The freight sector is an important component of China’s national economy. It is composed of multiple sub-sectors and has a complex internal structure. This internal structure can hide information on the freight sector’s operational performance. Previous studies on transportation operational performance made measurements based on the whole transportation sector, and all of these studies ignored the impacts that the internal structure of the sub-sectors have on performance, which leaves a gap in the research. To illustrate this structure, this study proposes a parallel slacks-based measure model to measure transportation efficiency, which can represent the freight sector’s operational performance. The efficiencies of transportation operations for the whole freight sector and its three sub-sectors are further measured, by treating the sub-sectors as parallel subunits. Then, the inefficiency sources from the sub-sectors can be identified by the proposed model. To detect the environmental impact on transportation operations, energy consumption and carbon dioxide emissions are also considered in the evaluation. On the basis of the proposed approach, an application of the Chinese freight sector from 2013 to 2017 is provided. The impacts of influential factors on transportation efficiency are also explored. The empirical findings can be illustrated as follows: (1) there exist significant disparities in regional transportation efficiencies in the freight sector and its sub-sectors; (2) the inefficient transportation performance of the Chinese freight sector mainly derives from the poor performance of the waterway sub-sector; and (3) freight volume and population density have positive impacts on the transportation efficiencies of the railway and highway sub-sectors. Finally, some policies for improving transportation efficiency are also provided.

This report was prepared as the result of work sponsored by the California Energy Commission. It does not necessarily represent the views of the Energy Commission, its employees or the State of California. The Energy Commission, the State of California, its employees, contractors and subcontractors make no warranty, express or implied, and assume no legal liability for the information in this report; nor does any party represent that the uses of this information will not infringe upon privately owned rights. This report has not been approved or disapproved by the California Energy Commission nor has the California Energy Commission passed upon the accuracy or adequacy of the information in this report.

The effects of neighborhood-scale land use and land cover (LULC) properties on observed air temperatures are investigated in two regions within Los Angeles County: Central Los Angeles and the San Fernando Valley (SFV). LULC properties of particular interest in this study are albedo and tree fraction. High spatial density meteorological observations are obtained from 76 personal weather-stations. Observed air temperatures were then related to the spatial mean of each LULC parameter within a 500 m radius “neighborhood” of each weather station, using robust regression for each hour of July 2015. For the neighborhoods under investigation, increases in roof albedo are associated with decreases in air temperature, with the strongest sensitivities occurring in the afternoon. Air temperatures at 14:00–15:00 local daylight time are reduced by 0.31 °C and 0.49 °C per 1 MW increase in daily average solar power reflected from roofs per neighborhood in SFV and Central Los Angeles, respectively. Per 0.10 increase in neighborhood average albedo, daily average air temperatures were reduced by 0.25 °C and 1.84 °C. While roof albedo effects on air temperature seem to exceed tree fraction effects during the day in these two regions, increases in tree fraction are associated with reduced air temperatures at night.

An extremely efficient flame retardant with low water solubility has been developed for bisphenol-A based polycarbonate. Potassium trimethylsilylbenzenesulfonate (KTSS) combining trimethylsilyl and sulfonate groups in its molecule is 7 times less water soluble and 5 times more effective in flame retardancy than potassium benzenesulfonylbenzenesulfonate (KSS), the commercial workhorse for polycarbonate (PC). At a loading of 0.02%, KTSS enables PC to achieve a solid UL-94 V0 rating and a limiting oxygen index (LOI) value of 34.4%, representing an increase of 8.5 units. The extremely high efficiency of KTSS stems from its great migration ability to the burning polymer surface facilitated by trimethylsilyl group, its timely release of active alkaline species that promote the charring process of PC, and the stabilization of char by silicon. In addition to the exceptional flame retardancy, PC/KTSS retains excellent physical properties of PC.