"大语言模型在高效生成文本的同时也带来了文本滥用的问题,如何有效地区分不同大模型生成的文本成为了关键的挑战。为了解决这个问题,本文首先构建了一个面向多分类的大模型生成文本检测任务的数据集LGT-AA,包含7个领域的人类和10个常用大模型生成的94k条文本;其次,本文提出了一种提取不同大模型生成文本的全局性区分性特征的方案,并与分布特征进行融合构建文本检测器,提升了对生成文本的检测能力。实验结果表明,本文提出的方法在不同模型组合下和不同生成模型类别下都取得了更优的性能。"

Chain-of-Thought (CoT) distillation has emerged as a promising paradigm to enhance the reasoning ability of small language models by imitating the reasoning and outputs of larger teacher models. However, existing approaches suffer from a critical limitation: a distribution mismatch between teacher-generated training trajectories and the student model’s own generative distribution. This mismatch leads to exposure bias during inference and often induces mode collapse or mode averaging, thereby degrading the student model’s generative diversity and robustness. To address these issues, we propose CoTD-PO (Chain-of-Thought Distillation with Preference Optimization), a reinforcement learning framework that shifts the training paradigm from passive imitation to active trajectory exploration. Instead of forcing the student to imitate exact teacher traces, our method enables the student to sample its own answer paths. To support training with non-open-source teacher models, we approximate the teacher’s output distribution through preference-based scoring. Furthermore, we adopt an offline iterative training procedure that enables stable and efficient optimization. Experiments on diverse open-ended generation tasks demonstrate that CoTD-PO significantly outperforms standard CoT distillation baselines, achieving higher output quality while mitigating mode collapse and preserving semantic diversity.