Waste is a valuable secondary carbon resource. In the linear economy, it is predominantly landfilled or incinerated. These disposal routes not only lead to diverse climate, environmental and societal problems; they also represent a loss of carbon resources. In a circular carbon economy, waste is used as a secondary carbon feedstock to replace fossil resources for production. This contributes to environmental protection and resource conservation. It furthermore increases a nation’s independence from imported fossil energy sources. China is at the start of its transition from a linear to circular carbon economy. It can thus draw on waste management experiences of other economies and assess the opportunities for transference to support its development of ‘zero waste cities’. This paper has three main focuses. First is an assessment of drivers for China’s zero waste cities initiative and the approaches that have been implemented to combat its growing waste crisis. Second is a sharing of Germany’s experience—a forerunner in the implementation of the waste hierarchy (reduce–reuse–recycle–recover–landfill) with extensive experience in circular carbon technologies—in sustainable waste management. Last is an identification of transference opportunities for China’s zero waste cities. Specific transference opportunities identified range from measures to promote waste prevention, waste separation and waste reduction, generating additional value via mechanical recycling, implementing chemical recycling as a recycling option before energy recovery to extending energy recovery opportunities.

Long aromatic polyamide chains are prepared from the corresponding monomers. The resultant polymer adopts a hollow helical conformation that is stabilized by intramolecular H-bonding interaction between side chains.

We reported the effect of the deposition time of barrier layers on optical and structural properties of high-efficiency green-light-emitting InGaN∕GaN multiple quantum wells (MQWs) by photoluminescence (PL) and high-resolution x-ray diffraction techniques. The MQW samples on (0001)-plane sapphire substrates were prepared with a ramping method by metalorganic chemical deposition. It was found that the structural or interface quality of the MQW system improved as the deposition time of barrier layers increased from 10 to 14min, but lattice relaxation was still observed. The relaxation degree decreases from 33% to 6% as the deposition time increases. Temperature-dependent PL measurements from 12 to 300K indicated that the integrated PL intensities start to decay rapidly as temperature rises above 50K for the sample with the shorter deposition time, and above 100K for the sample with the longer deposition time. The luminescence thermal quenching of the two samples suggests the two nonradiative recombination centers based on a fit to Arrhenius plot of the normalized integrated PL intensity over the entire temperature range. The first centers at higher temperatures show less difference for the two samples. The second centers at lower temperatures can be attributed to the trapping of carriers at the rough interface for the sample with the shorter deposition time and to the thermal quenching of bound excitons for the sample with the longer deposition time, respectively.