{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:1999:M5VFJAERCJBP4H53QXZ2ODHB5R","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"02081b3a4076b231aef766ae23aeb8794d8ab880f2924a9a50589f4f72f67e87","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat.str-el","submitted_at":"1999-08-03T08:46:16Z","title_canon_sha256":"03ddb8eaeadf4cd403ab6bbc4aa83b887594adc3e9705bf979e00cc9f24f46ec"},"schema_version":"1.0","source":{"id":"cond-mat/9908039","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"cond-mat/9908039","created_at":"2026-07-04T14:23:41Z"},{"alias_kind":"arxiv_version","alias_value":"cond-mat/9908039v1","created_at":"2026-07-04T14:23:41Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.cond-mat/9908039","created_at":"2026-07-04T14:23:41Z"},{"alias_kind":"pith_short_12","alias_value":"M5VFJAERCJBP","created_at":"2026-07-04T14:23:41Z"},{"alias_kind":"pith_short_16","alias_value":"M5VFJAERCJBP4H53","created_at":"2026-07-04T14:23:41Z"},{"alias_kind":"pith_short_8","alias_value":"M5VFJAER","created_at":"2026-07-04T14:23:41Z"}],"graph_snapshots":[{"event_id":"sha256:ce7121d36d6468f3964cf89359b241e930048cae4c65cd4026b430a688dd974d","target":"graph","created_at":"2026-07-04T14:23:41Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/cond-mat/9908039/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"The resistivity and thermopower of polycrystalline (Na,Ca)Co_2O_4 were measured and analyzed. Both the quantities increase with x, suggesting that the carrier density is decreased by the substitutions of Ca^{2+} for Na^{+}. Considering that the temperature dependence of the resistivity show a characteristic change with x, the conduction mechanism is unlikely to come from a simple electron-phonon scattering. As a reference for NaCo_2O_4, single crystals of a two-dimensional Co oxide (Bi,Pb)_2M_3Co_2O_9 (M=Sr and Ba) were studied. The Pb substitution decreases the resistivity, leaving the thermo","authors_text":"I. Terasaki, T. Itoh, T. Kawata, T. Kitajima","cross_cats":[],"headline":"","license":"","primary_cat":"cond-mat.str-el","submitted_at":"1999-08-03T08:46:16Z","title":"Transport Properties in (Na,Ca)Co_2O_4 Ceramics"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"cond-mat/9908039","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:7fd50a30569772667e64f44587d0d065fe3062197ad0c4246625cec6ca185473","target":"record","created_at":"2026-07-04T14:23:41Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"02081b3a4076b231aef766ae23aeb8794d8ab880f2924a9a50589f4f72f67e87","cross_cats_sorted":[],"license":"","primary_cat":"cond-mat.str-el","submitted_at":"1999-08-03T08:46:16Z","title_canon_sha256":"03ddb8eaeadf4cd403ab6bbc4aa83b887594adc3e9705bf979e00cc9f24f46ec"},"schema_version":"1.0","source":{"id":"cond-mat/9908039","kind":"arxiv","version":1}},"canonical_sha256":"676a5480911242fe1fbb85f3a70ce1ec6f2a827a364daeef44fe12299a09d884","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"676a5480911242fe1fbb85f3a70ce1ec6f2a827a364daeef44fe12299a09d884","first_computed_at":"2026-07-04T14:23:41.958302Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-07-04T14:23:41.958302Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"CBZk+wxijbpE9dkzMtfHjKGEX3huHGerWID+hczO8sUMaZFkxx9VETKRc2nAgbTJu0dEkRhWYVvd6ar+/PFEBw==","signature_status":"signed_v1","signed_at":"2026-07-04T14:23:41.958751Z","signed_message":"canonical_sha256_bytes"},"source_id":"cond-mat/9908039","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:7fd50a30569772667e64f44587d0d065fe3062197ad0c4246625cec6ca185473","sha256:ce7121d36d6468f3964cf89359b241e930048cae4c65cd4026b430a688dd974d"],"state_sha256":"11db5956d5b758127deb035875e95da99854422b92c5bf1709c17084920abc4d"}