F树脂乳液溶解法测定比粘的经验公式

本文提供了一种计算增比粘度的经验公式,为快速测量增比粘度提供了有利工具。

轻质承重灰砂制品的研制

本文主要介绍三组分灰砂砖的工艺过程与物理力学性能,其容重比粘土砖降低5.4%,标号在150号以上,优于粘土砖。同时解决了压制空心砖的成型、脱模等关键问题,为生产压制极细砂空心灰砂砖提供了参考资料。 240×115×(60～65)mm、15孔的空心砖标号在100～150号以上,容重比实心灰砂砖降低26.5%,是一种承重、保温、隔热、隔声的理想的墙体材料。

我和含羞草的那些事

我和我心爱的含羞草,就好比粘上了双面胶,永远也分不开了。每天中午吃过饭后,我都会跑到阳台上给我的含羞草浇一些水,和她聊会儿天,和她说我的心里话,她好像特别明白我的心思,一阵风吹过，她仿佛点着头，对我说：“原来是这样啊!”我们有了这样的感情，我更加喜爱这株含羞草了。

Numerical Simulation of Viscoelastic Extrudate Swell Through Elliptical Ring Die

The numerical simulation of extrudate swell is significant in extrusion processing.Precise prediction of extrudate swell is propitious to the control of melt flow and the quality of final products.A mathematical model of three-dimensional（3D）viscoelastic flow through elliptical ring die for polymer extrusion was investigated.The penalty function formulation of viscoelastic incompressible fluid was introduced to the finite element model to analyze 3D extrusion problem.The discrete elastic viscous split stress（DEVSS）and streamline-upwind PetrovGalerkin（SUPG）technology were used to obtain stable simulation results.Free surface was updated by updating the streamlines which needs less memory space.According to numerical simulation results,the effect of zero-shear viscosity and elongation parameter on extrudate swell was slight,but with the increase of volumetric flow rate and relax time the extrudate swell ratio increased markedly.Finally,the numerical simulation of extrudate swell flow for low-density polyethylene（LDPE）melts was investigated and the results agreed well with others’work.These conclusions provided quantitative basis for the forecasting extrudate swell ratio and the controlling of extrusion productivity shape.

Knockdown of liver-intestine cadherin decreases BGC823 cell invasiveness and metastasis in vivo

AIM:To assess BGC823 gastric cancer(GC) cell metastasis after knockdown of liver-intestine cadherin(CDH17) and the therapeutic value of CDH17-RNAilentivirus in vivo.METHODS:We evaluated primary tumor growth and assessed local infiltration and systemic tumor dissemination using an orthotopic implantation technique.The therapeutic value of CDH17 knockdown was examined by intratumoral administration of CDH17-RNA interference(RNAi)-lentivirus in an established GC tumor xenograft mouse model.Furthermore,a comparative proteomic approach was utilized to identify differentially expressed proteins in BGC823 and lenti-CDH17-miRneg cells following CDH17 knockdown.RESULTS:Metastases in the liver and lung appeared earlier and more frequently in animals with tumors derived from BGC823 or lenti-CDH17-miR-neg cells than in tumors derived from lenti-CDH17-miR-B cells.Average tumor weight and volume in the CDH17-RNAi-lentivirus-treated group were significantly lower than those in the control group(tumor volume:0.89 ± 0.04 cm 3 vs 1.16 ± 0.06 cm 3,P < 0.05;tumor weight:1.15 ± 0.58 g vs 2.09 ± 0.08 g,P < 0.05).Fifteen differentially expressed proteins were identified after CDH17 silencing in BGC823 cells,including a variety of cytoskeletal and chaperone proteins as well as proteins involved in metabolism,immunity/defense,cell proliferation and differentiation,cell cycle,and signal transduction.CONCLUSION:Our data establish a foundation for future studies of the comprehensive protein expression patterns and effects of CDH17 in GC.

Asymptotic Lifshitz-Like Solution in Lovelock Gravity (n=3)

With R^2 and R^3 corrections to asymptotical Lifshitz space-time, we obtain pure Lovelock gravity solution and solution with non-trivial matter in 7-dimensional space-time. Then we obtain the general solution for any arbitrary dimensional space. In this paper, we also study black brane solutions in 7-dimensionai Lifshitz space-time via the method of perturbation. And we popularize the black brane solution to arbitrary higher dimensions and discuss the ratio of shear viscosity to entropy density ratio η/s. Then we analyze the result of η/s to find that the correction of n-th （n ≥ 3） order Lovelock term has trivial influence to η/s.

Effect of Different Ratios of DL-type Starter Culture： Mould Geotrichum candidum on the Viscosity and Sensory Properties of Fermented Milk

A great variety of dairy products with different flavour, texture and health-promoting properties can be obtained from milk using different technologies and starter cultures. Fermented milks are consumed in many parts of the world and are relished for their acidic taste and health benefits. The aim of this study was to compare effects of different ratios of DL-type starter culture： mould Geotrichum candidum grown in milk on its viscosity and sensory properties on the 5th, 10th and 15th day of storage at 4 ~C~ in order to determine the best ratio to prepare fermented milk on basis of Iranian acceptance. We have examined the production of fermented milk by 80： 20, 70： 30, and 60：40 ratios of DL-type starter culture： mould Geotrichum candidum grown in milk. The results obtained from viscosity measurement and sensory evaluation showed no significant difference between these treatments used in the study and were not satisfactory; their viscosity was not accepted and scores attributed to odour and flavor of fermented milks by panelists were low.

Improved Correlations for Prediction of Viscosity of Iranian Crude Oils

Empirical equations for predicting the viscosity of Iranian crude oils above, at and below the bub-ble-point pressure were developed based on pressure-volume-temperature(PVT) data of 57 bottom hole samples collected from central, southern and offshore oil fields of Iran. Both statistical and graphical techniques were employed to evaluate these equations compared with other empirical correlations. The results show that the developed correlations present better accuracy and performance for predicting the viscosity of Iranian crude oils than those correlations in literature.

Using PVP/SDS Complex as a Probe to Study the Inclusion Complex of β-cyclodextrin with SDS in Aqueous Solution

PVP/SDS complex was applied as a probe to study the interaction between β-cyclodextrin （β-CD） and sodium dodecyl sulfate （SDS） in aqueous solution. It has been found that a critical concentration, namely cs, exists in the relative viscosity of solution containing PVP/SDS complex versus β-CD concentration plot. As the β-CD concentration is less than cs, the relative viscosity of solution decreases sharply by adding β-CD into solution successively. On the other hand, as the β-CD concentration is greater than cs, the relative viscosity of solution increases gradually by adding β-CD into solution. The decrease of the relative viscosity of solution containing PVP/SDS in the presence of β-CD is just due to the inclusion complex of β-CD with the guest molecule SDS. And, this inclusion interaction takes down SDS from the PVP chains in solution. The ratio of the host molecule β-CD to the guest molecule SDS can be calculated from Cs. In our experiment the inclusion ratio of β-CD to SDS is 1/1. The further experimental results indicate that cs is associated with SDS but free from PVP in PVP/SDS complex. However, the inclusion ratio of β-CD to SDS has proved to be independent of either SDS or PVP in PVP/SDS complex.

Study on optimum arrangement of hysteretic dampers in frame structure

The earthquake mitigation effect of hysteretic dampers is not only related to the number, stiffness, strength, deformation ability of dampers but also to the strength and stiffness of the structure. This paper studied the condition that structures should be in when the hysteretic dampers mitigated seismic action most effectively and made appropriate numerical analysis to verify the effectiveness of theory derivation. The inelastic seismic responses were analyzed for the SDOF system that the shear strength ratio of the damper system was taken differently and the result showed that when the ratio was in the vicinity of the optimum strength ratio of the damper system, the displacement of the structure was minimum and the energy dissipation of dampers was maximum, which indicated that the dampers mitigated seismic action most effectively. The result also indicated that the hysteretic dampers had significant earthquake mitigation effect when the strength ratio β changed in a relatively wide range.

VISCOSITY SOLUTIONS DEFINED BY RIGHT DIFFERENTIALS

Abstract. It is proved that for some partial differential equations, the classical notion ofviscosity solution can be defined via right-subdifferentials and superdifferentials of contin-uous functions.

The relationship between organic matter and specific surface area in <2 μm clay size fraction of muddy source rock

The adsorption of organic matter(OM)onto clay minerals has long been considered as a significant way of OM preservation in source rock.Here we analyzed the relationship between OM and the specific surface area(SSA)of <2μm clay size fraction isolated from 13 source rock cores collected from Dongying depression.Rock-Eval pyrolysis and N2 adsorption experiment were employed to probe the characteristics of OM and SSA(denoted SBET)in samples before and after OM extraction using trichloromethane.The results indicate that various kinds of OM occurrence coexist in clay size fraction and their contributions to hydrocarbon are different in each period of OM evolution.The occurrence and amount of OM affect the S BET of clay size fraction,and a nonlinear negative correlation between total organic carbon(TOC)and S BET can be recognized.The soluble OM(chloroform extract "A"),mainly stored in the pore space of clay size fraction,shows a negative correlation in amount with S BET.Our data also indicate that free hydrocarbon(S1)was stored mainly in the pore space and/or the surface of clay size fraction,whereas pyrolysis hydrocarbon(S2)was mingled mainly with clay minerals.Therefore,to understand various OM occurrences and their relationship with SBET in the clay size fraction is significant in the study of generation,accumulation,and migration of hydrocarbon in muddy source rock.

Respiration and Sorption of Water-Extractable Organic Carbon as Affected by Addition of Ca^(2+),Isolated Clay or Clay-Rich Subsoil to Sand

Clay addition to light-textured soils is used to ameliorate water repellency and to increase nutrient retention. However, clay addition may also increase the potential to bind organic matter and thus C sequestration. Divalent calcium ions （Ca2＋） play an important role in binding of organic matter to clay because they provide the bridge between the clay particles and organic matter which are both negatively charged. In the first experiment, quartz sand was mixed with clay isolated from a Vertosol at rates of 0, 50 and 300 g kg-1, finely ground mature wheat residues （20 g kg-1） and powdered CaSO4 at 0, 5 and 10 g kg-1. Soil respiration was measured over 28 d. Compared to the sand alone, addition of isolated clay at 300 g kg-1 increased cumulative respiration with a stronger increase than that at 50 g kg-1. Addition of CaSO4 increased electrical conductivity, decreased sodium adsorption ratio and reduced cumulative respiration. The latter can be explained by enhanced sorption of organic matter to clay via Ca2＋ bridges. In a second experiment, isolated clay or subsoil of the Vertosol without or with powdered CaSO4 at 10 g kg-1 were used for a batch sorption with water-extractable organic C （WEOC） from wheat straw followed by desorption with water. Addition of 10 g kg-1 CaSO4 increased sorption and decreased desorption of WEOC in both subsoil and isolated clay. In the third experiment, subsoil of the Vertosol was used for a batch sorption in which WEOC was added repeatedly. Repeated addition of WEOC increased the concentration of sorbed C but decreased the sorbed proportion of the added WEOC. This indicates that sorption of WEOC may be underestimated if it is added only once in batch sorption experaments.

Anorthite dissolution promoted by bacterial adhesion:Direct evidence from dialytic experiment

Bacterial adhesion is crucial to the dissolution of minerals and rocks. By employing dialysis method, we designed comparative experiments to investigate the dissolution behavior of anorthite with the mediation of both adhered and non-adhered Paenibacillus polymyxa. The results show that during 10 experimental days, the dissolution of anorthite was promoted considerably by P. polymyxa and metabolites. Nanoscale precipitates were formed in contact experiment. Anorthite has a higher release of Ca and lower releases of Al and Si in dialysis experiment than in contact experiment. The difference implies that the release of Ca is controlled by mechanism of proton-exchange, whereas those of A1 and Si are controlled by ligand-complexation in which A1-O-Si bonds are destroyed first. Kinetically the release of Ca is controlled mainly by surface reaction and leached-layer diffusion. Both of them are restrained by adhered bacteria. The releases of AI and Si are controlled mainly by surface reaction, which is accelerated by adhered bacteria.

In vitro comparison of the hemocompatibility of diamond-like carbon and carbon nitride coatings with different atomic percentages of N

Carbon nitride （CN,） and diamond-like carbon （DLC） coatings were prepared by dc magnetron sputtering at room temperature. Different partial pressures of N2 were used to synthesize CNx to evaluate the relationship between the atomic percentage of ni- trogen and hemocompatibility. Auger electron spectroscopy and atomic force microscopy indicated atomic percentages of N of 0.12 and 0.22 and that the CNx coatings were smooth. An in vitro study of the hemocompatibility of the coatings revealed that both CNx coatings had better anticoagulant properties and lower platelet adhesion than DLC. Compared with CN0.1〉 the CN0.22 coating showed longer dynamic clotting time （about 42 min）, static clotting time （23.6 min） and recalcification time （45.6 s）, as well as lower platelet adhesion （102 cells μm-2）, aggregation, and activation. The presence of nitrogen in the CNx coatings in- duced their enhanced hemocompatibility compared with DLC.

Biosynthesis, property comparison, and hemocompatibility of bacterial and haloarchaeal poly(3-hydroxybutyrate-co-3-hydroxyvalerate)

Polyhydroxyalkanoates （PHAs） are a class of natural biopolyesters accumulated intracellularly by many microorganisms. These polymers have attracted particular attention as green plastic in biomedical and industrial applications due to their good biodegradability and bio- compatibility. Poly（3-hydroxybutyrate-co-3-hydroxyvaler- ate） （PHBV） is one of the most common members of PHAs. However, there is no report comparing the properties of PHBV from different groups of producers, e.g., bacteria and haloarchaea. In this study, two types of PHBV copolymers were synthesized in Halogranum amylolyticum and Ralstonia eutropha, respectively, by feeding different carbon sources. They possessed a similar concentration of 3HV monomers （21 tool%） and were named PHBV-H （produced by H. arnylolyticum） and PHBV-B （produced by R. eutropha） based on their source. Interestingly, they exhibited different behaviors especially in thermal stabil- ity, melting temperature, crystallinity percentage, and mechanical properties. Furthermore, the films of PHBV-Hand PHBV-B possessed different surface properties, such as surface roughness, wettability, and surface free energy. The value of hemolysis on the PHBV-H film was lower in comparison with the PHBV-B film, although both values were within the limit of 5 % permissible for biomaterials. Notably, few inactivated platelets adhered to the surface of the PHBV-H film, whereas numerous activated platelets were seen on film PHBV-B. These results indicated that PHBV-H was a better potential component of blood-contact biomaterials than PHBV-B. Our study clearly revealed that the properties of PHAs are source dependent and haloarchaeal species provide a new opportunity for the production of desired PHAs.

Ignition of neutrino-dominated accretion disks

The vertical structure of neutrino-dominated accretion flows （NDAFs） in spherical coordinates is revisited. We define the ratio of the neutrino cooling rate to the viscous heating rate per unit volume, f=-qJqvis. The ignition region is presented when f〉0.5. The solutions show that NDAF is significantly thick. The ignition region is determined by the mass accretion rate and the vis- cosity parameter, which can be considered as the neutrino radiation-dominated region.

Genomic insights into the ESBL and MCR-l-producing ST648 Escherichia coli with multi-drug resistance

Polymyxin acts as an ultimate line of refuge against the severe infections by multidrug-resistant Gram- negative pathogens. This conventional idea is challenged dramatically by the recent discovery of mobile colistin resistance gene （mcr-1） is prevalent in food animals and human beings worldwide. More importantly, the mcr-1 gene was found to be co-localized with other antibiotic resistance genes, raising the possibility that super-bugs with pan-drug resistance are emerging. However, little is reported on the genomes of the mcr-l-positive bacterial host reservoirs. Here we report genome sequencing of three human isolates of the mcr-l-positive Escherichia coli （E15004, E15015 and E15017） and define general features through analyses of bacterial comparative genomics. Fur- ther genomic mining together with sequence typing allowed us to elucidate that the MCR-l-carrying E. coli E15017 belongs to the sequence type ST648 and copro- duces extended-spectrum β-1actamase （ESBL）. Given the fact that ST648 has been known to associate New Delhi metallo-β-1actamase 1 or ESBL, with either our results highlighted the possibility of ST648 as an epidemic clone with multidrug resistances.