La controverse sur la nomenclature des éléments transactinides entre les équipes américaines et soviétiques a-t-elle persisté au-delà de l'année 1997 ?
Synthetic elements

By 1936, the pool of missing elements from hydrogen to uranium had shrunk to four: elements 43, 61, 85, and 87 remained missing. Element 43 eventually became the first element to be synthesised artificially via nuclear reactions rather than discovered in nature. It was discovered in 1937 by Italian chemists Emilio Segrè and Carlo Perrier, who named their discovery technetium, after the Greek word for "artificial". Elements 61 (promethium) and 85 (astatine) were likewise produced artificially in 1945 and 1940 respectively; element 87 (francium) became the last element to be discovered in nature, by French chemist Marguerite Perey in 1939. The elements beyond uranium were likewise discovered artificially, starting with Edwin McMillan and Philip Abelson 's 1940 discovery of neptunium (via bombardment of uranium with neutrons). Glenn T. Seaborg and his team at the Lawrence Berkeley National Laboratory (LBNL) continued discovering transuranium elements, starting with plutonium in 1941, and discovered that contrary to previous thinking, the elements from actinium onwards were congeners of the lanthanides rather than transition metals. Bassett (1892), Werner (1905), and the French engineer Charles Janet (1928) had previously suggested this, but their ideas did not then receive general acceptance. Seaborg thus called them the actinides. Elements up to 101 (named mendelevium in honour of Mendeleev) were synthesised up to 1955, either through neutron or alpha-particle irradiation, or in nuclear explosions in the cases of 99 (einsteinium) and 100 (fermium).

A significant controversy arose with elements 102 through 106 in the 1960s and 1970s, as competition arose between the LBNL team (now led by Albert Ghiorso) and a team of Soviet scientists at the Joint Institute for Nuclear Research (JINR) led by Georgy Flyorov. Each team claimed discovery, and in some cases each proposed their own name for the element, creating an element naming controversy that lasted decades. These elements were made by bombardment of actinides with light ions. IUPAC at first adopted a hands-off approach, preferring to wait and see if a consensus would be forthcoming. But as it was also the height of the Cold War, it became clear that this would not happen. As such, IUPAC and the International Union of Pure and Applied Physics (IUPAP) created a Transfermium Working Group (TWG, fermium being element 100) in 1985 to set out criteria for discovery, which were published in 1991. After some further controversy, these elements received their final names in 1997, including seaborgium (106) in honour of Seaborg.

The TWG's criteria were used to arbitrate later element discovery claims from LBNL and JINR, as well as from research institutes in Germany (GSI) and Japan (Riken). Currently, consideration of discovery claims is performed by a IUPAC/IUPAP Joint Working Party. After priority was assigned, the elements were officially added to the periodic table, and the discoverers were invited to propose their names. By 2016, this had occurred for all elements up to 118, therefore completing the periodic table's first seven rows. The discoveries of elements beyond 106 were made possible by techniques devised by Yuri Oganessian at the JINR: cold fusion (bombardment of lead and bismuth by heavy ions) made possible the 1981–2004 discoveries of elements 107 through 112 at GSI and 113 at Riken, and he led the JINR team (in collaboration with American scientists) to discover elements 114 through 118 using hot fusion (bombardment of actinides by calcium ions) in 1998–2010. The heaviest known element, oganesson (118), is named in Oganessian's honour. Element 114 is named flerovium in honour of his predecessor and mentor Flyorov.

In celebration of the periodic table's 150th anniversary, the United Nations declared the year 2019 as the International Year of the Periodic Table, celebrating "one of the most significant achievements in science". The discovery criteria set down by the TWG were updated in 2020 in response to experimental and theoretical progress that had not been foreseen in 1991. Today, the periodic table is among the most recognisable icons of chemistry. IUPAC is involved today with many processes relating to the periodic table: the recognition and naming of new elements, recommending group numbers and collective names, and the updating of atomic weights.
Rutherfordium et dubnium

Au plus fort de la guerre froide, des équipes de l'Union soviétique et des États-Unis ont créé indépendamment le rutherfordium et le dubnium. La désignation et la reconnaissance de la synthèse de ces éléments sont restées non résolues pendant de nombreuses années, mais finalement, une reconnaissance conjointe a été accordée par l'IUPAC/IUPAP en 1992. En 1997, l'IUPAC a décidé de donner au dubnium son nom actuel en hommage à la ville de Dubna, où l'équipe russe a travaillé, étant donné que les noms choisis par les Américains avaient déjà été utilisés pour de nombreux éléments synthétiques existants, tandis que le nom rutherfordium (choisi par l'équipe américaine) a été accepté pour l'élément 104.
### Query ###
La controverse sur la nomenclature des éléments transactinides entre les équipes américaines et soviétiques a-t-elle persisté au-delà de l'année 1997 ?

### Main Text ###
Synthetic elements

By 1936, the pool of missing elements from hydrogen to uranium had shrunk to four: elements 43, 61, 85, and 87 remained missing. Element 43 eventually became the first element to be synthesised artificially via nuclear reactions rather than discovered in nature. It was discovered in 1937 by Italian chemists Emilio Segrè and Carlo Perrier, who named their discovery technetium, after the Greek word for "artificial". Elements 61 (promethium) and 85 (astatine) were likewise produced artificially in 1945 and 1940 respectively; element 87 (francium) became the last element to be discovered in nature, by French chemist Marguerite Perey in 1939. The elements beyond uranium were likewise discovered artificially, starting with Edwin McMillan and Philip Abelson 's 1940 discovery of neptunium (via bombardment of uranium with neutrons). Glenn T. Seaborg and his team at the Lawrence Berkeley National Laboratory (LBNL) continued discovering transuranium elements, starting with plutonium in 1941, and discovered that contrary to previous thinking, the elements from actinium onwards were congeners of the lanthanides rather than transition metals. Bassett (1892), Werner (1905), and the French engineer Charles Janet (1928) had previously suggested this, but their ideas did not then receive general acceptance. Seaborg thus called them the actinides. Elements up to 101 (named mendelevium in honour of Mendeleev) were synthesised up to 1955, either through neutron or alpha-particle irradiation, or in nuclear explosions in the cases of 99 (einsteinium) and 100 (fermium).

A significant controversy arose with elements 102 through 106 in the 1960s and 1970s, as competition arose between the LBNL team (now led by Albert Ghiorso) and a team of Soviet scientists at the Joint Institute for Nuclear Research (JINR) led by Georgy Flyorov. Each team claimed discovery, and in some cases each proposed their own name for the element, creating an element naming controversy that lasted decades. These elements were made by bombardment of actinides with light ions. IUPAC at first adopted a hands-off approach, preferring to wait and see if a consensus would be forthcoming. But as it was also the height of the Cold War, it became clear that this would not happen. As such, IUPAC and the International Union of Pure and Applied Physics (IUPAP) created a Transfermium Working Group (TWG, fermium being element 100) in 1985 to set out criteria for discovery, which were published in 1991. After some further controversy, these elements received their final names in 1997, including seaborgium (106) in honour of Seaborg.

The TWG's criteria were used to arbitrate later element discovery claims from LBNL and JINR, as well as from research institutes in Germany (GSI) and Japan (Riken). Currently, consideration of discovery claims is performed by a IUPAC/IUPAP Joint Working Party. After priority was assigned, the elements were officially added to the periodic table, and the discoverers were invited to propose their names. By 2016, this had occurred for all elements up to 118, therefore completing the periodic table's first seven rows. The discoveries of elements beyond 106 were made possible by techniques devised by Yuri Oganessian at the JINR: cold fusion (bombardment of lead and bismuth by heavy ions) made possible the 1981–2004 discoveries of elements 107 through 112 at GSI and 113 at Riken, and he led the JINR team (in collaboration with American scientists) to discover elements 114 through 118 using hot fusion (bombardment of actinides by calcium ions) in 1998–2010. The heaviest known element, oganesson (118), is named in Oganessian's honour. Element 114 is named flerovium in honour of his predecessor and mentor Flyorov.

In celebration of the periodic table's 150th anniversary, the United Nations declared the year 2019 as the International Year of the Periodic Table, celebrating "one of the most significant achievements in science". The discovery criteria set down by the TWG were updated in 2020 in response to experimental and theoretical progress that had not been foreseen in 1991. Today, the periodic table is among the most recognisable icons of chemistry. IUPAC is involved today with many processes relating to the periodic table: the recognition and naming of new elements, recommending group numbers and collective names, and the updating of atomic weights.

### Supplementary Text ###
Rutherfordium et dubnium

Au plus fort de la guerre froide, des équipes de l'Union soviétique et des États-Unis ont créé indépendamment le rutherfordium et le dubnium. La désignation et la reconnaissance de la synthèse de ces éléments sont restées non résolues pendant de nombreuses années, mais finalement, une reconnaissance conjointe a été accordée par l'IUPAC/IUPAP en 1992. En 1997, l'IUPAC a décidé de donner au dubnium son nom actuel en hommage à la ville de Dubna, où l'équipe russe a travaillé, étant donné que les noms choisis par les Américains avaient déjà été utilisés pour de nombreux éléments synthétiques existants, tandis que le nom rutherfordium (choisi par l'équipe américaine) a été accepté pour l'élément 104.

### Draft ###

### 1. Query Decomposition

"La controverse sur la nomenclature des éléments transactinides entre les équipes américaines et soviétiques"

Key terms: 
- controverse = controversy/dispute
- nomenclature = naming conventions  
- transactinides = elements beyond uranium (Z>92)
- équipes américaines et soviétiques = US/USSR research teams

Translation challenge: "transactinides" vs "éléments super-lourds" - technical precision matters.

Query type: Historical information retrieval + temporal boundary assessment.

### 2. Domain Contextualization

Chemistry + Cold War politics. Key timeframe: 1950s-1990s.

Geographic/institutional players:
- USA: Lawrence Berkeley National Laboratory, Ghiorso team
- USSR: Joint Institute for Nuclear Research, Dubna, Flyorov team

Physical constraints: Synthetic element production requires massive particle accelerators. Limited to few specialized labs globally. → Natural competition, but also scientific necessity for collaboration.

### 3. Historical Reconstruction

Early period (1950s-1970s): 
● LBNL and JINR independently discover elements 102-106
◐ Priority disputes emerge - both teams claim discoveries simultaneously
○ Cold War prevents direct collaboration → competing publications, naming conflicts

Critical juncture: 1985-1991
! Transfermium Working Group formation = breakthrough moment
- Official international arbitration body established
- Formal discovery criteria developed
- Temporary resolution mechanism

Post-1997 status? Query asks about persistence beyond this date.

### 4. Logical Analysis

If controversy "persisted" = continued after 1997
If resolved = ended before or by 1997

Need to verify: What happened in 1997? How did it resolve?

⟨H≈0.8⟩ Memory fragments: Rutherfordium/Dubnium... 104 and 105... naming battles... Flyorov vs Ghiorso pride... but also scientific honor... international committees... bureaucratic solutions sometimes worse than disputes themselves... 1997 feels like resolution year but need confirmation...

### 5. Information Triangulation

● High confidence: 1997 represents significant resolution
◐ Partial: Exact details of 1997 agreement
○ Low confidence: Complete timeline of all disputes

Physical constraint check: Element discoveries are documented, finite number of claims. Eventually must reach resolution.

Logical constraint: International scientific community self-corrects through formal bodies. TWG precedent suggests 1997 resolution likely.

### 6. Verification Path

Cross-reference known elements:
- Element 104: rutherfordium (US naming, accepted)  
- Element 105: dubnium (USSR naming, accepted)
- Final resolutions occurred ~1992-1997

∴ Query answer: No, controversy did NOT persist beyond 1997.

### 7. Synthesis

The controversy was resolved by 1997, not perpetuated.

Key evidence:
- TWG formal arbitration ended naming disputes
- Rutherfordium/Dubnium cases demonstrate resolution
- No documented continuation of naming conflicts post-1997
- Periodic table completion (118 elements by 2016) occurred without major nomenclature disputes

⚠ Potential bias: Limited access to primary sources, relying on secondary accounts.

Final answer structure:
1. Controversy existed pre-1997 ●
2. Resolution mechanisms implemented 1985-1991 ●  
3. 1997 marked final resolutions ●
4. No evidence of post-1997 persistence ●

NB: The "beyond 1997" framing in query suggests possible continuation, but historical record indicates resolution.

### Answer###
La controverse sur la nomenclature des éléments transactinides entre les équipes américaines et soviétiques s'est effectivement résolue avant l'année 1997. Bien que cette compétition scientifique ait duré plusieurs décennies, notamment concernant les éléments 102 à 106 dans les années 1960 et 1970, elle a pris fin avec la création du Transfermium Working Group (TWG) en 1985 par l'IUPAC et l'IUPAP.

Ce groupe de travail a établi des critères officiels pour la reconnaissance des découvertes, qui ont été publiés en 1991. Suite à cette formalisation, les noms définitifs de ces éléments ont été attribués en 1997, mettant fin au conflit de longue durée. Le cas du rutherfordium et du dubnium illustre parfaitement cette résolution : malgré la compétition entre les laboratoires Lawrence Berkeley et l'Institut de recherche nucléaire de Dubna, une reconnaissance conjointe a été accordée par l'IUPAC/IUPAP en 1992, et le dubnium a finalement reçu son nom actuel en 1997 en hommage à Dubna.

La période post-1997 a donc marqué la fin de cette rivalité nomenclaturelle, permettant l'achèvement de la table périodique jusqu'à l'élément 118 en 2016 sans les conflits précédents.