水资源承载力及其研究

文章简要介绍了我国水资源情况,分析了我国水资源承载力与可持续发展的关系,并阐述了水资源承载力 研究的特点和方法。     

DEPOSITIONAL AND DIAGENETIC HISTORY OF THE KERENDAN CARBONATE PLATFORM, OLIGOCENE, CENTRAL KALIMANTAN, INDONESIA

The Kerendan carbonate platform (Oligocene Berai Limestone) covers a subsurface area measuring approximately 11 by 16 km in the westernmost Kutei Basin, Central Kalimantan. Aggradation of the Kerendan platform occurred during a major Oligocene transgression, and is contemporaneous with aggradation and backstepping of the Barito shelf margin which was located approximately 30 km to the south. The Kerendan platform is approximately 1,000 m thick, and comprises three aggrading seismic sequences identified by the downlap of basinal strata at the platform margin and downlap of transgressive strata within the platform. Carbonate deposition started in the Late Eocene, and ended when the upper limestone sequence drowned and was covered with shale in the Late Oligocene (approximately 28.6 Ma). Three depositional areas can be distinguished in seismic sections: (1) a platform interior (lagoon); (2) a slightly raised platform rim (1–2 km wide); and (3) a basinward‐dipping platform margin and slope. The margin of the platform is identified by inflections on the seismic profiles where the relatively flat platform top begins to slope basinward. Depositional models from outcrops combined with core from three Kerendan wells were used to extrapolate depositional facies onto the seismically‐defined platform. Platform‐interior (lagoon) facies consist largely of fossiliferous wackestones and packstones, and porosities are generally lower than 5%. The platform rim is characterized by interbedded bioclastic wackestones, packstones, grainstones and boundstones, with grainstones increasing toward the platform margin. Porosity preferentially occurs in packstones, grainstones and boundstones. The platform‐rim deposits have greater porosity (5–13%) than the platform interior because the platform run is more grainstone‐rich, and because acidic waters compacting out of basinal shales concentrated dissolution near the platform margin. Pore types include vuggy porosity, microporosity within grains, and intercrystalline porosity in dolomite in the upper part of the platform rim. Different pore types have resulted in variable but locally very high permeabilities (greater than 100 mD). Permeabilities decrease with depth as vuggy pores decrease, and microporosity becomes dominant.     

The predominant contribution of oligopeptide transporter PepT1 to intestinal absorption of beta-lactam antibiotics in the rat small intestine

Although recent evidence suggests that certain beta-lactam antibiotics are absorbed via a specific transport mechanism, its nature is unclear. To confirm whether peptide transport in the rat can be largely ascribed to the intestinal oligopeptide transporter PepT1, the transporter has been functionally characterized and its significance in the intestinal absorption of beta-lactam antibiotics was evaluated. For evaluation of transport activity complementary RNA (cRNA) of rat PepT1 was synthesized in-vitro and expressed in Xenopus laevis oocytes. cRNA induced uptake of several beta-lactam antibiotics and the dipeptide [14C]glycylsarcosine; this was specifically inhibited by various dipeptides and tripeptides but not by their constituent amino acids or by tetra- or pentapeptides. The transport activity of PepT1 for beta-lactam antibiotics correlated well with their in-vivo intestinal transport and absorption. Furthermore, mutual inhibitory effects on uptake were observed between glyclsarcosine and beta-lactam antibiotics. Hybrid depletion of the functional expression of rat PepT1 in oocytes injected with rat intestinal epithelial total mRNA was studied using an antisense oligonucleotide corresponding to the 5'-coding region of PepT1. In oocytes injected with rat mRNA pre-hybridized with the antisense oligonucleotide against rat PepT1, the uptake of [14C]glycylsarcosine was almost completely abolished, whereas its uptake was not influenced by a sense oligonucleotide for the same region of PepT1. Similarly, the uptake of beta-lactam antibiotics was also reduced by the antisense oligonucleotide against rat PepT1. These results demonstrate that the intestinal proton-coupled oligopeptide transporter PepT1 plays a predominant role in the carrier-mediated intestinal absorption of beta-lactam antibiotics and native oligopeptides in the rat.     

Prediction of axial velocity profiles and solids hold-up in a rotary kiln

Axial bed depth profiles were experimentally measured in a rotary kiln containing ilmenite particles under steady state and transient conditions. The variables include feed rate of solids, inclination and rotational speed of the kiln. and dam height. The variation of the axial velocity with kiln axis was estimated. The semi-experimental model proposed by Perron and Bui (1990) was modified to include the effect of the variables of the present study. The mean residence time of solids was estimated from the fractional hold-up and expressed in terms of the process variables. The transients induced by a step change in any of the operating conditions were measured as variation of discharge rate of solids with time.     

Application of outranking methods to economic and financial justificaton of CIM systems

Traditional economic evaluation methods concentrate on maximizing or minimizing a single objective such as net present value and pay back period. In the last decade, there has been an increased awareness of the need to consider multiple attributes in the evaluation of advanced manufacturing systems. Various methods have recently been developed for the evaluation of CIM systems. This paper discusses multiattribute methods for justification of CIM systems and outranking methods including ELECTRE, ORESTE, and PROMETHEE.     

The Effect of Lactates on the Quality of Microwave-Cooked Chicken Patties during Storage

ABSTRACT:  The aim of this study was to determine the effect of adding 3.3% sodium lactate (SL), 0.25% calcium lactate (CL), and 1.65% SL along with 0.125% CL (SL+CL) on the physicochemical properties, cooking characteristics, and microbiological quality of microwave-cooked chicken patties compared to control (no added lactates). The addition of lactates did not affect the proximate composition of cooked chicken patties. The pH of CL- or SL+CL-containing patties was significantly ( P < 0.05) reduced compared to control or SL patties. The SL-containing patties had lower ( P < 0.05) a _w values compared to control or CL patties. The CL- or SL+CL-containing patties had lower denatured myoglobin and higher ( P < 0.05) cooking yield, surface redness (CIE a *), and chroma values. However, addition of CL alone resulted in higher total expressible fluid, indicating lower water-holding capacity. The CL-containing patties exhibited lower Warner–Bratzler shear force values and higher ( P < 0.05) penetrometer reading compared to the SL-containing patties, indicating soft texture. Thiobarbituric acid (TBA) values were significantly ( P < 0.05) reduced in all lactate-containing patties compared to control up to the 7th day of refrigerated storage under aerobic conditions. No difference ( P > 0.05) was observed in aerobic plate counts between control and lactate-added patties during 28-d storage.     

日毛绒狗信息重组价值增

一只毛绒狗的故事 “大红狗”是正流行在日本京都白领女性圈子里的一款玩具。它选用毛巾布料，因此手感良好，据宣传称它的红色能够刺激脑细胞，使人充满活力，所以兼具一定的医疗保健作用。很多白领女性都喜欢将它摆放在办公室的写字台上，而现在东京都三鹰市内各大商店正以2100日元（含税）的价格热销中。     

光纤光栅最佳切趾函数的研究

采用耦合模理论，给出了用传输矩阵法计算光纤Bragg光栅（FBG）特性的方法，进而得到了在不同切趾函数形式下的FBG反射谱的数值解。通过理论分析，给出了最佳切趾函数反射谱和群时延特性曲线。     

金属粉末注射成形技术的最新研究动态与发展趋势

简要阐述了粉末注射成形技术的特点与应用 ,并从粉末的制备、粘结剂体系的设计、注射成形过程及其计算机模拟等几个方面阐明了粉末注射成形技术的最新研究动态 ,最后提出了粉末注射成形技术的重要发展趋势     

Sorption,diffusion, and swelling characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) in water–acetic acid mixtures

Sorption, diffusion, and swelling characteristics of sodium alginate and its blend membranes with poly(vinyl alcohol) were investigated for water–acetic acid mixtures by using a gravimetric method at 30, 40, and 50°C. The membranes were characterized by X‐ray diffraction and Fourier transform infrared techniques. Concentration‐independent diffusion coefficients were obtained by applying Fick's relationship before completion of equilibrium sorption. Permeation coefficients were calculated from sorption and diffusion coefficients. Concentration profiles of liquids were computed considering the sheet geometry for the membrane by solving Fick's equation under suitable boundary conditions. Arrhenius activation parameters were computed for the transport processes. Experimental results and calculated quantities were discussed to understand membrane–solvent interactions. © 2004 Wiley Periodicals, Inc. J Appl Polym Sci 94: 1139–1150, 2004