Pressure and temperature dependence of the decomposition pathway of LiBH₄

Yan, Yigang,Remhof, Arndt,Hwang, Son-Jong,Li, Hai-Wen,Mauron, Philippe,Orimo, Shin-ichi,Zü,ttel, Andreas The Royal Society of Chemistry 2012 Physical chemistry chemical physics Vol.14 No.18

<P>The decomposition pathway is crucial for the applicability of LiBH<SUB>4</SUB> as a hydrogen storage material. We discuss and compare the different decomposition pathways of LiBH<SUB>4</SUB> according to the thermodynamic parameters and show the experimental ways to realize them. Two pathways, <I>i.e.</I> the direct decomposition into boron and the decomposition <I>via</I> Li<SUB>2</SUB>B<SUB>12</SUB>H<SUB>12</SUB>, were realized under appropriate conditions, respectively. By applying a H<SUB>2</SUB> pressure of 50 bar at 873 K or 10 bar at 700 K, LiBH<SUB>4</SUB> is forced to decompose into Li<SUB>2</SUB>B<SUB>12</SUB>H<SUB>12</SUB>. In a lower pressure range of 0.1 to 10 bar at 873 K and 800 K, the concurrence of both decomposition pathways is observed. Raman spectroscopy and <SUP>11</SUP>B MAS NMR measurements confirm the formation of an intermediate Li<SUB>2</SUB>B<SUB>12</SUB>H<SUB>12</SUB> phase (mostly Li<SUB>2</SUB>B<SUB>12</SUB>H<SUB>12</SUB> adducts, such as dimers or trimers) and amorphous boron.</P> <P>Graphic Abstract</P><P>The thermodynamic properties of LiBH<SUB>4</SUB> and its possible decomposition products and intermediates allow flexibility in selection of the decomposition pathway by tuning the external parameters such as pressure and temperature. <IMG SRC='http://pubs.rsc.org/services/images/RSCpubs.ePlatform.Service.FreeContent.ImageService.svc/ImageService/image/GA?id=c2cp40131b'> </P>

Influence of the properties of corundum aggregates on the strength and slag resistance of refractory castables

Wen Yan,Nan Li,Zheng Miao,Guangping Liu,Yuanyuan Li 한양대학교 세라믹연구소 2012 Journal of Ceramic Processing Research Vol.13 No.3

Three refractory castables containing corundum aggregates with different porosities, average pore size and strength and the same matrices were fabricated. The effects of the properties of corundum aggregates on the strength and slag resistance of refractory castables were investigated through an X-ray diffractometer (XRD), scanning electron microscopy (SEM), mercury porosimetry measurements, etc. It was found that the properties of corundum aggregates have an important effect on the bulk density, porosity, compressive strength and slag resistance of refractory castables, but have little effect on the flexural strength of refractory castables. Compared with a castable containing white fused corundum aggregate (with a porosity of 4.2% and a bulk density of 3.62 g/cm3), the castable containing a porous corundum aggregate (with a porosity of 42.0% and a bulk density of 2.29 g/cm3) has a higher porosity of 35.7%, a lower bulk density of 2.44 g/cm3, a lower but sufficient compressive strength (80.4 MPa) and a lower slag resistance, but has a similar flexural strength (20.3 MPa), and then has a potential application for a non-slag working lining of a ladle to decrease the consumption of energy and Al2O3 material.

Lysinibacillus tabacifolii sp. nov., a Novel Endophytic Bacterium Isolated from Nicotiana tabacum Leaves

Yan-Qing Duan,Song-Tao He,Qing-Qing Li,Ming-Feng Wang,Wen-Yuan Wang,Wei Zhe,Yong-Hong Cao,Ming-He Mo,Yu-Long Zhai,Wen-Jun Li 한국미생물학회 2013 The journal of microbiology Vol.51 No.3

A Gram-positive, catalase- and oxidase-positive, strictly aerobic, endospore-forming rod bacterium, designated K3514T, was isolated from the leaves of Nicotiana tabacum. The strain was able to grow at temperatures of 8–40°C, pH 5.0–10.0 and NaCl concentrations of 0–7%. The predominant quinones (>30%) of this strain were MK-7(H2) and MK-7. Phylogenetic analysis of 16S rRNA gene sequence showed that strain K3514T was affiliated to the genus Lysinibacillus, with its closest relatives being Lysinibacillus mangiferihumi (98.3% sequence similarity), Lysinibacillus sphaericus (97.9% sequence similarity), Lysinibacillus fusiformis (97.4% sequence similarity), and Lysinibacillus xylanilyticus (97.3% sequence similarity). However, low levels of DNA-DNA relatedness values suggested that the isolate was distinct from the other closest Lysinibacillus species. Additionally, based on analysis of morphological, physiological, and biochemical characteristics, the isolate could be differentiated from the closest known relatives. Therefore, based on polyphasic taxonomic data, the novel isolate likely represents a novel species, for which the name Lysinibacillus tabacifolii sp. nov. and the type strain K3514T (=KCTC 33042T =CCTCC AB 2012050T) are proposed.

Overexpression of the potato StEPF2 gene confers enhanced drought tolerance in Arabidopsis

Yanli Wang,Tian Xie,Chunli Zhang,Juanjuan Li,Zhi Wang,Hongbing Li,Xiping Liu,Li-Na Yin,Shi-Wen Wang,Sui-Qi Zhang,Xiping Deng,Qingbo Ke 한국식물생명공학회 2020 Plant biotechnology reports Vol.14 No.4

Epidermal patterning factor 2 (EPF2) is a negative regulator of stomatal development, and is essential for plant growth, development, and environmental stress responses. However, the role of EPF2 in potato (Solanum tuberosum) has not been investigated to date. Here, we cloned and characterized the potato EPF2-like gene (StEPF2). StEPF2 is predominantly intercellular space localized and its transcripts were rhythmically expressed, and showed the highest expression in apical unexpanded leaves. Expression of StEPF2 was markedly down-regulated in response to abscisic acid and sodium chloride treatments; however, upon the application of polyethylene glycol, the expression of StEPF2 peaked at 4 h and then decreased gradually. Overexpression of StEPF2 in Arabidopsis (OE) substantially reduced stomatal density and photosynthetic rate, but had little effects on plant growth. Under drought stress, OE lines maintained higher photosynthetic rates, photosystem II efficiency, and instantaneous water use efficiency than wild-type (WT) plants. Moreover, OE lines showed less water loss and hydrogen peroxide accumulation in detached leaves compared with WT plants. Thus, our results suggest that StEPF2 acts as a negative regulator of stomatal development in potato, indicating that the role of EPF2 is conserved across plant species. Overall, StEPF2 represents an important target for the development of drought-tolerant potato cultivars via genetic engineering.

Antiviral activity of Herba Patrinea (a Chinese medicinal herb) against respiratory syncytial virus in vitro

Li, Hong-Yuan,Li, Shan-Shan,Liu, Dian-Li,Dong, Yan-Mei,Tian, Wen-Jing Kyung Hee Oriental Medicine Research Center 2003 Oriental pharmacy and experimental medicine Vol.3 No.2

Respiratory syncytial virus (RSV) has long been considered an important cause of severe lower respiratory tract infection in infants and young children throughout the world. Unfortunately, no effective treatment of RSV exists. Therefore, New agents are needed to reduce the impact of RSV. We have studied the anti-viral effect of traditional Chinese midicinal herbs for over ten years and find Herba Patrinea (a Chinese medicinal herb) has the anti-RSV effect in vitro. In this study, the Herba Patrinea was extracted with hot water, condensed and sterilized. The cytotoxicity of the aqueous extract was tested by adding the diluted extract directly to HeLa cells and its effect on anti-RSV was estimated by the CPEI assay. As a result, the median cytotoxic concentration $(CC_{50})$ of Herba Patrinea was 32 mg/ ml by morphological observation, the median effective concentration (50% effective concentration, $EC_{50}$) of the Herba Patrinea against replication of the Long strain of RSV in HeLa cells were 1.25 mg/ml. The selectivity index $(SI=CC_{50}/EC{50})$ is 25.6. Moreover, Herba Patrinea gave a dose-dependent response in inhibiting RSV. In time of addition experiment, Herba Patrinea inhibited replication of RSV in HeLa cells when it was added at 0h, 2h, and 4h after virus infection. In summary, the results of this study suggest Herba Patrinea may be a novel anti-RSV drug and it is worthy of further studying.

Development of self-centring energy-dissipative rocking columns equipped with SMA tension braces

Yan-Wen Li,Michael C.H. Yam,Ping Zhang,Ke Ke,Yan-Bo Wang 국제구조공학회 2022 Structural Engineering and Mechanics, An Int'l Jou Vol.82 No.5

Energy-dissipative rocking (EDR) columns are a class of seismic mitigation device capable of dissipating seismic energy and preventing weak-story failure of moment resisting frames (MRFs). An EDR consists of two hinge-supported steel columns interconnected by steel dampers along its height. Under earthquakes, the input seismic energy can be dissipated by plastic energy of the steel dampers in the EDR column. However, the unrecoverable plastic deformation of steel dampers generally results in residual drifts in the structural system. This paper presents a proof-of-concept study on an innovative device, namely self-centring energy-dissipative rocking (SC-EDR) column, aiming at enabling self-centring capability of the EDR column by installing a set of shape memory alloy (SMA) tension braces. The working mechanism of the SC-EDR column is presented in detail, and the feasibility of the new device is carefully examined via experimental and numerical studies considering the parameters of the SMA bar diameter and the steel damper plate thickness. The seismic responses including load carrying capacities, stress distributions, base rocking behaviour, source of residual deformation, and energy dissipation are discussed in detail. A rational combination of the steel damper and the SMA tension braces can achieve excellent energy dissipation and self-centring performance.

Two new sesquiterpenoids from endophytic fungus J3 isolated from Mangrove Plant Ceriops tagal

Yan-Bo Zeng,Hai-Gang Gu,Wen-Jian Zuo,Li-Li Zhang,Hong-Jin Bai,Zhi-Kai Guo,Peter Proksch,Wen Li Mei,Hao Fu Dai 대한약학회 2015 Archives of Pharmacal Research Vol.38 No.5

Two new sesquiterpenoids, named 2a-hydroxyxylaranolB (1) and 4b-hydroxyxylaranol B (2), togetherwith a known diterpenoid 3,4-seco-sonderianol (3) wereisolated from the fermentation of endophytic fungus J3 ofCeriops tagal. Their structures were elucidated based onspectroscopic methods including 1D and 2D NMR(HMQC, 1H-1H COSY and HMBC). All compounds wereevaluated for their cytotoxic activities by MTT method,and compound 3 exhibited cytotoxic activities againstK562, SGC-7901, and BEL-7402 cell lines.

Several Strategic Issues Facing China's Mega-Cities

Wen-yan, Li Seoul City University 1996 SEOUL metropolitan FORA 96 Vol.1996 No.-

Application of Computed Tomography for Differential Diagnosis of Glioma Stoke and Simple Cerebral Hemorrhage

Li, Xiao-Li,Zhou, Fa-Ming,Shangguan, Shou-Qin,Zou, Wen-Qin,Deng, Yan-Qing,Chen, Tao,Chen, Guang-Hui Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.8

Objective: To explore the value of computed tomography (CT) in the differential diagnosis of glioma stroke and simple cerebral hemorrhage. Materials and Methods: A total of 45 patients with glioma stroke and stroke as the initial symptom in our hospital from Jun., 2009 to Oct., 2013 were selected along with 50 individuals with simple cerebral hemorrhage in the same period randomly collected as a control group. The CT results in both groups were analyzed and compared. Results: In the observation group, there were 25 patients with astrocytoma (55.6%), 11 with oligodendroglioma (24.4%), 8 with ependymoma (17.2%) and 1 with glioblastoma multiforma (GBM, 2.22%). Additionally, the major CT manifestation was coexistence of hemorrhage and tumor signs. By comparison, it could be found that the proportions of patients respectively with peripheral edema and space-occupying effect in the observation group were significantly higher than in the control group (P<0.01). Conclusions: Application of CT examination combined with medical history in patients has very important clinical value in the differential diagnosis of glioma stroke and simple cerebral hemorrhage.

Seismic collapse risk of RC frames with irregular distributed masonry infills

Yan-Wen Li,Michael C.H. Yam,Ke Cao 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.76 No.3

Masonry infills are normally considered as non-structural elements in design practice, therefore, the interaction between the bounding frame and the strength contribution of masonry infills is commonly ignored in the seismic analysis work of the RC frames. However, a number of typical RC frames with irregular distributed masonry infills have suffered from undesirable weak-story failure in major earthquakes, which indicates that ignoring the influence of masonry infills may cause great seismic collapse risk of RC frames. This paper presented the investigation on the risk of seismic collapse of RC frames with irregularly distributed masonry infills through a large number of nonlinear time history analyses (NTHAs). Based on the results of NTHAs, seismic fragility curves were developed for RC frames with various distribution patterns of masonry infills. It was found that the existence of masonry infills generally reduces the collapse risk of the RC frames under both frequent happened and very strong earthquakes, however, the severe irregular distribution of masonry infills, such as open ground story scenario, results in great risk of forming a weak story failure. The strong-column weak-beam (SCWB) ratio has been widely adopted in major seismic design codes to control the potential of weak story failures, where a SCWB ratio value about 1.2 is generally accepted as the lower limit. In this study, the effect of SCWB ratio on inter-story drift distribution was also parametrically investigated. It showed that improving the SCWB ratio of the RC frames with irregularly distributed masonry infills can reduce inter-story drift concentration index under earthquakes, therefore, prevent weak story failures. To achieve the same drift concentration index limit of the bare RC frame with SCWB ratio of about 1.2, which is specified in ACI318-14, the SCWB ratio of masonry-infilled RC frames should be no less than 1.5. For the open ground story scenario, this value can be as high as 1.8.