特朗普政府为何“退群”?

特朗普执政以来,美国政府频繁"退群"或"威胁退群"。究其原因,既有研究从国家实力、成本收益、制度制衡和领导人等视角进行了分析,虽不乏解释力,但也有不足。本文聚焦于影响特朗普政府决策的国内因素,基于国内政治成本视角探讨特朗普政府"退群"的原因。国内政治成本以民众、利益集团以及政党的态度为衡量标准,分为维系成本和退出成本。特朗普政府采取"退群"和"威胁退群"的不同策略与国内政治成本高低相关。当维系成本高、退出成本低时,特朗普政府会选择"退群"策略;当维系成本和退出成本都为高时,倾向于"威胁退群";当维系成本低、退出成本高,"不退群"更为常见;当维系成本和退出成本都为低时,即国内政治成本较弱,是否"退群"取决于其他因素。特朗普政府退出不利于以色列利益的"群"的目的是争取国内亲以色列团体的支持;威胁退出《北美自由贸易协定》(NAFTA)是特朗普政府经济单边主义的一部分,目的是通过增加就业争取国内民众的支持。以上两类不同"退群"策略的案例研究基本检验了本文的假设。2020年是美国大选之年,若特朗普继续执政,"退群"与否仍将是回应其支持者诉求的重要手段;若民主党候选人当选,随着影响决策的民众主体的改变,美国政府的"退群"政策将有所改变。

印度“退群”与RCEP谈判前景探析

印度参与RCEP谈判是经济因素与政治因素、国际因素和国内因素共同作用的结果,也是印度在其所处发展阶段和国际形势下所能够采取的较为理想的战略选择。印度的"退群"行为在很大程度上应归咎于莫迪政府面临的国内政治困境及其在这一背景下利益偏好的变化,本质上反映了印度对于自身经济实力和发展前景的信心不足,也体现了莫迪政府在协调国内各方利益和缓解国内舆论压力上的治理能力不足。更重要的是,印度"退群"映射出RCEP及其成员国自身存在的一些深层次问题,也反映了各成员国在区域经济合作发展方向上面临的两难困境。就RCEP的前景来看,未来印度重新加入RCEP的可能性较大,但考虑到印度的国内现状、各成员国参与谈判的物质成本、时间成本以及国际和地区形势,其他15个成员国率先签署协议,印度视情况重新考虑加入将是更加经济和务实的选择。

美国“退群”的根本原因及其严重后果

近年来,美国特朗普政府接连不断地对一些重要多边双边国际协议乃至国际组织、国际会议"退群"、退会、拒签、退约,而且愈演愈烈。美国"退群"的根本原因一是其霸权主义的极端表现;二是源于"美国优先"的极端民族主义;三是"退群"方式也与特朗普作为商人政治家的独特品格有关。美国"退群"造成一系列严重后果,一是具有严重的负面示范效应;二是现有国际秩序遭到严重破坏;三是增大了引发新一轮军备竞赛、危及世界和平的风险。

美国参与国际组织的“初一”和“十五”

特朗普总统领导下的美国频繁毁约,退出诸多国际组织,引起世界的广泛关注和讨论。其实美国"退群"不是特朗普总统首创,而是有历史可寻。围绕着"美国利益最大化"的目标,美国对国际组织的态度可谓是"初一""十五"不一样。总统的个人因素、政党倾向、单边主义传统等都在不同程度上发挥影响。作为国际组织的重要成员甚至是领导者,美国"退群"会导致国际多边机制领导力不足,带来不良示范,削弱国际合作的信心。

周期理论视角下特朗普政府“退群行动”动因探析

自特朗普执政以来,美国政府“退群行动”频发。从周期理论的视角看,特朗普政府大面积退出各类国际合作机制是美国外交向内向型周期转换的表现。其中,美国国内经济周期处于持续低迷状态、孤立主义情绪、行政与立法之间的紧张关系以及新兴国家快速崛起带来的挑战是美国对外战略向内收缩的动因所在。

Microbial Community Characteristics in a Degraded Wetland of the Yellow River Delta

Five different sites with a soluble salt gradient of 3.0-17.7 g kg^-1 dry soil from the coast to the inland were selected, and the microbial population size, activity and diversity in the rhizospheres of five common plant species and the adjacent bulk soils （non-rhizosphere） were compared in a degraded wetland of the Yellow River Delta, Shandong Province, China to study the effects of soil environment （salinity, seasonality, depth, and rhizosphere） on microbial communities and the wetland＇s ecological function, thus providing basic data for the bioremediation of degraded wetlands. There was a significant negative linear relationship between the salinity and the total number of microorganisms, overall microbial activity, or culturable microbial diversity. Salinity adversely affected the microbial community, and higher salinity levels resulted in smaller and less active microbial communities. Seasonal changes were observed in microbial activity but did not occur in the size and diversity. The microbial size, activity and diversity decreased with increasing soil depth. The size, activity and diversity of culturable microorganisms increased in the rhizospheres. All rhizospheres had positive effects on the microbial communities, and common seepweed had the highest rhizosphere effect. Three halophilic bacteria （Pseudomonas mendocina, Burkholderia glumae, and Acinetobacter johnsonii） were separated through BIOLOG identification, and common seepweed could be recommended for bioremediation of degraded wetlands in the Yellow River Delta.

Differentiation of Soil Fauna Populations in Conventional Tillage and No-Tillage Red Soil Ecosystems

In a field experiment, the populations of major soil fauna groups including earthworms, enchytraeids,arthropods and nematodes were examined in conventional tillage (CT) and no-tillage (NT) red soil ecosystems to evaluate their responses to tillage disturbance. Earthworms, macrry and micro-arthropods were stimulated under NT with earthworms showing the highest population increase by four times, while enchytraeids and nematodes favored CT system, predicting certain adaptability of these animals to plow-disturbed soil environment. On the basis of relative response index it was found that soil fauna was more sensitive to tillage than soil resource base (C and N pools) and microflora. The population structure of soil fauna was also affected by tillage treatments. Analysis on nematode trophic groups showed that bacteria-feeding and plant parasitic nematodes were more abundant in CT soil whereas the proportions of fungivores and omnivorepredators increased in NT soil. Possible reasons for the differentiation in both size and structure of the fauna population were discussed and the ecological significance involved in these changes was emphasized.

Soil Cellulase Activity and Fungal Community Responses to Wetland Degradation in the Zoige Plateau, China

Four soil types(peat, marsh, meadow, and sandy) in the Zoige Plateau of China are associated with the severity of wetland degradation. The effects of wetland degradation on the structure and abundance of fungal communities and cellulase activity were assessed in these 4 soil types at 3 depths using DGGE(Denatured Gradient Gel Electrophoresis), q PCR(Quantitative Real-time PCR),and 3,5-dinitrosalicylic acid assays. Cellulase activity and abundance of the fungal community declined in parallel to the level of wetland degradation(from least to most disturbed). DGGE analysis indicated a major shift in composition of fungal communities among the4 soil types consistent with the level of degradation.Water content(WC), organic carbon(OC), total nitrogen(TN), total phosphorus(TP), available nitrogen(AN), and available phosphorus(AP) were strongly correlated with cellulase activity and the structure and abundance of the fungal community.The results indicate that soil physicochemical properties(WC, OC, TN, TP, AN, and AP), cellulase activity, and diversity and abundance of fungal communities are sensitive indicators of the relative level of wetland degradation. WC was the major factorinvolved in Zoige wetland degradation and lower WC levels contributed to declines in the abundance and diversity of the fungal community and reduction in cellulase activity.

Dependent task assignment algorithm based on particle swarm optimization and simulated annealing in ad-hoc mobile cloud

In order to solve the problem of efficiently assigning tasks in an ad-hoc mobile cloud( AMC),a task assignment algorithm based on the heuristic algorithm is proposed. The proposed task assignment algorithm based on particle swarm optimization and simulated annealing( PSO-SA) transforms the dependencies between tasks into a directed acyclic graph( DAG) model. The number in each node represents the computation workload of each task and the number on each edge represents the workload produced by the transmission. In order to simulate the environment of task assignment in AMC,mathematical models are developed to describe the dependencies between tasks and the costs of each task are defined. PSO-SA is used to make the decision for task assignment and for minimizing the cost of all devices,which includes the energy consumption and time delay of all devices.PSO-SA also takes the advantage of both particle swarm optimization and simulated annealing by selecting an optimal solution with a certain probability to avoid falling into local optimal solution and to guarantee the convergence speed. The simulation results show that compared with other existing algorithms,the PSO-SA has a smaller cost and the result of PSO-SA can be very close to the optimal solution.

Crowned dens syndrome developed after an endoscopic retrograde cholangiopancreatography procedure

We present a unique case of crowned dens syndrome(CDS) that developed after endoscopic retrograde cholangiopancreatography(ERCP) in a patient who presented with fever and neck pain. Administration of non-steroidal anti-inflammatory drugs was extremely effective for relieving fever and neck pain, and in the improvement of inflammatory markers. To the best of our knowledge, this is the first case report of CDS caused by an ERCP procedure. In a patient with fever and neck pain after an ERCP procedure, CDS should be considered in the differential diagnosis.

Ant-cycle based on Metropolis rules for the traveling salesman problem

In this paper, recent developments of some heuristic algorithms were discussed. The focus was laid on the improvements of ant-cycle (AC) algorithm based on the analysis of the performances of simulated annealing (SA) and AC for the traveling salesman problem (TSP). The Metropolis rules in SA were applied to AC and turned out an improved AC. The computational results obtained from the case study indicated that the improved AC algorithm has advantages over the sheer SA or unmixed AC.

Responses of soil inhabiting nitrogen-cycling microbial communities to wetland degradation on the Zoige Plateau,China

The wetlands on the Zoige Plateau have experienced serious degradation,with most of the original marsh being converted to marsh meadow or meadow.Based on the 3 wetland degradation stages,we determined the effects of wetland degradation on the structure and relative abundance of nitrogencycling(nitrogen-fixing,ammonia-oxidizing,and denitrifying) microbial communities in 3 soil types(intact wetland:marsh soil;early degrading wetland:marsh meadow soil;and degraded wetland:meadow soil) using 454-pyrosequencing.The structure and relative abundance of nitrogen-cycling microbial communities differed in the 3 soil types.Proteobacteria was the predominant phylum in most soil samples but the most abundant soil nitrogenfixing and denitrifying microbial bacteria differed at the class,order,family,and genus levels among the 3soil types.At the genus level,the majority of nitrogenfixing bacterium sequences related to Bradyrhizobium were from marsh and marsh meadow soils;whereas those related to Geobacter originated from meadow soil.The majority of ammonia-oxidizing bacterium sequences related to Nitrosospira were from marsh(except for the 40-60 cm layer),marsh meadow and meadow soils;whereas those related to Candidatus Solibacter originated from 40-60 cm layer of marsh soil.The majority of denitrifying bacterium sequences related to Candidatus Solibacter and Anaeromyxobacter were from marsh and meadow soils;whereas those related to Herbaspirillum originated from meadow soil.The distribution of operational taxonomic units(OTUs)and species were correlated with soil type based upon Venn and Principal Coordinates Analysis(PCoA).Changes in soil type,caused by different water regimes were the most important factors influencing compositional changes in the nitrogen-fixing,ammonia-oxidizing,and denitrifying microbial communities.

On the Properties of the Solution of a Strongly Degenerate Parabolic Equation

For a strongly degenerate parabolic equation, we first use the results of Ph. Blanc[1] to get that the Neumann problem may not have a global classical solution. The reason is that the gradients of some local classical solutions blow up in finite time. And under some conditions, we get the global integral solution by the use of semigroup. Then, we give a sufficient condition under which the Neumann problem has a global classical solution. Finally. we study the asymptotic behaviour of the classical solution and prove that the solution converges to the mean of the initial value.

Shen's Experience in Application of the Drugs for Tonifying the Kidney to.Reduce and Withdraw Adrenocortical Hormone

Adrenocortical hormone (ACH) has antiinflammatory and antiallergic actions, changes stress state and controls the attack of some severe and obstinate diseases. The treatment of chronic diseases with ACH often leads to its dependence; especially oral administration of ACH for a long time is liable to inhibit the function of hypothalamus-pituitary-adrenocortical-thymic axis (HPAT), and results in the hypo-reservation of adrenal cortex. Hence, sudden ACH withdrawal or decrease often causes the disease recurrence, even adrenocortical crisis. Academician Shen Ziyin has a wealth of clinical experience in both the withdrawal and reduction of ACH and the keeping of therapeutical effectiveness to form his unique remedy in the application of drugs. Shen's rich experience is described as follows.

Advanced Coverage Optimization Techniques for Small Cell Clusters

Coverage challenge for small considered to be a optlmlzation is a main cell clusters which are promising solution to provide seamless cellular coverage for large indoor or outdoor areas. This paper focuses on small cell cluster coverage problems and proposes both centralized and distributed self-optimization methods. Modified Particle swarm optimization （MPSO） is introduced to centralized optimization which employs particle swarm optimization （PSO） and introduces a heuristic power control scheme to accelerate the algorithm to search tbr the global optimum solution. Distributed coverage optimization is modeled as a non-cooperative game, with a utility function considering both throughput and interference. An iterative power control algorithm is then proposed using game theory （DGT） which converges to Nash Equilibrium （NE）. Simulation results show that both MPSO and DGT have excellent performance in coverage optimization and outperform optimization using simulated annealing algorithm （SA）, reaching higher coverage ratio and throughput while with less iterations.

Variations of bacterial and fungal communities along a primary successional chronosequence in the Hailuogou glacier retreat area(Gongga Mountain, SW China)

New terrestrial habitats have emerged and a primary succession has developed in the retreat area （29°34＇N, 102°oo＇E, 2951-2886 m） after the retreat of the Hailuogou glacier. To investigate soil microbial changes along the primary successional chronosequence, mixed soil samples were collected at six sites at different ages （2 young sites, 2 mid-aged sites, and 2 old sites）. The RNA was extracted and amplified. Bacterial 16S rRNA and fungal 18S rRNA were analyzed using high-throughput 454 pyrosequencing analysis. Overall, pyrosequeneing showed that Proteobacteria, Acidobacteria, Baeteroidetes and Actinobacteria were the main bacterial phyla, and the fungal communities were strongly dominated by the phyla Ascomyeota and Basidiomyeota in the retreat area. The Shannon diversity index （Hshannon） of bacteria was 6.5 - 7.9, and that of fungi was 2.2 - 4.1 in these sites. For the bacterial communities, diversity and evenness values were highest on the mid-age sites and were relatively low on the young trend was observed for the and old sites. A similar fungal communities. In contrast, soil properties showed significant linear distributional trends （increase or decrease） with the age of the site. Combining the linear change patterns of soil properties, the highest values of bacterial and fungal evenness and diversity in the mid-aged sites indicated that there was less environmental stress and more niches for microbial communities in the middle successional stage compare with other stages. In addition, our analysis showed that microbial communities were the main drivers that build a soil organic matter pool to expedite pedogenesis for ecosystem succession. This primary succession in the Hailuogou glacier retreat area is developing rapidly compared with that in other glacier retreats.

Hybrid Strategy of Particle Swarm Optimization and Simulated Annealing for Optimizing Orthomorphisms

Orthomorphism on F2^n is a kind of elementary pemmtation with good cryptographic properties. This paper proposes a hybrid strategy of Particle Swarm Optimization （PSO） and Sirrmlated Annealing （SA） for finding orthomorphisrm with good cryptographic properties. By experiment based on this strategy, we get some orthorrorphisrm on F2^n = 5, 6, 7, 9, 10） with good cryptographic properties in the open document for the first time, and the optirml orthorrrphism on F found in this paper also does better than the one proposed by Feng Dengguo et al. in stream cipher Loiss in difference uniformity, algebraic degree, algebraic irrarnity and corresponding pernmtation polynomial degree. The PSOSA hybrid strategy for optimizing orthomerphism in this paper makes design of orthorrorphisrm with good cryptographic properties automated, efficient and convenient, which proposes a new approach to design orthornorphisrm.

Lifetime prediction for tantalum capacitors with multiple degradation measures and particle swarm optimization based grey model

A lifetime prediction method for high-reliability tantalum （Ta） capacitors was proposed, based on multiple degradation measures and grey model （GM）. For analyzing performance degradation data, a two-parameter model based on GM was developed. In order to improve the prediction accuracy of the two-parameter model, parameter selection based on particle swarm optimization （PSO） was used. Then, the new PSO-GM（1, 2, co） optimization model was constructed, which was validated experimentally by conducting an accelerated testing on the Ta capacitors. The experiments were conducted at three different stress levels of 85, 120, and 145℃. The results of two experiments were used in estimating the parameters. And the reliability of the Ta capacitors was estimated at the same stress conditions of the third experiment. The results indicate that the proposed method is valid and accurate.

试析印度对RCEP的政策立场及其变化

印度参与RCEP谈判的过程经历了从“犹豫不决”到“积极推进”再到“宣布退群”的“纠结”过程,它既体现了近期印度政府对RCEP态度和立场上的急剧转变,也反映了长期以来印度在RCEP政策上的反复不定。印度对RCEP的兴趣主要源于经济、政治和战略上的潜在长期收益,以及RCEP与印度社会经济发展现状和需求之间更高的契合度。然而,受短期经济成本和相对收益差异、RCEP自身缺陷、成员国之间互信不足等一系列因素的影响,印度始终未能打消疑虑,为加入RCEP做好物质上和心理上的充分准备。随着印度国内对RCEP问题的高度“政治化”和“特朗普冲击”下中美关系和亚太地区局势的急剧变化,莫迪政府在国际—国内双重博弈中对RCEP的利益偏好已出现重大变化,这是导致印度最终决定退出RCEP的最主要原因。

DEGENERATE SEMI-GROUP METHODS FOR THE EXPONENTIAL STABILITY OF THE FIRST ORDER SINGULAR DISTRIBUTED PARAMETER SYSTEMS

Exponential stability of the first order singular distributed parameter systems is discussedin the light of degenerate semi-group methods,which is described by the abstract developing equationin Hilbert space.The necessary and sufficient conditions concerning the exponential stability of thefirst order singular distributed parameter systems are given.