首页 | 官方网站   微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   24篇
  免费   3篇
工业技术   27篇
  2022年   1篇
  2021年   2篇
  2019年   1篇
  2018年   1篇
  2017年   2篇
  2013年   1篇
  2012年   4篇
  2011年   3篇
  2010年   2篇
  2009年   1篇
  2008年   1篇
  2007年   1篇
  2006年   1篇
  2003年   2篇
  1999年   1篇
  1998年   2篇
  1989年   1篇
排序方式: 共有27条查询结果,搜索用时 15 毫秒
1.
BACKGROUND: This study aimed to investigate the synthesis of zeolites from paper sludge ash (PSA) with added diatomite to remove both NH4+ and PO43? for water purification. The PSA had low Si and significant Ca contents. Four types of diatomite: white (T‐W) and brown (T‐B) from deposits of marine origin in Takanosu, and white (S‐W) and gray (S‐G) from lacustrine deposits in Shonai, were added to NaOH solution to increase the Si content and thereby synthesize zeolites with high cation exchange capacity (CEC). RESULTS: The order of the amounts of Si extracted from the diatomite to the alkali solution was S‐W > T‐W = T‐B > S‐G, which correlates with the amorphous SiO2 content of diatomite. The original ash without addition of diatomite yielded hydroxysodalite with CEC of about 1.0 mmol g?1. For all samples, the addition of diatomite to the solution yielded zeolite‐P with a higher CEC, but the addition of excess Si inhibited the synthesis of zeolite‐P, and the CEC of the product was low. A product with high CEC including zeolite‐P was obtained in a solution with around 500 mmol L?1 of Si concentration, and had the ability to remove both NH4+ and PO43?. CONCLUSION: Diatomite has the potential for used as an additive for the synthesis of high CEC zeolite from PSA. The product with zeolite‐P exhibited relatively high CEC, capacity for NH4+ uptake, and the ability to remove PO43? by precipitation, which is preferable for water purification applications. Copyright © 2008 Society of Chemical Industry  相似文献   
2.
Abstract— While laser projection has many advantages, there is a problem with speckle patterns generated as a result of interference of the laser beam and results in bad effects to observers. In 2010, a variable speckle generator, which produces an angular shift of incident light to the screen and generates variable speckle patterns, was suggested. In this study, the performance of a variable speckle generator by using a volume phase holographic beam shaper and scanning mirror was investigated in detail by evaluating both the objective and subjective speckle contrast. The morphology of the speckle pattern was also investigated when the variable speckle generator was activated. With a scanning VPH beam shaper, the objective speckle was effectively reduced because each point of the VPH beam shaper generated different speckle patterns and coherency among each pattern disappeared by using the scan process. On the other hand, subjective speckle was also dramatically reduced by changing the incident angle on the screen, which resulted in generating variable subjective speckle. It was also shown that the speckle reduction rate by using a variable speckle generator did not depend on the coherent length of a laser by evaluating the normalized speckle contrast against the angular shift on the screen.  相似文献   
3.
Herein we propose a production scheme for conductive films composed of thin graphite sheets with high crystallinity and polymeric resin. The crystalline graphite sheets were successfully produced from natural graphite powder by solution-phase synthesis of graphite intercalation compounds (GICs), following a wet planetary-ball milling under mild conditions. The shear forces in the milling pot lead to a peeling of graphite flakes. Taking into consideration the interlayer bonding force, the delamination should be preferentially done from the expanded GICs interlayer rather than intrinsic graphite one. Some composite films derived from the phenolic resin and flaky graphite sheets displayed much higher electrical conductivities compared to the film from the feed graphite particles. We also demonstrate the stage structure of synthetic GICs affected the film conductivity. The composite films made from exfoliated products of ground (around stage IV) GICs exhibited high electrical conductivity with a small amount of the graphite sheets.  相似文献   
4.
Rhodobacter sphaeroides RV (RV) is a hydrogen-producing bacterium exhibiting the highest yield of hydrogen production from organic acids such as lactate and acetate, which are the byproducts of hydrogen fermentation by hydrogen-producing anaerobic bacteria. Co-fermentation of the RV strain with anaerobic bacteria is an efficient method of hydrogen production. However, less than 21 mM acetate is produced by the anaerobic bacteria, which is too low for efficient hydrogen production by the RV strain; it requires approximately 75 mM acetate. In this study, 2 distinct isozymes of aldehyde dehydrogenase from Rhodospirillum rubrum were separately overexpressed in the RV strain. The recombinant RV strains that were designated as RVAD1 and RVAD2, exhibited 13-fold higher ALDH activities than the wild-type RV strain. Hydrogen yields of both of the recombinant strains were 1.4-fold higher than that of the RV strain in 21 mM acetate. In 43 mM acetate, the RVAD1 strain showed higher yield, though the RVAD2 strain showed lower yield as compared to that of the RV strain. In 64 mM acetate and all concentrations of lactate tested (21, 43 and 64 mM), the yields of the recombinant strains were lower than those of the RV strain. The intact (empty) expression plasmid increased the ALDH activity and had little effect on the hydrogen production in acetate, however, it decreased the production in lactate. At the beginning of the fermentation process, when very little hydrogen had been produced, the recombinant strains expressing the ALDH gene consumed smaller amounts of acetate compared to the wild-type strain. We have discussed the effects of ALDH on hydrogen production in this report.  相似文献   
5.
We investigated the stress–strain behavior of low molecular weight polycarbonate for optical disc grade (OD‐PC) under carbon dioxide (CO2) at various pressures, and compared the results with that under ambient pressure at various temperatures. Elongation at break decreased sharply with increased CO2 pressure at around 2 MPa, while the elastic modulus decreased gradually up to 6 MPa. These results indicate that the tensile property changed from ductile to brittle with increased CO2 pressure, although the molecular motion is accelerated due to the plasticization effect of CO2. Such ductile‐to‐brittle transition is similar to that observed under elevated temperatures caused by chain disentanglement due to accelerated molecular motion. Although the changes of tensile properties were similar, the craze structure obtained by the brittle behavior was different, i.e., a filamented‐craze structure was obtained under high‐pressure CO2, while a lace‐like one was obtained under elevated temperatures. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers  相似文献   
6.
Over the last century, IQ scores have been steadily rising, a phenomenon dubbed the Flynn effect. Because of the Flynn effect, IQ tests are periodically renormed, making them harder. Given that eligibility for mental retardation (MR) services relies heavily on IQ scores, renormed tests could have a significant impact on MR placements. In longitudinal IQ records from 9 sites around the country, students in the borderline and mild MR range lost an average of 5.6 points when retested on a renormed test and were more likely to be classified MR compared with peers retested on the same test. The magnitude of the effect is large and affects national policies on education, social security, the death penalty, and the military. This paper reports the perceptions of professionals as they relate to IQ score fluctuations in normal, borderline, and/or MR populations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
A 51-year-old male of von Recklinghausen's disease presented with huge retroperitoneal hematoma caused by spontaneous arterial rupture. He died of uncontrollable hemorrhage during the operation. Gross appearance of aorta, renal artery, celiac artery, pulmonary artery and lumbar artery were extremely fragile, and there was a complete rupture between aorta and lumbar artery. On the microscopic examination, significant medial dysplasia were demonstrated in these arteries. Arterial stenosis is well-known vascular complication in von Recklinghausen's disease. Spontaneous rupture of major artery, however, has been extremely uncommon. This is the 26th case reported in the world literature, and 21th case in the Japanese literature.  相似文献   
8.
The aim of this study was to determine the principal active molecules in the acid phosphatase (AcP) fraction of skim milk origin using immunostaining and AcP staining. The AcP fraction was separated from skim milk at 0.38 m NaCl using carboxymethyl cellulose chromatography at pH 5.2. The molecular mass of the active molecule in AcP fraction was estimated to be 80 kDa by immunostaining and AcP staining. The 80 kDa protein was analyzed by a protein sequencer, using the automated Edman degradation method; the first thirteen N-terminal amino acid sequence obtained were shown to be APRKNVRWXTIXQ. For that amino acid sequence, there was 84% (11/13 residues) homology with the amino acid sequence of bovine lactoferrin (LF). The AcP fraction and commercial LF showed a similar AcP activity profile, having an optimum pH of 4.5 and temperature of 60 °C. Thus, the AcP fraction from bovine skim milk was isolated and the principal active molecule present was tentatively identified as LF.  相似文献   
9.
Sodium-glucose co-transporter 2 (SGLT2) inhibitors facilitate urine glucose excretion by reducing glucose reabsorption, leading to ameliorate glycemic control. While the main characteristics of type 2 diabetes mellitus are insufficient insulin secretion and insulin resistance, SGLT2 inhibitors have some favorable effects on pancreatic β-cell function and insulin sensitivity. SGLT2 inhibitors ameliorate fatty liver and reduce visceral fat mass. Furthermore, it has been noted that SGLT2 inhibitors have cardio-protective and renal protective effects in addition to their glucose-lowering effect. In addition, several kinds of SGLT2 inhibitors are used in patients with type 1 diabetes mellitus as an adjuvant therapy to insulin. Taken together, SGLT2 inhibitors have amazing multifaceted effects that are far beyond prediction like some emerging magical medicine. Thereby, SGLT2 inhibitors are very promising as relatively new anti-diabetic drugs and are being paid attention in various aspects. It is noted, however, that SGLT2 inhibitors have several side effects such as urinary tract infection or genital infection. In addition, we should bear in mind the possibility of diabetic ketoacidosis, especially when we use SGLT2 inhibitors in patients with poor insulin secretory capacity.  相似文献   
10.
Kohei Inoue  Tomoe Sanada  Kazuo Kojima 《Carbon》2010,48(14):4209-8445
The longest-chain polyyne that has ever been synthesized is C24H2 by Estmond et al. [1] using the complicated acetylene coupling method. On the other hand, in simple liquid-phase laser ablation method, we have recently obtained the longest-chain polyyne of C22H2. In the present study, we report the synthesis of long-chain polyynes of C24H2 and C26H2 from graphite pellets in solvent of decalin by liquid-phase laser ablation. It is believed that the termination reaction on both ends of these polyyne molecules hardly occurs in decalin with relatively less number of hydrogen atoms and these long-chain polyynes could be synthesized.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司    京ICP备09084417号-23

京公网安备 11010802026262号