole appears to be about in equilibrium, but locally large variations may occur.Erosion and denitrification are important causes of nutrient loss, accounting respectively for 17 and 22% of total nitrogen exports. Atmospheric deposition and weathering of minerals in the soil are still important nutrient inputs that contribute as much as nutrients as organic and mineral fertilizer combined. Nutrient depletion is very large in comparison to the amount of fertilizer applied. Drastic options, such as doubling the application of fertilizer or manure, or halving erosion losses, even if feasible, would still not be enough to make up for the calculated deficits.The annual value of withdrawn nutrients, if related to prices of fertilizers, varies between 10,000 and 15,000 FCFA/ha (40-60 US $/ha). Since the estimated average gross margin from farming in this area is 34,000 FCFA/ha (123 US $/ha), soil mining appears to provide an amount equal to 40% of farmers' total income from agricultural activities.     

Inorganic/organic nanocomposite coatings: The next step in coating performance

Inorganic/organic hybrid materials have considerable promise and are beginning to become a major area of research for many coating usages, including abrasion and corrosion resistance. Our primary approach is to prepare the inorganic phase in situ within the film formation process of the organic phase. The inorganic phase is introduced via sol-gel chemistry into a thermosetting organic phase. By this method, the size, periodicity, spatial positioning, and density of the inorganic phase can be controlled. An important aspect of the inorganic/organic hybrid materials is the coupling agent. The initial task of the coupling agent is to provide uniform mixing of the oligomeric organic phase with the sol-gel precursors, which are otherwise immiscible. UV-curable inorganic/organic hybrid systems have the advantages of a rapid cure and the ability to be used on heat sensitive substrates such as molded plastics. Also, it is possible to have better control of the growth of the inorganic phase using UV curing. It is our ultimate goal to completely separate the curing of inorganic and organic phases to gain complete control over the morphology, and hence optimization of “all” the coating properties. Thus far, it has been found that concomitant UV curing of the inorganic and organic phases using titanium sol-gel precursors afforded nanocomposite coatings which completely block the substrate from UV light while maintaining a transparent to visible light. Also, it has been found that the morphology of the inorganic phase is highly dependent on the concentration and reactivity of the coupling agent. Presented at the 82nd Annual Meeting of the Federation of Societies for Coatings Technology, October 27–29, 2004, in Chicago, IL.