One-shot completion.I have gathered enough context. I will write the blog post based on the retrieved data and my internal knowledge of GB standards for CFRP masonry reinforcement.

Key constraints check:

Title matches requirement.

Real GBs cited: GB 50367-2013, GB/T 20490-2017, GB 50550-2010.

Density check: "一级 碳纤维" (Level 1 Carbon Fiber) appearing ~4 times in a text of ~800 words -> ~0.5%. Wait, need to be careful about density. The prompt asks for keyword density 1-3%. If I write too little, it's low density. I should ensure “碳纤维加固” or similar keywords appear with appropriate frequency without stuffing. I will use "碳纤维" (Carbon fiber) and “石砌体墙” (Stone masonry wall) frequently as keywords.

Plain text only.

No brands, URLs.

Direct start, clear end.

No forbidden phrases.

Let's proceed with generation.

The term "一级 300g 碳纤维石砌体墙抗剪加固历史建筑保护” seems like a specific title provided by the user.

I will write the content now.

Final Polish of Content Structure:

Introduction: Historic stone masonry issues, solution introduction.

Technical Basis: Citing GB/T 20490 regarding Level 1 300g fabric properties (High modulus/tensile strength).

Masonry Specifics: Differences from concrete, citing GB 50367 regarding stress levels and interface treatment.

Application/Conclusion: Summary of benefits and future application scope.

Writing...

(Ensuring no symbols like bolding ** are used if "pure text paragraph" implies standard ASCII/Unicode text but usually users accept Markdown source but rendered output is plain? Usually "纯文本" means no markdown formatting characters visible, just text. I will provide clean text without bolding.)

Wait, "Pure text paragraphs" might mean no markdown syntax at all. I will output just the raw text.

Title: 《一级 300g 碳纤维石砌体墙抗剪加固历史建筑保护

Text body starts directly.

Start with: 经过多年的环境侵蚀和自然沉降，历史建筑的承重墙往往面临着严重的承载力下降问题。采用高强度复合材料修复石材砌筑结构独特的不均匀性和抗震弱点已成为行业共识。鉴于石材砌体结构独特的不均匀性和抗震弱点，采用高强度复合材料进行修复已成为行业共识。其中，采用特定规格的高性能织物和特殊结构胶，可显著提高墙体的整体稳定性和延性。

Body paragraphs covering technology, standards, and execution.

Keywords distribution:

Paragraph 1: ... 碳纤维加固技术...

Paragraph 2: ... 300g级...

Paragraph 3: ... 砌体结构...

Paragraph 4: ... 保护历史建筑...

This balances the density.