一种新型烟气净化剂─—混合有机钙盐

制备了一种新型烟气净化剂─—混合有机钙盐。在模拟工业条件的喷雾干燥型反应器中,９００～１１００℃温度范围内,混合有机钙盐的快速脱硫的钙基利用率＞ＣａＡｃ２＞Ｃａ（ＯＨ）２＞ＣａＣＯ３：混合有机钙盐的脱硝利用率约是ＣａＡｃ２的２．５倍,而ＣａＣＯ３和Ｃａ（ＯＨ）２基本看不出脱硝能力。在实验条件下温度升高,净化剂的脱硫利用率略有增加,醋酸钙和混合有机钙盐的最佳脱硝温度大约在１０００℃;较低的氧浓度既有利于脱硫也有利于脱硝;有机钙净化剂的硫酸化能提高其脱硝能力。     

Clay‐Catalyzed Cracking Leads to Suppressed Flammability in Clay–Polyolefin Nanocomposites

Organoclay–polyolefin nanocomposites have been shown to exhibit slightly increased thermal stability and decreased flammability, compared to unfilled polyolefins. In contrast, we find that when the clay has not been organically modified, the resulting polyolefin nanocomposites are less thermally stable and, unexpectedly, also much less flammable. In this contribution, we investigate the mechanistic origins of these effects. Clay–polyolefin nanocomposites were prepared by in situ polymerization of ethylene or propylene, using a catalyst adsorbed onto the clay. Decreased thermal stability is attributed to clay‐catalyzed polymer decomposition, while decreased flammability arises in part from clay‐catalyzed formation of a polyaromatic char from olefins trapped in the material by the dispersed nanofiller.

     

A duplicated gene in the breakpoint regions of the 7q11.23 Williams-Beuren syndrome deletion encodes the initiator binding protein TFII-I and BAP-135, a phosphorylation target of BTK

We sequenced the nuclear small subunit of ribosomal DNA (SSU rDNA) from seven species within the insect-pathogenic order Entomophthorales. These sequences were aligned with other published SSU rDNA sequences and phylogenies were inferred using phenetic and cladistic methods. Based on three different phylogenetic methods the Entomophthorales (excluding Basidiobolus ranarum) is monophyletic; B. ranarum was more closely related to chytrids from Chytridiales and Neocallimasticales than to Entomophthorales, as was proposed by Nagahama et al. (Mycologia 87: 203-209, 1995). Nuclear characters (large nuclei containing conspicuous condensed chromatin and lack of a prominent nucleolus) were of predictive value for the monophyly of the family Entomophthoraceae. Conidial characters separate the Entomophthoraceae, which only includes obligate pathogens, into at least two lineages: one lineage with uninucleate conidia and another with multinucleate conidia. The two species of Conidiobolus studied were paraphyletic in our analyses and only distantly related to each other. This information may prove to be important in the use of these fungi as biocontrol agents.     

Proton potentiation of ATP-gated ion channel responses to ATP and Zn2+ in rat nodose ganglion neurons

1. The modulation by protons of ATP-gated ion channel responses to ATP and Zn2+ was studied in freshly isolated rat nodose ganglion neurons using the whole cell patch-clamp technique. 2. Reduced external pH enhanced, whereas elevated external pH suppressed, current activated by 10 microM ATP. The pH producing the half-maximal effect (EC50) at this ATP concentration was 7.1. 3. Acidification shifted the ATP concentration-response curve to the left, decreasing the EC50 for ATP, and alkalinization shifted the ATP concentration-response curve to the right, increasing the EC50 for ATP. Fitting the data to a single-site pH model yielded an apparent pKa of the site on the ATP-gated ion channel of 7.6. Between pH 6.8 and 7.8, a change of 0.1 pH unit was calculated to change the ATP EC50 by 4.03 microM. Changing pH did not alter the maximal response to ATP. 4. The potentiating effect of protons appeared to be due to a direct action on the ATP-gated channel, as it could not be explained by an increase in the concentration of one or more species of ATP. 5. Lowering pH also increased the potency of Zn2+ for enhancement of ATP-activated current without altering its maximal response. Changing the pH from 7.3 to 6.8 changed the Zn2+ EC50 from 12 to 1.7 microM. 6. The potentiation of ATP-activated current by protons could not be attributed solely to an increase in the affinity of the receptor for Zn2+, as the Zn2+ chelator N,N,N',N'-tetrakis(2-pyridylmethyl)ethylenediamine did not alter the effect of protons. 7. Protons and Zn2+ do not appear to act at the same site on ATP-gated channels, as responses to maximally effective concentrations of Zn2+ were enhanced further by protons and vice versa. 8. These results suggest that protons regulate the function of P2X purinoceptors in rat nodose ganglion neurons by modulating the affinity of the binding sites for ATP and Zn2+ on these receptor channels.     

Study on the copolymerization of propylene with norbornene using metallocene catalysts

The copolymerization of propylene with norbornene, using the metallocene catalysts Me₂Si(2-Me-Ind)₂ZrCl₂ and Ph₂C(Flu)(Cp)ZrCl₂ was evaluated. The presence of norbornene decreases the polymerization activity in both systems. In the Me₂Si(2-Me-Ind)₂ZrCl₂ system, the decrease is ca. 80?% using 0.5?mL of norbornene while the addition of 2?mL reduces the activity by 97?%. The molecular weight of the materials decreases between 27,000 and 37,000?g/mol in the presence of norbornene. The Ph₂C(Flu)(Cp)ZrCl₂/MAO system has the same tendency, but the norbornene has a lesser effect on the activity, with 2?mL of comonomer reducing the activity ca. 80?%. The molecular weight decreased significantly with this system as well. The elongation at break of some of the materials was 80 times higher than the homopolymer and the Young’s modulus slightly superior to the homopolymer. This indicates that it is possible to generate materials that keep the properties of a syndiotactic polypropylene but with good elastomeric properties.     

Pulsed-Beam Techniques Used with a Tandem Van De Graaff Accelerator

A compact pulsed-bean ion source injector was developed and installed on The University of Texas Tandem Accelerator. The injector consists of a direct extraction negative ion source coupled to a 100 keV Coskroft-Walton accelerator. Improvements in the arrangement and fabrication of the high voltage components of the injector are discussed. R. F. pulsing and klystron bunching of the ion beam is done before entering the tandem and a simple inexpensive method of rejecting the retrace component of the pulsed beam is presented. Pertinent pulsed beam characteristics measured under fast neutron time-of-flight experimental conditions are given.     

磁悬浮轴承的H∞鲁棒—模糊控制的研究

本文介绍了磁悬浮系统的组成以及它的工作原理，建立了数学模型，控制器采用了DSP芯片，对H∞鲁棒－模糊控制器进行了设计，并给出了仿真和实际控制结果。     

Distribution of polychlorinated biphenyls in a municipal wastewater treatment plant and environs.

Distribution of polychlorinated biphenyls (PCB) in sewage wastes at a municipal sewage treatment plant was studied, showing that the great bulk of PCBs entering such a treatment plant become adsorbed onto the grit chamber solids and the sludge that is passed from the anaerobic digesters. When appreciable quantities of PCBs are present in sewage, as was the case in this study, significant quantities can nevertheless pass with the effluents discharged from the treatment plant. The PCB concentrations in the treatment plant waters undergoing secondary and tertiary treatment tend to be consistent with the limited solubility properties of the PCBs. However, appreciably higher concentrations can be found in the sediments of waters receiving treatment plant discharges and bioaccumulation in fish is demonstrated readily. Also described are quantitative data on PCBs in soils fertilized with PCB-contaminated sludge.     

A biofuel supply chain equilibrium analysis with subsidy consideration

We consider a biofuel supply chain problem in which a farmer supplies two downstream refineries with nonidentical crops (corn and energy crop). The problem has been modeled as a multi leader single follower game to derive the farmer's decisions on land use as well as refineries' proposed prices to the farmer. We consider subsidizing the farmer and the refinery that uses the energy crop to study whether a subsidy plan can enhance the advanced biofuel production and meet the mandate of the Environmental Protection Agency (EPA). This mandate requires the production of 36 billion gallons of biofuel, out of which 21 billion gallons should be noncorn‐based biofuel. We solve the problem under four cases based on the willingness of the farmer to sell corn to the food market as well as the availability of land expansion for her. The Nash equilibrium is derived for all cases, and parametric analyses are used to study the effect of subsidies on the profit of the players and the total social welfare of the supply chain. We observe that a government's expenditure can be offset by the increase of the social welfare under certain circumstances. We find the minimum budget requirement to meet the EPA's mandate and show that a specific budget can be distributed in different ways while obtaining the same results.