China is thought to be the most important contributor to the global burden of carbonaceous aerosols, and residential coal combustion is the greatest emission source of black carbon (BC). In the present study, two high-efficiency household coalstovesaretestedtogetherwithhoneycomb-coal-briquettesandrawcoal-chunks of nine different coals. Coal-burning emissions are collected onto quartz fiber filters (QFFs) and analyzed by a thermal-optical transmittance (TOT) method. Emission factors (EFs) of particulate matter (PM), organic carbon (OC), and elemental carbon (EC) are systematically measured, and the average EFs are calculated by taking into account our previous data. For bituminous coal-briquette and -chunk, EFs of PM, OC, and EC are 7.33, 4.16, and 0.08 g/kg and 14.8, 5.93, and 3.81 g/kg, respectively; and for anthracite-briquette and -chunk, they are 1.21, 0.06, and 0.004 g/kg and 1.08, 0.10, and 0.007 g/kg, respectively. Annual estimates for PM, OC, and EC emissions in China are calculated for the years of 2000 and 2005 according to the EFs and coal consumptions, and the results are consistent with our previous estimates. Bituminous coal-chunk contributes 68% and 99% of the total OC and EC emissions from household coal burning, respectively. Additionally, a new model of Aethalometer (AE90) is introduced into the sampling system to monitor the real-time BC concentrations. On one hand, AE90 provides a set of EFs for optical BC in parallel to thermal-optical EC, and these two data are generally comparable, although BC/EC ratios vary in different coal/stove combinations. On the other hand, AE90 offers a chance to observe the variation of BC concentrations during whole burning cycles, which demonstrates that almost all BC emits into the flue during the initial period of 15 min after coal addition into household stoves.

Carbon nanotubes (CNTs) have been proved to be a novel type of nanostructure with unique structural, electronic and mechanical properties and have drawn extensive attention since their discovery. [1][2][3] Research over the past decade has revealed that the CNTs constitute a new form of carbon materials that are finding striking applications in many fields, such as energy conversion and storage, 4,5 electromechanical actuators, 6,7 chemical sensing 8 and so forth. Generally, the nanotubes can be divided into two categories: single-walled carbon nanotubes (SWNTs) and multi-walled carbon nanotubes (MWNTs). The former can be regarded as a graphene cylinder formed by rolling seamlessly a single graphene sheet along an (m,n) lattice vector in the sheet. The (m,n) indices is a central parameter governing the metallicity and chirality of the tubes. The latter is composed of coaxial multilayer graphene tubes with interlayer space of 0.34 nm. The diameter varies from 0.4 nm to 3 nm for the SWNTs and from 1.4 nm to 100 nm for the MWNTs (typical transmission electron microscopic images of the CNTs are shown in Fig. 1).Due to the unique physical and chemical properties and thus the striking applications in various research and industrial fields, the CNTs have drawn extensive interest over the past decade. To date, we have witnessed great successes in the synthesis of the CNTs and in understanding of their chemical and physical properties. Several excellent reviews concerning these issues have appeared in the literature. 9,10 Currently, increasing interests are being focused on the construction of the CNT-based functional nanodevices with novel properties for practical applications.On the other hand, the CNTs represent a new kind of carbonbased materials and are superior to other kinds of carbon materials commonly used in electrochemistry, such as glassy carbon (GC), graphite and diamond, mainly in the special structural features and unique electronic properties. As a result, besides their striking applications in other fields, study of the CNT electrochemistry thus far has revealed that these unique properties of the CNTs substantially make them useful for electrochemical investigations, e.g., electrocatalysis, direct electrochemistry of proteins and electroanalytical applications such as electrochemical sensors and biosensors. 11,12 The electroanalytical applications of the CNTs for construction of This review addresses recent developments in electrochemistry and electroanalytical chemistry of carbon nanotubes (CNTs). CNTs have been proved to possess unique electronic, chemical and structural features that make them very attractive for electrochemical studies and electrochemical applications. For example, the structural and electronic properties of the CNTs endow them with distinct electrocatalytic activities and capabilities for facilitating direct electrochemistry of proteins and enzymes from other kinds of carbon materials. These striking electrochemical properties of the CNTs pave the way to CNT-based bioelectrochemist...