There is considerable debate about the causes of grassland degradation and desertification in China. The discussion is rekindled by recent studies that claim restoration. The reversal in degradation is attributed to policies, which include the grazing ban and the pasture contract system. Contrarily, this article maintains that these studies disregard the complexity and multilayered nature of grassland degradation, and questions whether aforementioned policies have had this effect. In this context, we report on one of the first long-term surveys (1995 and 2011) of herders' perceptions. The survey (492 valid responses) represents two ecoregions: the semiarid desert/steppe and Loess Plateau pasture. Based on the data, we adopted a renewed analytical model for scientists, termed the CCC-Framework. The model calls for caution in proposing certain restoration measures when uncertainties are identified around a “triple C”: (1) condition of vegetation; (2) causality of degradation; and (3) costs of implementation. According to this framework, we establish uncertainty about the condition of allegedly restored vegetation, with particular reference to herders' perceived rise in nonpalatable grass species. Moreover, causality between grassland restoration and effect is difficult to ascertain due the short time frame in which most studies have been conducted. Lastly, it is doubtful whether to date undetermined ecological benefits outweigh implementation costs, especially as the survey pinpointed herders' loss of livelihood without alternative income, illegal grazing, low legal understanding, and limited access to grassland rights.@en

Photoelectrochemical (PEC) devices for solar water splitting require not only high solar to hydrogen conversion efficiency but also high chemical stability in strong acidic or alkaline electrolytes for long-term operation. Titanium dioxide (TiO₂) has been considered as a highly promising protection layer to achieve high chemical stability for solar water splitting devices, especially for silicon based monolithic photovoltaic electrochemical (PV-EC) systems, while there is a trade-off relationship between activity and stability in these devices: the high charge transport barrier at the PV (silicon based thin film solar cells)/TiO₂ interface and the high ohmic loss in TiO₂ films hinder the device performance, especially when a thick TiO₂ protection layer (preferred to enhance the chemical stability in the electrolyte) is used. Herein, we show that a hydrogen doped TiO₂ protection layer can break this traditional trend to increase the activity without deteriorating the stability, when thick protection layers are employed to ensure stability. We demonstrated significant performance enhancement in hydrogenated amorphous silicon/silicon germanium (a-Si:H/a-SiGe:H) photocathodes through this approach. On one hand, the H-doping can shift up the Fermi level and reduce the electron transport barrier at the interface of the PV/TiO₂ protection layer. On the other hand, the higher carrier density via H-doping leads to the enhancement of electron transport in TiO₂ films and a shorter depletion layer barrier. Thus, the H-doping results in a higher photocurrent output at 0 V vs. reversible hydrogen electrode (RHE), indicating the high potential of the H-doped TiO₂ protection layer for achieving stable and efficient monolithic solar water splitting devices.

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