Chinese researchers

Carbon nanotubes mixed with ruthenium oxide powder, and immersed in a liquid electrolyte, have been shown by a Chinese research group to function as supercapacilors with much larger capacitance per unit volume than is normally accessible (Ma et al. 2000). 

In 1997, a Chinese research group [78] used the colloidal solution of 70-nm-sized carboxylated latex particles as a subphase and spread mixtures of cationic and other surfactants at the air-solution interface. If the pH was sufficiently low (1.5-3.0), the electrostatic interaction between the polar headgroups of the monolayer and the surface groups of the latex particles was strong enough to attract the latex to the surface. A fairly densely packed array of particles could be obtained if a 2 1 mixture of octadecylamine and stearic acid was spread at the interface. The particle films could be transferred onto solid substrates using the LB technique. The structure was studied using transmission electron microscopy. 

Studies performed by Chinese researchers are of most interest in the context of the problem under consideration. In these studies, various alkylating agents were efficiently used in the synthesis of enantiomerically pure nitronates and ethyl nitroacetate derivatives (17) (Scheme 3.6, Eq. 5). 

A Chinese research team found <1997PS299> that derivative 21 of the new [l,3,4]thiadiazolo[3,2-f][l,3,5,2,]thia-diazaphosphorine ring system undergoes spontaneous oxidation on air, as shown in Scheme 5. Thus, storage of the dichloromethane solution of 21 for 48 h at room temperature results in formation of a mixture of 22 and 23. 

Chinese researchers reported a synthetic route to photochrome 16 (Scheme 7), in which the aldehyde functions are then transformed into cyclic acetals and thioacetals, methylol and dicyanoethylene groups (07T5437, 08T2576). Scheme 7 also gives (at the bottom) symmetrical photochrome 17 (where R are ferrocenyl substituents), which does not exhibit fluorescence in the initial state, but shows fluorescence in the cyclic form and which is also synthesized starting from dialdehyde 16 (08AFM302). 

The conventional and efficient method for the synthesis of dithienyl-maleimide 185, according Scheme 56, was described by Chinese researchers (06TL9227). 2,3-Bis(5-bromo-2-methylthiophen-3-yl)fumaronitrile 184 was hydrolyzed with sodium methoxide-methanol followed by N-meth-ylation with potassium ferf-butoxide and iodomethane to give the target compound 2,3-bis(5-bromo-2-methylthiophen-3-yl)-N-methylmaleimide. Subsequent modification of the latter afforded 186 containing two ferrocene fragments. 

In 1972, Chinese researchers isolated, by extraction at low temperature from a plant, a crystalline compound that they named qinghaosu [the name artemisinin (la) is preferred by Chemical Abstracts, RN 63968-64-9]. The plant source of artemisinin is a herb, Artemisia annua (Sweet wormwood), and the fact that artemisinin is a stable, easily crystallizable compound renders the extraction and purification processes reasonably straightforward. The key pharmacophore of this natural product is the 1,2,4-trioxane unit (2) and, in particular, the endoperoxide bridge. Reduction of the peroxide bridge to an ether provides an analogue, deoxyartemisinin 3, that is devoid of antimalarial activity. ... 

PATO has also been synthesized by a Chinese team [68] by the condensation of tetryl with 3-amino-l,2,4-triazole and their data on its thermal stability is in agreement with American investigators [69]. Chinese researchers have also reported two nitro derivatives of PATO with the following structures based on IR and NMR [68]. 

The first study of this kind was carried out by Chinese researchers in 2003 [144]. They prepared MIP beads for the SPE of tyrosine by simple suspension in water as well as by two-step swelling and suspension polymerisation. They found no substantial difference in the rebinding capacity of the beads prepared by the two methods. A more thorough analysis of various synthetic approaches to MIP beads was conducted a year later by Perez-Moral and Mayes [145]. They took a standard monomer mixture with propranolol as the template molecule and polymerised it by bulk polymerisation, suspension polymerisation, precipitation polymerisation, two-step-swelling polymerisation and emulsion core-shell polymerisation (see also Sect. 2.2.3). Care was taken to keep the polymerisation... 

The main barrier to greater commercial success has been its historic high cost until recently. Some believe the solution is to extract zein as a by-product in the manufacturing process for bioethanol. From a high-value added perspective, Chinese researches have conducted intensive research on the use of zein as a biomedical material (Dong et al., 2004). 

As mentioned, qinghaosu chemically belongs to the cadinane sesquiterpene therefore, the other sesquiterpene components in A. annua have been given preferential attention. From indigenous A. annua L., continuous phytochemical studies by Chinese researches in the early 1980s led to the excavation of another ten sesquiterpenes including deoxy-artemisinin (14), artemisinin D (15), artemisinin... 

Some Russian and Chinese researchers (Chen et al., 1999b) observed in the laboratory that as pH was increased, polymer adsorption was reduced. However,... 

Two major breakthroughs of the past few decades have renewed the assault of scientists to this infective disease. The first is the complete sequencing of the genome of Plasmodium falciparum [4] that is expected to provide useful information for the identification of new drug targets. The second is the discovery by Chinese researchers of artemisinin (qinghaosu), an endoperoxide sesquiterpene lactone, as the active principle of the sweet wormwood, Artemisia annua, an herbal remedy used in folk Chinese medicine for 2000 years [5]. This molecule and its... 

Chinese researchers continued to study the contents, distribution and sources of heavy metals in typical Chinese seawaters and deeply studied their forms and bioavailability. 

Recently, thus, the mechanical properties of the capsules doped with paraffin were considerably improved by another Chinese research team using MTMS in place of TEOS. The sol-gel encapsulation of paraffin in methylsilica takes place with both high encapsulation ratio (82%) and efficacy (no leaching of the melted paraffin) of the silica capsules, whereas the thermal stability and lowered flammability of the silica-microencapsulated paraffin is retained. 

Thermodynamic stabilities of ylides are known to be measured by the ease of carbanion formation through the removal of a proton from their precursors. A Chinese research group has now performed the calculations on about 80 experimentally-characterized N-, P-, and S-ylide precursors and developed an extensive scale of ylide thermodynamic stability that may find applications in synthetic organic chemistry. This theoretical protocol can reliably predict the pXa values of diverse structurally unrelated ylide precursors in DMSO with an error bar of ca. 1.6-1.9 pXa units. ... 

Some researches of Chinese researchers are devoted to the synthesis and study of properties of copolymers of arylenestersulfones and esterk-etones [427-429]. 

Chinese Research Center for Endemic Disease Control Harbin Medical College Harbin, China... 

The rough surface was produced by an abrasive wear process as shown in Fig. 1. The experimental conditions of the abrasive wear process were as follows. The size of specimen was 60 x 35 x 5 mm. The abrasive wear test was conducted on the turnplate abrasive wear test machine made by the Chinese Research Academy of Agricultural Machine (model JMM). The mixture comprised of 450-900 pm quartz sands 94 wt%, bentonite 3 wt%, and water of 3 wt% was used as abrasive to wear the specimens. The buried depth of the specimen was 40 mm (see Fig. 1). Three test material specimens (samples 1-3 in Fig. 1) and one comparative material specimen (sample 4 in Fig. 1) were fixed on the clamping apparatus at the same time. During the wear process, the specimens did not move, the turntable turned at 45 rpm causing the abrasive to move. This resulted in a relative movement between the specimen and the abrasive at the speed of 123.6 m/min. By means of the intermittent rotation of the clamping apparatus, every specimen from sample 1 to sample 4 was in turn located at the wear position at which the specimen was just buried in the abrasive to be worn. At the wear position the wear distance of each sample in each wear turn was 803.4 m ( wear distance is the distance of the relative movement between the specimen located at the wear position and the abrasive). Total wear distance of each specimen was 16068 m. 

Chinese researchers have reported lasing in noble gas mixtures excited by a fast-burst reactor, but have not followed up this work with publications in English. Japanese workers have investigated the usefulness of the 0.585-)um RPL line as a diagnostic for neutron flux in nuclear reactors (Yamanaka, 1997). 

Chinese researchers have tried combining dibromodiphenyl ether flame retardant with antimony trioxide and a nanoclay to make flame retardant polyamides. Better results were obtained than with similar samples without nanoclay. In particular the researchers achieved a very low peak heat release rate, and a V-0 rating in the UL-94 test. Carbon nanotubes are expected to show some benefit in FR terms. Nanoclays appear to stop PU from dripping, but their effectiveness is lost if the quaternary ammonimn compoimd used to treat the clay decomposes in the heat of a fire. 

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