サバルタン ハ カタル コト ガ デキルカ ヲ ヨミナオス タメ ニ キョウセイ ノ フィロソフィー ノ シテン カラ

本論文では、ガヤトリ・C・スピヴァクの『サバルタンは語ることができるか』を、共生学という立場から読み直すための論点の一部を整理する。難解であることで知られる同書に対し、テクストに内在する問題と、その受容に伴う問題という二つの方向からアプローチする。まず、テクストにおける問題として、スピヴァクによるフーコー・ドゥルーズ批判をとりあげ、立場の違いが議論の対象の違いへと繋がっていること、哲学的な議論そのものとその受容のプロセスとは切り分けられるべきであることを指摘する。次いで、受容に伴う問題としてrepresentation の翻訳と表記に焦点を当てる。同書の読み直しにより、批判を受け止めることで思想的立場の違いが相補性となり得ること、研究者が自らの代表性（vertretung）を自覚した上で、表現（darstellung）することの重要性をはじめ、共生を論じるための様々な示唆が得られることを示す。In this paper, we will discuss a few arguments for re-reading Gayatri C. Spivak’s “Can the Subaltern Speak?” from the standpoint of Kyosei studies (Critical Studies in Coexistence, Symbiosis, and Conviviality). First, we will discuss the relationship between the author’s position and the subject of research and point out that we should discuss the philosophical argument itself separately from the process of its reception. Next, we will focus on the translation and notation of “representation,” as this poses a problem with the paper’s reception.Through these discussions, we suggest that differences in ideological positions can become complementary by accepting criticism. We also show the importance of expression (darstellung) by researchers who are aware of their own representativeness (vertretung).論

Quantum State Manipulation of Atomically-Precise Gold Nanoclusters by Controlling Size & Structure

Atomically-precise gold nanoclusters have gained wide attentions due to their unique quantum state and related intriguing properties. These nanoclusters exhibit nonmetallic (i.e., molecular) electronic structure unlike bulk or plasmonic nanoparticle of gold. The non-metallic electronic structure of a nanocluster is very sensitive to the size and structure, even at the atomic level of difference. Recent progress in the atomically precise synthesis and crystallographic structure determination has provided chemists with the wide availability of nanoclusters with different size/structure for the exploration of novel functionalities. However, some fundamental questions are not clearly answered yet. For example, the critical role of the structure (e.g., core and/or surface) for the properties still remain unclear. The transition from non-metallic to metallic state has not been identified at the atomic level of precision due to the difficulty in atomically-controlled synthesis of a nanocluster near the transition size region (i.e., ~2 nm). The elucidation of the origin of surface plasmons also needs further investigation of the nascent state. In this thesis, I tackle the major issues of nanoscience by synthesis and structure determination of thiolate-protected gold nanoclusters. I first discuss oxidation-induced size/structure transformation (OIST) of atomically-precise Au nanoclusters from one stable size to another (Chapter 2). The observed transformation from [Au23(SR)16]− to Au28(SR)20 demonstrated the first case of novel synthetic procedure by oxidation as well as the atomic insights into the charge state control of a nanocluster. In Chapter 3 and 4, I discuss atomically-tailored core and/or surface structures of Au nanoclusters, and the effect on the optical properties. I have controlled the crystallize phase of the core structure in an atomically-precise Au30(SR)18 for the first time by a novel ligand-based strategy (Chapter 3). The ligand-based strategy realized the hexagonal-close packed (hcp) structure in the Au30(SR)18, unlike face-centered cubic (fcc) structure in previously reported Au30(SR’)18, and bulk or plasmonic NP of gold. Interestingly, the controlled crystalline phase in the same sized NP led to totally different properties. This work has demonstrated a strategy for controlling nanocluster structure (hcp vs. fcc) to tailor the optical properties without changing the size in atomic precision. I have also performed surface tailoring of Au nanoclusters to control the optical properties of Au nanoclusters (Chapter 4). Au103S2(SR)41 and Au102(SR’)44 nanoclusters are protected by different ligands (i.e., 2-naphthalenethiolate and paramercaptobenzoic acid) and the two nanoclusters show the same Au79 core but different surface structure. Steady-state spectroscopy revealed the same UV-Vis absorption profile of Au103 and Au102, but ultrafast spectroscopy identified different excited-state lifetimes (420 ps for Au103 vs. 3.5 ns for Au102). The correlation between spectroscopic and structural analyses has elucidated the critical role of core and/or surface structure of Au nanoclusters for their optical properties. The atomically-tailored optical properties discussed in Chapter 3 & 4 demonstrate a strategy for quantum state manipulation of non-metallic Au nanoclusters. In Chapter 5−8, I discuss the atomically-precise identification of the transition from non-metallic to metallic state of Au nanoclusters and the nascent state of surface plasmons. Chapter 5 describes the sharp transition from nonmetallic Au246(SR)80 to metallic Au279(SR)84 within merely 33 Au atoms, which goes against >50 years of theoretical prediction of a smooth transition. I overcame the difficulties in controlling the atomic monodispersity by a ligand-based strategy and successfully synthesized Au279. The “nascent” surface plasmon in Au279(SR)84 exhibited intriguing optical properties unseen in typical plasmons. Chapter 6 & 8 focus on the unique features of such a nascent surface plasmon near the transition size region. I have discovered anomalous electron dynamics in metallic Au333(SR)79 with unprecedented relaxation process, in addition to electron-phonon coupling and phonon-phonon coupling as seen in typical plasmonic Au nanoparticles (Chapter 6). The nascent state of surface plasmons is further explored through the synthesis and spectroscopic analysis of Au~300(TBBT)~84 and Au~310(pMBT)~80, resulted in the observation of intriguing electron dynamics (Chapter 8). Chapter 7 includes the discussion on the effect of alloying on the non-metallic to metallic transition through the case of Au130-xAgx nanoclusters with non-metallicity. Overall, the conclusion derived from this dissertation has provided critical insights (e.g., structure and/or size) into the quantum state of Au nanoclusters at atomic level. Further studies toward the direction will guide one to the strategy to engineer the functionality of nanomaterials by quantum state manipulation for the applications in optoelectronic, catalysis, and biomedicine, as well as quantum computing. <br