排序方式: 共有36条查询结果,搜索用时 15 毫秒
31.
Venture capital has proven to be an essential resource for economic growth, especially in some technological clusters. The focus is on the way the venture capitalist makes the investment decision and the portfolio selection. The aim of this paper is to formulate the venture capital investment problem through the Goal Programming model where the Financial Decision-Maker’s preferences will be explicitly incorporated through the concept of satisfaction functions. The proposed model will be illustrated by using data from an Italian venture capital fund. 相似文献
32.
Previous studies have shown that certain molecular substances taken in microsamples (droplets of about 1 μm3 in volume dispersed within an emulsion) crystallize into metastable crystalline phases. These compounds are studied in solution with benzene which does not show metastable polymorphism. The binaries benzene-1-2 dichlorobenzene, benzene-chloroform and benzene-nitrobenzene in emulsion are investigated by D.S.C. techniques. Metastable phases appear, too, and it is possible to draw metastable liquidus and locate metastable eutectics in the phase diagrams. In benzene-chloroform solution at least one new metastable phase is detected. In the benzene-nitrobenzene binary a metastable phase is detected, although neither benzene nor nitrobenzene show a metastable crystalline phase when they are pure. 相似文献
33.
Stereoretentive Copper‐Catalyzed Directed Thioglycosylation of C(sp2)−H Bonds of Benzamides
下载免费PDF全文
![点击此处可从《Chemistry (Weinheim an der Bergstrasse, Germany)》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Amélie Chabrier Dr. Alexandre Bruneau Sara Benmahdjoub Dr. Belkacem Benmerad Dr. Sabrina Belaid Jean‐Daniel Brion Dr. Mouâd Alami Dr. Samir Messaoudi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(42):15006-15010
An efficient thioglycosylation of C(sp2)?H bonds with thiosugars has been established for the first time. Using only Cu(OAc)2?H2O as a catalyst and Ag2CO3 as an additive in DMSO, the protocol proved to have broad scope, and a variety of complex thioglycosides have been prepared in good yields with exclusive β‐selectivity. 相似文献
34.
ABSTRACTIn this paper, SiO2 nanoparticle-doped polymer dispersed liquid crystal (PDLC) lenses are made from a mixture of prepolymer, 5CB liquid crystal and SiO2 nanoparticles by the polymerisation induced phase separation (PIPS) process. The effect of SiO2 nanoparticles on the electro-optical properties of PDLC ?lms are studied. It is established that SiO2 nanoparticles affect the microstructure of PDLC ?lms signi?cantly because of the formed agglomerates of SiO2 nanoparticles. Results show an improvement in the electro-optical properties and a decrease in the response time for doped systems with small amount of SiO2 nanoparticles. We also observe a shift of nematic–isotropic transition temperature as a function of SiO2 nanoparticle contents. A good agreement between the electro-optical study and thermophysical properties is reached. 相似文献
35.
Lazreg Aref H Gaaliche B Fekih A Mars M Aouni M Pierre Chaumon J Said K 《Natural product research》2011,25(3):310-319
The latex of fig fruit (Ficus carica) is used in traditional medicine for the treatment of skin infections such as warts and also diseases of possible viral origin. Five extracts (methanolic, hexanic, ethyl acetate, hexane-ethyl acetate (v/v) and chloroformic) of this species were investigated in?vitro for their antiviral potential activity against herpes simplex type 1 (HSV-1), echovirus type 11 (ECV-11) and adenovirus (ADV). To evaluate the capacity of the extracts to inhibit the replication of viruses, the following assays were performed: adsorption and penetration, intracellular inhibition and virucidal activity. Observation of cytopathic effects was used to determine the antiviral action. The hexanic and hexane-ethyl acetate (v/v) extracts inhibited multiplication of viruses by tested techniques at concentrations of 78 μg mL(-1). These two extracts were possible candidates as herbal medicines for herpes virus, echovirus and adenovirus infectious diseases. All extracts had no cytotoxic effect on Vero cells at all tested concentrations. 相似文献
36.
Salah KB Mahjoub MA Ammar S Michel L Millet-Clerc J Chaumont JP Mighri Z Aouni M 《Natural product research》2006,20(12):1110-1120
This study examines the in vitro antimicrobial and antioxidant activities of the methanolic extracts of three Salvia species from Tunisia: Salvia aegyptiaca L., S. argentea L. and S. verbenaca Ssp. clandestina L. Pugsley. The extracts inhibited the growth of dermatophytes and of bacteria responsible for unpleasant odours to varying degrees; the pathogenic yeasts Candida albicans and Cryptococcus neoformans, the filamentous fungi Aspergillus fumigatus and selected dog otitis bacteria were all resistant to each of the extracts. The extracts were screened for their antioxidant activities using 2,2-diphenyl-1-picrylhydrazyl free radical scavenging and 2,2'-azinobis(3-ethylbenzothiazoline-6-sulphonic acid) test systems, and gave positive results in both tests. The extracts of S. aegyptiaca were the most active in both tests, followed by those of S. verbenaca, then S. argentea. These results confirm the antimicrobial and antioxidant activities of the genus Salvia and underline the potential of these plants either as natural preservatives or in pharmaceutical applications. 相似文献