冷43块稠油油藏氮气泡沫调剖实验研究

在模拟辽河冷43块稠油油藏的烧结模型上进行了氮气泡沫调剖实验研究。起泡剂HL-1溶液与氮气质量比为1：1，驱替流量按相似条件求出，驱替程序包括：饱和地层水，水驱，氮气泡沫驱，后续水驱。常压下在均质模型中注入起泡剂溶液和氮气时，阻力因子随LH-1浓度增大而增大，随温度升高而略减小，在30、60、80℃下，0．5％LH-1浓度时分别为5．81，5．78，5．67；后续注水时残余阻力因子随温度升高略有减小，在以上3个温度下分别为1．83，1．78，1．68。在非均质模型上，在围压高于内压2MPa条件下，高渗低渗层流量比在水驱时为3．00～3．17。注入1．0％LH-1溶液和氮气时下降至1．44～1．67，后续水驱时回升至2．08～2．23；常压(0．1MPa)、60℃或80℃下该组流量比值相差不大；60℃、压力0．1、10、20MPa下的该流量比，注剂时分别为1．44，1．63，1．67，后续水驱时分别为2．08，2．08，2．13。两组实验结果表明：LH-1的浓度宜选择0．5％～0．6％；同时注入起泡剂溶液和氮气可在岩心中产生泡沫，泡沫先进入高渗层，起调剖和使后续泡沫流和水流转向的作用；在高压下泡沫仍具有这种调剖和使流体流转向能力，只是略有减弱。表2表4．     

Urban and regional distinctions for aggregating time series data

Abstract.  This article argues that using either the SIC or NAICS one-digit classifications as a method of aggregating two- and three-digit time series data can ignore important regional characteristics. We present a pairwise cointegration approach of aggregation where the aggregated sectors can vary widely across regions. By systematically constructing region-specific sectors from more detailed industries, we find that the level of agglomeration across rural and urban areas can affect the composition and number of local sectors in a region. We use the results pointing to rural/urban geographic distinctiveness to further consider the Carlino and Defina (1998, 1999 ) finding that monetary policy has disparate effects across regions in the U.S.     

ZA43合金液态挤压组织特征

通过对液态挤压ZA43合金宏观及微观组织的观察分析，研究其不同部位组织特征的成因及影响因素，探讨液态挤压件的成形特点，并提出改善和减少过渡区组织的措施。     

Estimation of real GDP and unrecorded economy in Turkey based on environmental data

This paper estimates the real gross domestic product (GDP) and unrecorded economy for Turkey using the Kalman filter technique. Using different tests, most of the research articles on energy policy investigate the causal relationship between energy consumption and GDP for different countries. On the other hand, other studies on climate change try to show the effects of both energy consumption and GDP on carbon dioxide (CO₂) emission. Since the unreported economy has an important weight in developing countries where the recorded (or official) GDP suffers from considerable measurement problems, investigation of the relationship between the recorded GDP and energy consumption may lead to biased results. In this paper, the economic variables (GDP, country population) as well as environmental variables (CO₂ emission, forest area) are used in order to estimate GDP, which is an unobserved variable in our model. The results clearly indicate that: first, the true GDP in Turkey, that our model estimates, is higher than the observed (recorded) GDP in the whole period of observation (1973–2003) and the size of unrecorded economy varies between 12 and 30 percent of the observed GDP; second, the gap between the true GDP and the observed GDP has an increasing trend; third, if the change in GDP per primary energy supply is smaller than the change in CO₂ per primary energy supply, then there may exist unrecorded economy.     

Chemical trail marking and following by caterpillars ofMalacosoma neustria

Chemical trail marking and following by gregarious caterpillars,Malacosoma neustria L. (Lepidoptera: Lasiocampidae), was studied in the laboratory. As in other species ofMalacosoma, larvae deposit a trail pheromone from a sternal secretory site when searching the host for food. Larvae in the vanguard of foraging columns establish chemical trails as they explore new territory. Marking behavior diminishes as successive unfed foragers utilize the trail. These exploratory trails are subsequently overmarked by fed larvae returning to the tent. Other foragers follow the trails of fed larvae in preference to trails of unfed larvae. Thus, like the eastern tent caterpillar,M. americanum, successful foragers ofM. neustria recruit colony-mates to feeding sites. The chemical activity of both recruitment and exploratory trails degrades slowly, suggesting that the trail pheromone ofM. neustria is a nonvolatile substance. Caterpillars ofM. neustria readily follow the nonvolatile trail pheromone which has been identified fromM. americanum, 5-cholestane-3,24-dione.     

Bounds on the OBDD-size of integer multiplication via universal hashing

Bryant [On the complexity of VLSI implementations and graph representations of boolean functions with applications to integer multiplication, IEEE Trans. Comput. 40 (1991) 205-213] has shown that any OBDD for the function MUL_n-1,n, i.e. the middle bit of the n-bit multiplication, requires at least 2^n/8 nodes. In this paper a stronger lower bound of essentially 2^n/2/61 is proven by a new technique, using a universal family of hash functions. As a consequence, one cannot hope anymore to verify e.g. 128-bit multiplication circuits using OBDD-techniques because the representation of the middle bit of such a multiplier requires more than 3·10¹⁷OBDD-nodes. Further, a first non-trivial upper bound of 7/3·2^4n/3 for the OBDD-size of MUL_n-1,n is provided.     

Inhibitory effect of Antrodia camphorata constituents on the Helicobacter pylori-associated gastric inflammation

Helicobacter pylori infection plays a crucial role in the pathogenesis of peptic ulcer, and gastric cancer. Among the 13 chemical constituents isolated from fruiting bodies of Antrodia camphorata, methyl antcinate B (4), antcins K (10) and A (12) displayed potential anti-H. pylori activity with inhibition zones of 13, 12 and 10 mm, respectively, at a concentration of 0.2 mM. The isolates 4 and 10 exhibited a dose response inhibition of H. pylori adhesion and invasion to AGS cells in a range of concentrations between 0.005 and 0.02 mM, while 12 has moderate effect at relatively higher concentration. Furthermore, at these concentrations (0.005–0.02 mM) the isolates 4 and 10 also inhibited the H. pylori-induced nuclear factor (NF)-кB activation, and the subsequent release of interleukin (IL)-8 in AGS cells. These results open the possibility of considering A. camphorata a chemopreventive agent for peptic ulcer or gastric cancer, but this bioactivity should be confirmed in vivo in the future.     

过氧化氢溶液中痕量离子吸附分离用氨基功能化SBA-15的制备及性能

通过后接枝法制备了氨基功能化SBA-15介孔氧化硅(S-N),用于吸附过氧化氢溶液中的金属和阴离子及有机杂质制高纯过氧化氢.研究了接枝量对吸附剂结构和性能的影响并发现S-N中的氮含量随接枝剂用量增加而增加,最高为1.83％.S-N保留了高度有序的六方孔道结构,但比表面积和孔体积均随接枝量增加而下降.在过氧化氢溶液中,各...     

Characterization of Aspergillus oryzae glycoside hydrolase family 43 β-xylosidase expressed in Escherichia coli

This is the first report of glycoside hydrolase family 43 β-xylosidase from Aspergillus oryzae. To characterize this enzyme, the recombinant enzyme was expressed in Escherichia coli. Unlike known β-xylosidases from fungal origins, the enzyme did not show substrate ambiguity and was stable at alkaline pH.