Since 1978, China has experienced a rapid loss of arable land, leading to centralizing of farmland protection policies. To understand the growing centralization, this paper has used the lens of the interactions among (1) unwillingness to protect farmland among diverse actors, (2) policy failure and (3) policy change. The growing centralization is an adaptive response to the unwillingness to protect farmland from local up to provincial government levels, and its associated policy failure. The article suggests that gradual centralization over the last almost 40 years has gone through three phases: centralization to county-level, centralization to provincial-level, and intensifying technical supervision from central government. In the first phase, the unwillingness to preserve farmland appeared at the levels of the rural household, village and township; in the second phase, county- and prefecture-level governments began to lose willingness to preserve farmland; and, in the third phase, provincial governments’ willingness to preserve farmland weakened. The current centralized system has succeeded, for the most part, in addressing the problem of asymmetric information about farmland preservation between central and local governments, but the basic planning problem regarding loss of farmland remains a challenge.

No abstract

Vacuum breakdown (also known as arc or discharge) occurs when a sufficiently high electric field is applied between two electrodes in vacuum. The discharge is driven by the formation of an intensively glowing plasma at the cathode, which is followed by the ignition of an anode flare that gradually expands and fills the gap. Although it has been shown that the anode electrode does not play a significant role in the breakdown initiation, the nature of the anodic glow is of paramount importance for understanding the breakdown evolution. In this work, we use time-and space-resolved spectroscopy to study the anode flare. By using different anode and cathode materials, we find that excitations from both anode and cathode ions and neutrals contribute to the anodic glow. This implies that the cathodic plasma expands towards the anode without emitting any detectable light and starts glowing only when it reaches and interacts with the anode electrode. This interaction causes the introduction of anodic species in the plasma. The latter starts producing an expanding glow which contains spectra from both the cathode and anode materials and gradually fills the gap as the plasma equilibrates. Finally, we observe that after a breakdown, cathode material deposits on the anode electrode, gradually coating it. After hundreds of breakdowns, this coating covers the anode, resulting in the decay and possible elimination of the anode material signal in the spectra.

With the rapid advancement of IT, more and more attempts have been made to incorporate this modern technology into education. Of the newest teaching and learning devices and approaches, the use of microlectures and the idea of flipped classroom model(known as FCM) have caught the attention of many teachers. While the new teaching device and the innovative teaching approach succeed in some teachers' classes, they are doomed to failure in others' for this new approach involves prerequisites of which many teachers might not be fully aware of before their teaching practice, the lack of which might become barriers. This paper presents a post hoc analysis of a failed case with FCM and attempts to discuss, at a macroscopic level, problems with preconditions for FCM that currently exist, in the hope that teachers who are making an attempt at FCM can be aware of these problems and thus would make better preparation for it so as not to repeat the failure should they conduct FCM in their teaching. As are revealed by a detailed analysis of the reasons and a further deliberation on the failure with regard to a successful case, students' inadaptability to unmonitored e-learning, teachers' inadequate knowledge of computer science and information technology, the lack of a desirable communication platform and restrictive syllabuses may all hinder the smooth application of FCM, among which, the lack of a desirable communication platform and teachers' lack of adequate knowledge of computer science and information technology have become a bottleneck in the application of FCM.