如何将多个向量合并为一个，同时替换每个向量中的元素

def merge_vectors(vectors):
    merged_vector = []
    for vector in vectors:
        for element in vector:
            # 替换元素的逻辑可以根据具体需求进行修改
            if element < 0:
                merged_vector.append(0)
            else:
                merged_vector.append(element)
    return merged_vector

# 示例用法
vector1 = [1, 2, 3]
vector2 = [4, 5, 6]
vector3 = [7, 8, 9]
vectors = [vector1, vector2, vector3]

merged_vector = merge_vectors(vectors)
print(merged_vector)